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Sample records for plain volcanic system

  1. Ages of plains volcanism on Mars

    Science.gov (United States)

    Hauber, Ernst; Jagert, Felix; Broz, Petr

    2010-05-01

    Plain-style volcanism [1] is widespread in the Tharsis and Elysium volcanic provinces on Mars, [2,3]. Detailed images and topographic data reveal the morphology and topography of clusters of low shields and associated lava flows. The landforms of plains volcanism on Mars have all well-known terrestrial analogues in basaltic volcanic regions, such as Hawaii, Iceland, and in particular the Snake River Plains [4]. The very gentle flank slopes (J. (1981) Icarus, 45, 586-601. [3] Hodges C.A. and Moore H.J. (1994) Atlas of volcanic features on Mars: USGS Prof. Paper 1534, 194 p. [4] Hauber E. et al. (2009) J. Volcanol. Geotherm. Res. 185, 69-95. [5] Wilson L. et al. (2009) J. Volcanol. Geotherm. Res. 185, 28-46. [6] Vaucher, J. et al. (2009) Icarus 204, 418-442. [7] Baratoux D. et al. (2009) J. Volcanol. Geotherm. Res. 185, 47-68. [8] Bleacher J.E. et al. (2009) J. Volcanol. Geotherm. Res. 185, 96-102. [9] Ivanov B.A. (2001) Space Sci. Rev. 96, 87-104. [10] Hartmann W.H. and Neukum G. (2001) Space Sci. Rev. 96, 165-194 [11] Kneissl T. et al. (2010) LPS XVI, submitted. [12] Michael, G.G. and Neukum G. (2010) Earth Planet. Sci. Lett., in press. . [13] Malin M.C. et al. (2007) JGR 112, E05S04, doi: 10.1029/2006JE002808.

  2. The Snake River Plain Volcanic Province: Insights from Project Hotspot

    Science.gov (United States)

    Shervais, J. W.; Potter, K. E.; Hanan, B. B.; Jean, M. M.; Duncan, R. A.; Champion, D. E.; Vetter, S.; Glen, J. M. G.; Christiansen, E. H.; Miggins, D. P.; Nielson, D. L.

    2017-12-01

    The Snake River Plain (SRP) Volcanic Province is the best modern example of a time-transgressive hotspot track beneath continental crust. The SRP began 17 Ma with massive eruptions of Columbia River basalt and rhyolite. After 12 Ma volcanism progressed towards Yellowstone, with early rhyolite overlain by basalts that may exceed 2 km thick. The early rhyolites are anorogenic with dry phenocryst assemblages and eruption temperatures up to 950C. Tholeiitic basalts have major and trace element compositions similar to ocean island basalts (OIB). Project Hotspot cored three deep holes in the central and western Snake River Plain: Kimama (mostly basalt), Kimberly (mostly rhyolite), and Mountain Home (lake sediments and basaslt). The Kimberly core documents rhyolite ash flows up to 700 m thick, possibly filling a caldera or sag. Chemical stratigraphy in Kimama and other basalt cores document fractional crystallization in relatively shallow magma chambers with episodic magma recharge. Age-depth relations in the Kimama core suggest accumulation rates of roughly 305 m/Ma. Surface and subsurface basalt flows show systematic variations in Sr-Nd-Pb isotopes with distance from Yellowstone interpreted to reflect changes in the proportion of plume source and the underlying heterogeneous cratonic lithosphere, which varies in age, composition, and thickness from west to east. Sr-Nd-Pb isotopes suggest <5% lithospheric input into a system dominated by OIB-like plume-derived basalts. A major flare-up of basaltic volcanism occurred 75-780 ka throughout the entire SRP, from Yellowstone in the east to Boise in the west. The youngest western SRP basalts are transitional alkali basalts that range in age from circa 900 ka to 2 ka, with trace element and isotopic compositions similar to the plume component of Hawaiian basalts. These observations suggest that ancient SCLM was replaced by plume mantle after the North America passed over the hotspot in the western SRP, which triggered renewed

  3. Geohazards (floods and landslides in the Ndop plain, Cameroon volcanic line

    Directory of Open Access Journals (Sweden)

    Wotchoko Pierre

    2016-07-01

    Full Text Available The Ndop Plain, located along the Cameroon Volcanic Line (CVL, is a volcano-tectonic plain, formed by a series of tectonic movements, volcanic eruptions and sedimentation phases. Floods (annually and landslides (occasionally occur with devastating environmental effects. However, this plain attracts a lot of inhabitants owing to its fertile alluvial soils. With demographic explosion in the plain, the inhabitants (143,000 people tend to farm and inhabit new zones which are prone to these geohazards. In this paper, we use field observations, laboratory analyses, satellite imagery and complementary methods using appropriate software to establish hazard (flood and landslide maps of the Ndop Plain. Natural factors as well as anthropogenic factors are considered.

  4. In-situ monitoring of deformation of clayey and volcanic sequences in the lacustrine plain of Iztapalapa, Mexico City

    Science.gov (United States)

    Carreon-Freyre, D.; Cerca, M.; Barrientos, B.; Gutierrez, R.; Blancas, D.

    2012-12-01

    Major cities of Central Mexico with lowering of land elevation problems are located in inter-volcanic and fault bounded basins within the central Trans-Mexican Volcanic Belt (TMVB). The most representative and studied case of ground deformation is Mexico City, where the Iztapalapa Municipality presents the highest population density. This area is located over the geological contact between the "Sierra de Santa Catarina" volcanic range and a lacustrine plain. Filling of lacustrine basins includes silty and clayey sediments as well as pyroclastic deposits (coarse and fine grained) and volcanic rocks layers. We used Ground Penetrating Radar (GPR) and MASW prospection to evaluate contrasts in the physical properties of fine grained soils and identify geometry of the deformational features and implemented a mechanical system for in situ monitoring in fractured sites. Deformational features in this basin reflect an interplay between the geological history (depositional conditions), load history, seismic activity, and faulting. Plastic mechanical behaviour predominates in these clayey sediments and differential deformation locally triggers brittle fracturing and/or subsidence of the surface. In this work we present the results of monitoring and characterization of ground deformation and fracturing in different sequences, our results show a dynamic interplay between the mechanisms of ground fracturing and the stress history of sedimentary sequences. Relating the mechanical behaviour of the studied sequences with variations of physical and geological properties should be taken into account to estimate land level lowering and risk of fracturing for urban development planning.

  5. The Volcanism Ontology (VO): a model of the volcanic system

    Science.gov (United States)

    Myer, J.; Babaie, H. A.

    2017-12-01

    We have modeled a part of the complex material and process entities and properties of the volcanic system in the Volcanism Ontology (VO) applying several top-level ontologies such as Basic Formal Ontology (BFO), SWEET, and Ontology of Physics for Biology (OPB) within a single framework. The continuant concepts in BFO describe features with instances that persist as wholes through time and have qualities (attributes) that may change (e.g., state, composition, and location). In VO, the continuants include lava, volcanic rock, and volcano. The occurrent concepts in BFO include processes, their temporal boundaries, and the spatio-temporal regions within which they occur. In VO, these include eruption (process), the onset of pyroclastic flow (temporal boundary), and the space and time span of the crystallization of lava in a lava tube (spatio-temporal region). These processes can be of physical (e.g., debris flow, crystallization, injection), atmospheric (e.g., vapor emission, ash particles blocking solar radiation), hydrological (e.g., diffusion of water vapor, hot spring), thermal (e.g., cooling of lava) and other types. The properties (predicates) relate continuants to other continuants, occurrents to continuants, and occurrents to occurrents. The ontology also models other concepts such as laboratory and field procedures by volcanologists, sampling by sensors, and the type of instruments applied in monitoring volcanic activity. When deployed on the web, VO will be used to explicitly and formally annotate data and information collected by volcanologists based on domain knowledge. This will enable the integration of global volcanic data and improve the interoperability of software that deal with such data.

  6. Fluids in volcanic and geothermal systems

    Science.gov (United States)

    Sigvaldason, Gudmundur E.

    -rift volcanism is accordingly not fed directly by mantle derived liquids. The model predicts that all volcanic fluids, with the exception of those which are associated with the most primitive olivine tholeiites, are partly or wholly recycled through all stages of hydrothermal and metamorphic reactions. In that sense associated volcanic and geothermal systems are a part of the same chemical fractionation column. It is concluded that the chemistry of fluids in volcanic and geothermal systems can be viewed in the perspective of predictable crustal fractionation processes before any conclusion need be drawn concerning more deep seated causes for chemical anomalies.

  7. Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex

    Science.gov (United States)

    Vogel, Sebastian; Märker, Michael

    2010-05-01

    SSP1.4 Understanding mixed siliciclastic-volcaniclastic depositional systems and their relationships with geodynamics or GD2.3/CL4.14/GM5.8/MPRG22/SSP3.5 Reconstruction of ancient continents: Dating and characterization of paleosurfaces Reconstructing the paleo-topography and paleo-environmental features of the Sarno River plain (Italy) before the AD 79 eruption of Somma-Vesuvius volcanic complex Sebastian Vogel[1] & Michael Märker[1] [1] Heidelberg Academy of Sciences and Humanities c/o University of Tübingen, Rümelinstraße 19-23, D-72070 Tübingen, Germany. Within the geoarchaeological research project "Reconstruction of the Ancient Cultural Landscape of the Sarno River Plain" undertaken by the German Archaeological Institute in cooperation with the Heidelberg Academy of Sciences and Humanities/University of Tübingen a methodology was developed to model the spatial dispersion of volcanic deposits of Somma-Vesuvius volcanic complex since its Plinian eruption AD 79. Eventually, this was done to reconstruct the paleo-topography and paleo-environment of the Sarno River plain before the eruption AD 79. We collected, localized and digitized more than 1,800 core drillings to gain a representative network of stratigraphical information covering the entire plain. Besides other stratigraphical data including the characteristics of the pre-AD 79 stratum, the depth to the pre-AD 79 paleo-surface was identified from the available drilling documentation. Instead of applying a simple interpolation of the drilling data, we reconstructed the pre-AD 79 paleo-surface with a sophisticated geostatistical methodology using a machine based learning approach based on classification and regression trees. We hypothesize that the present-day topography reflects the ancient topography, because the eruption of AD 79 coated the ancient topography, leaving ancient physiographic elements of the Sarno River plain still recognizable in the present-day topography. Therefore, a high resolution

  8. Volcanic Alert System (VAS) developed during the (2011-2013) El Hierro (Canary Islands) volcanic process

    Science.gov (United States)

    Ortiz, Ramon; Berrocoso, Manuel; Marrero, Jose Manuel; Fernandez-Ros, Alberto; Prates, Gonçalo; De la Cruz-Reyna, Servando; Garcia, Alicia

    2014-05-01

    In volcanic areas with long repose periods (as El Hierro), recently installed monitoring networks offer no instrumental record of past eruptions nor experience in handling a volcanic crisis. Both conditions, uncertainty and inexperience, contribute to make the communication of hazard more difficult. In fact, in the initial phases of the unrest at El Hierro, the perception of volcanic risk was somewhat distorted, as even relatively low volcanic hazards caused a high political impact. The need of a Volcanic Alert System became then evident. In general, the Volcanic Alert System is comprised of the monitoring network, the software tools for the analysis of the observables, the management of the Volcanic Activity Level, and the assessment of the threat. The Volcanic Alert System presented here places special emphasis on phenomena associated to moderate eruptions, as well as on volcano-tectonic earthquakes and landslides, which in some cases, as in El Hierro, may be more destructive than an eruption itself. As part of the Volcanic Alert System, we introduce here the Volcanic Activity Level which continuously applies a routine analysis of monitoring data (particularly seismic and deformation data) to detect data trend changes or monitoring network failures. The data trend changes are quantified according to the Failure Forecast Method (FFM). When data changes and/or malfunctions are detected, by an automated watchdog, warnings are automatically issued to the Monitoring Scientific Team. Changes in the data patterns are then translated by the Monitoring Scientific Team into a simple Volcanic Activity Level, that is easy to use and understand by the scientists and technicians in charge for the technical management of the unrest. The main feature of the Volcanic Activity Level is its objectivity, as it does not depend on expert opinions, which are left to the Scientific Committee, and its capabilities for early detection of precursors. As a consequence of the El Hierro

  9. GIS methodology for geothermal play fairway analysis: Example from the Snake River Plain volcanic province

    Science.gov (United States)

    DeAngelo, Jacob; Shervais, John W.; Glen, Jonathan; Nielson, Dennis L.; Garg, Sabodh; Dobson, Patrick; Gasperikova, Erika; Sonnenthal, Eric; Visser, Charles; Liberty, Lee M.; Siler, Drew; Evans, James P.; Santellanes, Sean

    2016-01-01

    Play fairway analysis in geothermal exploration derives from a systematic methodology originally developed within the petroleum industry and is based on a geologic and hydrologic framework of identified geothermal systems. We are tailoring this methodology to study the geothermal resource potential of the Snake River Plain and surrounding region. This project has contributed to the success of this approach by cataloging the critical elements controlling exploitable hydrothermal systems, establishing risk matrices that evaluate these elements in terms of both probability of success and level of knowledge, and building automated tools to process results. ArcGIS was used to compile a range of different data types, which we refer to as ‘elements’ (e.g., faults, vents, heatflow…), with distinct characteristics and confidence values. Raw data for each element were transformed into data layers with a common format. Because different data types have different uncertainties, each evidence layer had an accompanying confidence layer, which reflects spatial variations in these uncertainties. Risk maps represent the product of evidence and confidence layers, and are the basic building blocks used to construct Common Risk Segment (CRS) maps for heat, permeability, and seal. CRS maps quantify the variable risk associated with each of these critical components. In a final step, the three CRS maps were combined into a Composite Common Risk Segment (CCRS) map for analysis that reveals favorable areas for geothermal exploration. Python scripts were developed to automate data processing and to enhance the flexibility of the data analysis. Python scripting provided the structure that makes a custom workflow possible. Nearly every tool available in the ArcGIS ArcToolbox can be executed using commands in the Python programming language. This enabled the construction of a group of tools that could automate most of the processing for the project. Currently, our tools are repeatable

  10. Two depositional models for Pliocene coastal plain fluvial systems, Goliad Formation, south Texas Gulf Coastal plain

    International Nuclear Information System (INIS)

    Hoel, H.D.; Galloway, W.E.

    1983-01-01

    The Goliad Formation consists of four depositional systems-the Realitos and Mathis bed-load fluvial systems in the southwest and the Cuero and Eagle Lake mixed-load fluvial systems in the northeast. Five facies are recognized in the Realitos and Mathis bed-load fluvial systems: (1) primary channel-fill facies, (2) chaotic flood channel-fill facies, (3) complex splay facies, (4) flood plain facies, and (5) playa facies. A model for Realitos-Mathis depositional environments shows arid-climate braided stream complexes with extremely coarse sediment load, highly variable discharge, and marked channel instability. Broad, shallow, straight to slightly sinuous primary channels were flanked by wide flood channels. Flood channels passed laterally into broad, low-relief flood plains. Small playas occupied topographic lows near large channel axes. Three facies are recognized in the Cuero and Eagle Lake mixed-load fluvial systems: (1) channel-fill facies, (2) crevasse splay facies, and (3) flood plain facies. A model for Cuero-Eagle Lake depositional environments shows coarse-grained meander belts in a semi-arid climate. Slightly to moderately sinuous meandering streams were flanked by low, poorly developed natural levees. Crevasse splays were common, but tended to be broad and ill-defined. Extensive, low-relief flood plains occupied interaxial areas. The model proposed for the Realitos and Mathis fluvial systems may aid in recognition of analogous ancient depositional systems. In addition, since facies characteristics exercise broad controls on Goliad uranium mineralization, the proposed depositional models aid in defining target zones for Goliad uranium exploration

  11. Volcanic alert system (VAS) developed during the 2011-2014 El Hierro (Canary Islands) volcanic process

    Science.gov (United States)

    García, Alicia; Berrocoso, Manuel; Marrero, José M.; Fernández-Ros, Alberto; Prates, Gonçalo; De la Cruz-Reyna, Servando; Ortiz, Ramón

    2014-06-01

    The 2011 volcanic unrest at El Hierro Island illustrated the need for a Volcanic Alert System (VAS) specifically designed for the management of volcanic crises developing after long repose periods. The VAS comprises the monitoring network, the software tools for analysis of the monitoring parameters, the Volcanic Activity Level (VAL) management, and the assessment of hazard. The VAS presented here focuses on phenomena related to moderate eruptions, and on potentially destructive volcano-tectonic earthquakes and landslides. We introduce a set of new data analysis tools, aimed to detect data trend changes, as well as spurious signals related to instrumental failure. When data-trend changes and/or malfunctions are detected, a watchdog is triggered, issuing a watch-out warning (WOW) to the Monitoring Scientific Team (MST). The changes in data patterns are then translated by the MST into a VAL that is easy to use and understand by scientists, technicians, and decision-makers. Although the VAS was designed specifically for the unrest episodes at El Hierro, the methodologies may prove useful at other volcanic systems.

  12. Phreatomagmatic eruptions through unconsolidated coastal plain sequences, Maungataketake, Auckland Volcanic Field (New Zealand)

    Science.gov (United States)

    Agustín-Flores, Javier; Németh, Károly; Cronin, Shane J.; Lindsay, Jan M.; Kereszturi, Gábor; Brand, Brittany D.; Smith, Ian E. M.

    2014-04-01

    Maungataketake is a monogenetic basaltic volcano formed at ~ 85-89 ka in the southern part of the Auckland Volcanic Field (AVF), New Zealand. It comprises a basal 1100-m diameter tuff ring, with a central scoria/spatter cone and lava flows. The tuff ring was formed under hydrogeological and geographic conditions very similar to the present. The tuff records numerous density stratified, wet base surges that radiated outward up to 1 km, decelerating rapidly and becoming less turbulent with distance. The pyroclastic units dominantly comprise fine-grained expelled grains from various sedimentary deposits beneath the volcano mixed with a minor component of juvenile pyroclasts (~ 35 vol.%). Subtle lateral changes relate to deceleration with distance and vertical transformations are minor, pointing to stable explosion depths and conditions, with gradual transitions between units and no evidence for eruptive pauses. This volcano formed within and on ~ 60 m-thick Plio/Pleistocene, poorly consolidated, highly permeable shelly sands and silts (Kaawa Formation) capped by near-impermeable, water-saturated muds (Tauranga Group). These sediments rest on moderately consolidated Miocene-aged permeable turbiditic sandstones and siltstones (Waitemata Group). Magma-water fuelled thermohydraulic explosions remained in the shallow sedimentary layers, excavating fine-grained sediments without brittle fragmentation required. On the whole, the resulting cool, wet pyroclastic density currents were of low energy. The unconsolidated shallow sediments deformed to accommodate rapidly rising magma, leading to development of complex sill-like bodies and a range of magma-water contact conditions at any time. The weak saturated sediments were also readily liquefied to provide an enduring supply of water and fine sediment to the explosion loci. Changes in magma flux and/or subsequent stabilisation of the conduit area by a lava ring-barrier led to ensuing Strombolian and fire-fountaining eruption

  13. Volcanic systems of Iceland and their magma source

    Science.gov (United States)

    Sigmarsson, Olgeir

    2017-04-01

    Several active hot-spot volcanoes produce magma from mantle sources which composition varies on decadal time scale. This is probably best demonstrated by the recent work of Pietruszka and collaborators on Kilauea, Hawaii. In marked contrast, basalt lavas from volcanic system in Iceland located above the presumed centre of the Iceland mantle plume have uniform isotope composition over the last 10 thousand years. Volcanic systems are composed of a central volcano and a fissure swarm, or a combination of both and they represent a fundamental component of the neovolcanic zones in Iceland. Four such systems, those of Askja, Bárðarbunga, Kverkfjöll and Grímsvötn in central Iceland were chosen for investigation. The last three have central volcanoes covered by the Vatnajökull ice-sheet whereas part of their fissure swarms is ice-free. Tephra produced during subglacial eruptions together with lavas from the fissure swarms of Holocene age have been collected and analysed for Sr, Nd and Th isotope ratios. Those volcanic formations that can be univocally correlated to a given volcanic system display uniform isotope ratio but different from one volcanic system to another. An exception to this regularity is that Askja products have isotope ratios indistinguishable from those of Gímsvötn, but since these volcanic systems lies far apart their lava fields do not overlap. A practical aspect of these findings was demonstrated during the rifting event of Bárðarbunga and fissure eruption forming the Holuhraun lava field. Relatively low, O isotope ratios in these basalts and heterogeneous macrocrystal composition have been ascribed to important metabasaltic crustal contamination with or without crystal mush recycling. In that case a surprisingly efficient magma mixing and melt homogenization must have occurred in the past beneath the volcanic systems. One possibility is that during the rapid deglaciation much mantle melting occurred and melts accumulated at the mantle

  14. The scaling of experiments on volcanic systems

    Directory of Open Access Journals (Sweden)

    Olivier eMERLE

    2015-06-01

    Full Text Available In this article, the basic principles of the scaling procedure are first reviewed by a presentation of scale factors. Then, taking an idealized example of a brittle volcanic cone intruded by a viscous magma, the way to choose appropriate analogue materials for both the brittle and ductile parts of the cone is explained by the use of model ratios. Lines of similarity are described to show that an experiment simulates a range of physical processes instead of a unique natural case. The pi theorem is presented as an alternative scaling procedure and discussed through the same idealized example to make the comparison with the model ratio procedure. The appropriateness of the use of gelatin as analogue material for simulating dyke formation is investigated. Finally, the scaling of some particular experiments such as pyroclastic flows or volcanic explosions is briefly presented to show the diversity of scaling procedures in volcanology.

  15. Volcanic Ash Data Assimilation System for Atmospheric Transport Model

    Science.gov (United States)

    Ishii, K.; Shimbori, T.; Sato, E.; Tokumoto, T.; Hayashi, Y.; Hashimoto, A.

    2017-12-01

    The Japan Meteorological Agency (JMA) has two operations for volcanic ash forecasts, which are Volcanic Ash Fall Forecast (VAFF) and Volcanic Ash Advisory (VAA). In these operations, the forecasts are calculated by atmospheric transport models including the advection process, the turbulent diffusion process, the gravitational fall process and the deposition process (wet/dry). The initial distribution of volcanic ash in the models is the most important but uncertain factor. In operations, the model of Suzuki (1983) with many empirical assumptions is adopted to the initial distribution. This adversely affects the reconstruction of actual eruption plumes.We are developing a volcanic ash data assimilation system using weather radars and meteorological satellite observation, in order to improve the initial distribution of the atmospheric transport models. Our data assimilation system is based on the three-dimensional variational data assimilation method (3D-Var). Analysis variables are ash concentration and size distribution parameters which are mutually independent. The radar observation is expected to provide three-dimensional parameters such as ash concentration and parameters of ash particle size distribution. On the other hand, the satellite observation is anticipated to provide two-dimensional parameters of ash clouds such as mass loading, top height and particle effective radius. In this study, we estimate the thickness of ash clouds using vertical wind shear of JMA numerical weather prediction, and apply for the volcanic ash data assimilation system.

  16. Feasibility study on volcanic power generation system

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-07-01

    Investigations were carried out to determine the feasibility of volcanic power generation on Satsuma Io Island. Earthquakes were studied, as were the eruptions of subaerial and submarine hot springs. Hydrothermal rock alteration was studied and electrical surveys were made. General geophysical surveying was performed with thermocameras and radiation monitoring equipment. In particular, the Toyoba mine was studied, both with respect to its hot spring and its subsurface temperatures.

  17. The Earth System Science Pathfinder VOLCAM Volcanic Hazard Mission

    Science.gov (United States)

    Krueger, Arlin J.

    1999-01-01

    The VOLCAM mission is planned for research on volcanic eruptions and as a demonstration of a satellite system for measuring the location and density of volcanic eruption clouds for use in mitigating hazards to aircraft by the operational air traffic control systems. A requirement for 15 minute time resolution is met by flight as payloads of opportunity on geostationary satellites. Volcanic sulfur dioxide and ash are detected using techniques that have been developed from polar orbiting TOMS (UV) and AVHRR (IR) data. Seven band UV and three band IR filter wheel cameras are designed for continuous observation of the full disk of the earth with moderate (10 - 20 km) ground resolution. This resolution can be achieved with small, low cost instruments but is adequate for discrimination of ash and sulfur dioxide in the volcanic clouds from meteorological clouds and ozone. The false alarm rate is small through use of sulfur dioxide as a unique tracer of volcanic clouds. The UV band wavelengths are optimized to detect very small sulfur dioxide amounts that are present in pre-eruptive outgassing of volcanoes. The system is also capable of tracking dust and smoke clouds, and will be used to infer winds at tropopause level from the correlation of total ozone with potential vorticity.

  18. Is Kasei Valles (Mars) the largest volcanic channel in the solar system?

    Science.gov (United States)

    Leverington, David W.

    2018-02-01

    With a length of more than 2000 km and widths of up to several hundred kilometers, Kasei Valles is the largest outflow system on Mars. Superficially, the scabland-like character of Kasei Valles is evocative of terrestrial systems carved by catastrophic aqueous floods, and the system is widely interpreted as a product of outbursts from aquifers. However, as at other Martian outflow channels, clear examples of fluvial sedimentary deposits have proven difficult to identify here. Though Kasei Valles lacks several key properties expected of aqueous systems, its basic morphological and contextual properties are aligned with those of ancient volcanic channels on Venus, the Moon, Mercury, and Earth. There is abundant evidence that voluminous effusions of low-viscosity magmas occurred at the head of Kasei Valles, the channel system acted as a conduit for associated flows, and mare-style volcanic plains developed within its terminal basin. Combined mechanical and thermal incision rates of at least several meters per day are estimated to have been readily achieved at Kasei Valles by 20-m-deep magmas flowing with viscosities of 1 Pa s across low topographic slopes underlain by bedrock. If Kasei Valles formed through incision by magma, it would be the largest known volcanic channel in the solar system. The total volume of magma erupted at Kasei Valles is estimated here to have possibly reached or exceeded ∼5 × 106 km3, a volume comparable in magnitude to those that characterize individual Large Igneous Provinces on Earth. Development of other large outflow systems on Mars is expected to have similarly involved eruption of up to millions of cubic kilometers of magma.

  19. Radiocarbon dating of sediment cores from Hachinohe, the Kamikita Plain

    International Nuclear Information System (INIS)

    Hitoki, Eri; Nakamura, Toshio; Matsumoto, Yui; Tsuji, Sei-ichiro; Fujine, Hisashi

    2013-01-01

    We investigated stratigraphy and chronology by analyses of Holocene sediments and radiocarbon dating of sediment cores from the Kamikita Plain. On the Kamikita Plain, which faces the Pacific coast of Northeast Japan, marine and fluvial terraces covered with tephras derived from Towada and Hakkoda volcanoes are well developed. We clarified that Towada Chuseri tephra and fluvial deposits consisted of volcanic sediments influenced an alluvial depositional system in the Kamikita Plain after a maximum of the Jomon Transgression. (author)

  20. Plain formation on Mercury: tectonic implications

    International Nuclear Information System (INIS)

    Thomas, P.

    1980-01-01

    Four major plain units, plus intermediates, are distinguished on Mercury. The chronologic relationships between these plains indicate that plains formation was a permanent process on Mercury. Their location and morphology seem to indicate a possible volcanic origin for these plains. The relationships between tectonism and volcanism seems to indicate the global contraction is not the only tectonic process on Mercury. (Auth.)

  1. Exploring the Potential Impacts of Historic Volcanic Eruptions on the Contemporary Global Food System

    Science.gov (United States)

    Puma, Michael J.; Chon, S.; Wada, Y.

    2015-01-01

    A better understanding of volcanic impacts on crops is urgently needed, as volcanic eruptions and the associated climate anomalies can cause unanticipated shocks to food production. Such shocks are a major concern given the fragility of the global food system.

  2. 49 CFR 215.109 - Defective plain bearing box: Journal lubrication system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing box: Journal lubrication... Freight Car Components Suspension System § 215.109 Defective plain bearing box: Journal lubrication system...) Metal parts contacting the journal; or (e) Is— (1) Missing; or (2) Not in contact with the journal. ...

  3. A multidisciplinary system for monitoring and forecasting Etna volcanic plumes

    Science.gov (United States)

    Coltelli, Mauro; Prestifilippo, Michele; Spata, Gaetano; Scollo, Simona; Andronico, Daniele

    2010-05-01

    One of the most active volcanoes in the world is Mt. Etna, in Italy, characterized by frequent explosive activity from the central craters and from fractures opened along the volcano flanks which, during the last years, caused several damages to aviation and forced the closure of the Catania International Airport. To give precise warning to the aviation authorities and air traffic controller and to assist the work of VAACs, a novel system for monitoring and forecasting Etna volcanic plumes, was developed at the Istituto Nazionale di Geofisica e Vulcanologia, sezione di Catania, the managing institution for the surveillance of Etna volcano. Monitoring is carried out using multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager (SEVIRI) on board the Meteosat Second Generation geosynchronous satellite able to track the volcanic plume with a high time resolution, visual and thermal cameras used to monitor the explosive activity, three continuous wave X-band disdrometers which detect ash dispersal and fallout, sounding balloons used to evaluate the atmospheric fields, and finally field data collected after the end of the eruptive event needed to extrapolate important features of explosive activity. Forecasting is carried out daily using automatic procedures which download weather forecast data obtained by meteorological mesoscale models from the Italian Air Force national Meteorological Office and from the hydrometeorological service of ARPA-SIM; run four different tephra dispersal models using input parameters obtained by the analysis of the deposits collected after few hours since the eruptive event similar to 22 July 1998, 21-24 July 2001 and 2002-03 Etna eruptions; plot hazard maps on ground and in air and finally publish them on a web-site dedicated to the Italian Civil Protection. The system has been already tested successfully during several explosive events occurring at Etna in 2006, 2007 and 2008. These events produced eruption

  4. Elevated naturally occurring arsenic in a semiarid oxidizing system, Southern High Plains aquifer, Texas, USA

    International Nuclear Information System (INIS)

    Scanlon, B.R.; Nicot, J.P.; Reedy, R.C.; Kurtzman, D.; Mukherjee, A.; Nordstrom, D.K.

    2009-01-01

    High groundwater As concentrations in oxidizing systems are generally associated with As adsorption onto hydrous metal (Al, Fe or Mn) oxides and mobilization with increased pH. The objective of this study was to evaluate the distribution, sources and mobilization mechanisms of As in the Southern High Plains (SHP) aquifer, Texas, relative to those in other semiarid, oxidizing systems. Elevated groundwater As levels are widespread in the southern part of the SHP (SHP-S) aquifer, with 47% of wells exceeding the current EPA maximum contaminant level (MCL) of 10 μg/L (range 0.3-164 μg/L), whereas As levels are much lower in the north (SHP-N: 9% ≥ As MCL of 10 μg/L; range 0.2-43 μg/L). The sharp contrast in As levels between the north and south coincides with a change in total dissolved solids (TDS) from 395 mg/L (median north) to 885 mg/L (median south). Arsenic is present as arsenate (As V) in this oxidizing system and is correlated with groundwater TDS (Spearman's ρ = 0.57). The most likely current source of As is sorbed As onto hydrous metal oxides based on correlations between As and other oxyanion-forming elements (V, ρ = 0.88; Se, ρ = 0.54; B, ρ = 0.51 and Mo, ρ = 0.46). This source is similar to that in other oxidizing systems and constitutes a secondary source; the most likely primary source being volcanic ashes in the SHP aquifer or original source rocks in the Rockies, based on co-occurrence of As and F (ρ = 0.56), oxyanion-forming elements and SiO 2 (ρ = 0.41), which are found in volcanic ashes. High groundwater As concentrations in some semiarid oxidizing systems are related to high evaporation. Although correlation of As with TDS in the SHP aquifer may suggest evaporative concentration, unenriched stable isotopes (δ 2 H: -65 to -27; δ 18 O: -9.1 to -4.2) in the SHP aquifer do not support evaporation. High TDS in the SHP aquifer is most likely related to upward movement of saline water from the underlying Triassic Dockum aquifer. Mobilization

  5. Elevated naturally occurring arsenic in a semiarid oxidizing system, Southern High Plains aquifer, Texas, USA

    Science.gov (United States)

    Scanlon, Bridget R.; Nicot, J.-P.; Reedy, R.C.; Kurtzman, D.; Mukherjee, A.; Nordstrom, D. Kirk

    2009-01-01

    High groundwater As concentrations in oxidizing systems are generally associated with As adsorption onto hydrous metal (Al, Fe or Mn) oxides and mobilization with increased pH. The objective of this study was to evaluate the distribution, sources and mobilization mechanisms of As in the Southern High Plains (SHP) aquifer, Texas, relative to those in other semiarid, oxidizing systems. Elevated groundwater As levels are widespread in the southern part of the SHP (SHP-S) aquifer, with 47% of wells exceeding the current EPA maximum contaminant level (MCL) of 10 μg/L (range 0.3–164 μg/L), whereas As levels are much lower in the north (SHP-N: 9% ⩾ As MCL of 10 μg/L; range 0.2–43 μg/L). The sharp contrast in As levels between the north and south coincides with a change in total dissolved solids (TDS) from 395 mg/L (median north) to 885 mg/L (median south). Arsenic is present as arsenate (As V) in this oxidizing system and is correlated with groundwater TDS (Spearman’s ρ = 0.57). The most likely current source of As is sorbed As onto hydrous metal oxides based on correlations between As and other oxyanion-forming elements (V, ρ = 0.88; Se, ρ = 0.54; B, ρ = 0.51 and Mo, ρ = 0.46). This source is similar to that in other oxidizing systems and constitutes a secondary source; the most likely primary source being volcanic ashes in the SHP aquifer or original source rocks in the Rockies, based on co-occurrence of As and F (ρ = 0.56), oxyanion-forming elements and SiO2 (ρ = 0.41), which are found in volcanic ashes. High groundwater As concentrations in some semiarid oxidizing systems are related to high evaporation. Although correlation of As with TDS in the SHP aquifer may suggest evaporative concentration, unenriched stable isotopes (δ2H: −65 to −27; δ18O: −9.1 to −4.2) in the SHP aquifer do not support evaporation. High TDS in the SHP aquifer is most likely related to upward movement of saline water from the underlying

  6. The Plains of Venus

    Science.gov (United States)

    Sharpton, V. L.

    2013-12-01

    Volcanic plains units of various types comprise at least 80% of the surface of Venus. Though devoid of topographic splendor and, therefore often overlooked, these plains units house a spectacular array of volcanic, tectonic, and impact features. Here I propose that the plains hold the keys to understanding the resurfacing history of Venus and resolving the global stratigraphy debate. The quasi-random distribution of impact craters and the small number that have been conspicuously modified from the outside by plains-forming volcanism have led some to propose that Venus was catastrophically resurfaced around 725×375 Ma with little volcanism since. Challenges, however, hinge on interpretations of certain morphological characteristics of impact craters: For instance, Venusian impact craters exhibit either radar dark (smooth) floor deposits or bright, blocky floors. Bright floor craters (BFC) are typically 100-400 m deeper than dark floor craters (DFC). Furthermore, all 58 impact craters with ephemeral bright ejecta rays and/or distal parabolic ejecta patterns have bright floor deposits. This suggests that BFCs are younger, on average, than DFCs. These observations suggest that DFCs could be partially filled with lava during plains emplacement and, therefore, are not strictly younger than the plains units as widely held. Because the DFC group comprises ~80% of the total crater population on Venus the recalculated emplacement age of the plains would be ~145 Ma if DFCs are indeed volcanically modified during plains formation. Improved image and topographic data are required to measure stratigraphic and morphometric relationships and resolve this issue. Plains units are also home to an abundant and diverse set of volcanic features including steep-sided domes, shield fields, isolated volcanoes, collapse features and lava channels, some of which extend for 1000s of kilometers. The inferred viscosity range of plains-forming lavas, therefore, is immense, ranging from the

  7. Geomechanical characterization of volcanic rocks using empirical systems and data mining techniques

    OpenAIRE

    T. Miranda; L.R. Sousa; A.T. Gomes; J. Tinoco; C. Ferreira

    2018-01-01

    This paper tries to characterize volcanic rocks through the development and application of an empirical geomechanical system. Geotechnical information was collected from the samples from several Atlantic Ocean islands including Madeira, Azores and Canarias archipelagos. An empirical rock classification system termed as the volcanic rock system (VRS) is developed and presented in detail. Results using the VRS are compared with those obtained using the traditional rock mass rating (RMR) system....

  8. Rapid response of a hydrologic system to volcanic activity: Masaya volcano, Nicaragua

    Science.gov (United States)

    Pearson, S.C.P.; Connor, C.B.; Sanford, W.E.

    2008-01-01

    Hydrologic systems change in response to volcanic activity, and in turn may be sensitive indicators of volcanic activity. Here we investigate the coupled nature of magmatic and hydrologic systems using continuous multichannel time series of soil temperature collected on the flanks of Masaya volcano, Nicaragua, one of the most active volcanoes in Central America. The soil temperatures were measured in a low-temperature fumarole field located 3.5 km down the flanks of the volcano. Analysis of these time series reveals that they respond extremely rapidly, on a time scale of minutes, to changes in volcanic activity also manifested at the summit vent. These rapid temperature changes are caused by increased flow of water vapor through flank fumaroles during volcanism. The soil temperature response, ~5 °C, is repetitive and complex, with as many as 13 pulses during a single volcanic episode. Analysis of the frequency spectrum of these temperature time series shows that these anomalies are characterized by broad frequency content during volcanic activity. They are thus easily distinguished from seasonal trends, diurnal variations, or individual rainfall events, which triggered rapid transient increases in temperature during 5% of events. We suggest that the mechanism responsible for the distinctive temperature signals is rapid change in pore pressure in response to magmatism, a response that can be enhanced by meteoric water infiltration. Monitoring of distal fumaroles can therefore provide insight into coupled volcanic-hydrologic-meteorologic systems, and has potential as an inexpensive monitoring tool.

  9. Tracking changes in volcanic systems with seismic Interferometry

    Science.gov (United States)

    Haney, Matt; Alicia J. Hotovec-Ellis,; Bennington, Ninfa L.; Silvio De Angelis,; Clifford Thurber,

    2014-01-01

    The detection and evaluation of time-dependent changes at volcanoes form the foundation upon which successful volcano monitoring is built. Temporal changes at volcanoes occur over all time scales and may be obvious (e.g., earthquake swarms) or subtle (e.g., a slow, steady increase in the level of tremor). Some of the most challenging types of time-dependent change to detect are subtle variations in material properties beneath active volcanoes. Although difficult to measure, such changes carry important information about stresses and fluids present within hydrothermal and magmatic systems. These changes are imprinted on seismic waves that propagate through volcanoes. In recent years, there has been a quantum leap in the ability to detect subtle structural changes systematically at volcanoes with seismic waves. The new methodology is based on the idea that useful seismic signals can be generated “at will” from seismic noise. This means signals can be measured any time, in contrast to the often irregular and unpredictable times of earthquakes. With seismic noise in the frequency band 0.1–1 Hz arising from the interaction of the ocean with the solid Earth known as microseisms, researchers have demonstrated that cross-correlations of passive seismic recordings between pairs of seismometers yield coherent signals (Campillo and Paul 2003; Shapiro and Campillo 2004). Based on this principle, coherent signals have been reconstructed from noise recordings in such diverse fields as helioseismology (Rickett and Claerbout 2000), ultrasound (Weaver and Lobkis 2001), ocean acoustic waves (Roux and Kuperman 2004), regional (Shapiro et al. 2005; Sabra et al. 2005; Bensen et al. 2007) and exploration (Draganov et al. 2007) seismology, atmospheric infrasound (Haney 2009), and studies of the cryosphere (Marsan et al. 2012). Initial applications of ambient seismic noise were to regional surface wave tomography (Shapiro et al. 2005). Brenguier et al. (2007) were the first to

  10. Developing a hybrid solar/wind powered irrigation system for crops in the Great Plains

    Science.gov (United States)

    Some small scale irrigation systems (powered by wind or solar do not require subsidies, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. By adding a solar-photovoltaic (PV) array together with a wind...

  11. Volcanic features of Io

    International Nuclear Information System (INIS)

    Carr, M.H.; Masursky, H.; Strom, R.G.; Terrile, R.J.

    1979-01-01

    The volcanic features of Io as detected during the Voyager mission are discussed. The volcanic activity is apparently higher than on any other body in the Solar System. Its volcanic landforms are compared with features on Earth to indicate the type of volcanism present on Io. (U.K.)

  12. The Volcanic Hazards Assessment Support System for the Online Hazard Assessment and Risk Mitigation of Quaternary Volcanoes in the World

    Directory of Open Access Journals (Sweden)

    Shinji Takarada

    2017-12-01

    Full Text Available Volcanic hazards assessment tools are essential for risk mitigation of volcanic activities. A number of offline volcanic hazard assessment tools have been provided, but in most cases, they require relatively complex installation procedure and usage. This situation causes limited usage of volcanic hazard assessment tools among volcanologists and volcanic hazards communities. In addition, volcanic eruption chronology and detailed database of each volcano in the world are essential key information for volcanic hazard assessment, but most of them are isolated and not connected to and with each other. The Volcanic Hazard Assessment Support System aims to implement a user-friendly, WebGIS-based, open-access online system for potential hazards assessment and risk-mitigation of Quaternary volcanoes in the world. The users can get up-to-date information such as eruption chronology and geophysical monitoring data of a specific volcano using the direct link system to major volcano databases on the system. Currently, the system provides 3 simple, powerful and notable deterministic modeling simulation codes of volcanic processes, such as Energy Cone, Titan2D and Tephra2. The system provides deterministic tools because probabilistic assessment tools are normally much more computationally demanding. By using the volcano hazard assessment system, the area that would be affected by volcanic eruptions in any location near the volcano can be estimated using numerical simulations. The system is being implemented using the ASTER Global DEM covering 2790 Quaternary volcanoes in the world. The system can be used to evaluate volcanic hazards and move this toward risk-potential by overlaying the estimated distribution of volcanic gravity flows or tephra falls on major roads, houses and evacuation areas using the GIS-enabled systems. The system is developed for all users in the world who need volcanic hazards assessment tools.

  13. Solute geochemistry of the Snake River Plain regional aquifer system, Idaho and eastern Oregon

    International Nuclear Information System (INIS)

    Wood, W.W.; Low, W.H.

    1987-01-01

    Three geochemical methods were used to determine chemical reactions that control solute concentrations in the Snake River Plain regional aquifer system: (1) calculation of a regional solute balance within the aquifer and of mineralogy in the aquifer framework to identify solute reactions, (2) comparison of thermodynamic mineral saturation indices with plausible solute reactions, and (3) comparison of stable isotope ratios of the groundwater with those in the aquifer framework. The geothermal groundwater system underlying the main aquifer system was examined by calculating thermodynamic mineral saturation indices, stable isotope ratios of geothermal water, geothermometry, and radiocarbon dating. Water budgets, hydrologic arguments, and isotopic analyses for the eastern Snake River Plain aquifer system demonstrate that most, if not all, water is of local meteoric and not juvenile or formation origin. Solute balance, isotopic, mineralogic, and thermodynamic arguments suggest that about 20% of the solutes are derived from reactions with rocks forming the aquifer framework. Reactions controlling solutes in the western Snake river basin are believed to be similar to those in the eastern basin but the regional geothermal system that underlies the Snake river Plain contains total dissolved solids similar to those in the overlying Snake River Plain aquifer system but contains higher concentrations of sodium, bicarbonate, silica, fluoride, sulfate, chloride, arsenic, boron, and lithium, and lower concentrations of calcium, magnesium, and hydrogen. 132 refs., 30 figs., 27 tabs

  14. Antifriction coating of Cu-Fe-Al-Pb system for plain bearings

    Science.gov (United States)

    Kotenkov, Pavel; Kontsevoi, Yurii; Mejlakh, Anna; Pastukhov, Eduard; Shubin, Alexey; Goyda, Eduard; Sipatov, Ivan

    2017-09-01

    Aluminium, copper and their compounds are used in common as basis for antifriction coatings of plain bearings. Antifriction testing of plain bearings (based on Al and Cu) made by leading automotive manufacturers from Germany, Japan, USA, United Kingdom and Russia were carried out to make judicious selection of basis for development of new antifriction material. Testing was carried out using friction machine. It was defined that materials based on Cu provide better durability and robustness of plain bearings in comparison with Al based ones. The new antifriction composite coatings based on copper were developed taking into account the requirements specified for plain bearings of internal-combustion engine. Pilot samples of plain bearings with antifriction coatings of Cu-Fe-Al-Pb system were produced. The antifriction composite having Cu-5Fe-5Al5Fe2-10Pb (mass %) composition has demonstrated low friction factor and high wear-resistance. Metallographic analysis of pilot samples was carried out by means of optical and scanning electron microscopy.

  15. Automated detection and cataloging of global explosive volcanism using the International Monitoring System infrasound network

    Science.gov (United States)

    Matoza, Robin S.; Green, David N.; Le Pichon, Alexis; Shearer, Peter M.; Fee, David; Mialle, Pierrick; Ceranna, Lars

    2017-04-01

    We experiment with a new method to search systematically through multiyear data from the International Monitoring System (IMS) infrasound network to identify explosive volcanic eruption signals originating anywhere on Earth. Detecting, quantifying, and cataloging the global occurrence of explosive volcanism helps toward several goals in Earth sciences and has direct applications in volcanic hazard mitigation. We combine infrasound signal association across multiple stations with source location using a brute-force, grid-search, cross-bearings approach. The algorithm corrects for a background prior rate of coherent unwanted infrasound signals (clutter) in a global grid, without needing to screen array processing detection lists from individual stations prior to association. We develop the algorithm using case studies of explosive eruptions: 2008 Kasatochi, Alaska; 2009 Sarychev Peak, Kurile Islands; and 2010 Eyjafjallajökull, Iceland. We apply the method to global IMS infrasound data from 2005-2010 to construct a preliminary acoustic catalog that emphasizes sustained explosive volcanic activity (long-duration signals or sequences of impulsive transients lasting hours to days). This work represents a step toward the goal of integrating IMS infrasound data products into global volcanic eruption early warning and notification systems. Additionally, a better understanding of volcanic signal detection and location with the IMS helps improve operational event detection, discrimination, and association capabilities.

  16. Use of Low-Cost Acquisition Systems with an Embedded Linux Device for Volcanic Monitoring.

    Science.gov (United States)

    Moure, David; Torres, Pedro; Casas, Benito; Toma, Daniel; Blanco, María José; Del Río, Joaquín; Manuel, Antoni

    2015-08-19

    This paper describes the development of a low-cost multiparameter acquisition system for volcanic monitoring that is applicable to gravimetry and geodesy, as well as to the visual monitoring of volcanic activity. The acquisition system was developed using a System on a Chip (SoC) Broadcom BCM2835 Linux operating system (based on DebianTM) that allows for the construction of a complete monitoring system offering multiple possibilities for storage, data-processing, configuration, and the real-time monitoring of volcanic activity. This multiparametric acquisition system was developed with a software environment, as well as with different hardware modules designed for each parameter to be monitored. The device presented here has been used and validated under different scenarios for monitoring ocean tides, ground deformation, and gravity, as well as for monitoring with images the island of Tenerife and ground deformation on the island of El Hierro.

  17. Martian volcanism: A review

    International Nuclear Information System (INIS)

    Carr, M.H.

    1987-01-01

    Martian volcanism is reviewed. It is emphasized that lava plains constitute the major type of effusive flow, and can be differentiated by morphologic characteristics. Shield volcanoes, domes, and patera constitute the major constructional landforms, and recent work has suggested that explosive activity and resulting pyroclastic deposits may have been involved with formation of some of the small shields. Analysis of morphology, presumed composition, and spectroscopic data all indicate that Martian volcanism was dominantly basaltic in composition

  18. Geomechanical characterization of volcanic rocks using empirical systems and data mining techniques

    Directory of Open Access Journals (Sweden)

    T. Miranda

    2018-02-01

    Full Text Available This paper tries to characterize volcanic rocks through the development and application of an empirical geomechanical system. Geotechnical information was collected from the samples from several Atlantic Ocean islands including Madeira, Azores and Canarias archipelagos. An empirical rock classification system termed as the volcanic rock system (VRS is developed and presented in detail. Results using the VRS are compared with those obtained using the traditional rock mass rating (RMR system. Data mining (DM techniques are applied to a database of volcanic rock geomechanical information from the islands. Different algorithms were developed and consequently approaches were followed for predicting rock mass classes using the VRS and RMR classification systems. Finally, some conclusions are drawn with emphasis on the fact that a better performance was achieved using attributes from VRS.

  19. Density evaluation by computerized tomography in plain soils over different manipulation systems

    International Nuclear Information System (INIS)

    Pedrotti, Alceu

    1996-08-01

    The objective of this paper is the evaluation of a plain soil density in different culture systems determined by X ray computerized tomography.It was observed a larger variation in densities in soils profiles analysed. The identification of layers is better utilising computerized tomography than others technic

  20. Economic performance and sustainability of a novel intercropping system on the north China plain

    NARCIS (Netherlands)

    Huang, C.; Liu, Q.; Heerink, N.B.M.; Stomph, T.J.; Li, B.; Liu, R.; Zhang, H.; Wang, C.; Li, X.; Zhang, C.; Werf, van der W.; Zhang, F.

    2015-01-01

    Double cropping of wheat and maize is common on the North China Plain, but it provides limited income to rural households due to the small farm sizes in the region. Local farmers in Quzhou County have therefore innovated their production system by integration of watermelon as a companion cash crop

  1. Geomorphological Approach for Regional Zoning In The Merapi Volcanic Area

    Directory of Open Access Journals (Sweden)

    Langgeng Wahyu Santosa

    2013-07-01

    Full Text Available Geomorphologial approach can be used as the basic for identifying and analyzing the natural resources potentials, especially in volcanic landscape. Based on its geomorphology, Merapi volcanic landscape can be divided into 5 morphological units, i.e.: volcanic cone, volcanic slope, volcanic foot, volcanic foot plain, and fluvio-volcanic plain. Each of these morphological units has specific characteristic and natural resources potential. Based on the condition of geomorphology, the regional zoning can be compiled to support the land use planning and to maintain the conservation of environmental function in the Merapi Volcanic area.

  2. Grain size and shape analysis of the AD 1226 tephra layer, Reykjanes volcanic system

    Science.gov (United States)

    Ösp Magnúsdóttir, Agnes; Höskuldsson, Ármann; Larsen, Guðrún; Tumi Guðmunsson, Magnús; Sigurgeirsson, Magnús Á.

    2014-05-01

    Recent explosive eruptions in Iceland have drawn attention to long range tephra transport in the atmosphere. In Iceland tephra forming explosion eruptions are frequent, due to abundance of water. However, the volcanism on the island is principally basaltic. Volcanism along the Reykjanes Peninsula is divided into five distinct volcanic systems. Volcano-tectonic activity within these systems is periodic, with recurrence intervals in the range of 1 ka. Last volcano-tectonic sequence began around AD 940, shortly after settlement of Iceland, and lasted through AD 1340. During this period activity was characterized by basaltic fissure eruptions. Furthermore, this activity period on the Reykjanes peninsula began within the eastern most volcanic system and gradually moved towards the west across the peninsula. The 1226 eruption was a basaltic fissure eruption with in the Reykjanes volcanic system. The eruption began on land and gradually progressed towards the SW until the volcanic fissure extended into the sea. Water-magma interaction changed the eruption from effusive into explosive forming the largest tephra layer on the peninsula. Due to its close proximity to the Keflavik international airport and that of the capital of Iceland it is important to get an insight into, the characteristics, generation and distribution of such tephra deposits. In this eruption the tephra produced had an approximate volume of 0.1 km3 and covered an area of some 3500 km2 within the 0.5 cm isopach. Total grain size distribution of this tephra layer will be presented along with analysis of principal grain shapes of the finer portion of the tephra layer as a function of distance from the source. The tephra grain size is dominated by particles finer than 1 millimeter with an almost complete absence of large grains independent of distance from the source. Comprehensive understanding of the characteristics of tephra generated in this eruption can help us to understand hazards posed by future

  3. Mountain Plains Learning Experience Guide: Automotive Repair. Course: Brake Systems.

    Science.gov (United States)

    Schramm, C.; Osland, Walt

    One of twelve individualized courses included in an automotive repair curriculum, this course covers theory, operation, and repair of drum brakes, disc brakes, and brake system components. The course is comprised of six units: (1) Fundamentals of Brake Systems, (2) Master Cylinder, (3) Drum Brakes, (4) Disc Brakes, (5) Power Brakes, and (6)…

  4. Mountain Plains Learning Experience Guide: Automotive Repair. Course: Emission Systems.

    Science.gov (United States)

    Schramm, C.; Osland, Walt

    One of twelve individualized courses included in an automotive repair curriculum, this course covers the theory, testing, and servicing of automotive emission control systems. The course is comprised of one unit, Fundamentals of Emission Systems. The unit begins with a Unit Learning Experience Guide that gives directions for unit completion. The…

  5. Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

    Science.gov (United States)

    Lindholm, G.F.

    1996-01-01

    Regional aquifers underlying the 15,600-square-mile Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. The largest and most productive aquifers in the Snake River Plain are composed of Quaternary basalt of the Snake River Group, which underlies most of the 10,8000-square-mile eastern plain. Aquifer tests and simulation indicate that transmissivity of the upper 200 feet of the basalt aquifer in the eastern plain commonly ranges from about 100,000 to 1,000,000 feet squared per day. However, transmissivity of the total aquifer thickness may be as much as 10 million feet squared per day. Specific yield of the upper 200 feet of the aquifer ranges from about 0.01 to 0.20. Average horizontal hydraulic conductivity of the upper 200 feet of the basalt aquifer ranges from less than 100 to 9,000 feet per day. Values may be one to several orders of magnitude higher in parts in individual flows, such as flow tops. Vertical hydraulic conductivity is probably several orders of magnitude lower than horizontal hydraulic conductivity and is generally related to the number of joints. Pillow lava in ancestral Snake River channels has the highest hydraulic conductivity of all rock types. Hydraulic conductivity of the basalt decreases with depth because of secondary filling of voids with calcite and silica. An estimated 80 to 120 million acre-feet of water is believed to be stored in the upper 200 feet of the basalt aquifer in the eastern plain. The most productive aquifers in the 4,800-square-mile western plain are alluvial sand and gravel in the Boise River valley. Although aquifer tests indicate that transmissivity of alluvium in the Boise River valley ranges from 5,000 to 160,000 feet squared per day, simulation suggests that average transmissivity of the upper 500 feet is generally less than 20,000 feet squared per day. Vertically averaged horizontal hydraulic conductivity of the upper

  6. Dynamic cropping systems: Holistic approach for dryland agricultural systems in the northern Great Plains of North America

    Science.gov (United States)

    Cropping systems over the past century have developed greater crop specialization, more effectively conserve our soil and water resources, and are more resilient. The purpose of this chapter is to discuss the evolution of cropping systems in the Northern Great Plains and provide an approach to crop...

  7. Magmatic densities control erupted volumes in Icelandic volcanic systems

    Science.gov (United States)

    Hartley, Margaret; Maclennan, John

    2018-04-01

    Magmatic density and viscosity exert fundamental controls on the eruptibility of magmas. In this study, we investigate the extent to which magmatic physical properties control the eruptibility of magmas from Iceland's Northern Volcanic Zone (NVZ). By studying subaerial flows of known age and volume, we are able to directly relate erupted volumes to magmatic physical properties, a task that has been near-impossible when dealing with submarine samples dredged from mid-ocean ridges. We find a strong correlation between magmatic density and observed erupted volumes on the NVZ. Over 85% of the total volume of erupted material lies close to a density and viscosity minimum that corresponds to the composition of basalts at the arrival of plagioclase on the liquidus. These magmas are buoyant with respect to the Icelandic upper crust. However, a number of small-volume eruptions with densities greater than typical Icelandic upper crust are also found in Iceland's neovolcanic zones. We use a simple numerical model to demonstrate that the eruption of magmas with higher densities and viscosities is facilitated by the generation of overpressure in magma chambers in the lower crust and uppermost mantle. This conclusion is in agreement with petrological constraints on the depths of crystallisation under Iceland.

  8. Magmatic Densities Control Erupted Volumes in Icelandic Volcanic Systems

    Directory of Open Access Journals (Sweden)

    Margaret Hartley

    2018-04-01

    Full Text Available Magmatic density and viscosity exert fundamental controls on the eruptibility of magmas. In this study, we investigate the extent to which magmatic physical properties control the eruptibility of magmas from Iceland's Northern Volcanic Zone (NVZ. By studying subaerial flows of known age and volume, we are able to directly relate erupted volumes to magmatic physical properties, a task that has been near-impossible when dealing with submarine samples dredged from mid-ocean ridges. We find a strong correlation between magmatic density and observed erupted volumes on the NVZ. Over 85% of the total volume of erupted material lies close to a density and viscosity minimum that corresponds to the composition of basalts at the arrival of plagioclase on the liquidus. These magmas are buoyant with respect to the Icelandic upper crust. However, a number of small-volume eruptions with densities greater than typical Icelandic upper crust are also found in Iceland's neovolcanic zones. We use a simple numerical model to demonstrate that the eruption of magmas with higher densities and viscosities is facilitated by the generation of overpressure in magma chambers in the lower crust and uppermost mantle. This conclusion is in agreement with petrological constraints on the depths of crystallization under Iceland.

  9. Evaluation of groundwater quality and its suitability for drinking, domestic, and agricultural uses in the Banana Plain (Mbanga, Njombe, Penja) of the Cameroon Volcanic Line.

    Science.gov (United States)

    Ako, Andrew Ako; Shimada, Jun; Hosono, Takahiro; Ichiyanagi, Kimpei; Nkeng, George Elambo; Fantong, Wilson Yetoh; Eyong, Gloria Eneke Takem; Roger, Ntankouo Njila

    2011-12-01

    Groundwater quality of the Banana Plain (Mbanga, Njombe, Penja-Cameroon) was assessed for its suitability for drinking, domestic, and agricultural uses. A total of 67 groundwater samples were collected from open wells, springs, and boreholes. Samples were analyzed for physicochemical properties, major ions, and dissolved silica. In 95% of groundwater samples, calcium is the dominant cation, while sodium dominates in 5% of the samples. Eighty percent of the samples have HCO(3) as major anion, and in 20%, NO(3) is the major anion. Main water types in the study area are CaHCO(3), CaMgHCO(3), CaNaHCO(3), and CaNaNO(3)ClHCO(3). CO(2)-driven weathering of silicate minerals followed by cation exchange seemingly controls largely the concentrations of major ions in the groundwaters of this area. Nitrate, sulfate, and chloride concentrations strongly express the impact of anthropogenic activities (agriculture and domestic activities) on groundwater quality. Sixty-four percent of the waters have nitrate concentrations higher than the drinking water limit. Also limiting groundwater use for potable and domestic purposes are contents of Ca(2+), Mg(2+) and HCO(3) (-) and total hardness (TH) that exceed World Health Organization (WHO) standards. Irrigational suitability of groundwaters in the study area was also evaluated, and results show that all the samples are fit for irrigation. Groundwater quality in the Banana Plain is impeded by natural geology and anthropogenic activities, and proper groundwater management strategies are necessary to protect sustainably this valuable resource.

  10. Resolving the architecture of monogenetic feeder systems from exposures of extinct volcanic fields

    Science.gov (United States)

    Muirhead, J.; Van Eaton, A. R.; Re, G.; White, J. D. L.; Ort, M. H.

    2016-12-01

    Monogenetic volcanic fields pose hazards to a number of major cities worldwide. During an eruption, the evolution of the intrusive feeder network modulates eruption behavior and location, as well as the warning signs of impending activity. However, historical examples of monogenetic eruptions are rare, particularly those monitored with the modern tools required to constrain the geometry and interconnectivity of subsurface intrusive feeders (e.g., InSAR, GPS). Geologic exposures in extinct fields around the Colorado Plateau provide clues to the geometry of shallow intrusions (<1000 m depth) that feed monogenetic volcanoes. We present field- and satellite-based observations of exposed intrusions in the Hopi Buttes volcanic field (Arizona), which reveal that many eruptions were fed by interconnected dike-sill systems. Results from the Hopi Buttes show that volcanic cone alignment studies are biased to the identification of dike intrusions, and thereby neglect the important contributions of sills to shallow feeder systems. For example, estimates of intruded volumes in fields exhumed by uplift and erosion in Utah and Arizona show that sills make up 30 - 92% of the shallow intruded volume within 1000 m of the paleosurface. By transporting magma toward and away from eruptive conduits, these sills likely played a role in modulating eruption styles (e.g., explosive vs effusive) and controlling lateral vent migrations. Sill transitions at Hopi Buttes would have produced detectable surface uplifts, and illustrate the importance of geological studies for informing interpretations of geodetic and seismological data during volcanic crises.

  11. Evidence for young volcanism on Mercury from the third MESSENGER flyby.

    Science.gov (United States)

    Prockter, Louise M; Ernst, Carolyn M; Denevi, Brett W; Chapman, Clark R; Head, James W; Fassett, Caleb I; Merline, William J; Solomon, Sean C; Watters, Thomas R; Strom, Robert G; Cremonese, Gabriele; Marchi, Simone; Massironi, Matteo

    2010-08-06

    During its first two flybys of Mercury, the MESSENGER spacecraft acquired images confirming that pervasive volcanism occurred early in the planet's history. MESSENGER's third Mercury flyby revealed a 290-kilometer-diameter peak-ring impact basin, among the youngest basins yet seen, having an inner floor filled with spectrally distinct smooth plains. These plains are sparsely cratered, postdate the formation of the basin, apparently formed from material that once flowed across the surface, and are therefore interpreted to be volcanic in origin. An irregular depression surrounded by a halo of bright deposits northeast of the basin marks a candidate explosive volcanic vent larger than any previously identified on Mercury. Volcanism on the planet thus spanned a considerable duration, perhaps extending well into the second half of solar system history.

  12. Application of a radiotelemetric system to evaluate the performance of enteric coated and plain aspirin tablets.

    Science.gov (United States)

    Lui, C Y; Oberle, R; Fleisher, D; Amidon, G L

    1986-05-01

    The bioavailability of enteric coated and plain aspirin tablets was studied in four beagle dogs. Blood sampling for enteric coated tablets was planned with the aid of a radiotelemetric system. The release of aspirin from its dosage form was detected by monitoring the change in intestinal pH. Aspirin and salicylic acid levels in plasma obtained from the enteric coated dosage form exhibited familiar concentration versus time absorption profiles. Variation in the plasma concentrations of these two compounds within each dog studied (four runs each) was relatively small when time zero was adjusted to the commencement of tablet dissolution. The plasma levels obtained from plain aspirin (three runs each), however, show atypical absorption. The estimated absolute bioavailability was 0.432 +/- 0.0213 and 0.527 +/- 0.0260 for enteric coated and plain aspirin, respectively. Other pharmacokinetic parameters for these two dosage forms such as the highest observed plasma concentration (Cmax) (10.9 +/- 0.535 microgram/mL versus 13.6 +/- 1.88 micrograms/mL) and the time to reach Cmax (tmax) (26.6 +/- 1.94 min versus 31.0 +/- 7.04 min) agree well. The mean values for gastric emptying time, in vivo coating dissolution time, and in vivo disintegration/dissolution time of the tablet core for enteric coated aspirin are 48.7 +/- 7.23 min, 44.3 +/- 3.80 min, and 34.7 +/- 2.04 min, respectively.

  13. Metallogenic hydrothermal solution system of post volcanic magma in Xiangshan ore field

    International Nuclear Information System (INIS)

    Xu Hengli; Shao Fei; Zou Maoqin

    2009-01-01

    This paper has systematically described uranium metallogenic characteristics of Xiangshan ore field.Sources of metallogenic materials are discussed in different temporal and spatial scale. Combining with background analysis of metallogenic tectonic-magmatic-geodynamics, formation and evolution of metallogenic hydrothermal solution system in Xiangshan volcanic basin are studied. Metallogenic hydrothermal solution system in Xiangshan ore field is considered as the objective product of systematic evolution of hydrothermal solution in post volcanic magma constrained by regional tectonic environment. In time scale, metallogenic hydrothermal solution system developed for about 50 Ma, but its active spaces varied in different time domains. So temporal and spatial distribution of uranium mineralization is constrained. Further exploration for the ore field is also suggested in this paper. (authors)

  14. The Maryland Coastal Plain Aquifer Information System: A GIS-based tool for assessing groundwater resources

    Science.gov (United States)

    Andreasen, David C.; Nardi, Mark R.; Staley, Andrew W.; Achmad, Grufron; Grace, John W.

    2016-01-01

    Groundwater is the source of drinking water for ∼1.4 million people in the Coastal Plain Province of Maryland (USA). In addition, groundwater is essential for commercial, industrial, and agricultural uses. Approximately 0.757 × 109 L d–1 (200 million gallons/d) were withdrawn in 2010. As a result of decades of withdrawals from the coastal plain confined aquifers, groundwater levels have declined by as much as 70 m (230 ft) from estimated prepumping levels. Other issues posing challenges to long-term groundwater sustainability include degraded water quality from both man-made and natural sources, reduced stream base flow, land subsidence, and changing recharge patterns (drought) caused by climate change. In Maryland, groundwater supply is managed primarily by the Maryland Department of the Environment, which seeks to balance reasonable use of the resource with long-term sustainability. The chief goal of groundwater management in Maryland is to ensure safe and adequate supplies for all current and future users through the implementation of appropriate usage, planning, and conservation policies. To assist in that effort, the geographic information system (GIS)–based Maryland Coastal Plain Aquifer Information System was developed as a tool to help water managers access and visualize groundwater data for use in the evaluation of groundwater allocation and use permits. The system, contained within an ESRI ArcMap desktop environment, includes both interpreted and basic data for 16 aquifers and 14 confining units. Data map layers include aquifer and ­confining unit layer surfaces, aquifer extents, borehole information, hydraulic properties, time-series groundwater-level data, well records, and geophysical and lithologic logs. The aquifer and confining unit layer surfaces were generated specifically for the GIS system. The system also contains select groundwater-quality data and map layers that quantify groundwater and surface-water withdrawals. The aquifer

  15. GIS database and discussion for the distribution, composition, and age of Cenozoic volcanic rocks of the Pacific Northwest Volcanic Aquifer System study area

    Science.gov (United States)

    Sherrod, David R.; Keith, Mackenzie K.

    2018-03-30

    A substantial part of the U.S. Pacific Northwest is underlain by Cenozoic volcanic and continental sedimentary rocks and, where widespread, these strata form important aquifers. The legacy geologic mapping presented with this report contains new thematic categorization added to state digital compilations published by the U.S. Geological Survey for Oregon, California, Idaho, Nevada, Utah, and Washington (Ludington and others, 2005). Our additional coding is designed to allow rapid characterization, mainly for hydrogeologic purposes, of similar rocks and deposits within a boundary expanded slightly beyond that of the Pacific Northwest Volcanic Aquifer System study area. To be useful for hydrogeologic analysis and to be more statistically manageable, statewide compilations from Ludington and others (2005) were mosaicked into a regional map and then reinterpreted into four main categories on the basis of (1) age, (2) composition, (3) hydrogeologic grouping, and (4) lithologic pattern. The coding scheme emphasizes Cenozoic volcanic or volcanic-related rocks and deposits, and of primary interest are the codings for composition and age.

  16. Surface Textures and Features Indicative of Endogenous Growth at the McCartys Flow Field, NM, as an Analog to Martian Volcanic Plains

    Science.gov (United States)

    Bleacher, Jacob E.; Crumpler, L. S.; Garry, W. B.; Zimbelman, J. R.; Self, S.; Aubele, J. C.

    2012-01-01

    Basaltic lavas typically form channels or tubes, which are recognized on the Earth and Mars. Although largely unrecognized in the planetary community, terrestrial inflated sheet flows also display morphologies that share many commonalities with lava plains on Mars. The McCartys lava flow field is among the youngest (approx.3000 yrs) basaltic flows in the continental United States. The southwest sections of the flow displays smooth, flat-topped plateaus with irregularly shaped pits and hummocky inter-plateau units that form a polygonal surface. Plateaus are typically elongate in map view, up to 20 m high and display lineations within the glassy crust. Lineated surfaces occasionally display small < 1m diameter lava coils. Lineations are generally straight and parallel each other, sometimes for over 100 meters. The boundaries between plateaus and depressions are also lineated and tilted to angles sometimes approaching vertical. Plateau-parallel cracks, sometimes containing squeeze-ups, mark the boundary between tilted crust and plateau. Some plateau depressions display level floors with hummocky surfaces, while some are bowl shaped with floors covered in broken lava slabs. The lower walls of pits sometimes display lateral, sagged lava wedges. Infrequently, pit floors display the upper portion of a tumulus from an older flow. In some places the surface crust has been disrupted forming a slabby texture. Slabs are typically on the scale of a meter or less across and no less than 7-10 cm thick. The slabs preserve the lineated textures of the undisturbed plateau crust. It appears that this style of terrain represents the emplacement of an extensive sheet that experiences inflation episodes within preferred regions where lateral spreading of the sheet is inhibited, thereby forming plateaus. Rough surfaces represent inflation-related disruption of pahoehoe lava and not a a lava. Depressions are often the result of non-inflation and can be clearly identified by lateral

  17. A comparison of native tallgrass prairie and plains bluestem forage systems for cow-calf production in the southern great plains.

    Science.gov (United States)

    Coleman, S W; Phillips, W A; Volesky, J D; Buchanan, D

    2001-07-01

    The objective of this study was to compare an introduced warm-season perennial grass (plains bluestem, Bothriochloa ischaemum) to native tallgrass prairie for cow-calf production. Three systems were used, two based on tallgrass prairie with two different forms of protein supplementation and one based on plains bluestem as the primary forage. The systems were as follows: 1) native tallgrass prairie with pelleted oilseed meal as the winter protein supplement (native-control); 2) native tallgrass prairie with limited access to wheat pasture as the winter protein supplement (native-wheat); and 3) plains bluestem with limited access to wheat pasture as the protein supplement (bluestem-wheat). Oilseed meal protein supplements were fed twice weekly. Cows grazing wheat pasture were allowed 6 h of grazing twice weekly. Ninety-nine cows per year were used over the 3-yr study. Cows were sired by either Charolais, Gelbvieh, Angus, or Hereford bulls out of commercial Angus-Hereford dams. Calves were sired by Simmental bulls. Calving and weaning rate increased over time but did not differ among systems or breed types. System did not influence the size or body condition score of cows or the performance of calves, but changes in the weight and condition scores of cows were greater on either native system than on the bluestem-wheat system. Cows from Charolais and Gelbvieh bulls were taller (P < 0.05), and heavier (P < 0.05), and weaned heavier (P < 0.05) calves than cows from Angus or Hereford bulls. The weight of cows on the bluestem-wheat system tended to decrease over time, whereas cows grazing on the native systems tended to gain weight over time. The native-control system was the most profitable system based on cow production. If excess hay produced from the bluestem-wheat system was sold as a cash crop, then this system was the most profitable. In general, we conclude that limit-grazing wheat pasture is a viable alternative to oilseed meal as protein supplement for wintering

  18. Dilatation of the hemiazygos system on plain films of the chest

    International Nuclear Information System (INIS)

    Catalano, D.

    1983-01-01

    The enlargement of the hemiazygos system and the superior intercostal vein as a collateral pathway in cases of obstruction of the superior or the inferior vena cava is recognizable on the frontal and lateral plain chest films. It appears in frontal radiographs as an additional line parallel to the left paraspinal line with a bulging at the level or superiorly to the aortic knob and continuing with the shadow of the left brachiocephalic vessels. In the lateral chest view it is evident as an inhomogeneous soft tissue density posteriorly to the lower third of the trachea. (orig.) [de

  19. Amphibole Thermometry and a Comparison of Results from Plutonic and Volcanic Systems

    Science.gov (United States)

    Sherman, T. M.; Putirka, K. D.; De Los Reyes, A. M. A.; Ratschbacher, B. C.

    2015-12-01

    Recent work (Ridolfi and Renzulli 2014) shows that amphiboles can be used to infer magmatic temperatures, even without knowledge of co-existing liquids. Here, we apply this approach, using new calibrations, to investigate felsic-mafic magma interactions, in a volcanic (Lassen Volcanic Center, a Cascade volcano) and plutonic (the Jurassic Guadalupe Igneous Complex) system. Preliminary data suggest that volcanic processes, as might be expected, preserve higher temperatures than plutonic materials (on average, volcanic amphiboles recorded 907±57.3°C while plutonic amphiboles recorded 764±59.7°C). We also find that the average T of a given mineral grain decreases with increased mineral size such that those crystallized below 800°C sometimes reach sizes beyond ~1mm, while those near 900°C appear truncated to ~0.3mm. It is not clear if T is the only control on amphibole crystal growth; however, our results would imply that larger grains not only require more time to grow but require continued undercooling. Significant cooling or heating is also recorded in many volcanically- and plutonically-grown grains, which may reflect transitioning between magmas of different T and composition. Core-to-rim cooling trends (with a common T of drop of 80oC) likely represent mafic-to-felsic magma transitions, whereas core-to-rim heating of similar magnitudes indicate a felsic-mafic transition. Some grains, though, exhibit a constant T (in the range 700-900°C) from core to rim, which perhaps indicates some shielding from magma mixing processes. Amphiboles might thus provide a reliable record of the intensity of magma mingling and mixing experienced by any particular enclave. Interestingly, volcanically-derived amphiboles appear to mostly record cooling towards the rims, while their plutonic counterparts tend to experience heating. It would thus appear that at Lassen, amphiboles are unaffected by later mafic magma recharge, but at the GIC, the plutonic amphiboles are more likely to

  20. A synoptic climatology of derecho producing mesoscale convective systems in the North-Central Plains

    Science.gov (United States)

    Bentley, Mace L.; Mote, Thomas L.; Byrd, Stephen F.

    2000-09-01

    Synoptic-scale environments favourable for producing derechos, or widespread convectively induced windstorms, in the North-Central Plains are examined with the goal of providing pattern-recognition/diagnosis techniques. Fifteen derechos were identified across the North-Central Plains region during 1986-1995. The synoptic environment at the initiation, mid-point and decay of each derecho was then evaluated using surface, upper-air and National Center for Atmospheric Research (NCAR)/National Center for Environmental Prediction (NCEP) reanalysis datasets.Results suggest that the synoptic environment is critical in maintaining derecho producing mesoscale convective systems (DMCSs). The synoptic environment in place downstream of the MCS initiation region determines the movement and potential strength of the system. Circulation around surface low pressure increased the instability gradient and maximized leading edge convergence in the initiation region of nearly all events regardless of DMCS location or movement. Other commonalities in the environments of these events include the presence of a weak thermal boundary, high convective instability and a layer of dry low-to-mid-tropospheric air. Of the two corridors sampled, northeastward moving derechos tend to initiate east of synoptic-scale troughs, while southeastward moving derechos form on the northeast periphery of a synoptic-scale ridge. Other differences between these two DMCS events are also discussed.

  1. Applicability of `GREATEM' system in mapping geothermal regions in volcanic areas

    Science.gov (United States)

    Verma, S. K.; Mogi, T.; Abd Allah, S.

    2010-12-01

    The ‘GREATEM’ helicopter borne TEM system employs a long grounded cable as transmitter while a light weight receiver coil is flown below a helicopter. This arrangement greatly simplifies the flying logistics and speed of the survey. Also there is very little reduction in the anomaly amplitude when the survey altitude is increased. This is a great advantage particularly in volcanic regions usually having rough topography, as the ‘GREATEM’ survey can be done with helicopter flying at a safe height. Many volcanic areas have anomalous geothermal regions containing hydrothermal fluids. Eruption of volcanoes may cause changes in the thermal character and spatial distribution of these regions. Mapping of these regions is important as they may be associated with hazards. Sometimes, if the temperature is high and volume of the geothermal region is large, they can provide a good source of geothermal energy. Applicability of ‘GREATEM’ system in mapping geothermal regions in volcanic areas is studied by numerical modeling. We have considered a 3D conductor at a shallow depth (50 t0 100m), representing the anomalous geothermal region with dimensions of 500m X 500m X 500m. Different types of geological host environment are considered by varying their resistivities from 10 Ohm.m to 2000 Ohm.m. The ‘GREATEM’ response is analyzed as ‘Percentage Difference (PD)’ over the response produced by the host environment. It is found that the “GREATEM’ system can delineate the geothermal region well. Many geothermal regions are associated with a deeper (> 1 km) reservoir of much larger dimensions. In this situation also it is found that the ‘GREATEM’ system can pick up the response of the shallower geothermal region against the background response of different types of geological host environment containing the deeper reservoir (Figure 1).

  2. A first Event-tree for the Bárðarbunga volcanic system (Iceland): from the volcanic crisis in 2014 towards a tool for hazard assessment

    Science.gov (United States)

    Barsotti, Sara; Tumi Gudmundsson, Magnús; Jónsdottir, Kristín; Vogfjörd, Kristín; Larsen, Gudrun; Oddsson, Björn

    2015-04-01

    Bárdarbunga volcano is part of a large volcanic system that had its last confirmed eruption before the present unrest in 1910. This system is partially covered by ice within the Vatnajökull glacier and it extends further to the NNE as well as to SW. Based on historical data, its eruptive activity has been predominantly characterized by explosive eruptions, originating beneath the glacier, and important effusive eruptions in the ice-free part of the system itself. The largest explosive eruptions took place on the southern side of the fissure system in AD 1477 producing about 10 km3 of tephra. Due to the extension and location of this volcanic system, the range of potential eruptive scenarios and associated hazards is quite wide. Indeed, it includes: inundation, due to glacial outburst; tephra fallout, due to ash-rich plume generated by magma-water interaction; abundant volcanic gas release; and lava flows. Most importantly these phenomena are not mutually exclusive and might happen simultaneously, creating the premise for a wide spatial and temporal impact. During the ongoing volcanic crisis at Bárdarbunga, which started on 16 August, 2014, the Icelandic Meteorological Office, together with the University of Iceland and Icelandic Civil Protection started a common effort of drawing, day-by-day, the potential evolution of the ongoing rifting event and, based on the newest data from the monitoring networks, updated and more refined scenarios have been identified. Indeed, this volcanic crisis created the occasion for pushing forward the creation of the first Event-tree for the Bárðarbunga volcanic system. We adopted the approach suggested by Newhall and Pallister (2014) and a preliminary ET made of nine nodes has been constructed. After the two initial nodes (restless and genesis) the ET continues with the identification of the location of aperture of future eruptive vents. Due to the complex structure of the system and historical eruptions, this third node

  3. A study on the characteristics of site-scale fracture system in granite and volcanic rock

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Su; Kim, Chun Soo; Bae, Dae Seok; Park, Byoung Yoon; Koh, Young Kown [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-03-01

    The safety of waste disposal can be achieved by a complete isolation of radioactive wastes from biosphere or by a retardation of nuclide migration to reach an acceptable dose level. For the deep geological disposal of high-level radioactive waste, the potential pathways of nuclide primarily depend on the spatial distribution characteristics of conductive fractures. Major key issues in the quantification of fracture system for a disposal site are involved in classification criteria, hydraulic parameters, geometry, field investigation methods etc. This research aims to characterize the spatial distribution characteristics of conductive fractures in granite and volcanic rock mass. 10 refs., 32 figs., 13 tabs. (Author)

  4. Volcanic stratigraphy: A review

    Science.gov (United States)

    Martí, Joan; Groppelli, Gianluca; Brum da Silveira, Antonio

    2018-05-01

    Volcanic stratigraphy is a fundamental component of geological mapping in volcanic areas as it yields the basic criteria and essential data for identifying the spatial and temporal relationships between volcanic products and intra/inter-eruptive processes (earth-surface, tectonic and climatic), which in turn provides greater understanding of the geological evolution of a region. Establishing precise stratigraphic relationships in volcanic successions is not only essential for understanding the past behaviour of volcanoes and for predicting how they might behave in the future, but is also critical for establishing guidelines for exploring economic and energy resources associated with volcanic systems or for reconstructing the evolution of sedimentary basins in which volcanism has played a significant role. Like classical stratigraphy, volcanic stratigraphy should also be defined using a systematic methodology that can provide an organised and comprehensive description of the temporal and spatial evolution of volcanic terrain. This review explores different methods employed in studies of volcanic stratigraphy, examines four case studies that use differing stratigraphic approaches, and recommends methods for using systematic volcanic stratigraphy based on the application of the concepts of traditional stratigraphy but adapted to the needs of volcanological environment.

  5. Performance of Plain Woven Jute Fabric-Reinforced Polyester Matrix Composite in Multilayered Ballistic System

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2018-02-01

    Full Text Available The ballistic performance of plain woven jute fabric-reinforced polyester matrix composites was investigated as the second layer in a multilayered armor system (MAS. Volume fractions of jute fabric, up to 30 vol %, were mixed with orthophthalic polyester to fabricate laminate composites. Ballistic tests were conducted using high velocity 7.62 mm ammunition. The depth of penetration caused by the bullet in a block of clay witness, simulating a human body, was used to evaluate the MAS ballistic performance according to the international standard. The fractured materials after tests were analyzed by scanning electron microscopy (SEM. The results indicated that jute fabric composites present a performance similar to that of the much stronger Kevlar™, which is an aramid fabric laminate, as MAS second layer with the same thickness. The mechanism of this similar ballistic behavior as well as the comparative advantages of the jute fabric composites over the Kevlar™ are discussed.

  6. Implementation of AN Agricultural Environmental Information System (aeis) for the Sanjiang Plain, Ne-China

    Science.gov (United States)

    Zhao, Q.; Brocks, S.; Lenz-Wiedemann, V.; Miao, Y.; Jiang, R.; Chen, X.; Zhang, F.; Bareth, G.

    2012-07-01

    The Sino-German Project between the China Agricultural University and the University of Cologne, Germany, focuses on regional agro-ecosystem modelling. One major focus of the cooperation activity is the establishment of joint rice field experiment research in Jiansanjiang, located in the Sanjiang Plain (Heilongjiang Province, north-eastern part of China), to investigate the different agricultural practices and their impact on yield and environment. An additional task is to set-up an Agricultural Environmental Information System (AEIS) for the Sanjiang Plain (SJP), which covers more than 100 000 km2. Research groups from Geography (e.g. GIS & Remote Sensing) and Plant Nutrition (e.g. Precision Agriculture) are involved in the project. The major aim of the AEIS for the SJP is to provide information about (i) agriculture in the region, (ii) the impact of agricultural practices on the environment, and (iii) simulation scenarios for sustainable strategies. Consequently, the AEIS for the SJP provides information for decision support and therefore could be regarded as a Spatial Decision Support System (SDSS), too. The investigation of agricultural and environmental issues has a spatial context, which requires the management, handling, and analysis of spatial data. The use of GIS enables the capture, storage, analysis and presentation of spatial data. Therefore, GIS is the major tool for the set-up of the AEIS for the SJP. This contribution presents the results of linking agricultural statistics with GIS to provide information about agriculture in the SJP and discusses the benefits of this method as well as the integration of methods to produce new data.

  7. Multiteide Project: Multiparametric characterization of the activity of Teide-Pico Viejo volcanic system

    Science.gov (United States)

    Domínguez Cerdeña, Itahiza; Villasante-Marcos, Victor; Meletlidis, Stavros; Sainz-Maza, Sergio; Abella, Rafael; Torres, Pedro A.; Sánchez, Nieves; Luengo-Oroz, Natividad; José Blanco, María; García-Cañada, Laura; Pereda de Pablo, Jorge; Lamolda, Héctor; Moure, David; Del Fresno, Carmen; Finizola, Anthony; Felepto, Alicia

    2017-04-01

    Teide-Pico Viejo complex stands for one of the major natural volcanic hazards in the Canary Islands, due to the expected types of eruptions in the area and the high number of inhabitants in Tenerife Island. Therefore, it is necessary to have a volcanic alert system able to afford a precise assessment of the current state of the complex. For this purpose, the knowledge of the expected signals at each volcanic activity level is required. Moreover, the external effects that can affect the measurements shall be distinguished, external influences as the atmosphere are qualitatively known but have not been quantified yet. The objective of the project is to collect, analyze and jointly and continuously evaluate over time geophysical, geodetic, geochemical and meteorological data from the Teide-Pico Viejo complex and its surroundings. A continuous multiparametric network have been deployed in the area, which, together with the data provided by the Volcano Monitoring Network of the Instituto Geográfico Nacional (IGN) and data from other institutions will provide a comprehensive set of data with high resolution in both space and time. This multiparametric network includes a seismic array, two self-potential lines for continuous measurements, five magnetometers and two weather stations. The network will be complemented with 8 CGPS stations, one tiltmeter, 10 seismic stations, and four thermometric stations on the fumaroles of Teide volcano that IGN already manage in Tenerife. The data will be completed with the results from different repeated surveys of self potential, soil temperature and CO2 diffuse flux in several pre-established areas on top of Teide throughout the entire duration of project. During the project, new computation tools will be developed to study the correlation between the different parameters analyzed. The results obtained will characterize the possible seasonal fluctuations of each parameter and the variations related to meteorological phenomena. In

  8. Experimental Observations of Multiscale Dynamics of Viscous Fluid Behavior: Implications in Volcanic Systems

    Science.gov (United States)

    Arciniega-Ceballos, A.; Spina, L.; Scheu, B.; Dingwell, D. B.

    2015-12-01

    We have investigated the dynamics of Newtonian fluids with viscosities (10-1000 Pa s; corresponding to mafic to intermediate silicate melts) during slow decompression, in a Plexiglas shock tube. As an analogue fluid we used silicon oil saturated with Argon gas for 72 hours. Slow decompression, dropping from 10 MPa to ambient pressure, acts as the excitation mechanism, initiating several processes with their own distinct timescales. The evolution of this multi-timescale phenomenon generates complex non-stationary microseismic signals, which have been recorded with 7 high-dynamic piezoelectric sensors located along the conduit. Correlation analysis of these time series with the associated high-speed imaging enables characterization of distinct phases of the dynamics of these viscous fluids and the extraction of the time and the frequency characteristics of the individual processes. We have identified fluid-solid elastic interaction, degassing, fluid mass expansion and flow, bubble nucleation, growth, coalescence and collapse, foam building and vertical wagging. All these processes (in fine and coarse scales) are sequentially coupled in time, occur within specific pressure intervals, and exhibit a localized distribution in space. Their coexistence and interactions constitute the stress field and driving forces that determine the dynamics of the system. Our observations point to the great potential of this experimental approach in the understanding of volcanic processes and volcanic seismicity.

  9. ASI-Volcanic Risk System (SRV): a pilot project to develop EO data processing modules and products for volcanic activity monitoring, first results.

    Science.gov (United States)

    Silvestri, M.; Musacchio, M.; Buongiorno, M. F.; Dini, L.

    2009-04-01

    The Project called Sistema Rischio Vulcanico (SRV) is funded by the Italian Space Agency (ASI) in the frame of the National Space Plan 2003-2005 under the Earth Observations section for natural risks management. The SRV Project is coordinated by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) which is responsible at national level for the volcanic monitoring. The project philosophy is to implement, by incremental versions, specific modules which allow to process, store and visualize through Web GIS tools geophysical parameters suitable for volcanic risk management. The ASI-SRV is devoted to the development of an integrated system based on Earth Observation (EO) data to respond to specific needs of the Italian Civil Protection Department (DPC) and improve the monitoring of Italian active volcanoes during all the risk phases (Pre Crisis, Crisis and Post Crisis). The ASI-SRV system provides support to risk managers during the different volcanic activity phases and its results are addressed to the Italian Civil Protection Department (DPC). SRV provides the capability to manage the import many different EO data into the system, it maintains a repository where the acquired data have to be stored and generates selected volcanic products. The processing modules for EO Optical sensors data are based on procedures jointly developed by INGV and University of Modena. This procedures allow to estimate a number of parameters such as: surface thermal proprieties, gas, aerosol and ash emissions and to characterize the volcanic products in terms of composition and geometry. For the analysis of the surface thermal characteristics, the available algorithms allow to extract information during the prevention phase and during the Warning and Crisis phase. In the prevention phase the thermal analysis is directed to the identification of temperature variation on volcanic structure which may indicate a change in the volcanic activity state. At the moment the only sensor that

  10. Maja Valles, Mars: A Multi-Source Fluvio-Volcanic Outflow Channel System

    Science.gov (United States)

    Keske, A.; Christensen, P. R.

    2017-12-01

    The resemblance of martian outflow channels to the channeled scablands of the Pacific Northwest has led to general consensus that they were eroded by large-scale flooding. However, the observation that many of these channels are coated in lava issuing from the same source as the water source has motivated the alternative hypothesis that the channels were carved by fluid, turbulent lava. Maja Valles is a circum-Chryse outflow channel whose origin was placed in the late Hesperian by Baker and Kochel (1979), with more recent studies of crater density variations suggesting that its formation history involved multiple resurfacing events (Chapman et al., 2003). In this study, we have found that while Maja Valles indeed host a suite of standard fluvial landforms, its northern portion is thinly coated with lava that has buried much of the older channel landforms and overprinted them with effusive flow features, such as polygons and bathtub rings. Adjacent to crater pedestals and streamlined islands are patches of dark, relatively pristine material pooled in local topographic lows that we have interpreted as ponds of lava remaining from one or more fluid lava flows that flooded the channel system and subsequently drained, leaving marks of the local lava high stand. Despite the presence of fluvial landforms throughout the valles, lava flow features exist in the northern reaches of the system alone, 500-1200 km from the channels' source. The flows can instead be traced to a collection of vents in Lunae Plaum, west of the valles. In previously studied fluvio-volcanic outflow systems, such as Athabasca Valles, the sources of the volcanic activity and fluvial activity have been indistinguishable. In contrast, Maja Valles features numerous fluvio-volcanic landforms bearing similarity to those identified in other channel systems, yet the source of its lava flows is distinct from the source of its channels. Furthermore, in the absence of any channels between the source of the lava

  11. Unravelling the magmatic system beneath a monogenetic volcanic complex (Jagged Rocks Complex, Hopi Buttes, AZ, USA)

    Science.gov (United States)

    Re, G.; Palin, J. M.; White, J. D. L.; Parolari, M.

    2017-12-01

    The Jagged Rocks complex is the eroded remnant of the plumbing systems of closely spaced monogenetic alkaline volcanic centres in the southern Hopi Buttes Volcanic Field (AZ, USA). It contains different clinopyroxene populations with distinctive textures and geochemical patterns. In the Northwestern part of the complex, which exposes the best developed system of conduits, most of the clinopyroxenes consist of large- to medium-sized resorbed cores overgrown by euhedral rims (type 1), small moderately resorbed greenish cores with the same overgrown rims (type 2), and phlogopite as an accessory phase. By contrast, in the Southern part of the complex the majority of clinopyroxenes are euhedral with oscillatory zonation (type 3) and are accompanied by minor euhedral olivine. The differences between these mineral assemblages indicate a composite history of crystallization and magmatic evolution for the two parts of the complex, governed by different mechanisms and ascent patterns from a single source at 50 km depth (16 kbar). The Northwest system preserves a high-pressure assemblage that cooled rapidly from near-liquidus conditions, suggesting direct ascent from the source to the surface at high-to-moderate transport rates (average 1.25 m/s). By contrast, the Southern system represents magma that advanced upward at much lower overall ascent rates, stalling at times to form small-volume mid-crustal storage zones (e.g., sills or a network of sheeted intrusions); this allowed the re-equilibration of the magma at lower pressure ( 30 km; 8 kbar), and led to nucleation and growth of euhedral clinopyroxene and olivine phenocrysts.

  12. Environmental isotope study related to groundwater age, flow system and saline water origin in Quaternary aquifers of North China Plain

    International Nuclear Information System (INIS)

    Zhang Zhigan; Payne, B.R.

    1988-01-01

    An isotopic hydrology section across the North China Plain has been studied to investigate problems of groundwater age, flow system and saline water origin in a semi-arid pre-mountain artesian basin. Two local and one regional flow system along the section have been recognized. Turnover time of water for alluvial fan, shallow and regional systems are estimated to be the order of 10 2 , 10 3 , and 10 4 years respectively. Specific flow rates for the three systems have been calculated. Only less than 5 percent of flow from alluvial fan is drained by the regional flow system and the rest, in natural conditions, discharges at surface in the front edge of an alluvial fan and forms a groundwater discharge belt at a good distance away from the mountain foot. Developed in the alluvial plain and coastal plain areas the shallow flow system embraces a series of small local systems. Groundwater in these systems appears to be the salt carrier during continental salinization. It washes salt out of the recharge area and deep-occurred strata by circulating and carries it up to the surface in lowland areas. Consequently, in parallel with salinization at surface a desalinization process occurs at depth, which provides an additional explanation for the existing thick deep fresh water zone in most arid and semi-arid regions, where continental salting process is in progress. (author). 6 refs, 8 figs, 4 tabs

  13. Intercomparison of SO2 camera systems for imaging volcanic gas plumes

    Science.gov (United States)

    Kern, Christoph; Lübcke, Peter; Bobrowski, Nicole; Campion, Robin; Mori, Toshiya; Smekens, Jean-François; Stebel, Kerstin; Tamburello, Giancarlo; Burton, Mike; Platt, Ulrich; Prata, Fred

    2015-07-01

    SO2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO2 cameras. In the first part of the experiment, the various technical designs are compared and the advantages and drawbacks of individual design options are considered. Though the ideal design was found to be dependent on the specific application, a number of general recommendations are made. Next, a time series of images recorded by all instruments at Stromboli Volcano (Italy) is compared. All instruments were easily able to capture SO2 clouds emitted from the summit vents. Quantitative comparison of the SO2 load in an individual cloud yielded an intra-instrument precision of about 12%. From the imagery, emission rates were then derived according to each group's standard retrieval process. A daily average SO2 emission rate of 61 ± 10 t/d was calculated. Due to differences in spatial integration methods and plume velocity determination, the time-dependent progression of SO2 emissions varied significantly among the individual systems. However, integration over distinct degassing events yielded comparable SO2 masses. Based on the intercomparison data, we find an approximate 1-sigma precision of 20% for the emission rates derived from the various SO2 cameras. Though it may still be improved in the future, this is currently within the typical accuracy of the measurement and is considered sufficient for most applications.

  14. Intercomparison of SO2 camera systems for imaging volcanic gas plumes

    Science.gov (United States)

    Kern, Christoph; Lübcke, Peter; Bobrowski, Nicole; Campion, Robin; Mori, Toshiya; Smekens, Jean-Francois; Stebel, Kerstin; Tamburello, Giancarlo; Burton, Mike; Platt, Ulrich; Prata, Fred

    2015-01-01

    SO2 camera systems are increasingly being used to image volcanic gas plumes. The ability to derive SO2 emission rates directly from the acquired imagery at high time resolution allows volcanic process studies that incorporate other high time-resolution datasets. Though the general principles behind the SO2 camera have remained the same for a number of years, recent advances in CCD technology and an improved understanding of the physics behind the measurements have driven a continuous evolution of the camera systems. Here we present an intercomparison of seven different SO2 cameras. In the first part of the experiment, the various technical designs are compared and the advantages and drawbacks of individual design options are considered. Though the ideal design was found to be dependent on the specific application, a number of general recommendations are made. Next, a time series of images recorded by all instruments at Stromboli Volcano (Italy) is compared. All instruments were easily able to capture SO2 clouds emitted from the summit vents. Quantitative comparison of the SO2 load in an individual cloud yielded an intra-instrument precision of about 12%. From the imagery, emission rates were then derived according to each group's standard retrieval process. A daily average SO2 emission rate of 61 ± 10 t/d was calculated. Due to differences in spatial integration methods and plume velocity determination, the time-dependent progression of SO2 emissions varied significantly among the individual systems. However, integration over distinct degassing events yielded comparable SO2 masses. Based on the intercomparison data, we find an approximate 1-sigma precision of 20% for the emission rates derived from the various SO2 cameras. Though it may still be improved in the future, this is currently within the typical accuracy of the measurement and is considered sufficient for most applications.

  15. Application of MODFLOW and geographic information system to groundwater flow simulation in North China Plain, China

    Science.gov (United States)

    Wang, Shiqin; Shao, Jingli; Song, Xianfang; Zhang, Yongbo; Huo, Zhibin; Zhou, Xiaoyuan

    2008-10-01

    MODFLOW is a groundwater modeling program. It can be compiled and remedied according to the practical applications. Because of its structure and fixed data format, MODFLOW can be integrated with Geographic Information Systems (GIS) technology for water resource management. The North China Plain (NCP), which is the politic, economic and cultural center of China, is facing with water resources shortage and water pollution. Groundwater is the main water resource for industrial, agricultural and domestic usage. It is necessary to evaluate the groundwater resources of the NCP as an entire aquifer system. With the development of computer and internet information technology it is also necessary to integrate the groundwater model with the GIS technology. Because the geological and hydrogeological data in the NCP was mainly in MAPGIS format, the powerful function of GIS of disposing of and analyzing spatial data and computer languages such as Visual C and Visual Basic were used to define the relationship between the original data and model data. After analyzing the geological and hydrogeological conditions of the NCP, the groundwater flow numerical simulation modeling was constructed with MODFLOW. On the basis of GIS, a dynamic evaluation system for groundwater resources under the internet circumstance was completed. During the process of constructing the groundwater model, a water budget was analyzed, which showed a negative budget in the NCP. The simulation period was from 1 January 2002 to 31 December 2003. During this period, the total recharge of the groundwater system was 49,374 × 106 m3 and the total discharge was 56,530 × 106 m3 the budget deficit was -7,156 × 106 m3. In this integrated system, the original data including graphs and attribution data could be stored in the database. When the process of evaluating and predicting groundwater flow was started, these data were transformed into files that the core program of MODFLOW could read. The calculated water

  16. Risks associated with volcanic ash fallout from Mt.Etna with reference to industrial filtration systems

    International Nuclear Information System (INIS)

    Milazzo, Maria Francesca; Ancione, Giuseppa; Salzano, Ernesto; Maschio, Giuseppe

    2013-01-01

    The recent eruption of the Icelandic volcano has focused the worldwide attention on volcanic ash effects for the population, road, rail and air traffic and production activities. This paper aims to study of technological (industrial) accidental scenarios triggered by ash fallout and, more specifically, to define and quantify the potential damage on filtration systems. Malfunctions due to the filter clogging and service interruptions caused by the rupture of the filtering surface have been analysed in order to define the vulnerability of the equipment to such damages. Results are given in terms of threshold values of deposit on the filtering surface and exceedance probability curves of ash concentrations and the duration of the ash emission. This data can be easily implemented in the standard risk assessment with the aim to include the estimation of Natural-Technological (Na-Tech) hazards

  17. Stable chlorine isotope compositions in waters from the Kusatsu-Shirane volcanic system, Japan

    International Nuclear Information System (INIS)

    Musashi, Masaaki

    1999-01-01

    Chlorine stable isotope compositions (δ 37 Cl, per-mil: per mille, vs. a standard sea water, SMOC) of six waters collected in 1984 from Kusatsu area (three springs), Manza area (two springs), and a crater lake Yugama, in the Kusatsu-Shirane volcanic system, Japan, are analysed with the overall precision of 0.12 per mille (2σ). The δ 37 Cl values range between -0.05 per mille and +0.20 per mille (the mean, +0.04 per mille), and are nearly equal to that of the sea water. And the values are not significantly different between the Kusatsu and Manza areas, although their thermal features have a strong chemical and geological variations with a geographical separation of over 8 km between the two areas. (author)

  18. Hydrogeology and hydrologic conditions of the Northern Atlantic Coastal Plain aquifer System from Long Island, New York, to North Carolina

    Science.gov (United States)

    Masterson, John P.; Pope, Jason P.; Monti, Jack; Nardi, Mark R.; Finkelstein, Jason S.; McCoy, Kurt J.

    2013-11-14

    The seaward-dipping sedimentary wedge that underlies the Northern Atlantic Coastal Plain forms a complex groundwater system. This major source of water provides for public and domestic supply and serves as a vital source of freshwater for industrial and agricultural uses throughout the region. Population increases and land-use and climate changes, however, have led to competing demands for water. The regional response of the aquifer system to these stresses poses regional challenges for water-resources management at the State level because hydrologic effects often extend beyond State boundaries. In response to these challenges, the U.S. Geological Survey Groundwater Resources Program began a regional assessment of the groundwater availability of the Northern Atlantic Coastal Plain aquifer system in 2010.

  19. Tectonic Constraints on the Evolution of Geothermal Systems in the Central Andean Volcanic Zone (CAVZ)

    Science.gov (United States)

    Veloso, E. E.; Tardani, D.; Aron, F.; Elizalde, J. D.; Sanchez-Alfaro, P.; Godoy, B.

    2017-12-01

    South of 19°S, geothermal fields and Pliocene-to-Holocene volcanic centers of the Central Andean Volcanic Zone are spatially associated with distinct, large-scale fault systems disrupting the volcanic arc, which control the architecture and dynamics of the fluids reservoirs at shallow crustal levels. Based on an extensive compilation of structural, lithological and isotopic data, and satellite imagery band-ratio analyses, we produced detailed maps of 13 areas comprising 19 identified and/or potential geothermal fields, to examine if particular local-scale tectonic configurations are associated to fluids migrating from different crustal levels. We defined three main tectonic environments according to the specific, kilometer-scale structural arrangement and its spatial relation to the geothermal surface manifestations. T1, dominated by left-lateral, pure strike-slip motion on a NW-trending duplex-like geometry with geothermal fields located along the faults - in turn distributed into five major subparallel zones cutting across the orogenic belt between ca. 20° and 27°S. T2, dominated by shortening on a series of N-trending thrust faults and fault-propagated folds, cut and displaced by the above mentioned NW-trending faults, with geothermal fields hosted at fault intersections and at fold hinges. And T3, characterized by transtension accommodated by NW-to-WNW-trending left-lateral/normal faults, with hot-springs lying along the fault traces. Interestingly, each of the independently defined tectonic environments has distinctive helium (in fluids) and strontium (in lavas) isotopic signatures and estimated geothermal reservoir temperatures. T1 shows a large 4He contribution, low 87Sr/86Sr ratio and temperatures varying between ca. 220°-310°C; T3 low 4He and high 87Sr/86Sr ratio and temperature (260°-320°C); T2 isotopic values fall between T1 and T3, yet showing the lowest (130°-250°C) temperatures. We suggest that these particular isotopic signatures are due to

  20. The Role of Boron Chloride and noble gas isotope ratios in Taupo Volcanic Zone geothermal systems

    International Nuclear Information System (INIS)

    Hulston, J.R.

    1995-01-01

    The model of the geothermal system in which deep circulating groundwater con noble gases, at air saturated water concentrations, mixes with hot fluids of man origin at depth, is extended to include the effect of interaction of the ascending fluid with both solid and gaseous phases of basement (or other) rocks 'en route' the surface. It is demonstrated that this interaction is responsible for most of CO/sub 2/ in the Taupo Volcanic Zone (TVZ) geothermal systems. It is proposed th the modelling of this interaction might be accomplished by techniques similar to those used for the understanding of the oxygen isotope shift found in geothermal systems. The water rock interaction experiments of Ellis and Mahon (1964, 1967) provides some data on the kinetic rates for B and Cl dissolution from rocks like to be encountered in the geothermal system, but further information on the behaviour of B may be needed. If these problems can be overcome this modelling technique has promise for the estimation of the recharge of geothermal systems a hence the sustainability of these systems. (author). 17 refs., 4 figs

  1. The Pliocene initiation and Early Pleistocene volcanic disruption of the palaeo-Gediz fluvial system, Western Turkey

    NARCIS (Netherlands)

    Maddy, D.; Demir, T.; Bridgland, D.R.; Veldkamp, A.; Stemerdink, C.; Schriek, van der T.; Schreve, D.

    2007-01-01

    In this paper, we report our latest observations concerning a Pliocene and Early Pleistocene record from Western Turkey. The sedimentary sequence described comprises the fluvial deposits of an Early Pleistocene palaeo-Gediz river system and its tributaries prior to the onset of volcanism around Kula

  2. A Tephra Database With an Intelligent Correlation System, Mono-Inyo Volcanic Chain, CA

    Science.gov (United States)

    Bursik, M.; Rogova, G.

    2004-12-01

    We are assembling a web-accessible, relational database of information on past eruptions of the Mono-Inyo volcanic chain, eastern California. The PostgreSQL database structure follows the North American Data Model and CordLink. The database allows us to extract the features diagnostic of particular pyroclastic layers, as well as lava domes and flows. The features include depth in the section, layer thickness and internal stratigraphy, mineral assemblage, major and trace element composition, tephra componentry and granulometry, and radiocarbon age. Our working hypotheses are that 1) the database will prove useful for unraveling the complex recent volcanic history of the Mono-Inyo chain 2) aided by the use of an intelligent correlation system integrated into the database system. The Mono-Inyo chain consists of domes, craters and flows that stretch for 50 km north-south, subparallel to the Sierran range front fault system. Almost all eruptions within the chain probably occurred less than 50,000 years ago. Because of the variety of magma and eruption types, and the migration of source regions in time and space, it is nontrivial to discern patterns of behaviour. We have explored the use of multiple artificial neural networks combined within the framework of the Dempster-Shafer theory of evidence to construct a hybrid information processing system as an aid in the correlation of Mono-Inyo pyroclastic layers. It is hoped that such a system could provide information useful to discerning eruptive patterns that would otherwise be difficult to sort and categorize. In a test case on tephra layers at known sites, the intelligent correlation system was able to categorize observations correctly 96% of the time. In a test case with layers at one unknown site, and using a pairwise comparison of the unknown site with the known sites, a one-to-one correlation between the unknown site and the known sites was found to sometimes be poor. Such a result could be used to aid a

  3. An Early-Warning System for Volcanic Ash Dispersal: The MAFALDA Procedure

    Science.gov (United States)

    Barsotti, S.; Nannipieri, L.; Neri, A.

    2006-12-01

    Forecasts of the dispersal of volcanic ash is a fundamental goal in order to mitigate its potential impact on urbanized areas and transport routes surrounding explosive volcanoes. To this aim we developed an early- warning procedure named MAFALDA (Modeling And Forecasting Ash Loading and Dispersal in the Atmosphere). Such tool is able to quantitatively forecast the atmospheric concentration of ash as well as the ground deposition as a function of time over a 3D spatial domain.\\The main features of MAFALDA are: (1) the use of the hybrid Lagrangian-Eulerian code VOL-CALPUFF able to describe both the rising column phase and the atmospheric dispersal as a function of weather conditions, (2) the use of high-resolution weather forecasting data, (3) the short execution time that allows to analyse a set of scenarios and (4) the web-based CGI software application (written in Perl programming language) that shows the results in a standard graphical web interface and makes it suitable as an early-warning system during volcanic crises.\\MAFALDA is composed by a computational part that simulates the ash cloud dynamics and a graphical interface for visualizing the modelling results. The computational part includes the codes for elaborating the meteorological data, the dispersal code and the post-processing programs. These produces hourly 2D maps of aerial ash concentration at several vertical levels, extension of "threat" area on air and 2D maps of ash deposit on the ground, in addition to graphs of hourly variations of column height.\\The processed results are available on the web by the graphical interface and the users can choose, by drop-down menu, which data to visualize. \\A first partial application of the procedure has been carried out for Mt. Etna (Italy). In this case, the procedure simulates four volcanological scenarios characterized by different plume intensities and uses 48-hrs weather forecasting data with a resolution of 7 km provided by the Italian Air Force.

  4. Volcano alert level systems: managing the challenges of effective volcanic crisis communication

    Science.gov (United States)

    Fearnley, C. J.; Beaven, S.

    2018-05-01

    Over the last four decades, volcano observatories have adopted a number of different communication strategies for the dissemination of information on changes in volcanic behaviour and potential hazards to a wide range of user groups. These commonly include a standardised volcano alert level system (VALS), used in conjunction with other uni-valent communication techniques (such as information statements, reports and maps) and multi-directional techniques (such as meetings and telephone calls). This research, based on interviews and observation conducted 2007-2009 at the five US Geological Survey (USGS) volcano observatories, and including some of the key users of the VALS, argues for the importance of understanding how communicating volcanic hazard information takes place as an everyday social practice, focusing on the challenges of working across the boundaries between the scientific and decision-making communities. It is now widely accepted that the effective use, value and deployment of information across science-policy interfaces of this kind depend on three criteria: the scientific credibility of the information, its relevance to the needs of stakeholders and the legitimacy of both the information and the processes that produced it. Translation and two-way communication are required to ensure that all involved understand what information is credible and relevant. Findings indicate that whilst VALS play a role in raising awareness of an unfolding situation, supplementary communication techniques are crucial in facilitating situational understanding of that situation, and the uncertainties inherent to its scientific assessment, as well as in facilitating specific responses. In consequence, `best practice' recommendations eschew further standardisation, and focus on the in situ cultivation of dialogue between scientists and stakeholders as a means of ensuring that information, and the processes through which it is produced are perceived to be legitimate by all

  5. Investigating Volcanic-Hydrothermal Systems in Dominica, Lesser Antilles: Temporal Changes in the Chemical Composition of Hydrothermal Fluids for Volcanic Monitoring Using Geothermometers

    Science.gov (United States)

    Onyeali, M. M. C.; Joseph, E. P.; Frey, H. M.

    2017-12-01

    Dominica has an abundance of volcanic activity, with nine potentially active volcanoes, many of which have highly active volcanic-hydrothermal systems. The waters are predominantly acid-sulphate in character (SO4=100-4200 mg/L, pH≤4), and likely formed because of dilution of acidic gases in near surface oxygenated groundwater. The waters are of primarily meteoric origin, but are likely affected by evaporation effects at/near the surface, with δ18O ranging from -1.75 to 10.67‰, and δD from -6.1 to 14.5‰. With updated water chemistry and isotopic data from five hydrothermal areas (Boiling Lake, Valley of Desolation, Sulphur Springs, Wotten Waven, Cold Soufriere) for the period 2014 to 2017, we will re-evaluate the characteristics of these systems, which were last reported in 2011. We will present updated reservoir temperatures using a variety of geothermometers and provide insight into water-rock interactions taking place in the reservoirs. Recent changes in chemistry of the waters have indicated that while the origin of the hydrothermal systems are still dominantly meteoric (δ18O = -3 to 8‰ and δD = -5 to 18‰), surface evaporation effects and variable amounts of mixing with shallow ground waters play an important role. Fumaroles appear to reflect a deeper source contribution as compared to thermal waters with differences in acidity, temperature, TDS, δ18O, and δD observed. The general composition of the waters for most of the hydrothermal systems studied indicate no significant changes, with the exception of the Boiling Lake, which experienced a draining event in November 2016 which lasted for 6 weeks. Decreases in temperature, pH, Na, K, and Cl were seen post draining, while SO4 remained relatively low (66 ppm), but showed a small increase. The chemistry of the Boiling Lake appears to show significant changes in response to changes in the groundwater system. Changes in the groundwater system at the lake observed during the 2004/2005 draining, which

  6. An automated fog monitoring system for the Indo-Gangetic Plains based on satellite measurements

    Science.gov (United States)

    Patil, Dinesh; Chourey, Reema; Rizvi, Sarwar; Singh, Manoj; Gautam, Ritesh

    2016-05-01

    Fog is a meteorological phenomenon that causes reduction in regional visibility and affects air quality, thus leading to various societal and economic implications, especially disrupting air and rail transportation. The persistent and widespread winter fog impacts the entire the Indo-Gangetic Plains (IGP), as frequently observed in satellite imagery. The IGP is a densely populated region in south Asia, inhabiting about 1/6th of the world's population, with a strong upward pollution trend. In this study, we have used multi-spectral radiances and aerosol/cloud retrievals from Terra/Aqua MODIS data for developing an automated web-based fog monitoring system over the IGP. Using our previous and existing methodologies, and ongoing algorithm development for the detection of fog and retrieval of associated microphysical properties (e.g. fog droplet effective radius), we characterize the widespread fog detection during both daytime and nighttime. Specifically, for the night time fog detection, the algorithm employs a satellite-based bi-spectral brightness temperature difference technique between two spectral channels: MODIS band-22 (3.9μm) and band-31 (10.75μm). Further, we are extending our algorithm development to geostationary satellites, for providing continuous monitoring of the spatial-temporal variation of fog. We anticipate that the ongoing and future development of a fog monitoring system would be of assistance to air, rail and vehicular transportation management, as well as for dissemination of fog information to government agencies and general public. The outputs of fog detection algorithm and related aerosol/cloud parameters are operationally disseminated via http://fogsouthasia.com/.

  7. Characterization of open and closed volcanic systems in Indonesia and Mexico using InSAR time series

    Science.gov (United States)

    Chaussard, E.; Amelung, F.; Aoki, Y.

    2013-08-01

    use 2007-2011 Advanced Land Observing Satellite (ALOS) data to perform an arc-wide interferometric synthetic aperture radar (InSAR) time series survey of the Trans-Mexican Volcanic Belt (TMVB) and to study time-dependent ground deformation of four Indonesian volcanoes selected following the 2007-2009 study of Chaussard and Amelung (2012). Our objectives are to examine whether arc volcanoes exhibit long-term edifice-wide cyclic deformation patterns that can be used to characterize open and closed volcanic systems and to better constrain in which cases precursory inflation is expected. We reveal deformation cycles at both regularly active and previously inactive Indonesian volcanoes, but we do not detect deformation in the TMVB, reflecting a lower activity level. We identify three types of relationships between deformation and activity: inflation prior to eruption and associated with or followed by deflation (Kerinci and Sinabung), inflation without eruption and followed by slow deflation (Agung), and eruption without precursory deformation (Merapi, Colima, and Popocatépetl; at Merapi, no significant deformation is detected even during eruption). The first two cases correspond to closed volcanic systems and suggest that the traditional model of magmatic systems and eruptive cycles do apply to andesitic volcanoes (i.e., inflation and deflation episodes associated with magma accumulation or volatile exsolution in a crustal reservoir followed by eruptions or in situ cooling). In contrast, the last case corresponds to open volcanic systems where no significant pressurization of the magmatic reservoirs is taking place prior to eruptions and thus no long-term edifice-wide ground deformation can be detected. We discuss these results in terms of InSAR's potential for forecasting volcanic unrest.

  8. Shallow seismicity in volcanic system: what role does the edifice play?

    Science.gov (United States)

    Bean, Chris; Lokmer, Ivan

    2017-04-01

    Seismicity in the upper two kilometres in volcanic systems is complex and very diverse in nature. The origins lie in the multi-physics nature of source processes and in the often extreme heterogeneity in near surface structure, which introduces strong seismic wave propagation path effects that often 'hide' the source itself. Other complicating factors are that we are often in the seismic near-field so waveforms can be intrinsically more complex than in far-field earthquake seismology. The traditional focus for an explanation of the diverse nature of shallow seismic signals is to call on the direct action of fluids in the system. Fits to model data are then used to elucidate properties of the plumbing system. Here we show that solutions based on these conceptual models are not unique and that models based on a diverse range of quasi-brittle failure of low stiffness near surface structures are equally valid from a data fit perspective. These earthquake-like sources also explain aspects of edifice deformation that are as yet poorly quantified.

  9. Explosive to Effusive Transition in Intermediate Volcanism: An Analysis of Changing Magma System Conditions in Dominica

    Science.gov (United States)

    Bersson, J.; Waters, L. E.; Frey, H. M.; Nicolaysen, K. P.; Manon, M. R. F.

    2017-12-01

    The oscillation between explosive and effusive intermediate (59-62 wt% SiO2) volcanism in the Roseau Valley on Dominica, an island in the Lesser Antilles Arc, provides an opportunity to investigate temporal changes in the magmatic system. Here, we test the relationship between the Roseau ignimbrites (1-65 ka) and the Micotrin dome ( 1.1 ka) which are proposed to originate from the same magmatic system, with a detailed petrologic analysis of phenocrysts to determine commonalities or changes in pre-eruptive conditions (i.e., intensive variables). The ignimbrites are saturated in five phenocrysts (plagioclase + orthopyroxene + clinopyroxene + ilmenite + magnetite ± amphibole ± quartz), and the lava dome contains the same assemblage, but with notable differences: amphiboles are entirely reacted, and quartz occurs in greater abundance. Plagioclase in the ignimbrites ranges in composition from An46-93, and those in the dome range from An46-85. Two Fe-Ti oxide geo-thermometry reveal pre-eruptive temperatures from 730-820°C for three different ignimbrite units, whereas the pre-eruptive temperature for the dome is slightly hotter (850±23°C). Values of fO2 (relative to NNO) derived from Fe-Ti oxide oxygen-barometry range from +0.3 to +1.32 ΔNNO for the ignimbrites, which overlap with those from the dome (+0.5 to +0.9 ΔNNO). Pre-eruptive temperatures, plagioclase compositions, whole rock and glass compositions are incorporated into a plagioclase-liquid hygrometer to determine pre-eruptive melt H2O contents for each sample. H2O contents for ignimbrites range from 7.1-9.3 wt%, and those from the lava dome range from 6.7-7.1 wt%. Application of a H2O solubility model shows that water contents for the Roseau magmas correspond to pressures of 3-5 kbar. The most notable difference between the explosive and effusive magmas is that the lava dome has a higher pre-eruptive temperature than the ignimbrites. However, the results collectively suggest that more recent volcanism in

  10. Towards groundwater neutral cropping systems in the Alluvial Fans of the North China Plain

    NARCIS (Netherlands)

    Oort, van P.A.J.; Wang, G.; Vos, J.; Meinke, H.; Li, B.G.; Huang, J.K.; Werf, van der W.

    2016-01-01

    Groundwater levels in the North China Plain (NCP), the bread basket of China, have dropped more than one meter per year over the last 40 years, putting at risk the long term productivity of this region. Groundwater decline is most severe in the Alluvial Fans where our study site is located.

  11. Alarm systems detect volcanic tremor and earthquake swarms during Redoubt eruption, 2009

    Science.gov (United States)

    Thompson, G.; West, M. E.

    2009-12-01

    We ran two alarm algorithms on real-time data from Redoubt volcano during the 2009 crisis. The first algorithm was designed to detect escalations in continuous seismicity (tremor). This is implemented within an application called IceWeb which computes reduced displacement, and produces plots of reduced displacement and spectrograms linked to the Alaska Volcano Observatory internal webpage every 10 minutes. Reduced displacement is a measure of the amplitude of volcanic tremor, and is computed by applying a geometrical spreading correction to a displacement seismogram. When the reduced displacement at multiple stations exceeds pre-defined thresholds and there has been a factor of 3 increase in reduced displacement over the previous hour, a tremor alarm is declared. The second algorithm was to designed to detect earthquake swarms. The mean and median event rates are computed every 5 minutes based on the last hour of data from a real-time event catalog. By comparing these with thresholds, three swarm alarm conditions can be declared: a new swarm, an escalation in a swarm, and the end of a swarm. The end of swarm alarm is important as it may mark a transition from swarm to continuous tremor. Alarms from both systems were dispatched using a generic alarm management system which implements a call-down list, allowing observatory scientists to be called in sequence until someone acknowledged the alarm via a confirmation web page. The results of this simple approach are encouraging. The tremor alarm algorithm detected 26 of the 27 explosive eruptions that occurred from 23 March - 4 April. The swarm alarm algorithm detected all five of the main volcanic earthquake swarm episodes which occurred during the Redoubt crisis on 26-27 February, 21-23 March, 26 March, 2-4 April and 3-7 May. The end-of-swarm alarms on 23 March and 4 April were particularly helpful as they were caused by transitions from swarm to tremor shortly preceding explosive eruptions; transitions which were

  12. Highway 61 Revisited: Finding Drivers for Hypoxia in Aquatic Systems in the Mississippi Alluvial Plain

    Science.gov (United States)

    Shields, F., Jr.; Murdock, J. N.; Lizotte, R. E., Jr.; Knight, S. S.; Locke, M. A.; Testa, S., III

    2011-12-01

    Streams and lakes in the intensively cultivated Mississippi River alluvial plain frequently experience periods of hypoxia that are evidence of ecological stress. Although hydrologic perturbations and sediments and nutrients derived from nonpoint sources are likely drivers of these conditions, the most efficient pathway for obtaining partial ecological recovery (e.g., N load reduction or P load reduction or flow augmentation or erosion control) is not clear. To gain deeper understanding of these systems, three similar ~20 km2 watersheds in northwestern Mississippi were selected for study and instrumented for collection of hydrologic and water quality data in 2011. Aquatic systems within each watershed consisted of shallow natural lakes embedded in networks of sporadically flowing ditches, natural channels and wetlands, with hydrology strongly impacted by irrigation withdrawals from groundwater and return flows to surface water bodies. Waters were usually turbid, with mean Secchi disk readings 10-15 cm and mean suspended solids concentrations 200-600 mg/L. Strong diurnal fluctuations in dissolved oxygen concentration (DO) occurred even in the wetter, cooler winter months, with up to 50% of daily means below state standards (5 mg/L). The average diurnal range (daily max-daily min) in DO varied from 0.9 to 2.5 mg/L for lakes and from 1.7 to 6.0 mg/L for channels. Attendant extreme diurnal variations in temperature and pH were also observed. Observations of chlorophyll a concentrations, water column phytoplankton, and attached algae indicate the importance of algal photosynthesis and respiration to DO levels, but these processes are limited by light availability and N and P concentrations in a complex fashion. Light levels are governed by channel width, water depth and turbidity, which is due to suspended sediment and algae. Preliminary nutrient limitation studies showed both N and P limit algal growth, and microbial production and respiration. N and N+P co

  13. Volcanic Flooding Experiments in Impact Basins and Heavily Cratered Terrain Using LOLA Data: Patterns of Resurfacing and Crater Loss

    Science.gov (United States)

    Whitten, Jennifer L.; Head, James W.; Neumann, Gregory A.; Zuber, Maria T.; Smith, David E.

    2012-01-01

    Terrestrial planetary bodies are characterized by extensive, largely volcanic deposits covering their surfaces. On Earth large igneous provinces (LIPs) abound, maria cover the nearside of the Moon, and volcanic plains cover large portions of Venus, Mars and Mercury.

  14. Simulating Effects of Long Term Use of Wastewater on Farmers Health Using System Dynamics Modeling (Case Study: Varamin Plain

    Directory of Open Access Journals (Sweden)

    Hamzehali Alizadeh

    2017-06-01

    Full Text Available Introduction: Agricultural activity in Varamin plain has been faced with many challenges in recent years, due to vicinity to Tehran the capital of Iran (competition for Latian dam reservoir, and competition with Tehran south network in allocation of Mamlou dam reservoir and treated wastewater of south wastewater treatment plant. Mamlou and Latian dam reservoirs, due to increase of population and industry sectors, allocated to urban utilization of Tehran. Based on national policy, the treated wastewater should be replaced with Latian dam reservoir water to supply water demand of agricultural sector. High volume transmission of wastewater to Varamin plain, will be have economical, environmental, and social effects. Several factors effect on wastewater management and success of utilization plans and any change in these factors may have various feedbacks on the other elements of wastewater use system. Hence, development of a model with capability of simulation of all factors, aspects and interactions that affect wastewater utilization is very necessary. The main objective of present study was development of water integrated model to study long-term effects of irrigation with Tehran treated wastewater, using system dynamics modeling (SD approach. Materials and Methods: Varamin Plain is one of the most important agricultural production centers of the country due to nearness to the large consumer market of Tehran and having fertile soil and knowledge of agriculture. The total agricultural irrigated land in Varamin Plain is 53486 hectares containing 17274 hectares of barley, 16926 hectares of wheat, 3866 hectares of tomato, 3521 hectares of vegetables, 3556 hectares of alfalfa, 2518 hectares of silage maize, 1771 hectares of melon, 1642 hectares of cotton, 1121 hectares of cucumber and 1291 hectares of other crops. In 2006 the irrigation requirement of the crop pattern was about 690 MCM and the actual agriculture water consumption was about 620 MCM

  15. Volcanic eruptions on Io

    Science.gov (United States)

    Strom, R. G.; Schneider, N. M.; Terrile, R. J.; Hansen, C.; Cook, A. F.

    1981-01-01

    Nine eruption plumes which were observed during the Voyager 1 encounter with Io are discussed. During the Voyager 2 encounter, four months later, eight of the eruptions were still active although the largest became inactive sometime between the two encounters. Plumes range in height from 60 to over 300 km with corresponding ejection velocities of 0.5 to 1.0 km/s and plume sources are located on several plains and consist of fissures or calderas. The shape and brightness distribution together with the pattern of the surface deposition on a plume 3 is simulated by a ballistic model with a constant ejection velocity of 0.5 km/s and ejection angles which vary from 0-55 deg. The distribution of active and recent eruptions is concentrated in the equatorial regions and indicates that volcanic activity is more frequent and intense in the equatorial regions than in the polar regions. Due to the geologic setting of certain plume sources and large reservoirs of volatiles required for the active eruptions, it is concluded that sulfur volcanism rather than silicate volcanism is the most likely driving mechanism for the eruption plumes.

  16. Estimation of age of Dali-Ganis rifting and associated volcanic activity, Venus

    Science.gov (United States)

    Basilevsky, A. T.

    1993-01-01

    This paper deals with the estimation of age for the Dali and Ganis Chasma rift zones and their associated volcanism based on photogeologic analysis of stratigraphic relations of rift-associated features with impact craters which have associated features indicative of their age. The features are radar-dark and parabolic, and they are believed to be mantles of debris derived from fallout of the craters' ejecta. They are thought to be among the youngest features on the Venusian surface, so their 'parent' craters must also be very young, evidently among the youngest 10 percent of Venus' crater population. Dali Chasma and Ganis Chasma are a part of a system of rift zones contained within eastern Aphrodite and Atla Regio which is a significant component of Venus tectonics. The rifts of this system are fracture belts which dissect typical Venusian plains with rare islands of tessera terrain. The rift zone system consists of several segments following each other (Diane, Dali, Ganis) and forming the major rift zone line, about 10,000 km long, which has junctions with several other rift zones, including Parga Chasma Rift. The junctions are usually locations of rift-associated volcanism in the form of volcanic edifices (Maat and Ozza Montes) or plain-forming flows flooding some areas within the rift zones and the adjacent plains.

  17. Asia-Pacific Region Global Earthquake and Volcanic Eruption Risk Management (G-EVER) project and a next-generation real-time volcano hazard assessment system

    Science.gov (United States)

    Takarada, S.

    2012-12-01

    The first Workshop of Asia-Pacific Region Global Earthquake and Volcanic Eruption Risk Management (G-EVER1) was held in Tsukuba, Ibaraki Prefecture, Japan from February 23 to 24, 2012. The workshop focused on the formulation of strategies to reduce the risks of disasters worldwide caused by the occurrence of earthquakes, tsunamis, and volcanic eruptions. More than 150 participants attended the workshop. During the workshop, the G-EVER1 accord was approved by the participants. The Accord consists of 10 recommendations like enhancing collaboration, sharing of resources, and making information about the risks of earthquakes and volcanic eruptions freely available and understandable. The G-EVER Hub website (http://g-ever.org) was established to promote the exchange of information and knowledge among the Asia-Pacific countries. Several G-EVER Working Groups and Task Forces were proposed. One of the working groups was tasked to make the next-generation real-time volcano hazard assessment system. The next-generation volcano hazard assessment system is useful for volcanic eruption prediction, risk assessment, and evacuation at various eruption stages. The assessment system is planned to be developed based on volcanic eruption scenario datasets, volcanic eruption database, and numerical simulations. Defining volcanic eruption scenarios based on precursor phenomena leading up to major eruptions of active volcanoes is quite important for the future prediction of volcanic eruptions. Compiling volcanic eruption scenarios after a major eruption is also important. A high quality volcanic eruption database, which contains compilations of eruption dates, volumes, and styles, is important for the next-generation volcano hazard assessment system. The volcanic eruption database is developed based on past eruption results, which only represent a subset of possible future scenarios. Hence, different distributions from the previous deposits are mainly observed due to the differences in

  18. Late Holocene evolution of a coupled, mud-dominated delta plain–chenier plain system, coastal Louisiana, USA

    Directory of Open Access Journals (Sweden)

    M. P. Hijma

    2017-11-01

    Full Text Available Major deltas and their adjacent coastal plains are commonly linked by means of coast-parallel fluxes of water, sediment, and nutrients. Observations of the evolution of these interlinked systems over centennial to millennial timescales are essential to understand the interaction between point sources of sediment discharge (i.e. deltaic distributaries and adjacent coastal plains across large spatial (i.e. hundreds of kilometres scales. This information is needed to constrain future generations of numerical models to predict coastal evolution in relation to climate change and other human activities. Here we examine the coastal plain (Chenier Plain, CP adjacent to the Mississippi River delta, one of the world's largest deltas. We use a refined chronology based on 22 new optically stimulated luminescence and 22 new radiocarbon ages to test the hypothesis that cyclic Mississippi subdelta shifting has influenced the evolution of the adjacent CP. We show that over the past 3 kyr, accumulation rates in the CP were generally 0–1 Mt yr−1. However, between 1.2 and 0.5 ka, when the Mississippi River shifted to a position more proximal to the CP, these rates increased to 2.9 ±1.1 Mt yr−1 or 0.5–1.5 % of the total sediment load of the Mississippi River. We conclude that CP evolution during the past 3 kyr was partly a direct consequence of shifting subdeltas, in addition to changing regional sediment sources and modest rates of relative sea-level (RSL rise. The RSL history of the CP during this time period was constrained by new limiting data points from the base of overwash deposits associated with the cheniers. These findings have implications for Mississippi River sediment diversions that are currently being planned to restore portions of this vulnerable coast. Only if such diversions are located in the western portion of the Mississippi Delta plain could they potentially contribute to sustaining the CP shoreline. Our findings

  19. Stratigraphy of the Martian northern plains

    Science.gov (United States)

    Tanaka, K. L.

    1993-01-01

    The northern plains of Mars are roughly defined as the large continuous region of lowlands that lies below Martian datum, plus higher areas within the region that were built up by volcanism, sedimentation, tectonism, and impacts. These northern lowlands span about 50 x 10(exp 6) km(sup 2) or 35 percent of the planet's surface. The age and origin of the lowlands continue to be debated by proponents of impact and tectonic explanations. Geologic mapping and topical studies indicate that volcanic, fluvial, and eolian deposition have played major roles in the infilling of this vast depression. Periglacial, glacial, fluvial, eolian, tectonic, and impact processes have locally modified the surface. Because of the northern plains' complex history of sedimentation and modification, much of their stratigraphy was obscured. Thus the stratigraphy developed is necessarily vague and provisional: it is based on various clues from within the lowlands as well as from highland areas within and bordering the plains. The results are summarized.

  20. Numerical Simulation of a Non-volcanic Hydrothermal System Caused by Formation of a High Permeability Fracture Zone

    Science.gov (United States)

    Oka, Daisuke; Ehara, Sachio; Fujimitsu, Yasuhiro

    2010-05-01

    Because in the Japanese islands the earth crust activity is very active, a disposal stratum for high-level radioactive waste produced by reprocessing the spent nuclear fuel from nuclear power plants will be selected in the tectonically stable areas in which the waste can be disposed underground safely for a long term and there is no influence of earthquakes, seismic activities, volcanic activities, upheaval, sedimentation, erosion, climate and global sea level change and so on, which causes the risk of the inflow of the groundwater to destroy the disposal site or the outflow to the ground surface. However, even if the disposal stratum in such condition will be chosen, in case that a new high permeability fracture zone is formed by the earthquake, and a new hydrothermal system may be formed for a long term (thousands or millions years) and the system may affect the disposal site. Therefore, we have to understand the feature of the non-volcanic hydrothermal system through the high permeability fracture zone. We estimated such influence by using HYDROTHERM Ver2.2 (Hayba & Ingebritsen, 1994), which is a three-dimensional numerical reservoir simulator. The model field is the northwestern part of Kego Fault, which was formed by a series of earthquakes called "the 2005 Fukuoka Prefecture Western Offshore Earthquakes" (the main shock of Mjma 7.0 on 20 March 2005) in Kyushu, Japan. The results of the numerical simulations show the development of a low temperature hydrothermal system as a new fracture zone is formed, in case that there is no volcanic heat source. The results of the simulations up to 100,000 years after formation of the fracture zone show that the higher heat flow and the wider and more permeable fracture zone accelerate the development of the hydrothermal system in the fracture zone. As a result of calculation of up to10 million years, we clarified the evolutional process of the non-volcanic hydrothermal system through the high permeability fracture zone. At

  1. Utopia Plain

    Science.gov (United States)

    2006-01-01

    5 March 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a dark-toned, cratered plain in southwest Utopia Planitia. Large, light-toned, windblown ripples reside on the floors of many of the depressions in the scene, including a long, linear, trough. Location near: 30.3oN, 255.3oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  2. Soil Fertility and Radicular System Depth of Sand Coastal Plain Forest

    Science.gov (United States)

    Casagrande, José Carlos; Akemi Sato, Claudia; Reis-Duarte, Rose Mary; Soares, Marcio Roberto; Sérgio Galvão Bueno, Mário

    2010-05-01

    The sand coastal plain vegetation (Restinga Forest) is a type of ecosystem associated with the Atlantic Forest constituted of mosaics, which occur in areas of great ecological diversity. This vegetation is currently assigned as edaphic communities. In this study we present data on soil fertility in different vegetation physiognomies to discuss on abiotic factors related to Restinga Forest stability and recovery potential. This work was carried out in several points of Restinga Forest in the litoral coast of the state of São Paulo, namely: State Park of the Serra do Mar, Picinguaba, in the city of Ubatuba (23°20' e 23°22' S / 44°48' e 44°52' W); State Park of Anchieta Island, in the city of Ubatuba (45°02' e 45°05' W / 23°31' e 23° 45' S); Restinga Forest in the residential joint ownership Riviera of São Lourenço, in the city of Bertioga (46°08' W e 23°51' S); Ecological Station Juréia-Itatins, Ecological Station of Chauas , in the city of Iguape (24°45' S e 47°33' W) and State Park of Cardoso Island, Pereirinha Restinga Forest, in the city of Cananéia (25°03'05" e 25°18'18" S / 47°53'48" e 48° 05'42" W), Brazil. Sampling was carried out as follows in every area above mentioned. One sample was made of 15 subsamples of each area collected in each depth (one in 0 - 5, 5 - 10, 10 - 15, 15 - 20, and another in 0 - 20, 20 - 40, 40 and 60 cm). Soil characteristics analyzed were pH, P, Na, K, Ca, Mg, S, H + Al, Al, B, Cu, Fe, Mn, Zn contents and base saturation, cation exchange capacity and aluminum saturation. All areas investigated showed very low contents of phosphorous, calcium and magnesium. The base saturation, less than 10, was low due to low amounts of Na, K, Ca and Mg, indicating low nutritional reserve into the soil. The nutritional reserve is present primarily in a depth of 15 cm, although mainly in the vegetable biomass. The level of calcium and magnesium were mainly low in the subsurface soil layer, associate with high concentration of

  3. Preliminary delineation of natural geochemical reactions, Snake River Plain aquifer system, Idaho National Engineering Laboratory and vicinity, Idaho

    International Nuclear Information System (INIS)

    Knobel, L.L.; Bartholomay, R.C.; Orr, B.R.

    1997-05-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, is conducting a study to determine the natural geochemistry of the Snake River Plain aquifer system at the Idaho National Engineering Laboratory (INEL), Idaho. As part of this study, a group of geochemical reactions that partially control the natural chemistry of ground water at the INEL were identified. Mineralogy of the aquifer matrix was determined using X-ray diffraction and thin-section analysis and theoretical stabilities of the minerals were used to identify potential solid-phase reactants and products of the reactions. The reactants and products that have an important contribution to the natural geochemistry include labradorite, olivine, pyroxene, smectite, calcite, ferric oxyhydroxide, and several silica phases. To further identify the reactions, analyses of 22 representative water samples from sites tapping the Snake River Plain aquifer system were used to determine the thermodynamic condition of the ground water relative to the minerals in the framework of the aquifer system. Principal reactions modifying the natural geochemical system include congruent dissolution of olivine, diopside, amorphous silica, and anhydrite; incongruent dissolution of labradorite with calcium montmorillonite as a residual product; precipitation of calcite and ferric oxyhydroxide; and oxidation of ferrous iron to ferric iron. Cation exchange reactions retard the downward movement of heavy, multivalent waste constituents where infiltration ponds are used for waste disposal

  4. Distribution of biologic, anthropogenic, and volcanic constituents as a proxy for sediment transport in the San Francisco Bay Coastal System

    Science.gov (United States)

    McGann, Mary; Erikson, Li H.; Wan, Elmira; Powell, Charles; Maddocks, Rosalie F.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Although conventional sediment parameters (mean grain size, sorting, and skewness) and provenance have typically been used to infer sediment transport pathways, most freshwater, brackish, and marine environments are also characterized by abundant sediment constituents of biological, and possibly anthropogenic and volcanic, origin that can provide additional insight into local sedimentary processes. The biota will be spatially distributed according to its response to environmental parameters such as water temperature, salinity, dissolved oxygen, organic carbon content, grain size, and intensity of currents and tidal flow, whereas the presence of anthropogenic and volcanic constituents will reflect proximity to source areas and whether they are fluvially- or aerially-transported. Because each of these constituents have a unique environmental signature, they are a more precise proxy for that source area than the conventional sedimentary process indicators. This San Francisco Bay Coastal System study demonstrates that by applying a multi-proxy approach, the primary sites of sediment transport can be identified. Many of these sites are far from where the constituents originated, showing that sediment transport is widespread in the region. Although not often used, identifying and interpreting the distribution of naturally-occurring and allochthonous biologic, anthropogenic, and volcanic sediment constituents is a powerful tool to aid in the investigation of sediment transport pathways in other coastal systems.

  5. Groundwater flow processes and mixing in active volcanic systems: the case of Guadalajara (Mexico)

    Science.gov (United States)

    Hernández-Antonio, A.; Mahlknecht, J.; Tamez-Meléndez, C.; Ramos-Leal, J.; Ramírez-Orozco, A.; Parra, R.; Ornelas-Soto, N.; Eastoe, C. J.

    2015-09-01

    other active volcanic systems on Earth.

  6. Genetic approach to the development of crop production systems on savanna soils of the Eastern plains of Colombia

    International Nuclear Information System (INIS)

    Valencia R, Ruben Alfredo; Leal Monsalve, Dario

    1996-01-01

    The savanna region of the eastern plains of Colombia is characterized by its low fertility with reduced soil content of calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P) and sulfur (S); low pH; high exchangeable aluminum (Al); high al saturation and high soil fragility, however these acid soils offer several advantages which make them ideal for sustainable agriculture, such as 1) abundant and adequate rainfall distribution from April to November, 2) flat topography, 3) good physical soil characteristics and, 4) large potential area. The eastern plains of Colombia comprise about 26 million hectares, 53% of them have good drainage and are currently under extensive cattle grazing systems with no or little technology practices and inherent low productivity. Low cost soil management technology is needed to utilize efficient/y these vast areas. Key technology components must include the identification of suitable crop species and cultivars that can tolerate al and absorb N in the presence of excess Al. Research on crop production systems to incorporate this huge area into food production has been led by ICA and CORPOICA toward the generation of crop varieties suitable to acid soil conditions and the development of adequate technology practices to preserve the ecosystem. The goal of the systemic approach is to develop sustainable technology with the participation of a multidisciplinary group

  7. BIOCHEM-ORCHESTRA: A tool for evaluating chemical speciation and ecotoxicological impacts of heavy metals on river flood plain systems

    International Nuclear Information System (INIS)

    Vink, J.P.M.; Meeussen, J.C.L.

    2007-01-01

    The chemical speciation model BIOCHEM was extended with ecotoxicological transfer functions for uptake of metals (As, Cd, Cu, Ni, Pb, and Zn) by plants and soil invertebrates. It was coupled to the object-oriented framework ORCHESTRA to achieve a flexible and dynamic decision support system (DSS) to analyse natural or anthropogenic changes that occur in river systems. The DSS uses the chemical characteristics of soils and sediments as input, and calculates speciation and subsequent uptake by biota at various scenarios. Biotic transfer functions were field-validated, and actual hydrological conditions were derived from long-term monitoring data. The DSS was tested for several scenarios that occur in the Meuse catchment areas, such as flooding and sedimentation of riverine sediments on flood plains. Risks are expressed in terms of changes in chemical mobility, and uptake by flood plain key species (flora and fauna). - A diagnostic risk-assessment tool for heavy metals, based on biotic and abiotic interactions, compares risks under different environmental scenarios

  8. Saline systems of the Great Plains of western Canada: an overview of the limnogeology and paleolimnology

    Science.gov (United States)

    Last, William M; Ginn, Fawn M

    2005-01-01

    In much of the northern Great Plains, saline and hypersaline lacustrine brines are the only surface waters present. As a group, the lakes of this region are unique: there is no other area in the world that can match the concentration and diversity of saline lake environments exhibited in the prairie region of Canada and northern United States. The immense number of individual salt lakes and saline wetlands in this region of North America is staggering. Estimates vary from about one million to greater than 10 million, with densities in some areas being as high as 120 lakes/km2. Despite over a century of scientific investigation of these salt lakes, we have only in the last twenty years advanced far enough to appreciate the wide spectrum of lake types, water chemistries, and limnological processes that are operating in the modern settings. Hydrochemical data are available for about 800 of the lake brines in the region. Composition, textural, and geochemical information on the modern bottom sediments has been collected for just over 150 of these lakes. Characterization of the biological and ecological features of these lakes is based on even fewer investigations, and the stratigraphic records of only twenty basins have been examined. The lake waters show a considerable range in ionic composition and concentration. Early investigators, concentrating on the most saline brines, emphasized a strong predominance of Na+ and SO4-2 in the lakes. It is now realized, however, that not only is there a complete spectrum of salinities from less than 1 ppt TDS to nearly 400 ppt, but also virtually every water chemistry type is represented in lakes of the region. With such a vast array of compositions, it is difficult to generalize. Nonetheless, the paucity of Cl-rich lakes makes the northern Great Plains basins somewhat unusual compared with salt lakes in many other areas of the world (e.g., Australia, western United States). Compilations of the lake water chemistries show distinct

  9. Salinization of porewater in a multiple aquitard-aquifer system in Jiangsu coastal plain, China

    Science.gov (United States)

    Li, Jing; Liang, Xing; Zhang, Yanian; Liu, Yan; Chen, Naijia; Abubakari, Alhassan; Jin, Menggui

    2017-12-01

    Chemical and isotopic compositions were analyzed in porewater squeezed from a clayey aquitard in Jiangsu coastal plain, eastern China, to interpret the salinity origin, chemical evolution and water-mass mixing process. A strong geochemical fingerprint was obtained with an aligned Cl/Br ratio of 154 in the salinized aquitard porewater over a wide Cl- concentration range (396-9,720 mg/L), indicating that porewater salinity is likely derived from a mixing with old brine with a proportion of less than 20%. Very small contributions of brine exerted limited effects on water stable isotopes. The relationships between porewater δ18O and δD indicate that shallow and intermediate porewaters could be original seawater and were subsequently diluted with modern meteoric water, whereas deep porewaters with depleted stable isotopic values were probably recharged during a cooler period and modified by evaporation and seawater infiltration. The cation-Cl relationship and mineralogy of associated strata indicate that porewater has been chemically modified by silicate weathering and ion-exchange reactions. 87Sr/86Sr ratios of 0.7094-0.7112 further confirm the input source of silicate minerals. Numerical simulations were used to evaluate the long-term salinity evolution of the deep porewater. The alternations of boundary conditions (i.e., the third aquifer mixed with brine at approximately 70 ka BP, followed by recharge of glacial meltwater at 20-25 ka BP, and then mixing with Holocene seawater at 7-10 ka BP) are responsible for the shift in porewater salinity. These timeframes correspond with the results of previous studies on ancient marine transgression-regression in Jiangsu coastal plain.

  10. Application of a Hybrid Detection and Location Scheme to Volcanic Systems

    Science.gov (United States)

    Thurber, C. H.; Lanza, F.; Roecker, S. W.

    2017-12-01

    We are using a hybrid method for automated detection and onset estimation, called REST, that combines a modified version of the nearest-neighbor similarity scheme of Rawles and Thurber (2015; RT15) with the regression approach of Kushnir et al. (1990; K90). This approach incorporates some of the windowing ideas proposed by RT15 into the regression techniques described in K90. The K90 and RT15 algorithms both define an onset as that sample where a segment of noise at earlier times is most "unlike" a segment of data at later times; the main difference between the approaches is how one defines "likeness." Hence, it is fairly straightforward to adapt the RT15 ideas to a K90 approach. We also incorporated the running mean normalization scheme of Bensen et al. (2007), used in ambient noise pre-processing, to reduce the effects of coherent signals (such as earthquakes) in defining noise segments. This is especially useful for aftershock sequences, when the persistent high amplitudes due to many earthquakes biases the true noise level. We use the fall-off of the K90 estimation function to assign uncertainties and the asymmetry of the function as a causality constraint. The detection and onset estimation stage is followed by iterative pick association and event location using a grid-search method. Some fine-tuning of some parameters is generally required for optimal results. We present 2 applications of this scheme to data from volcanic systems: Makushin volcano, Alaska, and Laguna del Maule (LdM), Chile. In both cases, there are permanent seismic networks, operated by the Alaska Volcano Observatory (AVO) and Observatorio Volcanológico de Los Andes del Sur (OVDAS), respectively, and temporary seismic arrays were deployed for a year or more. For Makushin, we have analyzed a year of data, from summer 2015 to summer 2016. The AVO catalog has 691 events in our study volume; REST processing yields 1784 more events. After quality control, the event numbers are 151 AVO events and

  11. Historical volcanism and the state of stress in the East African Rift System

    Directory of Open Access Journals (Sweden)

    Geoffrey Wadge

    2016-09-01

    Full Text Available Crustal extension at the East African Rift System (EARS should, as a tectonic ideal, involve a stress field in which the direction of minimum horizontal stress is perpendicular to the rift. A volcano in such a setting should produce dykes and fissures parallel to the rift. How closely do the volcanoes of the EARS follow this? We answer this question by studying the 21 volcanoes that have erupted historically (since about 1800 and find that 7 match the (approximate geometrical ideal. At the other 14 volcanoes the orientation of the eruptive fissures/dykes and/or the axes of the host rift segments are oblique to the ideal values. To explain the eruptions at these volcanoes we invoke local (non-plate tectonic variations of the stress field caused by: crustal heterogeneities and anisotropies (dominated by NW structures in the Protoerozoic basement, transfer zone tectonics at the ends of offset rift segments, gravitational loading by the volcanic edifice (typically those with 1-2 km relief and magmatic pressure in central reservoirs. We find that the more oblique volcanoes tend to have large edifices, large eruptive volumes and evolved and mixed magmas capable of explosive behaviour. Nine of the volcanoes have calderas of varying ellipticity, 6 of which are large, reservoir-collapse types mainly elongated across rift (e.g. Kone and 3 are smaller, elongated parallel to the rift and contain active lava lakes (e.g. Erta Ale, suggesting different mechanisms of formation and stress fields. Nyamuragira is the only EARS volcano with enough sufficiently well-documented eruptions to infer its long-term dynamic behaviour. Eruptions within 7 km of the volcano are of relatively short duration (<100 days, but eruptions with more distal fissures tend to have greater obliquity and longer durations, indicating a changing stress field away from the volcano. There were major changes in long-term magma extrusion rates in 1977 (and perhaps in 2002 due to major along

  12. Importance of Geodetically Controlled Topography to Constrain Rates of Volcanism and Internal Magma Plumbing Systems

    Science.gov (United States)

    Glaze, Lori S.; Baloga, S. M.; Garvin, James B.; Quick, Lynnae C.

    2014-01-01

    Investigation of lava flow deposits is a key component of Investigation II.A.1 in the VEXAG Goals, Objectives and Investigations. Because much of the Venus surface is covered in lava flows, characterization of lava flow emplacement conditions(eruption rate and eruption duration) is critical for understanding the mechanisms through which magma is stored and released onto the surface as well as for placing constraints on rates of volcanic resurfacing throughout the geologic record preserved at the surface.

  13. Adaptable pattern recognition system for discriminating Melanocytic Nevi from Malignant Melanomas using plain photography images from different image databases.

    Science.gov (United States)

    Kostopoulos, Spiros A; Asvestas, Pantelis A; Kalatzis, Ioannis K; Sakellaropoulos, George C; Sakkis, Theofilos H; Cavouras, Dionisis A; Glotsos, Dimitris T

    2017-09-01

    The aim of this study was to propose features that evaluate pictorial differences between melanocytic nevus (mole) and melanoma lesions by computer-based analysis of plain photography images and to design a cross-platform, tunable, decision support system to discriminate with high accuracy moles from melanomas in different publicly available image databases. Digital plain photography images of verified mole and melanoma lesions were downloaded from (i) Edinburgh University Hospital, UK, (Dermofit, 330moles/70 melanomas, under signed agreement), from 5 different centers (Multicenter, 63moles/25 melanomas, publicly available), and from the Groningen University, Netherlands (Groningen, 100moles/70 melanomas, publicly available). Images were processed for outlining the lesion-border and isolating the lesion from the surrounding background. Fourteen features were generated from each lesion evaluating texture (4), structure (5), shape (4) and color (1). Features were subjected to statistical analysis for determining differences in pictorial properties between moles and melanomas. The Probabilistic Neural Network (PNN) classifier, the exhaustive search features selection, the leave-one-out (LOO), and the external cross-validation (ECV) methods were used to design the PR-system for discriminating between moles and melanomas. Statistical analysis revealed that melanomas as compared to moles were of lower intensity, of less homogenous surface, had more dark pixels with intensities spanning larger spectra of gray-values, contained more objects of different sizes and gray-levels, had more asymmetrical shapes and irregular outlines, had abrupt intensity transitions from lesion to background tissue, and had more distinct colors. The PR-system designed by the Dermofit images scored on the Dermofit images, using the ECV, 94.1%, 82.9%, 96.5% for overall accuracy, sensitivity, specificity, on the Multicenter Images 92.0%, 88%, 93.7% and on the Groningen Images 76.2%, 73.9%, 77

  14. Glacial vs. Interglacial Period Contrasts in Midlatitude Fluvial Systems, with Examples from Western Europe and the Texas Coastal Plain

    Science.gov (United States)

    Blum, M.

    2001-12-01

    Mixed bedrock-alluvial valleys are the conveyor belts for sediment delivery to passive continental margins. Mapping, stratigraphic and sedimentologic investigations, and development of geochronological frameworks for large midlatitude rivers of this type, in Western Europe and the Texas Coastal Plain, provide for evaluation of fluvial responses to climate change over the last glacial-interglacial period, and the foundations for future quantitative evaluation of long profile evolution, changes through time in flood magnitude, and changes in storage and flux of sediments. This paper focuses on two issues. First, glacial vs. interglacial period fluvial systems are fundamentally different in terms of channel geometry, depositional style, and patterns of sediment storage. Glacial-period systems were dominated by coarse-grained channel belts (braided channels in Europe, large-wavelength meandering in Texas), and lacked fine-grained flood-plain deposits, whereas Holocene units, especially those of late Holocene age, contain appreciable thicknesses of flood-plain facies. Hence, extreme overbank flooding was not significant during the long glacial period, most flood events were contained within bankfull channel perimeters, and fine sediments were bypassed through the system to marine basins. By contrast, extreme overbank floods have been increasingly important during the relatively short Holocene, and a significant volume of fine sediment is sequestered in flood-plain settings. Second, glacial vs. interglacial systems exhibit different amplitudes and frequencies of fluvial adjustment to climate change. High-amplitude but low-frequency adjustments characterized the long glacial period, with 2-3 extended periods of lateral migration and sediment storage puncuated by episodes of valley incision. Low-amplitude but high-frequency adjustments have been more typical of the short Holocene, when there has been little net valley incision or net changes in sediment storage, but

  15. Woodville Karst Plain, North Florida

    OpenAIRE

    2006-01-01

    Map showing the largest mapped underwater cave systems and conduit flow paths confirmed by tracer testing relative to surface streams, sinkholes and potentiometric surface of the Florida aquifer in the Woodville Karst Plain, Florida

  16. Using LiCSAR as a fast-response system for the detection and the monitoring of volcanic unrest

    Science.gov (United States)

    Albino, F.; Biggs, J.; Hatton, E. L.; Spaans, K.; Gaddes, M.; McDougall, A.

    2017-12-01

    Based on the Smithsonian Institution volcano database, a total of 13256 volcanoes exist on Earth with 1273 having evidence of eruptive or unrest activity during the Holocene. InSAR techniques have proven their ability to detect and to quantify volcanic ground deformation on a case-by-case basis. However, the use of InSAR for the daily monitoring of every active volcano requires the development of automatic processing that can provide information in a couple of hours after a new radar acquisition. The LiCSAR system (http://comet.nerc.ac.uk/COMET-LiCS-portal/) answers this requirement by processing the vast amounts of data generated daily by the EU's Sentinel-1 satellite constellation. It provides now high-resolution deformation data for the entire Alpine-Himalayan seismic belt. The aim of our study is to extend LiCSAR system to the purpose of volcano monitoring. For each active volcano, the last Sentinel products calculated (phase, coherence and amplitude) will be available online in the COMET Volcano Deformation Database. To analyse this large amount of InSAR products, we develop an algorithm to automatically detect ground deformation signals as well as changes in coherence and amplitude in the time series. This toolbox could be a powerful fast-response system for helping volcanological observatories to manage new or ongoing volcanic crisis. Important information regarding the spatial and the temporal evolution of each ground deformation signal will also be added to the COMET database. This will benefit to better understand the conditions in which volcanic unrest leads to an eruption. Such worldwide survey enables us to establish a large catalogue of InSAR products, which will also be suitable for further studies (mapping of new lava flows, modelling of magmatic sources, evaluation of stress interactions).

  17. Global Volcanism on Mercury at About 3.8 Ga

    Science.gov (United States)

    Byrne, P. K.; Ostrach, L. R.; Denevi, B. W.; Head, J. W., III; Hauck, S. A., II; Murchie, S. L.; Solomon, S. C.

    2014-12-01

    Smooth plains occupy c. 27% of the surface of Mercury. Embayment relations, spectral contrast with surroundings, and morphologic characteristics indicate that the majority of these plains are volcanic. The largest deposits are located in Mercury's northern hemisphere and include the extensive northern plains (NP) and the Caloris interior and exterior plains (with the latter likely including basin material). Both the NP and Caloris deposits are, within statistical error, the same age (~3.8-3.9 Ga). To test whether this age reflects a period of global volcanism on Mercury, we determined crater size-frequency distributions for four smooth plains units in the planet's southern hemisphere interpreted to be volcanic. Two deposits are situated within the Beethoven and Tolstoj impact basins; two are located close to the Debussy and the Alver and Disney basins, respectively. Each deposit hosts two populations of craters, one that postdates plains emplacement and one that consists of partially to nearly filled craters that predate the plains. This latter population indicates that some time elapsed between formation of the underlying basement and plains volcanism, though we cannot statistically resolve this interval at any of the four sites. Nonetheless, we find that the age given by the superposed crater population in each case is ~3.8 Ga, and crater density values are consistent with those for the NP and Caloris plains. This finding supports a global phase of volcanism near the end of the late heavy bombardment of Mercury and may indicate a period of widespread partial melting of Mercury's mantle. Notably, superposition relations between smooth plains, degraded impact structures, and contractional landforms suggest that by this time interior cooling had already placed Mercury's lithosphere in horizontal compression, tending to inhibit voluminous dike-fed volcanism such as that inferred responsible for the NP. Most smooth plains units, including the Caloris plains and our

  18. Radioisotope distribution characteristics of the groundwater system in volcanic-type U deposits and isotope-dating estimation of the system

    International Nuclear Information System (INIS)

    Zhou Bingguan

    1988-01-01

    On the basis of groundwater sample measurements collected from the uranogenic belt of Mesozoic volcanic rocks in East China, the distribution characteristics of radioisotopes, including the total U content (CΣu), the activity of nuclides (Aui) or their activity ratio (ARu) and the relationship among the three ((Aui,ARu)=f(CΣu)), have been studied. Also, it is performed for radioactive water halos in the area to be divided into four various mineralization tendencies: (1) the convergent tendency of negative correlation, which has the genetic relationship with the primary U accumulation in volcanic rocks; (2) the scattered tendency of positive correlation, which is intimately related to epigenetic U mineralization in the supergene zone of volcanic rocks or in the sandstones; (3) the both positive and negative multiple-correlative tendency, which indicates that the primary volcanic-type U deposit has been leached and destroyed, and the secondary U enrichment has occurred within the supergene zone; (4) non-correlative tendency, which mainly results from increasing dispersion U. For the above recognitions, an evolution model for radioactive water halos related to this type of U deposit has been derived, and an attempt to estimate the radioisotopic age of the groundwater system also has been made. (author). 14 refs, 9 figs, 2 tabs

  19. Regional implications of heat flow of the Snake River Plain, Northwestern United States

    Science.gov (United States)

    Blackwell, D. D.

    1989-08-01

    The Snake River Plain is a major topographic feature of the Northwestern United States. It marks the track of an upper mantle and crustal melting event that propagated across the area from southwest to northeast at a velocity of about 3.5 cm/yr. The melting event has the same energetics as a large oceanic hotspot or plume and so the area is the continental analog of an oceanic hotspot track such as the Hawaiian Island-Emperor Seamount chain. Thus, the unique features of the area reflect the response of a continental lithosphere to a very energetic hotspot. The crust is extensively modified by basalt magma emplacement into the crust and by the resulting massive rhyolite volcanism from melted crustal material, presently occurring at Yellowstone National Park. The volcanism is associated with little crustal extension. Heat flow values are high along the margins of the Eastern and Western Snake River Plains and there is abundant evidence for low-grade geothermal resources associated with regional groundwater systems. The regional heat flow pattern in the Western Snake River Plains reflects the influence of crustal-scale thermal refraction associated with the large sedimentary basin that has formed there. Heat flow values in shallow holes in the Eastern Snake River Plains are low due to the Snake River Plains aquifer, an extensive basalt aquifer where water flow rates approach 1 km/yr. Below the aquifer, conductive heat flow values are about 100 mW m -2. Deep holes in the region suggest a systematic eastward increase in heat flow in the Snake River Plains from about 75-90 mW m -2 to 90-110 mW m -2. Temperatures in the upper crust do not behave similarly because the thermal conductivity of the Plio-Pleistocene sedimentary rocks in the west is lower than that in the volcanic rocks characteristic of the Eastern Snake River Plains. Extremely high heat loss values (averaging 2500 mW m -2) and upper crustal temperatures are characteristic of the Yellowstone caldera.

  20. Structural characteristic of the Eastern Plains soils of Colombia, submitted to several handling systems

    International Nuclear Information System (INIS)

    Amezquita, E; Saenz J I; Thomas, R J; Vera, R R; Hoyos, P; Molina, D L; Chavez, L F

    1997-01-01

    Soil productivity and sustainability depends on the building and/or conservation of an adequate and dynamic equilibrium between physical, chemical and biological properties and processes in the volume of soil explored by roots, so that there is no constraints in the availability of water and nutrients to plants. Soil structure is one of the soil properties that are more vulnerable to the intensity of use in tropical soils. Aggregate size distribution, aggregate stability and pore size distribution are some of the attributes that are usually used to describe structural changes and can act as indicators of structural sustainability. This paper presents and discusses the behavior of these attributes under different soil management treatments (native savanna, Brachiaria alone; Brachiaria + legume and monocrop) in the Colombian Eastern plains soil classified as Typic haplustox Kaolinitic iso-hyperthermic. These results showed highly statistical significant differences between treatments in the parameters studied and allow concluding that aggregate size distribution and stability could be indicators of susceptibility to degradation

  1. Mitigating Groundwater Depletion in North China Plain with Cropping System that Alternate Deep and Shallow Rooted Crops

    Directory of Open Access Journals (Sweden)

    Xiao-Lin Yang

    2017-06-01

    Full Text Available In the North China Plain, groundwater tables have been dropping at unsustainable rates of 1 m per year due to irrigation of a double cropping system of winter wheat and summer maize. To reverse the trend, we examined whether alternative crop rotations could save water. Moisture contents were measured weekly at 20 cm intervals in the top 180 cm of soil as part of a 12-year field experiment with four crop rotations: sweet potato→ cotton→ sweet potato→ winter wheat-summer maize (SpCSpWS, 4-year cycle; peanuts → winter wheat-summer maize (PWS, 2-year cycle; ryegrass–cotton→ peanuts→ winter wheat-summer maize (RCPWS, 3-year cycle; and winter wheat-summer maize (WS, each year. We found that, compared to WS, the SpCSpWS annual evapotranspiration was 28% lower, PWS was 19% lower and RCPWS was 14% lower. The yield per unit of water evaporated improved for wheat within any alternative rotation compared to WS, increasing up to 19%. Average soil moisture contents at the sowing date of wheat in the SpCSpWS, PWS, and RCPWS rotations were 7, 4, and 10% higher than WS, respectively. The advantage of alternative rotations was that a deep rooted crop of winter wheat reaching down to 180 cm followed shallow rooted crops (sweet potato and peanut drawing soil moisture from 0 to 120 cm. They benefited from the sequencing and vertical complementarity of soil moisture extraction. Thus, replacing the traditional crop rotation with cropping system that involves rotating with annual shallow rooted crops is promising for reducing groundwater depletion in the North China Plain.

  2. Validating predictions made by a thermo-mechanical model of melt segregation in sub-volcanic systems

    Science.gov (United States)

    Roele, Katarina; Jackson, Matthew; Morgan, Joanna

    2014-05-01

    A quantitative understanding of the spatial and temporal evolution of melt distribution in the crust is crucial in providing insights into the development of sub-volcanic crustal stratigraphy and composition. This work aims to relate numerical models that describe the base of volcanic systems with geophysical observations. Recent modelling has shown that the repetitive emplacement of mantle-derived basaltic sills, at the base of the lower crust, acts as a heat source for anatectic melt generation, buoyancy-driven melt segregation and mobilisation. These processes form the lowermost architecture of complex sub-volcanic networks as upward migrating melt produces high melt fraction layers. These 'porosity waves' are separated by zones with high compaction rates and have distinctive polybaric chemical signatures that suggest mixed crust and mantle origins. A thermo-mechanical model produced by Solano et al in 2012 has been used to predict the temperatures and melt fractions of successive high porosity layers within the crust. This model was used as it accounts for the dynamic evolution of melt during segregation and migration through the crust; a significant process that has been neglected in previous models. The results were used to input starting compositions for each of the layers into the rhyolite-MELTS thermodynamic simulation. MELTS then determined the approximate bulk composition of the layers once they had cooled and solidified. The mean seismic wave velocities of the polymineralic layers were then calculated using the relevant Voight-Reuss-Hill mixture rules, whilst accounting for the pressure and temperature dependence of seismic wave velocity. The predicted results were then compared with real examples of reflectivity for areas including the UK, where lower crustal layering is observed. A comparison between the impedance contrasts at compositional boundaries is presented as it confirms the extent to which modelling is able to make predictions that are

  3. Diffuse Carbon Dioxide Degassing Monitoring at Santa Ana-Izalco-Coatepeque Volcanic System, El Salvador, Central America

    Science.gov (United States)

    Olmos, R.; Barahona, F.; Cartagena, R.; Soriano, T.; Salazar, J.; Hernandez, P.; Perez, N.; Notsu, K.; Lopez, D.

    2001-12-01

    Santa Ana volcanic complex (0.22 Ma), located 40 Km west of San Salvador, comprises Santa Ana, Izalco, and Cerro Verde stratovolcanoes, the Coatepeque collapse caldera, as well as several cinder cones and explosion craters. Most recent activity has occurred at Izalco (1966) and Santa Ana which shows a permanent acidic crater lake with an intense fumarolic activity. In addition, Santa Ana exhibits a SO2-rich rising plume though no local seismicity has been reported. Weak fumarolic activity is also present at two locations within the Santa Ana volcanic complex: the summit crater of Izalco and Cerro Pacho at Coatepeque caldera. Other important structural features of this volcanic complex are two fault/fissure systems running NNW-SSE that can be identified by the alignment of the stratovolcanoes and numerous cinder cones and explosion craters. In January 2001, a 7.6 magnitude earthquake occurred about 150 Km SE of Santa Ana volcano. A soil gas and CO2 efflux survey was performed to evaluate the impact of this seismic event upon the diffuse degassing rates in Santa Ana volcanic complex in March 2001. A total of 450 soil gas and diffuse CO2 efflux measurements were carried out covering an area of 209.5 Km2. CO2 efflux ranged from non-detectable values to 293 gm-2d-1, with a median of 8.9 gm-2d-1 and an upper quartile of 5.2 gm-2d-1. The CO2 efflux spatial distribution reveals the existence of areas with CO2 efflux higher than 60 gm-2d-1 associated to the fault/fissure systems of NNW-SSE orientation. One of these areas, Cerro Pacho, was selected for the continuous monitoring of diffuse CO2 efflux in late May 2001. Secular variations of diffuse CO2 efflux ranged from 27.4 to 329 gm-2d-1 with a median of 130 gm-2d-1 and a quartile range of 59.3 gm-2d-1. An increasing trend of 43 gm-2d-1 was observed between May and August 2001 overlapped to high-frequency minor fluctuations related to meteorological variables' changes. However, a larger observation time-span is needed to

  4. Field-trip guides to selected volcanoes and volcanic landscapes of the western United States

    Science.gov (United States)

    ,

    2017-06-23

    The North American Cordillera is home to a greater diversity of volcanic provinces than any comparably sized region in the world. The interplay between changing plate-margin interactions, tectonic complexity, intra-crustal magma differentiation, and mantle melting have resulted in a wealth of volcanic landscapes.  Field trips in this guide book collection (published as USGS Scientific Investigations Report 2017–5022) visit many of these landscapes, including (1) active subduction-related arc volcanoes in the Cascade Range; (2) flood basalts of the Columbia Plateau; (3) bimodal volcanism of the Snake River Plain-Yellowstone volcanic system; (4) some of the world’s largest known ignimbrites from southern Utah, central Colorado, and northern Nevada; (5) extension-related volcanism in the Rio Grande Rift and Basin and Range Province; and (6) the eastern Sierra Nevada featuring Long Valley Caldera and the iconic Bishop Tuff.  Some of the field trips focus on volcanic eruptive and emplacement processes, calling attention to the fact that the western United States provides opportunities to examine a wide range of volcanological phenomena at many scales.The 2017 Scientific Assembly of the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) in Portland, Oregon, was the impetus to update field guides for many of the volcanoes in the Cascades Arc, as well as publish new guides for numerous volcanic provinces and features of the North American Cordillera. This collection of guidebooks summarizes decades of advances in understanding of magmatic and tectonic processes of volcanic western North America. These field guides are intended for future generations of scientists and the general public as introductions to these fascinating areas; the hope is that the general public will be enticed toward further exploration and that scientists will pursue further field-based research.

  5. Candidate constructional volcanic edifices on Mercury

    OpenAIRE

    Wright, J.; Rothery, D. A.; Balme, M. R.; Conway, S. J.

    2018-01-01

    [Introduction] Studies using MESSENGER data suggest that Mercury’s crust is predominantly a product of effusive volcanism that occurred in the first billion years following the planet’s formation. Despite this planet-wide effusive volcanism, no constructional volcanic edifices, characterized by a topographic rise, have hitherto been robustly identified on Mercury, whereas constructional volcanoes are common on other planetary bodies in the solar system with volcanic histories. Here, we descri...

  6. Volcanic-plutonic connections and metal fertility of highly evolved magma systems: A case study from the Herberton Sn-W-Mo Mineral Field, Queensland, Australia

    Science.gov (United States)

    Cheng, Yanbo; Spandler, Carl; Chang, Zhaoshan; Clarke, Gavin

    2018-03-01

    Understanding the connection between the highly evolved intrusive and extrusive systems is essential to explore the evolution of high silicic magma systems, which plays an important role in discussions of planetary differentiation, the growth of continents, crustal evolution, and the formation of highly evolved magma associated Sn-W-Mo mineral systems. To discern differences between "fertile" and "non-fertile" igneous rocks associated with Sn-W-Mo mineralization and reveal the genetic links between coeval intrusive and extrusive rocks, we integrate whole rock geochemistry, geochronology and Hf isotope signatures of igneous zircons from contemporaneous plutonic and volcanic rocks from the world-class Herberton Mineral Field of Queensland, Australia. The 310-300 Ma intrusive rocks and associated intra-plutonic W-Mo mineralization formed from relatively oxidized magmas after moderate degrees of crystal fractionation. The geochemical and isotopic features of the coeval volcanic succession are best reconciled utilizing the widely-accepted volcanic-plutonic connection model, whereby the volcanic rocks represent fractionated derivatives of the intrusive rocks. Older intrusions emplaced at 335-315 Ma formed from relatively low fO2 magmas that fractionated extensively to produce highly evolved granites that host Sn mineralization. Coeval volcanic rocks of this suite are compositionally less evolved than the intrusive rocks, thereby requiring a different model to link these plutonic-volcanic sequences. In this case, we propose that the most fractionated magmas were not lost to volcanism, but instead were effectively retained at the plutonic level, which allowed further localized build-up of volatiles and lithophile metals in the plutonic environment. This disconnection to the volcanism and degassing may be a crucial step for forming granite-hosted Sn mineralization. The transition between these two igneous regimes in Herberton region over a ∼30 m.y. period is attributed to

  7. Petrography and petrology of the Nornahraun eruption of the Bárðarbunga volcanic system, Iceland

    Science.gov (United States)

    Guðfinnsson, Guðmundur H.; Halldórsson, Sæmundur Ari; Bali, Enikő; Jakobsson, Sigurður; Sverrisdóttir, Guðrún; Höskuldssson, Ármann; Riishuus, Morten S.; Þórðarson, Þorvaldur; The 2014 Nornahraun Eruption Team

    2015-04-01

    The on-going fissure eruption north of Dyngjujökull is becoming the largest of its kind in Iceland since the 1783-84 Laki eruption. The erupted lava is olivine tholeiite, containing up to 5% normative olivine. It is relatively macrocryst-poor, initially containing less than 1% phenocrysts by volume, increasing to over 1% as the eruption has progressed. Plagioclase is the dominant macrocryst phase but olivine and augite are also present. In most of the samples, crystallization of the groundmass is substantial, with plagioclase and augite as the key groundmass minerals and minor olivine. It features subophitic texture, typical for olivine tholeiites, where the interstitial glass contains dendritic Fe-Ti oxide. During the first two months of the eruption, magma composition has been constant, displaying uniform major and trace element composition and nearly uniform isotopic compositions (Halldórsson et al. (a), this session). The major and trace element contents, in addition to the isotope ratios of lead, are indistinguishable from basalts in the Bárðarbunga volcanic system (Halldórsson et al. (b), this session). The compositional trends are consistent with crystallization along the ol-plag-cpx cotectic. Crystallization depth estimates, based on the pressure dependence of the cotectic (Yang et al., 1996), indicate that the magma equilibrated at a minimum depth between 6-9 km, consistent with depth estimates derived from CO2-bearing fluid inclusions trapped in plagioclase phenocrysts (Bali et al., this session). The bulk of the earthquakes associated with this volcano-tectonic episode are also in this range (e.g., Sigmundsson et al., 2015). Calculations with several different magma geothermometers suggest that the temperature of the magma as it rises to the surface is about 1170-1180°C, in good agreement with on-site measurements by thermal imaging cameras. The eruption has been characterized by steady, high emission of SO2. The sulfur-rich nature of the lava is

  8. Water and gas geochemistry of the Calatrava Volcanic Province (CVP) hydrothermal system (Ciudad Real, central Spain)

    Science.gov (United States)

    Vaselli, Orlando; Nisi, Barbara; Tassi, Franco; Giannini, Luciano; Grandia, Fidel; Darrah, Tom; Capecchiacci, Francesco; del Villar, Pèrez

    2013-04-01

    An extensive geochemical and isotopic investigation was carried out in the water and gas discharges of the Late Miocene-Quaternary Calatrava Volcanic Province (CVP) (Ciudad Real, Spain) with the aim reconstruct the fluid circulation in the area. CVP consists of a series of scattered (monogenetic) vents from where alkaline lava flows and pyroclastic deposits formed in two different periods. The first stage (8.7-6.4 Ma) mainly included ultra-potassic mafic extrusives, whilst the second stage (4.7-1.75 Ma) prevalently originated alkaline and ultra-alkaline volcanics. Both stages were followed by a volcanic activity that extended up to 1.3 and 0.7 Ma, respectively. This area can likely be regarded as one of the most important emitting zones of CO2 in the whole Peninsular Spain along with that of Selva-Emporda in northeastern Spain (Cataluña) and it can be assumed as one of the best examples of natural analogues of CO2 leakages in Spain. This latter aspect is further evidenced by the relatively common water-gas blast events that characterize the CCVF. In the last few years the presence of a CO2-pressurized reservoir at a relatively shallow level as indeed caused several small-sized explosion particularly during the drilling of domestic wells. The fluid discharging sites are apparently aligned along well-defined directions: NW-SE and NNW-SSE and subordinately, ENE-WSW, indicating a clear relationship between the thermal discharges and the volcanic centers that also distribute along these lineaments. The CVP waters are mostly hypothermal (up to 33 °C) and are generally Mg(Ca)-HCO3 in composition and occasionally show relatively high concentrations of Fe and Mn, with pH and electrical conductivity down to 5.5 and up to 6.5 mS/cm, respectively. The oxygen and hydrogen isotopes suggest a meteoric origin for these waters. The mantle source of these volcanic products is apparently preserved in the many CO2-rich (up to 990,000 mmol/mol) gas discharges that characterize CVP

  9. Trends and transformation of nutrients and pesticides in a Coastal Plain aquifer system, United States

    Science.gov (United States)

    Denver, J.M.; Tesoriero, A.J.; Barbaro, J.R.

    2010-01-01

    Four local-scale sites in areas with similar corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] agriculture were studied to determine the effects of different hydrogeologic settings of the Northern Atlantic Coastal Plain (NACP) on the transport of nutrients and pesticides in groundwater. Settings ranged from predominantly well-drained soils overlying thick, sandy surficial aquifers to predominantly poorly drained soils with complex aquifer stratigraphy and high organic matter content. Apparent age of groundwater, dissolved gases, N isotopes, major ions, selected pesticides and degradates, and geochemical environments in groundwater were studied. Agricultural chemicals were the source of most dissolved ions in groundwater. Specific conductance was strongly correlated with reconstructed nitrate (the sum of N in nitrate and N gas) (R2 = 0.81, p < 0.0001), and is indicative of the relative degree of agricultural effects on groundwater. Trends in nitrate were primarily related to changes in manure and fertilizer use at the well-drained sites where aquifer conditions were consistently oxic. Nitrate was present in young groundwater but completely removed over time through denitrification at the poorly drained sites where there were variations in chemical input and in geochemical environment. Median concentrations of atrazine (6-chloro-N-ethyl-N'-(1- methylethyl)-1,3,5-triazine-2,4-diamine), metolachlor (2-chloro-N-(2-ethyl-6- methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide), and some of their common degradates were higher at well-drained sites than at poorly drained sites, with concentrations of degradates generally higher than those of the parent compounds at all sites. An increase in the percentage of deethylatrazine to total atrazine over time at one well-drained site may be related to changes in manure application. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  10. Density evaluation by computerized tomography in plain soils over different manipulation systems; Avaliacao da densidade pelo metodo da tomografia computadorizada de um planossolo sob diferentes sistemas de manejo

    Energy Technology Data Exchange (ETDEWEB)

    Pedrotti, Alceu [Lavras Univ., MG (Brazil). Dept. de Ciencia do Solo; Pauletto, Eloy Antonio [Pelotas Univ., RS (Brazil). Dept. de Solos; Crestana, Silvio [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Centro Nacional de Pesquisa e Desenvolvimento de Instrumentacao Agropecuaria (CNPDIA)

    1996-08-01

    The objective of this paper is the evaluation of a plain soil density in different culture systems determined by X ray computerized tomography.It was observed a larger variation in densities in soils profiles analysed. The identification of layers is better utilising computerized tomography than others technic 1 fig.

  11. Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system From Long Island, New York, to North Carolina

    Science.gov (United States)

    Masterson, John P.; Pope, Jason P.; Fienen, Michael N.; Monti, Jr., Jack; Nardi, Mark R.; Finkelstein, Jason S.

    2016-08-31

    Executive SummaryThe U.S. Geological Survey began a multiyear regional assessment of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system in 2010 as part of its ongoing regional assessments of groundwater availability of the principal aquifers of the Nation. The goals of this national assessment are to document effects of human activities on water levels and groundwater storage, explore climate variability effects on the regional water budget, and provide consistent and integrated information that is useful to those who use and manage the groundwater resource. As part of this nationwide assessment, the USGS evaluated available groundwater resources within the NACP aquifer system from Long Island, New York, to northeastern North Carolina.The northern Atlantic Coastal Plain physiographic province depends heavily on groundwater to meet agricultural, industrial, and municipal needs. The groundwater assessment of the NACP aquifer system included an evaluation of how water use has changed over time; this evaluation primarily used groundwater budgets and development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends.This assessment focused on multiple spatial and temporal scales to examine changes in groundwater pumping, storage, and water levels. The regional scale provides a broad view of the sources and demands on the system with time. The sub-regional scale provides an evaluation of the differing response of the aquifer system across geographic areas allowing for closer examination of the interaction between different aquifers and confining units and the changes in these interactions under pumping and recharge conditions in 2013 and hydrologic stresses as much as 45 years in the future. By focusing on multiple scales, water-resource managers may utilize this study to understand system response to changes as they affect the system as a whole.The NACP aquifer system extends from

  12. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Cratering histories of the intercrater plains. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    The intercrater plains of Mercury and the Moon are defined, in part, by their high densities of small craters. The crater size frequency statistics presented in this chapter may help constrain the relative ages and origins of these surfaces. To this end, the effects of common geologic processes on crater frequency statistics are compared with the diameter frequency distributions of the intercrater regions of the Moon and Mercury. Such analyses may determine whether secondary craters dominate the distribution at small diameters, and whether volcanic plains or ballistic deposits form the intercrater surface. Determining the mass frequency distribution and flux of the impacting population is a more difficult problem. The necessary information such as scaling relationships between projectile energy and crater diameter, the relative fluxes of solar system objects, and the absolute ages of surface units is model dependent and poorly constrained, especially for Mercury.

  13. Geothermal alteration of basaltic core from the Snake River Plain, Idaho

    Science.gov (United States)

    Sant, Christopher J.

    The Snake River Plain is located in the southern part of the state of Idaho. The eastern plain, on which this study focuses, is a trail of volcanics from the Yellowstone hotspot. Three exploratory geothermal wells were drilled on the Snake River Plain. This project analyzes basaltic core from the first well at Kimama, north of Burley, Idaho. The objectives of this project are to establish zones of geothermal alteration and analyze the potential for geothermal power production using sub-aquifer resources on the axial volcanic zone of the Snake River Plain. Thirty samples from 1,912 m of core were sampled and analyzed for clay content and composition using X-ray diffraction. Observations from core samples and geophysical logs are also used to establish alteration zones. Mineralogical data, geophysical log data and physical characteristics of the core suggest that the base of the Snake River Plain aquifer at the axial zone is located 960 m below the surface, much deeper than previously suspected. Swelling smectite clay clogs pore spaces and reduces porosity and permeability to create a natural base to the aquifer. Increased temperatures favor the formation of smectite clay and other secondary minerals to the bottom of the hole. Below 960 m the core shows signs of alteration including color change, formation of clay, and filling of other secondary minerals in vesicles and fractured zones of the core. The smectite clay observed is Fe-rich clay that is authigenic in some places. Geothermal power generation may be feasible using a low temperature hot water geothermal system if thermal fluids can be attained near the bottom of the Kimama well.

  14. Planning report for the Gulf Coast Regional Aquifer-System Analysis in the Gulf of Mexico coastal plain, United States

    Science.gov (United States)

    Grubb, Hayes F.

    1984-01-01

    Large quantities of water for municipal, industrial and agriculture use are supplied from the aquifers in Tertiary and younger sediments over an area of about 225,000 square miles in the Coastal Plain of Alabama, Arkansas, Florida, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, and Texas. Three regional aquifer systems, the Mississippi Embayment aquifer system, the Coastal Lowlands aquifer system, and the Texas Coastal Uplands aquifer system have been developed to varying degrees throughout the area. A variety of problems has resulted from development such as movement of the saline-freshwater interface into parts of aquifers that were previously fresh, lowering of the potentiometric surface with resulting increases in pumping lift, and land-surface subsidence due to the compaction of clays within the aquifer. Increased demand for ground water is anticipated to meet the needs of urban growth, expanded energy development, and growth of irrigated agriculture. The U. S. Geological Survey initiated an eightyear study in 1981 to define the geohydrologic framework, describe the chemistry of the ground water, and to analyze the regional ground-water flow patterns. The objectives, plan, and organization of the study are described in this report and the major tasks to be undertaken are outlined.

  15. Case study of developing an integrated water and nitrogen scheme for agricultural systems on the North China Plain

    Science.gov (United States)

    Liu, Y.; Tao, F.; Luo, Y.; Ma, J.

    2013-12-01

    Appropriate irrigation and nitrogen fertilization, along with suitable crop management strategies, are essential prerequisites for optimum yields in agricultural systems. This research attempts to provide a scientific basis for sustainable agricultural production management for the North China Plain and other semi-arid regions. Based on a series of 72 treatments over 2003-2008, an optimized water and nitrogen scheme for winter wheat/summer maize cropping system was developed. Integrated systems incorporating 120 mm of water with 80 kg N ha-1 N fertilizer were used to simulate winter wheat yields in Hebei and 120 mm of water with 120 kg N ha-1 were used to simulate winter wheat yields in Shandong and Henan provinces in 2000-2007. Similarly, integrated treatments of 40 kg N ha-1 N fertilizer were used to simulate summer maize yields in Hebei, and 80 kg N ha-1 was used to simulate summer maize yields in Shandong and Henan provinces in 2000-2007. Under the optimized scheme, 341.74 107 mm ha-1 of water and 575.79 104 Mg of urea fertilizer could be saved per year under the wheat/maize rotation system. Despite slight drops in the yields of wheat and maize in some areas, water and fertilizer saving has tremendous long-term eco-environmental benefits.

  16. Carbon isotope ratios of great plains soils and in wheat-fallow systems

    International Nuclear Information System (INIS)

    Follett, R.F.; Paul, E.A.; Leavitt, S.W.; Halvorson, A.D.; Lyon, D.; Peterson, G.A.

    1997-01-01

    The purposes of this study were to improve knowledge of regional vegetation patterns of C3 and C4 plants in the North American Great Plains and to use delta 13C methodology and long-term research sites to determine contributions of small-grain crops to total soil organic carbon (SOC) now present. Archived and recent soil samples were used. Detailed soil sampling was in 1993 at long-term sites near Akron, CO, and Sidney, NE. After soil sieving, drying, and deliming, SOC and delta 13C were determined using an automated C/N analyzer interfaced to an isotope-ratio mass spectrometer. Yield records from long-term experimental sites were used to estimate the amount of C3 plant residue C returned to the soil. Results from delta 13C analyses of soils from near Waldheim, Saskatchewan, to Big Springs, TX, showed a strong north to south decrease in SOC derived from C3 plants and a corresponding increase from C4 plants. The delta 13C analyses gave evidence that C3 plant residue C (possibly from shrubs) is increasing at the Big Springs, TX, and Lawton, OK, sites. Also, delta 13C analyses of subsoil and topsoil layers shows evidence of a regional shift to more C3 species, possibly because of a cooler climate during the past few hundreds to thousands of years. Data from long-term research sites indicate that the efficiency of incorporation of small-grain crop residue C was about 5.4% during 84 yr at Akron, CO, and about 10.5% during 20 yr at Sidney, NE. The 14C age of the SOC at 0- to 10-cm depth was 193 yr and at 30 to 45 cm was 4000 yr; 14C age of nonhydrolyzable C was 2000 and 7000 yr for these same two respective depths. Natural partitioning of the 13C isotope by the photosynthetic pathways of C3 and C4 plants provides a potentially powerful tool to study SOC dynamics at both regional and local scales

  17. Fluid circulation and structural system of Cerritos Colorados geothermal field in La Primavera volcanic caldera (Mexico) inferred from geophysical surveys

    Science.gov (United States)

    Bolós, X.; Cifuentes-Nava, G.; Macias, J. L.; Sosa-Ceballos, G.; García-Tenorio, F.; Albor, M., III; Juarez, M.; Gamez, V.

    2017-12-01

    Hydrothermal activity in volcanic calderas is the consequence of energy transfer between deep magmatic chambers and subsurface layers saturated in water. This hydrothermal system is generated by convection of the groundwater supplied by meteoric water recharged and the ascent of hot volcanic gasses exsolved from deep magma reservoirs. Calderas are heterogeneous geological structures that due to their formation and evolution produced a complex stratigraphy. All of these heterogeneities can be affected by deformation and also by the presence of fractures and faults which constitute the main pathways whereby hydrothermal fluids can move easily through the surface as spring discharges and fumarolic activity. Geophysical methods have been used in the last decades to investigate the relationship between structural geology and hydrothermal systems in different volcanic areas around the world. In this work, we have focused on the role of subsurface structures to understand and localize the pathways of fluids related to the hydrothermal system of the Cerritos Colorados geothermal field. We focused in the central area of the caldera (P12 well and Cerritos Colorados graben), where active hydrothermal activity is evidenced by fumaroles, thermal anomalies, CO2 diffuse emission, and sulfur precipitation. We have applied a self-potential method (SP) that combined with temperature measurements that allowed to identify the main infiltration and ascending fluid zones in the area, and their specific surface temperature coinciding with fumarolic activity. From this data we an applied Electrical Resistivity Tomography (ERT) survey in two selected places. One ERT profile (1.2 km in length) was located in the P12 well area. A 3D resistivity model used with the equatorial method was carried out on the Cerritos Colorados graben area. Combining the results of the SP, TºC, and ERT data with a detailed structural map we identified the main degassing zones (i.e. fumaroles) that correspond to

  18. Structural Characteristics of Nocturnal Mesoscale Convective Systems in the U.S. Great Plains as Observed During the PECAN Field Campaign

    Science.gov (United States)

    Bodine, D. J.; Dougherty, E.; Rasmussen, K. L.; Torres, A. D.

    2015-12-01

    During the summer in the U.S. Great Plains, some of the heaviest precipitation falls from large thunderstorm complexes known as Mesoscale Convective Systems (MCSs). These frequently occurring MCSs are often nocturnal in nature, so the dynamics associated with these systems are more elusive than those in the daytime. The Plains Elevated Convection at Night (PECAN) field campaign was launched over a 7-week period as an endeavor to better understand nocturnal MCSs occurring in the Great Plains. PECAN featured a dense array of ground-based and airborne instruments to observe nocturnal MCS, including dual-polarization radars at multiple frequencies, mobile mesonets, and sounding units. Our role in PECAN involved deploying Ott Parsivel disdrometers to gain information on drop size distributions (DSDs) and fall speeds. Analysis of disdrometer data in conjunction with radar data presented using Contour Frequency by Altitude Diagrams (CFADs) and high-resolution radiosonde data allows for a structural comparison of PECAN MCS cases to previously identified MCS archetypes. Novel insights into the structural evolution of nocturnal MCSs in relation to their synoptic, mesoscale, and thermodynamic environments are presented, using data collected from dense and numerous observation platforms. Understanding the environmental conditions that result in different nocturnal MCS configurations is useful for gaining insight into precipitation distributions and potential severe weather and flooding hazards in the Great Plains.

  19. The 2006 Eruption of Raoul Volcano (Kermadecs): A Phreato-magmatic Event From a Hydrothermally-Sealed Volcanic Conduit System.

    Science.gov (United States)

    Christenson, B. W.; Reyes, A. G.; Werner, C. A.

    2006-12-01

    The March 17, 2006 eruption from Raoul volcano (Kermadec Islands, NZ), which tragically claimed the life of NZ Department of Conservation staff member Mark Kearney, is being interpreted as a magmatic-hydrothermal event triggered by shaking associated with regional earthquake swarm activity. Although the eruption released ca. 200 T of SO2, thus confirming its magmatic nature, it occurred without significant precursory volcanic seismicity, and without any of the precursory responses of the volcanic hydrothermal system which were observed prior to the last eruption in 1964. Raoul Island has a long and varied eruption history dating back > 1.4 ma, and has been hydrothermally active throughout historic time. Present day fumarolic and hotspring discharges within Raoul caldera point to the existence of a small but well established, mixed meteoric - seawater hydrothermal system within the volcano. Magmatic signatures are apparent in fumarolic gas discharges, but are heavily masked by their interaction with hydrothermal system fluids (eg. near complete scrubbing of sulphur and halogen gases from the boiling point fumarolic discharges). A diffuse degassing study conducted in 2004 revealed that ca. 80 T/d CO2 is passively discharged from the volcano, suggesting that ongoing (albeit low level) convective degassing of magma occurs at depth. Interestingly, vent locations from the 2006 eruption correspond to areas of relatively low CO2 discharge on the crater floor in 2004. This, in conjunction with the preliminary findings of abundant hydrothermal mineralisation (calcite, anhydrite, quartz) in eruption ejecta, suggests that the main volcanic conduits had become effectively sealed during the interval since the last eruption. Calcite-hosted fluid inclusions are CO2 clathrate-bearing, and have relatively low homogenisation temperatures (165-180 °C), suggesting that the seal environment was both gas-charged and shallowly seated (< 200 m). Shaking associated with the regional

  20. Volcanic risk

    International Nuclear Information System (INIS)

    Rancon, J.P.; Baubron, J.C.

    1995-01-01

    This project follows the previous multi-disciplinary studies carried out by the French Bureau de Recherches Geologiques et Minieres (BRGM) on the two active volcanoes of the French lesser Antilles: Mt Pelee (Martinique) and Soufriere (Guadeloupe) for which geological maps and volcanic risk studies have been achieved. The research program comprises 5 parts: the study of pyroclastic deposits from recent eruptions of the two volcanoes for a better characterization of their eruptive phenomenology and a better definition of crisis scenarios; the study of deposits and structures of active volcanoes from Central America and the study of eruptive dynamics of andesite volcanoes for a transposition to Antilles' volcanoes; the starting of a methodological multi-disciplinary research (volcanology, geography, sociology...) on the volcanic risk analysis and on the management of a future crisis; and finally, the development of geochemical survey techniques (radon, CO 2 , H 2 O) on active volcanoes of Costa-Rica and Europe (Fournaise, Furnas, Etna) and their application to the Soufriere. (J.S.). 9 refs., 3 figs

  1. Volcanic eruption plumes on Io

    International Nuclear Information System (INIS)

    Strom, R.G.; Terrile, R.J.; Masursky, H.; Hansen, C.

    1979-01-01

    The detection of an umbrella-shaped plume extending about 280 km above the bright limb of Io was one of the most important discoveries made during the Voyager 1 encounter with the jovian system. This discovery proves that Io is volcanically active at present, and the number and magnitude of these eruptions indicate that Io is the most volcanically active body so far discovered in the Solar System. Preliminary analyses of these eruptive plumes are presented. (U.K.)

  2. Blind Geothermal System Exploration in Active Volcanic Environments; Multi-phase Geophysical and Geochemical Surveys in Overt and Subtle Volcanic Systems, Hawai’i and Maui

    Energy Technology Data Exchange (ETDEWEB)

    Fercho, Steven [Ormat Nevada, Inc., Reno, NV (United States); Owens, Lara [Ormat Nevada, Inc., Reno, NV (United States); Walsh, Patrick [Ormat Nevada, Inc., Reno, NV (United States); Drakos, Peter [Ormat Nevada, Inc., Reno, NV (United States); Martini, Brigette [Corescan Inc., Ascot (Australia); Lewicki, Jennifer L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kennedy, Burton M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-08-01

    Suites of new geophysical and geochemical exploration surveys were conducted to provide evidence for geothermal resource at the Haleakala Southwest Rift Zone (HSWRZ) on Maui Island, Hawai’i. Ground-based gravity (~400 stations) coupled with heli-bourne magnetics (~1500 line kilometers) define both deep and shallow fractures/faults, while also delineating potentially widespread subsurface hydrothermal alteration on the lower flanks (below approximately 1800 feet a.s.l.). Multi-level, upward continuation calculations and 2-D gravity and magnetic modeling provide information on source depths, but lack of lithologic information leaves ambiguity in the estimates. Additionally, several well-defined gravity lows (possibly vent zones) lie coincident with magnetic highs suggesting the presence of dike intrusions at depth which may represent a potentially young source of heat. Soil CO2 fluxes were measured along transects across geophysically-defined faults and fractures as well as young cinder cones along the HSWRZ. This survey generally did not detect CO2 levels above background, with the exception of a weak anomalous flux signal over one young cinder cone. The general lack of observed CO2 flux signals on the HSWRZ is likely due to a combination of lower magmatic CO2 fluxes and relatively high biogenic surface CO2 fluxes which mix with the magmatic signal. Similar surveys at the Puna geothermal field on the Kilauea Lower East Rift Zone (KLERZ) also showed a lack of surface CO2 flux signals, however aqueous geochemistry indicated contribution of magmatic CO2 and He to shallow groundwater here. As magma has been intercepted in geothermal drilling at the Puna field, the lack of measured surface CO2 flux indicative of upflow of magmatic fluids here is likely due to effective “scrubbing” by high groundwater and a mature hydrothermal system. Dissolved inorganic carbon (DIC) concentrations, δ13C compositions and 3He/4He values were sampled at Maui from several shallow

  3. Supervolcanoes within an ancient volcanic province in Arabia Terra, Mars.

    Science.gov (United States)

    Michalski, Joseph R; Bleacher, Jacob E

    2013-10-03

    Several irregularly shaped craters located within Arabia Terra, Mars, represent a new type of highland volcanic construct and together constitute a previously unrecognized Martian igneous province. Similar to terrestrial supervolcanoes, these low-relief paterae possess a range of geomorphic features related to structural collapse, effusive volcanism and explosive eruptions. Extruded lavas contributed to the formation of enigmatic highland ridged plains in Arabia Terra. Outgassed sulphur and erupted fine-grained pyroclastics from these calderas probably fed the formation of altered, layered sedimentary rocks and fretted terrain found throughout the equatorial region. The discovery of a new type of volcanic construct in the Arabia volcanic province fundamentally changes the picture of ancient volcanism and climate evolution on Mars. Other eroded topographic basins in the ancient Martian highlands that have been dismissed as degraded impact craters should be reconsidered as possible volcanic constructs formed in an early phase of widespread, disseminated magmatism on Mars.

  4. Distribution of Areal Strain on Mercury: Insights into the Interaction of Volcanism and Global Contraction

    Science.gov (United States)

    Peterson, G. A.; Johnson, C. L.; Byrne, P. K.; Phillips, R. J.

    2018-05-01

    Wrinkle ridges within volcanic plains on Mercury host just as much shortening strain as lobate scarps and high relief ridges, suggesting that wrinkle ridges have accommodated much more strain from global contraction than previously thought.

  5. Investigating Crustal Scale Fault Systems Controlling Volcanic and Hydrothermal Fluid Processes in the South-Central Andes, First Results from a Magnetotelluric Survey

    Science.gov (United States)

    Pearce, R.; Mitchell, T. M.; Moorkamp, M.; Araya, J.; Cembrano, J. M.; Yanez, G. A.; Hammond, J. O. S.

    2017-12-01

    At convergent plate boundaries, volcanic orogeny is largely controlled by major thrust fault systems that act as magmatic and hydrothermal fluid conduits through the crust. In the south-central Andes, the volcanically and seismically active Tinguiririca and Planchon-Peteroa volcanoes are considered to be tectonically related to the major El Fierro thrust fault system. These large scale reverse faults are characterized by 500 - 1000m wide hydrothermally altered fault cores, which possess a distinct conductive signature relative to surrounding lithology. In order to establish the subsurface architecture of these fault systems, such conductivity contrasts can be detected using the magnetotelluric method. In this study, LEMI fluxgate-magnetometer long-period and Metronix broadband MT data were collected at 21 sites in a 40km2 survey grid that surrounds this fault system and associated volcanic complexes. Multi-remote referencing techniques is used together with robust processing to obtain reliable impedance estimates between 100 Hz and 1,000s. Our preliminary inversion results provide evidence of structures within the 10 - 20 km depth range that are attributed to this fault system. Further inversions will be conducted to determine the approximate depth extent of these features, and ultimately provide constraints for future geophysical studies aimed to deduce the role of these faults in volcanic orogeny and hydrothermal fluid migration processes in this region of the Andes.

  6. Nitrous oxide emissions from a Northern Great Plains soil as influenced by nitrogen management and cropping systems.

    Science.gov (United States)

    Dusenbury, M P; Engel, R E; Miller, P R; Lemke, R L; Wallander, R

    2008-01-01

    Field measurements of N2O emissions from soils are limited for cropping systems in the semiarid northern Great Plains (NGP). The objectives were to develop N2O emission-time profiles for cropping systems in the semiarid NGP, define important periods of loss, determine the impact of best management practices on N2O losses, and estimate direct N fertilizer-induced emissions (FIE). No-till (NT) wheat (Triticum Aestivum L.)-fallow, wheat-wheat, and wheat-pea (Pisum sativum), and conventional till (CT) wheat-fallow, all with three N regimes (200 and 100 kg N ha(-1) available N, unfertilized control); plus a perennial grass-alfalfa (Medicago sativa L.) system were sampled over 2 yr using vented chambers. Cumulative 2-yr N2O emissions were modest in contrast to reports from more humid regions. Greatest N2O flux activity occurred following urea-N fertilization (10-wk) and during freeze-thaw cycles. Together these periods comprised up to 84% of the 2-yr total. Nitrification was probably the dominant process responsible for N2O emissions during the post-N fertilization period, while denitrification was more important during freeze-thaw cycles. Cumulative 2-yr N2O-N losses from fertilized regimes were greater for wheat-wheat (1.31 kg N ha(-1)) than wheat-fallow (CT and NT) (0.48 kg N ha(-1)), and wheat-pea (0.71 kg N ha(-1)) due to an additional N fertilization event. Cumulative losses from unfertilized cropping systems were not different from perennial grass-alfalfa (0.28 kg N ha(-1)). Tillage did not affect N2O losses for the wheat-fallow systems. Mean FIE level was equivalent to 0.26% of applied N, and considerably below the Intergovernmental Panel on Climate Change mean default value (1.25%).

  7. Seismically active column and volcanic plumbing system beneath the island arc of the Izu-Bonin subduction zone

    Science.gov (United States)

    Špičák, Aleš; Vaněk, Jiří; Hanuš, Václav

    2009-12-01

    A detailed spatio-temporal analysis of teleseismic earthquake occurrence (mb > 4.0) along the convergent margin of the Izu-Bonin-Mariana arc system reveals an anomalously high concentration of events between 27° and 30.5°N, beneath a chain of seamounts between Tori-shima and Nishino-shima volcanoes. This seismicity is dominated by the 1985/1986 earthquake swarm represented in the Engdahl-van der Hilst-Buland database by 146 earthquakes in the body wave magnitude range 4.3-5.8 and focal depth range 1-100 km. The epicentral cluster of the swarm is elongated parallel to the volcanic chain. Available focal mechanisms are consistent with an extensional tectonic regime and reveal nodal planes with azimuths close to that of the epicentral cluster. Earthquakes of the 1985/1986 swarm occurred in seven time phases. Seismic activity migrated in space from one phase to the other. Earthquake foci belonging to individual phases of the swarm aligned in vertically disposed seismically active columns. The epicentral zones of the columns are located in the immediate vicinity of seamounts Suiyo and Mokuyo, recently reported by the Japanese Meteorological Agency as volcanically active. The three observations-episodic character of earthquake occurrence, column-like vertically arranged seismicity pattern, and existence of volcanic seamounts at the seafloor above the earthquake foci-led us to interpret the 1985/1986 swarm as a consequence of subduction-related magmatic and/or fluid activity. A modification of the shallow earthquake swarm magmatic model of D. Hill fits earthquake foci distribution, tectonic stress orientation and fault plane solutions. The 1985/1986 deep-rooted earthquake swarm in the Izu-Bonin region represents an uncommon phenomenon of plate tectonics. The portion of the lithospheric wedge that was affected by the swarm should be composed of fractured rigid, brittle material so that the source of magma and/or fluids which might induce the swarm should be situated at a

  8. Cropping Systems Dynamics in the Lower Gangetic Plains of India using Geospatial Technologies

    Directory of Open Access Journals (Sweden)

    K. R. Manjunath

    2012-08-01

    Full Text Available Cropping system study is useful to understand the overall sustainability of agricultural system. Capturing the change dynamics of cropping systems, especially spatial and temporal aspects, is of utmost importance in overall planning and management of natural resources. This paper highlights the remote sensing based cropping systems change-dynamics assessment. Current study is aimed at use of multidate-multisensor data for deriving the seasonal cropping pattern maps and deriving the remote sensing based cropping system performance indicators during 1998–99 and 2004–05 in West- Bengal state of India. The temporal assessment of the changes of cropping systems components such as cropping pattern and indices for the study years 1998–99 and 2004–05 have been brought out. The results indicate that during the six years of time the kharif cropping pattern has almost remained the same, being a rice dominant system. A notable point is the decrease in the aus rice due to readjusting the cropping system practice to suit the two crop systems in many places was observed. Marginal variations in mustard and wheat areas during rabi season was observed. The boro (summer rice area has almost remained constant. The rice-fallow-fallow (R-F-F rotation reduced by about 4 percent while the rice-fallow-rice (R-F-R increased by about 7 percent percent. The Area Diversity Index reduced by about 38 percent in 2004 which may be attributed to decrease in kharif pulses and minor crops during kharif and summer. However, diversity during rabi season continued to remain high. The increase in Multiple Cropping Index was observed predominantly in the southern part of the state. Cultivated Land Utilization Index shows an increase by about 0.05.

  9. Evaluation of the North American Land Data Assimilation System over the southern Great Plains during the warm season

    Science.gov (United States)

    Robock, Alan; Luo, Lifeng; Wood, Eric F.; Wen, Fenghua; Mitchell, Kenneth E.; Houser, Paul R.; Schaake, John C.; Lohmann, Dag; Cosgrove, Brian; Sheffield, Justin; Duan, Qingyun; Higgins, R. Wayne; Pinker, Rachel T.; Tarpley, J. Dan; Basara, Jeffery B.; Crawford, Kenneth C.

    2003-11-01

    North American Land Data Assimilation System (NLDAS) land surface models have been run for a retrospective period forced by atmospheric observations from the Eta analysis and actual precipitation and downward solar radiation to calculate land hydrology. We evaluated these simulations using in situ observations over the southern Great Plains for the periods of May-September of 1998 and 1999 by comparing the model outputs with surface latent, sensible, and ground heat fluxes at 24 Atmospheric Radiation Measurement/Cloud and Radiation Testbed stations and with soil temperature and soil moisture observations at 72 Oklahoma Mesonet stations. The standard NLDAS models do a fairly good job but with differences in the surface energy partition and in soil moisture between models and observations and among models during the summer, while they agree quite well on the soil temperature simulations. To investigate why, we performed a series of experiments accounting for differences between model-specified soil types and vegetation and those observed at the stations, and differences in model treatment of different soil types, vegetation properties, canopy resistance, soil column depth, rooting depth, root density, snow-free albedo, infiltration, aerodynamic resistance, and soil thermal diffusivity. The diagnosis and model enhancements demonstrate how the models can be improved so that they can be used in actual data assimilation mode.

  10. A conceptual framework and monitoring strategy for movement of saltwater in the coastal plain aquifer system of Virginia

    Science.gov (United States)

    Mcfarland, E. Randolph

    2015-09-04

    A conceptual framework synthesizes previous studies to provide an understanding of conditions, processes, and relations of saltwater to groundwater withdrawal in the Virginia Coastal Plain aquifer system. A strategy for monitoring saltwater movement is based on spatial relations between the saltwater-transition zone and 612 groundwater-production wells that were regulated during 2013 by the Virginia Department of Environmental Quality. The vertical position and lateral distance and direction of the bottom of each production well’s screened interval was calculated relative to previously published groundwater chloride iso-concentration surfaces. Spatial analysis identified 81 production wells completed in the Yorktown-Eastover and Potomac aquifers that are positioned in closest proximity to the 250-milligrams-per-liter chloride surface, and from which chloride concentrations are most likely to increase above the U.S. Environmental Protection Agency’s 250-milligrams-per-liter secondary maximum-contaminant level. Observation wells are specified to distinguish vertical upconing from lateral intrusion among individual production wells. To monitor upconing, an observation well is to be collocated with each production well and completed at about the altitude of the 250-milligrams-per-liter chloride iso-concentration surface. To monitor lateral intrusion, a potential location of an observation well is projected from the bottom of each production well’s screened interval, in the lateral direction to the underlying chloride surface to a distance of 1 mile.

  11. Expansionary Adaptive Transformations of Socio-Hydrological Systems (SHSs): The Case of Drought in Messara Plain, Crete, Greece.

    Science.gov (United States)

    Sapountzaki, Kalliopi; Daskalakis, Ioannis

    2018-05-01

    The paper attempts to document the ontology of socio-hydrological systems (SHSs), propose approaches of delimitation of SHSs' (territorial) boundaries, and investigate operational aspects of their adaptation to drought including repercussions on sustainability. To this end, a series of hypotheses are tested: (a) SHSs contain social subsystems with different expectations regarding water resources, different adaptive capacities, adaptation limits and prospects of sustainability, (b) SHSs do not adapt homogenously; some of their subsystems manage optimum adaptation, others fail to adapt and (c) territorial transformation of SHSs (e.g., through expansion of SHSs) may be the result of differential adaptation and sustainability potential within the SHS owing to power relations. After testing above hypotheses in the SHS of Messara Plain, Crete, the authors found out that powerful and dynamic sub-SHSs expand or break the boundaries of the initial SHS by establishing new relationships with other SHSs for the sake of resilience resources. Conversely, powerless sub-SHSs incapable to adapt descend and disappear. Therefore, territorial transformation of SHSs comes about from a combination of successful and failed adaptations, or in other words from different adaptation limits within SHSs. Consequently, water management and local development planning to guarantee adaptability to drought for all should be based on SHSs' analysis and management, not on jurisdictional areas or hydrological basins.

  12. ANG coal gasification project management control system report. [Great Plains project

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Much time, money and effort has been spent in the forefront of this project for project controls. The work breakdown structure for the systems has been custom designed. The systems, both manual and computerized, have been well scrutinized and chosen by ANG to represent the most cost effective and efficient way of controlling a project the magnitude of $1.5 billion. These systems have been developed in a manner so that information can be gathered as detailed or as summarized as necessary, and in the most timely and expeditious ways.

  13. The questa magmatic system: Petrologic, chemical and isotopic variations in cogenetic volcanic and plutonic rocks of the latir volcanic field and associated intrusives, northern New Mexico

    International Nuclear Information System (INIS)

    Johnson, C.M.

    1986-01-01

    Field, chemical and isotopic data demonstrate that nearly all igneous rocks at Questa resulted from interactions between mantle-derived parental magmas and the crust. Strontium, neodymium and lead isotope ratios of early andesites to rhyolites (28 to 26 Ma) indicate that these magmas assimilated > 25% lower crust. Injection of basaltic magmas extensively modified the strontium and neodymium but not the lead isotope compositions of the lower crust. Eruption of comendite magmas and the peralkaline Amalia Tuff 26 Ma is correlated with inception of regional extension. Lead isotope ratios identify different sources for the metaluminous granites and the peralkaline rocks. 26 Ma metaluminous granite to granodiorite intrusions have chemical and isotopic compositions to those of the precaldera intermediate-composition rocks, and are interpreted as representing the solidified equivalents of the precaldera magmatic episode. However, both conventional and ion-microprobe isotopic data prohibit significant assimilation of crustal rocks at the level of exposure, suggesting that the plutons were emplaced a relatively crystal-rich mushes which did not have sufficient heat to assimilate country rocks. This suggest that in some cases plutonic rocks are better than volcanic rocks in representing the isotopic compositions of their source regions, because the assimilation potential of crystal-rich magmas is significantly less than that of largely liquid magmas

  14. Rock–water interactions and pollution processes in the volcanic aquifer system of Guadalajara, Mexico, using inverse geochemical modeling

    International Nuclear Information System (INIS)

    Morán-Ramírez, J.; Ledesma-Ruiz, R.; Mahlknecht, J.; Ramos-Leal, J.A.

    2016-01-01

    In order to understand and mitigate the deterioration of water quality in the aquifer system underlying Guadalajara metropolitan area, an investigation was performed developing geochemical evolution models for assessment of groundwater chemical processes. The models helped not only to conceptualize the groundwater geochemistry, but also to evaluate the relative influence of anthropogenic inputs and natural sources of salinity to the groundwater. Mixing processes, ion exchange, water–rock–water interactions and nitrate pollution and denitrification were identified and confirmed using mass-balance models constraint by information on hydrogeology, groundwater chemistry, lithology and stability of geochemical phases. The water–rock interactions in the volcanic setting produced a dominant Na−HCO_3 water type, followed by Na−Mg−Ca−HCO_3 and Na−Ca−HCO_3. For geochemical evolution modeling, flow sections were selected representing recharge and non-recharge processes and a variety of mixing conditions. Recharge processes are dominated by dissolution of soil CO_2 gas, calcite, gypsum, albite and biotite, and Ca/Na exchange. Non-recharge processes show that the production of carbonic acid and Ca/Na exchange are decreasing, while other minerals such as halite and amorphous SiO_2 are precipitated. The origin of nitrate pollution in groundwater are fertilizers in rural plots and wastewater and waste disposal in the urban area. This investigation may help water authorities to adequately address and manage groundwater contamination. - Highlights: • The Inverse geochemical modeling was used to study to processes occurring in a volcanic aquifer. • Three flow sections were selected to apply inverse hydrogeochemical modeling. • Three main groundwater flows were identified: a local, intermediate and regional flow. • The models show that in the study area that groundwater is mixed with local recharge. • In the south, the aquifer has thermal influence.

  15. Geothermal Alteration of Basaltic Core from the Snake River Plain, Idaho

    OpenAIRE

    Sant, Christopher Joseph

    2012-01-01

    The Snake River Plain is located in the southern part of the state of Idaho. The eastern plain, on which this study focuses, is a trail of volcanics from the Yellowstone hotspot. Three exploratory geothermal wells were drilled on the Snake River Plain. This project analyzes basaltic core from the first well at Kimama, north of Burley, Idaho. The objectives of this project are to establish zones of geothermal alteration and analyze the potential for geothermal power production using sub-aquife...

  16. Constraints of texture and composition of clinopyroxene phenocrysts of Holocene volcanic rocks on a magmatic plumbing system beneath Tengchong, SW China

    Science.gov (United States)

    Hu, Jun-Hao; Song, Xie-Yan; He, Hai-Long; Zheng, Wen-Qin; Yu, Song-Yue; Chen, Lie-Meng; Lai, Chun-Kit

    2018-04-01

    Understanding processes of magma replenishment in a magma plumbing system is essential to predict eruption potential of a dormant volcano. In this study, we present new petrologic and thermobarometric data for youngest lava flows from the Holocene Heikongshan volcano in the Tengchong area, SW China. Clinopyroxene phenocrysts from the trachytic lava flows display various textural/compositional zoning styles (i.e., normal, reverse and oscillatory). Such zoning patterns are indicative of an open magmatic plumbing system with multiphase magma replenishment and mixing, which were likely a key drive of the volcanic eruptions. Thermobarometric calculations of these zoned clinopyroxene phenocrysts yield crystallization pressures of 3.8-7.1 kbar (peak at 4.5-7.0 kbar), corresponding to a magma chamber at depths of 14-21 km. The calculated depths are consistent with the large low-resistivity body at 12-30 km beneath the Heikongshan volcano, implying that the magmatic plumbing system may still be active. Recent earthquakes in the Tengchong area suggest that the regional strike-slip faulting are still active, and may trigger future volcanic eruptions if the magma chamber(s) beneath the Tengchong volcanic field is disturbed, in spite of the volcanic quiescence since 1609 CE.

  17. Productivity and sustainability of rainfed wheat-soybean system in the North China Plain

    NARCIS (Netherlands)

    Qin, Wei; Wang, Daozhong; Guo, Xisheng; Yang, Taiming; Oenema, Oene

    2015-01-01

    A quantitative understanding of yield response to water and nutrients is key to improving the productivity and sustainability of rainfed cropping systems. Here, we quantified the effects of rainfall, fertilization (NPK) and soil organic amendments (with straw and manure) on yields of a rainfed

  18. Lidar sounding of volcanic plumes

    Science.gov (United States)

    Fiorani, Luca; Aiuppa, Alessandro; Angelini, Federico; Borelli, Rodolfo; Del Franco, Mario; Murra, Daniele; Pistilli, Marco; Puiu, Adriana; Santoro, Simone

    2013-10-01

    Accurate knowledge of gas composition in volcanic plumes has high scientific and societal value. On the one hand, it gives information on the geophysical processes taking place inside volcanos; on the other hand, it provides alert on possible eruptions. For this reasons, it has been suggested to monitor volcanic plumes by lidar. In particular, one of the aims of the FP7 ERC project BRIDGE is the measurement of CO2 concentration in volcanic gases by differential absorption lidar. This is a very challenging task due to the harsh environment, the narrowness and weakness of the CO2 absorption lines and the difficulty to procure a suitable laser source. This paper, after a review on remote sensing of volcanic plumes, reports on the current progress of the lidar system.

  19. Seasonal variability of the inorganic carbon system in a large coastal plain estuary

    Science.gov (United States)

    Joesoef, Andrew; Kirchman, David L.; Sommerfield, Christopher K.; Cai, Wei-Jun

    2017-11-01

    Carbonate geochemistry research in large estuarine systems is limited. More work is needed to understand how changes in land-use activity influence watershed export of organic and inorganic carbon, acids, and nutrients to the coastal ocean. To investigate the seasonal variation of the inorganic carbon system in the Delaware Estuary, one of the largest estuaries along the US east coast, dissolved inorganic carbon (DIC), total alkalinity (TA), and pH were measured along the estuary from June 2013 to April 2015. In addition, DIC, TA, and pH were periodically measured from March to October 2015 in the nontidal freshwater Delaware, Schuylkill, and Christina rivers over a range of discharge conditions. There were strong negative relationships between river TA and discharge, suggesting that changes in HCO3- concentrations reflect dilution of weathering products in the drainage basin. The ratio of DIC to TA, an understudied but important property, was high (1.11) during high discharge and low (0.94) during low discharge, reflecting additional DIC input in the form of carbon dioxide (CO2), most likely from terrestrial organic matter decomposition, rather than bicarbonate (HCO3-) inputs due to drainage basin weathering processes. This is also a result of CO2 loss to the atmosphere due to rapid water transit during the wet season. Our data further show that elevated DIC in the Schuylkill River is substantially different than that in the Delaware River. Thus, tributary contributions must be considered when attributing estuarine DIC sources to the internal carbon cycle versus external processes such as drainage basin mineralogy, weathering intensity, and discharge patterns. Long-term records in the Delaware and Schuylkill rivers indicate shifts toward higher alkalinity in estuarine waters over time, as has been found in other estuaries worldwide. Annual DIC input flux to the estuary and export flux to the coastal ocean are estimated to be 15.7 ± 8.2 × 109 mol C yr-1 and 16

  20. In situ Volcanic Plume Monitoring with small Unmanned Aerial Systems for Cal/Val of Satellite Remote Sensing Data: CARTA-UAV 2013 Mission (Invited)

    Science.gov (United States)

    Diaz, J. A.; Pieri, D. C.; Bland, G.; Fladeland, M. M.

    2013-12-01

    The development of small unmanned aerial systems (sUAS) with a variety of sensor packages, enables in situ and proximal remote sensing measurements of volcanic plumes. Using Costa Rican volcanoes as a Natural Laboratory, the University of Costa Rica as host institution, in collaboration with four NASA centers, have started an initiative to develop low-cost, field-deployable airborne platforms to perform volcanic gas & ash plume research, and in-situ volcanic monitoring in general, in conjunction with orbital assets and state-of-the-art models of plume transport and composition. Several gas sensors have been deployed into the active plume of Turrialba Volcano including a miniature mass spectrometer, and an electrochemical SO2 sensor system with temperature, pressure, relative humidity, and GPS sensors. Several different airborne platforms such as manned research aircraft, unmanned aerial vehicles, tethered balloons, as well as man-portable in-situ ground truth systems are being used for this research. Remote sensing data is also collected from the ASTER and OMI spaceborne instruments and compared with in situ data. The CARTA-UAV 2013 Mission deployment and follow up measurements successfully demonstrated a path to study and visualize gaseous volcanic emissions using mass spectrometer and gas sensor based instrumentation in harsh environment conditions to correlate in situ ground/airborne data with remote sensing satellite data for calibration and validation purposes. The deployment of such technology improves on our current capabilities to detect, analyze, monitor, model, and predict hazards presented to aircraft by volcanogenic ash clouds from active and impending volcanic eruptions.

  1. Seasonal variability of the inorganic carbon system in a large coastal plain estuary

    Directory of Open Access Journals (Sweden)

    A. Joesoef

    2017-11-01

    Full Text Available Carbonate geochemistry research in large estuarine systems is limited. More work is needed to understand how changes in land-use activity influence watershed export of organic and inorganic carbon, acids, and nutrients to the coastal ocean. To investigate the seasonal variation of the inorganic carbon system in the Delaware Estuary, one of the largest estuaries along the US east coast, dissolved inorganic carbon (DIC, total alkalinity (TA, and pH were measured along the estuary from June 2013 to April 2015. In addition, DIC, TA, and pH were periodically measured from March to October 2015 in the nontidal freshwater Delaware, Schuylkill, and Christina rivers over a range of discharge conditions. There were strong negative relationships between river TA and discharge, suggesting that changes in HCO3− concentrations reflect dilution of weathering products in the drainage basin. The ratio of DIC to TA, an understudied but important property, was high (1.11 during high discharge and low (0.94 during low discharge, reflecting additional DIC input in the form of carbon dioxide (CO2, most likely from terrestrial organic matter decomposition, rather than bicarbonate (HCO3− inputs due to drainage basin weathering processes. This is also a result of CO2 loss to the atmosphere due to rapid water transit during the wet season. Our data further show that elevated DIC in the Schuylkill River is substantially different than that in the Delaware River. Thus, tributary contributions must be considered when attributing estuarine DIC sources to the internal carbon cycle versus external processes such as drainage basin mineralogy, weathering intensity, and discharge patterns. Long-term records in the Delaware and Schuylkill rivers indicate shifts toward higher alkalinity in estuarine waters over time, as has been found in other estuaries worldwide. Annual DIC input flux to the estuary and export flux to the coastal ocean are estimated to be 15.7 ± 8.2

  2. HIDING IN PLAIN SIGHT: RECORD-BREAKING COMPACT STELLAR SYSTEMS IN THE SLOAN DIGITAL SKY SURVEY

    International Nuclear Information System (INIS)

    Sandoval, Michael A.; Vo, Richard P.; Romanowsky, Aaron J.; Strader, Jay; Choi, Jieun; Conroy, Charlie; Jennings, Zachary G.; Villaume, Alexa; Brodie, Jean P.; Foster, Caroline; Norris, Mark A.; Janz, Joachim; Forbes, Duncan A.

    2015-01-01

    Motivated by the recent, serendipitous discovery of the densest known galaxy, M60-UCD1, we present two initial findings from a follow-up search, using the Sloan Digital Sky Survey, Subaru/Suprime-Cam, and Hubble Space Telescope imaging, and SOuthern Astrophysical Research (SOAR)/Goodman spectroscopy. The first object discovered, M59-UCD3, has a similar size to M60-UCD1 (half-light radius of r h ∼ 20 pc) but is 40% more luminous (M V ∼ −14.6), making it the new densest-known galaxy. The second, M85-HCC1, has a size like a typical globular cluster (GC; r h ∼ 1.8 pc) but is much more luminous (M V ∼ −12.5). This hypercompact cluster is by far the densest confirmed free-floating stellar system, and is equivalent to the densest known nuclear star clusters. From spectroscopy, we find that both objects are relatively young (∼9 and ∼3 Gyr, respectively), with metal-abundances that resemble those of galaxy centers. Their host galaxies show clear signs of large-scale disturbances, and we conclude that these dense objects are the remnant nuclei of recently accreted galaxies. M59-UCD3 is an ideal target for follow-up with high-resolution imaging and spectroscopy to search for an overweight central supermassive black hole as was discovered in M60-UCD1. These findings also emphasize the potential value of ultra-compact dwarfs and massive GCs as tracers of the assembly histories of galaxies

  3. HIDING IN PLAIN SIGHT: RECORD-BREAKING COMPACT STELLAR SYSTEMS IN THE SLOAN DIGITAL SKY SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, Michael A.; Vo, Richard P.; Romanowsky, Aaron J. [Department of Physics and Astronomy, San José State University, One Washington Square, San Jose, CA 95192 (United States); Strader, Jay [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Choi, Jieun; Conroy, Charlie [Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Jennings, Zachary G.; Villaume, Alexa [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Brodie, Jean P. [University of California Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States); Foster, Caroline [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); Norris, Mark A. [Max Planck Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Janz, Joachim; Forbes, Duncan A. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia)

    2015-07-20

    Motivated by the recent, serendipitous discovery of the densest known galaxy, M60-UCD1, we present two initial findings from a follow-up search, using the Sloan Digital Sky Survey, Subaru/Suprime-Cam, and Hubble Space Telescope imaging, and SOuthern Astrophysical Research (SOAR)/Goodman spectroscopy. The first object discovered, M59-UCD3, has a similar size to M60-UCD1 (half-light radius of r{sub h} ∼ 20 pc) but is 40% more luminous (M{sub V} ∼ −14.6), making it the new densest-known galaxy. The second, M85-HCC1, has a size like a typical globular cluster (GC; r{sub h} ∼ 1.8 pc) but is much more luminous (M{sub V} ∼ −12.5). This hypercompact cluster is by far the densest confirmed free-floating stellar system, and is equivalent to the densest known nuclear star clusters. From spectroscopy, we find that both objects are relatively young (∼9 and ∼3 Gyr, respectively), with metal-abundances that resemble those of galaxy centers. Their host galaxies show clear signs of large-scale disturbances, and we conclude that these dense objects are the remnant nuclei of recently accreted galaxies. M59-UCD3 is an ideal target for follow-up with high-resolution imaging and spectroscopy to search for an overweight central supermassive black hole as was discovered in M60-UCD1. These findings also emphasize the potential value of ultra-compact dwarfs and massive GCs as tracers of the assembly histories of galaxies.

  4. Multitasking in academia: Effective combinations of research, education and public outreach illustrated by a volcanic ash warning system

    Science.gov (United States)

    Bye, B. L.; Plag, H.

    2011-12-01

    Science permeates our society. Its role and its perceived importance evolves with time. Scientists today are highly specialized, yet society demands they master a variety of skills requiring not only a number of different competencies but also a broad mindset. Scientists are subjected to a meritocracy in terms of having to produce scientific papers. Peer-reviewed scientific publications used to be sufficient to meet the various laws and regulations with respect to dissemination of scientific results. This has dramatically changed; both expressed directly through public voices (such as in the climate change discourses), but also by politicians and policy makers. In some countries research funding now comes with specific requirements concerning public outreach that go way beyond peer-reviewed publications and presentation at scientific conferences. Science policies encourage multidisciplinary cooperation and scientific questions themselves often cannot be answered without knowledge and information from several scientific areas. Scientists increasingly need to communicate knowledge and results in more general terms as well as educating future generations. A huge challenge lies in developing the knowledge, human capacity and mindset that will allow an individual academician to contribute to education, communicate across scientific fields and sectors in multidisciplinary cross sectoral cooperations and also reach out to the general public while succeeding within the scientific meritocracy. We demonstrate how research, education and communication within and outside academia can effectively be combined through a presentation of the International Airways Volcano Watch that encompasses an operational volcanic ash warning system for the aviation industry. This presentation will show the role of science throughout the information flow, from basic science to the pilots' decision-making. Furthermore, it will illustrate how one can connect specific scientific topics to societal

  5. Carbon dioxide diffuse emission and thermal energy release from hydrothermal systems at Copahue-Caviahue Volcanic Complex (Argentina)

    Science.gov (United States)

    Chiodini, Giovanni; Cardellini, Carlo; Lamberti, María Clara; Agusto, Mariano; Caselli, Alberto; Liccioli, Caterina; Tamburello, Giancarlo; Tassi, Franco; Vaselli, Orlando; Caliro, Stefano

    2015-10-01

    The north-western sector of Caviahue caldera (Argentina), close to the active volcanic system of Copahue, is characterized by the presence of several hydrothermal sites that host numerous fumarolic emissions, anomalous soil diffuse degassing of CO2 and hot soils. In March 2014, measurements of soil CO2 fluxes in 5 of these sites (namely, Las Máquinas, Las Maquinitas I, Las Maquinitas II, Anfiteatro, and Termas de Copahue) allowed an estimation that 165 t of deeply derived CO2 is daily released. The gas source is likely related to a relatively shallow geothermal reservoir containing a single vapor phase as also suggested by both the geochemical data from the 3 deep wells drilled in the 1980s and gas geoindicators applied to the fumarolic discharges. Gas equilibria within the H-C-O gas system indicate the presence of a large, probably unique, single phase vapor zone at 200-210 °C feeding the hydrothermal manifestations of Las Máquinas, Las Maquinitas I and II and Termas de Copahue. A natural thermal release of 107 MW was computed by using CO2 as a tracer of the original vapor phase. The magmatic signature of the incondensable fumarolic gases, the wide expanse of the hydrothermal areas and the remarkable high amount of gas and heat released by fluid expulsion seem to be compatible with an active magmatic intrusion beneath this portion of the Caviahue caldera.

  6. The structure environment, rock-magma system, mineral-forming series and pattern of volcanic mineral-forming of uranium deposit in southeast of China

    International Nuclear Information System (INIS)

    Yu Dagan

    1992-01-01

    The Volcanic uranium deposit of rock-magma belt-the Mid-Cz Volcano in the Southeast of China mainly formed around 120 ∼ 130 Ma and 90 ∼ 100 Ma Which is in harmony with the two rock magma activities of k within the region. The rock-magma system of this period formed around the turning period from pressure to tension in the continent margin of southeast China, which is mainly characterized by the appearance of A-type granite and alkaline, sub-alkaline rocks (trachyte, trachyandensite, trachybasalt, basic rock alkaline basalt). The uranium deposit is controlled by the base rift of dissection to the mantle, the volcanic basin is of the double characteristics of transversal rift valley basin (early period) ad tension rift valley basin (laster period). The leading role of the deep source is stressed in terms of internal-forming series of volcanic uranium deposits is considered to exist; and also in terms of internal-forming series of volcanic uranium deposits is considered to exist; and also in terms of mineral-forming patterns, the multi-pattern led by the deep-source is stressed, including the mineral-forming pattern of uranium deposit of continental thermos, repeated periphery mineral-forming pattern of uranium deposit and the mineral-forming pattern of uranium deposit of rising pole-like thermos. Ten suggestions are put forward to the next mineral-search according to the above thoughts

  7. Seismic evidence for arc segmentation, active magmatic intrusions and syn-rift fault system in the northern Ryukyu volcanic arc

    Science.gov (United States)

    Arai, Ryuta; Kodaira, Shuichi; Takahashi, Tsutomu; Miura, Seiichi; Kaneda, Yoshiyuki

    2018-04-01

    Tectonic and volcanic structures of the northern Ryukyu arc are investigated on the basis of multichannel seismic (MCS) reflection data. The study area forms an active volcanic front in parallel to the non-volcanic island chain in the eastern margin of the Eurasian plate and has been undergoing regional extension on its back-arc side. We carried out a MCS reflection experiment along two across-arc lines, and one of the profiles was laid out across the Tokara Channel, a linear bathymetric depression which demarcates the northern and central Ryukyu arcs. The reflection image reveals that beneath this topographic valley there exists a 3-km-deep sedimentary basin atop the arc crust, suggesting that the arc segment boundary was formed by rapid and focused subsidence of the arc crust driven by the arc-parallel extension. Around the volcanic front, magmatic conduits represented by tubular transparent bodies in the reflection images are well developed within the shallow sediments and some of them are accompanied by small fragments of dipping seismic reflectors indicating intruded sills at their bottoms. The spatial distribution of the conduits may suggest that the arc volcanism has multiple active outlets on the seafloor which bifurcate at crustal depths and/or that the location of the volcanic front has been migrating trenchward over time. Further distant from the volcanic front toward the back-arc (> 30 km away), these volcanic features vanish, and alternatively wide rift basins become predominant where rapid transitions from normal-fault-dominant regions to strike-slip-fault-dominant regions occur. This spatial variation in faulting patterns indicates complex stress regimes associated with arc/back-arc rifting in the northern Okinawa Trough.[Figure not available: see fulltext.

  8. A volcanic activity alert-level system for aviation: review of its development and application in Alaska

    Science.gov (United States)

    Guffanti, Marianne; Miller, Thomas P.

    2013-01-01

    An alert-level system for communicating volcano hazard information to the aviation industry was devised by the Alaska Volcano Observatory (AVO) during the 1989–1990 eruption of Redoubt Volcano. The system uses a simple, color-coded ranking that focuses on volcanic ash emissions: Green—normal background; Yellow—signs of unrest; Orange—precursory unrest or minor ash eruption; Red—major ash eruption imminent or underway. The color code has been successfully applied on a regional scale in Alaska for a sustained period. During 2002–2011, elevated color codes were assigned by AVO to 13 volcanoes, eight of which erupted; for that decade, one or more Alaskan volcanoes were at Yellow on 67 % of days and at Orange or Red on 12 % of days. As evidence of its utility, the color code system is integrated into procedures of agencies responsible for air-traffic management and aviation meteorology in Alaska. Furthermore, it is endorsed as a key part of globally coordinated protocols established by the International Civil Aviation Organization to provide warnings of ash hazards to aviation worldwide. The color code and accompanying structured message (called a Volcano Observatory Notice for Aviation) comprise an effective early-warning message system according to the United Nations International Strategy for Disaster Reduction. The aviation color code system currently is used in the United States, Russia, New Zealand, Iceland, and partially in the Philippines, Papua New Guinea, and Indonesia. Although there are some barriers to implementation, with continued education and outreach to Volcano Observatories worldwide, greater use of the aviation color code system is achievable.

  9. Diffuse H_{2} emission: a useful geochemical tool to monitor the volcanic activity at El Hierro volcano system

    Science.gov (United States)

    Pérez, Nemesio M.; Melián, Gladys; González-Santana, Judit; Barrancos, José; Padilla, Germán; Rodríguez, Fátima; Padrón, Eleazar; Hernández, Pedro A.

    2016-04-01

    The occurrence of interfering processes affecting reactive gases as CO2 during its ascent from magmatic bodies or hydrothermal systems toward the surface environment hinders the interpretation of their enrichments in the soil atmosphere and fluxes for volcano monitoring purposes (Marini and Gambardella, 2005). These processes include gas scrubbing by ground-waters and interaction with rocks, decarbonatation processes, biogenic production, etc. Within the rest of the soil gases, particularly interest has been addressed to light and highly mobile gases. They offer important advantages for the detection of vertical permeability structures, because their interaction with the surrounding rocks or fluids during the ascent toward the surface is minimum. H2 is one of the most abundant trace species in volcano-hydrothermal systems and is a key participant in many redox reactions occurring in the hydrothermal reservoir gas (Giggenbach, 1987). Although H2 can be produced in soils by N2-fixing and fertilizing bacteria, soils are considered nowadays as sinks of molecular hydrogen (Smith-Downey et al., 2006). Because of its chemical and physical characteristics, H2 generated within the crust moves rapidly and escapes to the atmosphere. These characteristics make H2 one of the best geochemical indicators of magmatic and geothermal activity at depth. El Hierro is the youngest and the SW-most of the Canary Islands and the scenario of the last volcanic eruption of the archipelago, a submarine eruption that took place 2 km off the southern coast of the island from October 2011 to March 2012. Since at El Hierro Island there are not any surface geothermal manifestations (fumaroles, etc), we have focused our studies on soil degassing surveys. Here we show the results of soil H2 emission surveys that have been carried out regularly since mid-2012. Soil gas samples were collected in ˜600 sites selected based on their accessibility and geological criteria. Soil gases were sampled at ˜40

  10. Lunar cryptomaria: Physical characteristics, distribution, and implications for ancient volcanism

    Science.gov (United States)

    Whitten, Jennifer L.; Head, James W.

    2015-02-01

    Cryptomaria, lunar volcanic deposits obscured by crater and basin impact ejecta, can provide important information about the thermal and volcanic history of the Moon. The timing of cryptomare deposition has implications for the duration and flux of mare basalt volcanism. In addition, knowing the distribution of cryptomaria can provide information about mantle convection and lunar magma ocean solidification. Here we use multiple datasets (e.g., M3, LOLA, LROC, Diviner) to undertake a global analysis to identify the general characteristics (e.g., topography, surface roughness, rock abundance, albedo, etc.) of lunar light plains in order to better distinguish between ancient volcanic deposits (cryptomaria) and impact basin and crater ejecta deposits. We find 20 discrete regions of cryptomaria, covering approximately 2% of the Moon, which increase the total area covered by mare volcanism to 18% of the lunar surface. Comparisons of light plains deposits indicate that the two deposit types (volcanic and impact-produced) are best distinguished by mineralogic data. On the basis of cryptomaria locations, the distribution of mare volcanism does not appear to have changed in the time prior to its exposed mare basalt distribution. There are several hypotheses explaining the distribution of mare basalts, which include the influence of crustal thickness, mantle convection patterns, asymmetric distribution of source regions, KREEP distribution, and the influence of a proposed Procellarum impact basin. The paucity of farside mare basalts means that multiple factors, such as crustal thickness variations and mantle convection, are likely to play a role in mare basalt emplacement.

  11. The Geothermal Systems along the Watukosek fault system (East Java, Indonesia):The Arjuno-Welirang Volcanic Complex and the Lusi Mud-Eruption

    Science.gov (United States)

    Inguaggiato, Salvatore; Mazzini, Adriano; Vita, Fabio; Sciarra, Alessandra

    2016-04-01

    The Java Island is characterized by an intense volcanic activity with more then 100 active volcanoes. Moreover, this island is also known by the presence of many mud volcanoes and hydrothermal springs. In particular, in the 2006 several sudden hot mud eruptions, with fluids around 100° C, occurred in the NE side of the island resulting in a prominent eruption named Lusi (contraction of Lumpur Sidoarjo) located along the major Watukosek strike-slip fault zone. The Watukosek fault system, strikes from the Arjuno-Welirang volcanic complex, intersects Lusi and extends towards the NE of the Java island. Conversely of the normal mud eruptions (cold fluids emitted in a short time period of few days), the Lusi eruption was characterized by a persistent effusive hot fluids emissions for a long-time period of, so far, nearly a decade. Moreover, the isotopic composition of emitted gases like Helium showed a clear magmatic origin. For this reasons we decided to investigate the near Arjuno-Welirang complex located on the same strike-slip fault. Arjuno-Welirang is a twin strato-volcano system located in the East of Java along the Watukosek fault, at about 25 km SW respect to the Lusi volcano system. It features two main peaks: Arjuno (3339 masl) and Welirang (3156 masl). The last recorded eruptive activity took place in August 1950 from the flanks of Kawah Plupuh and in October 1950 from the NW part of the Gunung Welirang. This strato-volcano is characterized by a S-rich area, with high T-vent fumarole at least up to 220° C (and likely higher), located mainly in the Welirang crater. In addition, several hot springs vent from the flanks of the volcano, indicate the presence of a large hydrothermal system. During July 2015, in the framework of the Lusi Lab project (ERC grant n° 308126), we carried out a geochemical field campaign on the Arjuno-Welirang volcano hydrothermal system area, sampling water and dissolved gases from the thermal and cold springs located on the flanks of

  12. GeoNetGIS: a Geodetic Network Geographical Information System to manage GPS networks in seismic and volcanic areas

    Science.gov (United States)

    Cristofoletti, P.; Esposito, A.; Anzidei, M.

    2003-04-01

    This paper presents the methodologies and issues involved in the use of GIS techniques to manage geodetic information derived from networks in seismic and volcanic areas. Organization and manipulation of different geodetical, geological and seismic database, give us a new challenge in interpretation of information that has several dimensions, including spatial and temporal variations, also the flexibility and brand range of tools available in GeoNetGIS, make it an attractive platform for earthquake risk assessment. During the last decade the use of geodetic networks based on the Global Positioning System, devoted to geophysical applications, especially for crustal deformation monitoring in seismic and volcanic areas, increased dramatically. The large amount of data provided by these networks, combined with different and independent observations, such as epicentre distribution of recent and historical earthquakes, geological and structural data, photo interpretation of aerial and satellite images, can aid for the detection and parameterization of seismogenic sources. In particular we applied our geodetic oriented GIS to a new GPS network recently set up and surveyed in the Central Apennine region: the CA-GeoNet. GeoNetGIS is designed to analyze in three and four dimensions GPS sources and to improve crustal deformation analysis and interpretation related with tectonic structures and seismicity. It manages many database (DBMS) consisting of different classes, such as Geodesy, Topography, Seismicity, Geology, Geography and Raster Images, administrated according to Thematic Layers. GeoNetGIS represents a powerful research tool allowing to join the analysis of all data layers to integrate the different data base which aid for the identification of the activity of known faults or structures and suggesting the new evidences of active tectonics. A new approach to data integration given by GeoNetGIS capabilities, allow us to create and deliver a wide range of maps, digital

  13. The Role of Siliceous Hydrothermal Breccias in the Genesis of Volcanic Massive Sulphide Deposits - Ancient and Recent Systems

    Science.gov (United States)

    Costa, I. A.; Barriga, F. J.; Fouquet, Y.

    2014-12-01

    Siliceous hydrothermal breccias were sampled in two Mid-Atlantic Ridge active sites: Lucky Strike and Menez Gwen. These hydrothermal fields are located in the border of the Azorean plateau, southwest of the Azores islands where the alteration processes affecting basaltic rocks are prominent (Costa et al., 2003). The hydrothermal breccias are genetically related with the circulation of low temperature hydrothermal fluids in diffuse vents. The groundmass of these breccias precipitates from the fluid and consolidates the clastic fragments mostly composed of basalt. The main sources are the surrounding volcanic hills. Breccias are found near hydrothermal vents and may play an important role in the protection of subseafloor hydrothermal deposits forming an impermeable cap due to the high content in siliceous material. The amorphous silica tends to precipitate when the fluid is conductively cooled as proposed by Fouquet et al. (1998) after Fournier (1983). The process evolves gradually from an initial stage where we have just the fragments and circulating seawater. The ascending hydrothermal fluid mixes with seawater, which favours the precipitation of the sulphide components. Sealing of the initially loose fragments begins, the temperature rises below this crust, and the processes of mixing fluid circulation and conductive cooling are simultaneous. At this stage the fluid becomes oversaturated with respect to amorphous silica. This form of silica can precipitate in the open spaces of the porous sulphides and seal the system. Normally this can happen at low temperatures. At this stage the hydrothermal breccia is formed creating a progressively less permeable, eventually impermeable cap rock at the surface. Once the fluid is trapped under this impermeable layer, conductive cooling is enhanced and mixing with seawater is restricted, making the precipitation of amorphous silica more efficient. Since the first discovery and description of recent mineralized submarine

  14. 49 CFR 215.113 - Defective plain bearing wedge.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing wedge. 215.113 Section 215... Suspension System § 215.113 Defective plain bearing wedge. A railroad may not place or continue in service a car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

  15. A Land Systems Science Framework for Bridging Land System Architecture and Landscape Ecology: A Case Study from the Southern High Plains

    Directory of Open Access Journals (Sweden)

    Jacqueline M. Vadjunec

    2018-02-01

    Full Text Available Resource-use decisions affect the ecological and human components of the coupled human and natural system (CHANS, but a critique of some frameworks is that they do not address the complexity and tradeoffs within and between the two systems. Land system architecture (LA was suggested to account for these tradeoffs at multiple levels/scales. LA and landscape ecology (LE focus on landscape structure (i.e., composition and configuration of land-use and land-cover change [LULCC] and the processes (social-ecological resulting from and shaping LULCC. Drawing on mixed-methods research in the Southern Great Plains, we develop a framework that incorporates LA, LE, and governance theory. Public land and water are commons resources threatened by overuse, degradation, and climate change. Resource use is exacerbated by public land and water policies at the state- and local-levels. Our framework provides a foundation for investigating the mechanisms of land systems science (LSS couplings across multiple levels/scales to understand how and why governance impacts human LULCC decisions (LA and how those LULCC patterns influence, and are influenced by, the underlying ecological processes (LE. This framework provides a mechanism for investigating the feedbacks between and among the different system components in a CHANS that subsequently impact future human design decisions.

  16. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.; Delworth, Thomas L.; Ramaswamy, V.; Stouffer, Ronald J.; Wittenberg, Andrew; Zeng, Fanrong

    2009-01-01

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean

  17. Pesticide use in the wheat-maize double cropping systems of the North China Plain: Assessment, field study, and implications.

    Science.gov (United States)

    Brauns, Bentje; Jakobsen, Rasmus; Song, Xianfang; Bjerg, Poul L

    2018-03-01

    In the North China Plain (NCP), rising inputs of pesticides have intensified the environmental impact of farming activities in recent decades by contributing to surface water and groundwater contamination. In response to this, the Chinese government imposed stricter regulations on pesticide approval and application, and better monitoring strategies are being developed. However, sufficient and well-directed research on the accumulation and impact of different pesticides is needed for informed decision-making. In this study, current pesticide use, and recent and current research on water contamination by pesticides in the NCP are reviewed and assessed. Additionally, a small-scale field study was performed to determine if residuals from currently-used pesticides in the NCP can be detected in surface water, and in connected shallow groundwater. The contaminants of interest were commonly used pesticides on winter wheat-summer maize fields (the dominant cropping system in the NCP), such as 2,4-D and atrazine. Sampling took place in May, July, and October 2013; and March 2014. Results from our literature research showed that sampling is biased towards surface water monitoring. Furthermore, most studies focus on organic chlorinated pesticides (OCPs) like the isomers of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), which were banned in China in 1983. However, currently-used herbicides like 2,4-D and atrazine were detected in river water and groundwater in all samplings of our field study. The highest concentrations of 2,4-D and atrazine were found in the river water, ranging up to 3.00 and 0.96μg/L, respectively. The monitoring of banned compounds was found to be important because several studies indicate that they are still accumulating in the environment and/or are still illegally in use. However, supported by our own data, we find that the monitoring in groundwater and surface water of currently permitted pesticides in China needs equal

  18. Insights from gas and water chemistry on the geothermal system of the Domuyo volcanic complex (Patagonia, Argentina)

    Science.gov (United States)

    Tassi, F.; Liccioli, C.; Chiodini, G.; Agusto, M.; Caselli, A. T.; Caliro, S.; Vaselli, O.; Pecoraino, G.

    2015-12-01

    This study focuses on the geochemistry of geothermal fluids discharging from the western flank of the Domuyo volcanic complex (Argentina), which is hosted within an extensional basins that interrupts the Andes at latitudes comprises between 35° and 39°S. The analytical results of gas and water samples collected during three sampling campaigns (2013, 2014 and 2015) are presented and discussed in order to: i) evaluate the equilibrium temperature(s) of the main fluid reservoir, ii) provide information on the origin of the fluid discharges and the secondary processes controlling their chemistry. Geothermometry based on the chemical composition of thermal waters indicates a maximum equilibrium temperature of 220 °C. This temperature, coupled with the measured amount of discharged Cl, suggest that the total energy released from this system is 1.1±0.2 GW. Atmospheric gases from a thick shallow aquifer contaminate most gas emissions, masking the chemical features of the deep fluid component, with the only exception of a jet fumarole located at 3,000 m a.s.l. (Bramadora). The H2O-CO2-CH4-H2-CO-C3H6-C3H8 composition of this gas emission was used to construct a geochemical conceptual model showing that the hydrothermal reservoir is liquid-dominated and thermally stratified, with temperatures ranging from 180 to 270 °C. The helium isotopic ratios (up to 6.8 Ra) and the δ13C-CO2 values (from -7.05 to -7.75 ‰ V-PDB) indicate that mantle degassing represents the dominant primary source for this dormant volcano. These results highlight the huge potential of this system as energy resource for the region. Accordingly, the regional authorities have recently planned and approved an investigation project aimed to provide further insights into the fluid geochemistry and the geostructural assessment in this promising area.

  19. Superficial alteration mineralogy in active volcanic systems: An example of Poás volcano, Costa Rica

    Science.gov (United States)

    Rodríguez, Alejandro; van Bergen, Manfred J.

    2017-10-01

    The alteration mineralogy in the crater area of Poás volcano (Costa Rica) has been studied to constrain acid fluid-rock interaction processes and conditions relevant for the formation of sulphate-bearing mineral assemblages found on the surface of Mars. Individual sub-environments, which include the hyperacid lake (Laguna Caliente), ephemeral hot springs, fumarole vents and areas affected by acid rain and/or spray from the lake, are marked by distinct secondary mineral associations, with sulphates commonly as prevailing component. The sulphates occur in a wide mineralogical diversity comprising gypsum/anhydrite, various polyhydrated Al-sulphates, alunite-jarosite group minerals, halotrichite-, voltaite- and copiapite-group minerals, epsomite and römerite. Depending on the sub-environment, they are variably associated with clay minerals (kaolinite-group and smectite-group), zeolites, SiO2-polymorphs, Fe-(hydro)oxides, Ti-oxides, native sulphur, sulphides, chlorides, fluorides, phosphates and carbonates. Geochemical modelling was performed to identify mechanisms responsible for the formation of the secondary minerals found in the field, and to predict their possible stability under conditions not seen at the surface. The results indicate that the appearance of amorphous silica, hematite, anhydrite/gypsum, pyrite, anatase and kaolinite is relatively insensitive to the degree of acidity of the local aqueous system. On the other hand, alunite-jarosite group minerals, elemental sulphur and Al(OH)SO4 only form under acidic conditions (pH rain or brine spray. Modelling suggests that their formation required a repetitive sequence of olivine dissolution and evaporation in an open system involving limited amounts of fluid. The mineral variety in the crater of Poás is remarkably similar to sulphate-bearing assemblages considered to be the product of acid-sulphate alteration on Mars. The analogy suggests that comparable fluid-rock interaction controls operated in Martian

  20. Bi-decadal variability excited in the coupled ocean-atmosphere system by strong tropical volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Zanchettin, D.; Lorenz, S.; Lohmann, K.; Jungclaus, J.H. [Max Planck Institute for Meteorology, Ocean in the Earth System Department, Hamburg (Germany); Timmreck, C. [Max Planck Institute for Meteorology, Atmosphere in the Earth System Department, Hamburg (Germany); Graf, H.-F. [University of Cambridge, Centre for Atmospheric Science, Cambridge (United Kingdom); Rubino, A. [Ca' Foscari University, Department of Environmental Sciences, Venice (Italy); Krueger, K. [Leibniz-Institute of Marine Sciences, IFM-GEOMAR, Kiel (Germany)

    2012-07-15

    Decadal and bi-decadal climate responses to tropical strong volcanic eruptions (SVEs) are inspected in an ensemble simulation covering the last millennium based on the Max Planck Institute - Earth system model. An unprecedentedly large collection of pre-industrial SVEs (up to 45) producing a peak annual-average top-of-atmosphere radiative perturbation larger than -1.5 Wm{sup -2} is investigated by composite analysis. Post-eruption oceanic and atmospheric anomalies coherently describe a fluctuation in the coupled ocean-atmosphere system with an average length of 20-25 years. The study provides a new physically consistent theoretical framework to interpret decadal Northern Hemisphere (NH) regional winter climates variability during the last millennium. The fluctuation particularly involves interactions between the Atlantic meridional overturning circulation and the North Atlantic gyre circulation closely linked to the state of the winter North Atlantic Oscillation. It is characterized by major distinctive details. Among them, the most prominent are: (a) a strong signal amplification in the Arctic region which allows for a sustained strengthened teleconnection between the North Pacific and the North Atlantic during the first post-eruption decade and which entails important implications from oceanic heat transport and from post-eruption sea ice dynamics, and (b) an anomalous surface winter warming emerging over the Scandinavian/Western Russian region around 10-12 years after a major eruption. The simulated long-term climate response to SVEs depends, to some extent, on background conditions. Consequently, ensemble simulations spanning different phases of background multidecadal and longer climate variability are necessary to constrain the range of possible post-eruption decadal evolution of NH regional winter climates. (orig.)

  1. [Applicability of agricultural production systems simulator (APSIM) in simulating the production and water use of wheat-maize continuous cropping system in North China Plain].

    Science.gov (United States)

    Wang, Lin; Zheng, You-fei; Yu, Qiang; Wang, En-li

    2007-11-01

    The Agricultural Production Systems Simulator (APSIM) was applied to simulate the 1999-2001 field experimental data and the 2002-2003 water use data at the Yucheng Experiment Station under Chinese Ecosystem Research Network, aimed to verify the applicability of the model to the wheat-summer maize continuous cropping system in North China Plain. The results showed that the average errors of the simulations of leaf area index (LAI), biomass, and soil moisture content in 1999-2000 and 2000-2001 field experiments were 27.61%, 24.59% and 7.68%, and 32.65%, 35.95% and 10.26%, respectively, and those of LAI and biomass on the soils with high and low moisture content in 2002-2003 were 26.65% and 14.52%, and 23.91% and 27.93%, respectively. The simulations of LAI and biomass accorded well with the measured values, with the coefficients of determination being > 0.85 in 1999-2000 and 2002-2003, and 0.78 in 2000-2001, indicating that APSIM had a good applicability in modeling the crop biomass and soil moisture content in the continuous cropping system, but the simulation error of LAI was a little larger.

  2. Volcanic Eruptions and Climate

    Science.gov (United States)

    LeGrande, Allegra N.; Anchukaitis, Kevin J.

    2015-01-01

    Volcanic eruptions represent some of the most climatically important and societally disruptive short-term events in human history. Large eruptions inject ash, dust, sulfurous gases (e.g. SO2, H2S), halogens (e.g. Hcl and Hbr), and water vapor into the Earth's atmosphere. Sulfurous emissions principally interact with the climate by converting into sulfate aerosols that reduce incoming solar radiation, warming the stratosphere and altering ozone creation, reducing global mean surface temperature, and suppressing the hydrological cycle. In this issue, we focus on the history, processes, and consequences of these large eruptions that inject enough material into the stratosphere to significantly affect the climate system. In terms of the changes wrought on the energy balance of the Earth System, these transient events can temporarily have a radiative forcing magnitude larger than the range of solar, greenhouse gas, and land use variability over the last millennium. In simulations as well as modern and paleoclimate observations, volcanic eruptions cause large inter-annual to decadal-scale changes in climate. Active debates persist concerning their role in longer-term (multi-decadal to centennial) modification of the Earth System, however.

  3. Isotopic and chemical composition of water and steam discharges from volcanic-magmatic-hydrothermal systems of the Guanacaste Geothermal Province, Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Giggenbach, W.F. (Department of Scientific and Industrial Research, Petone (New Zealand). Chemistry Div.); Soto, R.C. (Instituto Costarricense de Electricidad, San Jose (Costa Rica))

    1992-07-01

    The Guanacaste Geothermal Province encompasses three major geothermal systems, each centered on its respective volcanic structure: Rincon de la Vieja to the NW, Miravalles in the center and Tenorio to the SE. Each shows corresponding sets of surface manifestations: vapor discharges from fumaroles and steam-heated pools at altitudes >500 m; lower temperature SO{sub 4}-Cl springs on the lower slopes of the respective volcano; and cooler neutral Cl springs to the S of the volcanic chain, at altitudes <500 m. The production of HCO{sub 3}-rich waters is limited to a narrow belt stretching to the S of Miravalles volcano. Chemical and isotopic evidence suggests that the neutral Cl waters, also discharged from deep wells, are derived from a more primitive Cl-SO{sub 4} water formed by transfer of readily mobilised, originally magmatic constituents to deeply circulating groundwater. (author).

  4. Machine-readable files developed for the High Plains Regional Aquifer-System analysis in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming

    Science.gov (United States)

    Ferrigno, C.F.

    1986-01-01

    Machine-readable files were developed for the High Plains Regional Aquifer-System Analysis project are stored on two magnetic tapes available from the U.S. Geological Survey. The first tape contains computer programs that were used to prepare, store, retrieve, organize, and preserve the areal interpretive data collected by the project staff. The second tape contains 134 data files that can be divided into five general classes: (1) Aquifer geometry data, (2) aquifer and water characteristics , (3) water levels, (4) climatological data, and (5) land use and water use data. (Author 's abstract)

  5. Scientific and public responses to the ongoing volcanic crisis at Popocatépetl Volcano, Mexico: Importance of an effective hazards-warning system

    Science.gov (United States)

    De la Cruz-Reyna, Servando; Tilling, Robert I.

    2008-01-01

    Volcanic eruptions and other potentially hazardous natural phenomena occur independently of any human actions. However, such phenomena can cause disasters when a society fails to foresee the hazardous manifestations and adopt adequate measures to reduce its vulnerability. One of the causes of such a failure is the lack of a consistent perception of the changing hazards posed by an ongoing eruption, i.e., with members of the scientific community, the Civil Protection authorities and the general public having diverging notions about what is occurring and what may happen. The problem of attaining a perception of risk as uniform as possible in a population measured in millions during an evolving eruption requires searching for communication tools that can describe—as simply as possible—the relations between the level of threat posed by the volcano, and the level of response of the authorities and the public. The hazards-warning system adopted at Popocatépetl Volcano, called the Volcanic Traffic Light Alert System(VTLAS), is a basic communications protocol that translates volcano threat into seven levels of preparedness for the emergency-management authorities, but only three levels of alert for the public (color coded green–yellow–red). The changing status of the volcano threat is represented as the most likely scenarios according to the opinions of an official scientific committee analyzing all available data. The implementation of the VTLAS was intended to reduce the possibility of ambiguous interpretations of intermediate levels by the endangered population. Although the VTLAS is imperfect and has not solved all problems involved in mass communication and decision-making during a volcanic crisis, it marks a significant advance in the management of volcanic crises in Mexico.

  6. Copahue Geothermal System: A Volcanic Environment with Rich Extreme Prokaryotic Biodiversity.

    Science.gov (United States)

    Urbieta, María Sofía; Porati, Graciana Willis; Segretín, Ana Belén; González-Toril, Elena; Giaveno, María Alejandra; Donati, Edgardo Rubén

    2015-07-08

    The Copahue geothermal system is a natural extreme environment located at the northern end of the Cordillera de los Andes in Neuquén province in Argentina. The geochemistry and consequently the biodiversity of the area are dominated by the activity of the Copahue volcano. The main characteristic of Copahue is the extreme acidity of its aquatic environments; ponds and hot springs of moderate and high temperature as well as Río Agrio. In spite of being an apparently hostile location, the prokaryotic biodiversity detected by molecular ecology techniques as well as cultivation shows a rich and diverse environment dominated by acidophilic, sulphur oxidising bacteria or archaea, depending on the conditions of the particular niche studied. In microbial biofilms, found in the borders of the ponds where thermal activity is less intense, the species found are completely different, with a high presence of cyanobacteria and other photosynthetic species. Our results, collected during more than 10 years of work in Copahue, have enabled us to outline geomicrobiological models for the different environments found in the ponds and Río Agrio. Besides, Copahue seems to be the habitat of novel, not yet characterised autochthonous species, especially in the domain Archaea.

  7. Copahue Geothermal System: A Volcanic Environment with Rich Extreme Prokaryotic Biodiversity

    Directory of Open Access Journals (Sweden)

    María Sofía Urbieta

    2015-07-01

    Full Text Available The Copahue geothermal system is a natural extreme environment located at the northern end of the Cordillera de los Andes in Neuquén province in Argentina. The geochemistry and consequently the biodiversity of the area are dominated by the activity of the Copahue volcano. The main characteristic of Copahue is the extreme acidity of its aquatic environments; ponds and hot springs of moderate and high temperature as well as Río Agrio. In spite of being an apparently hostile location, the prokaryotic biodiversity detected by molecular ecology techniques as well as cultivation shows a rich and diverse environment dominated by acidophilic, sulphur oxidising bacteria or archaea, depending on the conditions of the particular niche studied. In microbial biofilms, found in the borders of the ponds where thermal activity is less intense, the species found are completely different, with a high presence of cyanobacteria and other photosynthetic species. Our results, collected during more than 10 years of work in Copahue, have enabled us to outline geomicrobiological models for the different environments found in the ponds and Río Agrio. Besides, Copahue seems to be the habitat of novel, not yet characterised autochthonous species, especially in the domain Archaea.

  8. Isotope hydrology of some hydrothermal systems of the Kurilo-Kamchatskay volcanic region

    International Nuclear Information System (INIS)

    Esikov, A.D.

    1990-01-01

    The hydrogen and oxygen isotope composition of underground and surface (thermal and cold) waters, as well as local precipitation waters from the geothermal fields of the Uzon caldera, the Mutnovsky volcano (Kamchatka), and the Baransky volcano (island of Iturup) have been analysed. As has been demonstrated, hydrothermal solutions were formed due to hypogene circulation of water originating from local precipitation. Observed variations in the isotope composition of the water are easily explained by underground boiling of hydrothermal solutions and their exchange with bedrock, and also by the processes of non-steady evaporation of water under differing surface conditions and the widely-spread mutual intermixing of waters of different origin. Data on the isotope composition of 50 samples from the region studied are to be found in the paper. The method of constructing diagrams in coordinates of δD vs δ 18 O is discussed in detail, reflecting a single-step separation of the thermal fluid. Data obtained during the analysis of the thermal fields estimates the processes forming the isotope composition of the world's geothermal sub-aerial systems as being unique. (author)

  9. Multiple sources of selenium in ancient seafloor hydrothermal systems: Compositional and Se, S, and Pb isotopic evidence from volcanic-hosted and volcanic-sediment-hosted massive sulfide deposits of the Finlayson Lake District, Yukon, Canada

    Science.gov (United States)

    Layton-Matthews, Daniel; Leybourne, Matthew I.; Peter, Jan M.; Scott, Steven D.; Cousens, Brian; Eglington, Bruce M.

    2013-09-01

    Volcanic-hosted massive sulfide (VHMS) and volcanic-sediment-hosted massive sulfide (VSHMS; i.e., hosted by both volcanic and sedimentary rocks) deposits in the Finlayson Lake District, Yukon, Canada, provide a unique opportunity to study the influence of seafloor and sub-seafloor hydrothermal processes on the formation of Se-poor (GP4F VHMS deposit; 7 ppm Se average), intermediate (Kudz Ze Kayah—KZK VHMS deposit; 200 ppm Se average), and Se-enriched (Wolverine VSHMS deposit; 1100 ppm Se average) mineralization. All three deposits are hosted by mid-Paleozoic (˜360-346 Ma) felsic volcanic rocks, but only the Wolverine deposit has voluminous coeval carbonaceous argillites (black shales) in the host rock package. Here we report the first application of Se isotope analyses to ancient seafloor mineralization and use these data, in conjunction with Pb and S isotope analyses, to better understand the source(s) and depositional process(es) of Se within VHMS and VSHMS systems. The wide range of δ82Se (-10.2‰ to 1.3‰, relative to NIST 3149), δ34S (+2.0‰ to +12.8‰ CDT), and elevated Se contents (up to 5865 ppm) within the Wolverine deposit contrast with the narrower range of δ82Se (-3.8‰ to -0.5‰), δ34S (9.8‰ to 13.0‰), and lower Se contents (200 ppm average) of the KZK deposit. The Wolverine and KZK deposits have similar sulfide depositional histories (i.e., deposition at the seafloor, with concomitant zone refining). The Se in the KZK deposit is magmatic (leaching or degassing) in origin, whereas the Wolverine deposit requires an additional large isotopically negative Se source (i.e. ˜-15‰ δ82Se). The negative δ82Se values for the Wolverine deposit are at the extreme light end for measured terrestrial samples, and the lightest observed for hypogene sulfide minerals, but are within calculated equilibrium values of δ82Se relative to NIST 3149 (˜30‰ at 25 °C between SeO4 and Se2-). We propose that the most negative Se isotope values at the

  10. Seismically active column and volcanic plumbing system beneath the island arc of the Izu-Bonin subduction zone

    Czech Academy of Sciences Publication Activity Database

    Špičák, Aleš; Vaněk, Jiří; Hanuš, Václav

    2009-01-01

    Roč. 179, č. 3 (2009), s. 1301-1312 ISSN 0956-540X Institutional research plan: CEZ:AV0Z30120515 Keywords : seismicity and tectonics * volcano seismology * subduction zone processes * volcanic arc processes * magma migration and fragmentation * Pacific Ocean Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.435, year: 2009

  11. Assessing groundwater availability and the response of the groundwater system to intensive exploitation in the North China Plain by analysis of long-term isotopic tracer data

    Science.gov (United States)

    Su, Chen; Cheng, Zhongshuang; Wei, Wen; Chen, Zongyu

    2018-03-01

    The use of isotope tracers as a tool for assessing aquifer responses to intensive exploitation is demonstrated and used to attain a better understanding of the sustainability of intensively exploited aquifers in the North China Plain. Eleven well sites were selected that have long-term (years 1985-2014) analysis data of isotopic tracers. The stable isotopes δ18O and δ2H and hydrochemistry were used to understand the hydrodynamic responses of the aquifer system, including unconfined and confined aquifers, to groundwater abstraction. The time series data of 14C activity were also used to assess groundwater age, thereby contributing to an understanding of groundwater sustainability and aquifer depletion. Enrichment of the heavy oxygen isotope (18O) and elevated concentrations of chloride, sulfate, and nitrate were found in groundwater abstracted from the unconfined aquifer, which suggests that intensive exploitation might induce the potential for aquifer contamination. The time series data of 14C activity showed an increase of groundwater age with exploitation of the confined parts of the aquifer system, which indicates that a larger fraction of old water has been exploited over time, and that the groundwater from the deep aquifer has been mined. The current water demand exceeds the sustainable production capabilities of the aquifer system in the North China Plain. Some measures must be taken to ensure major cuts in groundwater withdrawals from the aquifers after a long period of depletion.

  12. Spatial and temporal variations of diffuse CO2 degassing at El Hierro volcanic system: Relation to the 2011-2012 submarine eruption

    Science.gov (United States)

    Melián, Gladys; Hernández, Pedro A.; Padrón, Eleazar; Pérez, Nemesio M.; Barrancos, José; Padilla, Germán.; Dionis, Samara; Rodríguez, Fátima; Calvo, David; Nolasco, Dacil

    2014-09-01

    We report herein the results of extensive diffuse CO2 emission surveys performed on El Hierro Island in the period 1998-2012. More than 17,000 measurements of the diffuse CO2 efflux were carried out, most of them during the volcanic unrest period that started in July 2011. Two significant precursory signals based on geochemical and geodetical studies suggest that a magma intrusion processes might have started before 2011 in El Hierro Island. During the preeruptive and eruptive periods, the time series of the diffuse CO2 emission released by the whole island experienced two significant increases. The first started almost 2 weeks before the onset of the submarine eruption, reflecting a clear geochemical anomaly in CO2 emission, most likely due to increasing release of deep-seated magmatic gases to the surface. The second one, between 24 October and 27 November 2011, started before the most energetic seismic events of the volcanic-seismic unrest. The data presented here demonstrate that combined continuous monitoring studies and discrete surveys of diffuse CO2 emission provide important information to optimize the early warning system in volcano monitoring programs and to monitor the evolution of an ongoing volcanic eruption, even though it is a submarine eruption.

  13. Evaluating the Impact of Drought Stresses on Groundwater System in Bagh- Malek Plain by Discharge Pattern Changes

    Directory of Open Access Journals (Sweden)

    R. Lalehzari

    2016-02-01

    Full Text Available Introduction: Groundwater is the largest resource of water supplement and shortages of surface water supplies in drought conditions that requires an increase in groundwater discharge. Groundwater flow dependson the subsurface properties such as hydraulic gradient (water table gradient or head loss in artesian condition and hydrodynamic coefficients. The flow treatment is analyzed with an accurate estimation of effective parameters in groundwater equation. This function is obtained using the continuous equation. Inlet and outlet flows of a cell are equal to storage amounts in the continuous equation. Analytical solution of this equation is complex, so numerical methods are developed including finite element and finite difference methods. For example, Feflow is a groundwater modeling tool that makesuse of finite element method (Reynolds and Marimuthu, 2007. Modflow as a finite difference three-dimensional model simulated underground flow under steady and unsteady conditions in anisotropic and non-homogeneous porous media. Modflow is designed to simulate aquifer systems in which saturated-flow conditions exist, Darcy’s Law applies, the density of groundwater is constant, and the principal directions of horizontal hydraulic conductivity or transmissivity do not vary within the system. In Modflow, an aquifer system is replaced by a discretized domain consisting of an array of nodes and the associated finite difference blocks. Groundwater modeling and water table prediction by this model have the acceptable results, because many different informations of water resource system are applied. Many people and organizations have contributed to the development of an effective groundwater monitoring system, as well as experimental and modeling studies (Lalehzari et al., 2013. The objective of this paper is investigation of hydraulic and physical conditions. So, a numerical model has to be developed by PMWIN software for Bagh-i Malek aquifer to calculate

  14. Linking Groundwater Use and Stress to Specific Crops Using the Groundwater Footprint in the Central Valley and High Plains Aquifer Systems, U.S.

    Science.gov (United States)

    Wada, Y.; Esnault, L.; Gleeson, T.; Heinke, J.; Gerten, D.; Flanary, E.; Bierkens, M. F.; Van Beek, L. P.

    2014-12-01

    A number of aquifers worldwide are being depleted, mainly by agricultural activities, yet groundwater stress has not been explicitly linked to specific agricultural crops. Using the newly-developed concept of the groundwater footprint (the area required to sustain groundwater use and groundwater-dependent ecosystem services), we develop a methodology to derive crop-specific groundwater footprints. We illustrate this method by calculating high resolution groundwater footprint estimates of crops in two heavily used aquifer systems: the Central Valley and High Plains, U.S. In both aquifer systems, hay and haylage, corn and cotton have the largest groundwater footprints, which highlights that most of the groundwater stress is induced by crops meant for cattle feed. Our results are coherent with other studies in the High Plains but suggest lower groundwater stress in the Central Valley, likely due to artificial recharge from surface water diversions which were not taken into account in previous estimates. Uncertainties of recharge and irrigation application efficiency contribute the most to the total relative uncertainty of the groundwater footprint to aquifer area ratios. Our results and methodology will be useful for hydrologists, water resource managers, and policy makers concerned with which crops are causing the well-documented groundwater stress in semiarid to arid agricultural regions around the world.

  15. Thermobarometry of Whangarei volcanic field lavas, New Zealand: Constraints on plumbing systems of small monogenetic basalt volcanoes

    Science.gov (United States)

    Shane, Phil; Coote, Alisha

    2018-04-01

    The intra-plate, basaltic Whangarei volcanic field (WVF) is a little-studied cluster of Quaternary monogenetic volcanoes in northern New Zealand. Clinopyroxene-melt equilibria provides an insight to the ascent and storage of the magmas that is not evident from whole-rock-scale geochemistry. Basalts from two of the younger volcanoes contain a population of equilibrium and disequilibrium clinopyroxene phenocrysts. Many of the crystals are resorbed, and are characterised by diffuse, patchy zoning, and low MgO (Mg#70-80) and Cr2O3 contents. Such crystals also occur as relic cores in other phenocrysts. These grew in a magma that was more evolved than that of the host rock composition. Equilibrium clinopyroxenes are enriched in MgO (Mg#83-88) and Cr2O3 ( 0.4-0.9 wt%), and occur as reverse-zoned crystals, and rim/mantle overgrowths on relic cores of other crystals. These crystals and rim/mantles zones nucleated in magma with a composition similar to that of the host rock. The textural relationships demonstrate that a mafic magma intruded a more silicic resident magma, resulting in crystal-exchange and entrainment of antecrysts. Clinopyroxene-melt equilibria indicate that the crystallisation occurred at temperatures in the range 1135-1195 °C, and pressures in the range 290-680 MPa. The dominant pressure mode (400-550 MPa) equates to depths of about 15-19 km which coincides with a present-day body of partial melt in the crust. Higher pressures indicated by subordinate crystal populations indicate staged ascent and crystallisation above the Moho ( 26 km depth). Thus, the magmatic system is envisaged as a crystal mush column through the lower and mid crust. Such crystallisation histories are perhaps not expected in low flux, monogenetic magma systems, and reflect the importance of the crustal density structure beneath the volcanoes. Future activity could be preceded by seismic events in the lower crust as the magmas intrude localised crystal mush bodies.

  16. Volcanism and associated hazards: the Andean perspective

    Science.gov (United States)

    Tilling, R. I.

    2009-12-01

    Andean volcanism occurs within the Andean Volcanic Arc (AVA), which is the product of subduction of the Nazca Plate and Antarctica Plates beneath the South America Plate. The AVA is Earth's longest but discontinuous continental-margin volcanic arc, which consists of four distinct segments: Northern Volcanic Zone, Central Volcanic Zone, Southern Volcanic Zone, and Austral Volcanic Zone. These segments are separated by volcanically inactive gaps that are inferred to indicate regions where the dips of the subducting plates are too shallow to favor the magma generation needed to sustain volcanism. The Andes host more volcanoes that have been active during the Holocene (past 10 000 years) than any other volcanic region in the world, as well as giant caldera systems that have produced 6 of the 47 largest explosive eruptions (so-called "super eruptions") recognized worldwide that have occurred from the Ordovician to the Pleistocene. The Andean region's most powerful historical explosive eruption occurred in 1600 at Huaynaputina Volcano (Peru). The impacts of this event, whose eruptive volume exceeded 11 km3, were widespread, with distal ashfall reported at distances >1000 km away. Despite the huge size of the Huaynaputina eruption, human fatalities from hazardous processes (pyroclastic flows, ashfalls, volcanogenic earthquakes, and lahars) were comparatively small owing to the low population density at the time. In contrast, lahars generated by a much smaller eruption (Colombia) killed about 25 000 people - the worst volcanic disaster in the Andean region as well as the second worst in the world in the 20th century. The Ruiz tragedy has been attributed largely to ineffective communications of hazards information and indecisiveness by government officials, rather than any major deficiencies in scientific data. Ruiz's disastrous outcome, however, together with responses to subsequent hazardous eruptions in Chile, Colombia, Ecuador, and Peru has spurred significant

  17. Geothermal Prospecting with Remote Sensing and Geographical Information System Technologies in Xilingol Volcanic Field in the Eastern Inner Mongolia, NE China

    Science.gov (United States)

    Peng, F.; Huang, S.; Xiong, Y.; Zhao, Y.; Cheng, Y.

    2013-05-01

    Geothermal energy is a renewable and low-carbon energy source independent of climate change. It is most abundant in Cenozoic volcanic areas where high temperature can be obtained within a relatively shallow depth. Like other geological resources, geothermal resource prospecting and exploration require a good understanding of the host media. Remote sensing (RS) has the advantages of high spatial and temporal resolution and broad spatial coverage over the conventional geological and geophysical prospecting, while geographical information system (GIS) has intuitive, flexible, and convenient characteristics. In this study, we apply RS and GIS technics in prospecting the geothermal energy potential in Xilingol, a Cenozoic volcanic field in the eastern Inner Mongolia, NE China. Landsat TM/ETM+ multi-temporal images taken under clear-sky conditions, digital elevation model (DEM) data, and other auxiliary data including geological maps of 1:2,500,000 and 1:200,000 scales are used in this study. The land surface temperature (LST) of the study area is retrieved from the Landsat images with the single-channel algorithm on the platform of ENVI developed by ITT Visual Information Solutions. Information of linear and circular geological structure is then extracted from the LST maps and compared to the existing geological data. Several useful technologies such as principal component analysis (PCA), vegetation suppression technique, multi-temporal comparative analysis, and 3D Surface View based on DEM data are used to further enable a better visual geologic interpretation with the Landsat imagery of Xilingol. The Preliminary results show that major faults in the study area are mainly NE and NNE oriented. Several major volcanism controlling faults and Cenozoic volcanic eruption centers have been recognized from the linear and circular structures in the remote images. Seven areas have been identified as potential targets for further prospecting geothermal energy based on the visual

  18. Estimate of regional groundwater recharge rate in the Central Haouz Plain, Morocco, using the chloride mass balance method and a geographical information system

    Science.gov (United States)

    Ait El Mekki, Ouassil; Laftouhi, Nour-Eddine; Hanich, Lahoucine

    2017-07-01

    Located in the extreme northwest of Africa, the Kingdom of Morocco is increasingly affected by drought. Much of the country is characterised by an arid to semi-arid climate and the demand for water is considerably higher than the supply, particularly on the Haouz Plain in the centre of the country. The expansion of agriculture and tourism, in addition to industrial development and mining, have exacerbated the stress on water supplies resulting in drought. It is therefore necessary to adopt careful management practices to preserve the sustainability of the water resources in this region. The aquifer recharge rate in the piedmont region that links the High Atlas and the Central Haouz Plain was estimated using the chloride mass balance hydrochemical method, which is based on the relationship between the chloride concentrations in groundwater and rainwater. The addition of a geographical information system made it possible to estimate the recharge rate over the whole 400 km2 of the study area. The results are presented in the form of a map showing the spatialized recharge rate, which ranges from 13 to 100 mm/year and the recharge percentage of the total rainfall varies from 3 to 25 % for the hydrological year 2011-2012. This approach will enable the validation of empirical models covering areas >6200 km2, such as the Haouz nappe.

  19. Pesticide use in the wheat-maize double cropping systems of the North China Plain: Assessment, field study, and implications

    DEFF Research Database (Denmark)

    Brauns, Bentje; Jakobsen, Rasmus; Song, Xianfang

    2018-01-01

    In the North China Plain (NCP), rising inputs of pesticides have intensified the environmental impact of farming activities in recent decades by contributing to surface water and groundwater contamination. In response to this, the Chinese government imposed stricter regulations on pesticide...... contamination by pesticides in the NCP are reviewed and assessed. Additionally, a small-scale field study was performed to determine if residuals from currently-used pesticides in the NCP can be detected in surface water, and in connected shallow groundwater. The contaminants of interest were commonly used...... studies focus on organic chlorinated pesticides (OCPs) like the isomers of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), which were banned in China in 1983. However, currently-used herbicides like 2,4-D and atrazine were detected in river water and groundwater in all samplings...

  20. Nitrous oxide and methane emissions from optimized and alternative cereal cropping systems on the North China Plain: A two-year field study

    International Nuclear Information System (INIS)

    Gao, Bing; Ju, Xiaotang; Su, Fang; Meng, Qingfeng; Oenema, Oene; Christie, Peter; Chen, Xinping; Zhang, Fusuo

    2014-01-01

    The impacts of different crop rotation systems with their corresponding management practices on grain yield, greenhouse gas emissions, and fertilizer nitrogen (N) and irrigation water use efficiencies are not well documented. This holds especially for the North China Plain which provides the staple food for hundreds of millions of people and where groundwater resources are polluted with nitrate and depleted through irrigation. Here, we report on fertilizer N and irrigation water use, grain yields, and nitrous oxide (N 2 O) and methane (CH 4 ) emissions of conventional and optimized winter wheat–summer maize double-cropping systems, and of three alternative cropping systems, namely a winter wheat–summer maize (or soybean)–spring maize system, with three harvests in two years; and a single spring maize system with one crop per year. The results of this two-year study show that the optimized double-cropping system led to a significant increase in grain yields and a significant decrease in fertilizer N use and net greenhouse gas intensity, but the net greenhouse gas N 2 O emissions plus CH 4 uptake and the use of irrigation water did not decrease relative to the conventional system. Compared to the conventional system the net greenhouse gas emissions, net greenhouse gas intensity and use of fertilizer N and irrigation water decreased in the three alternative cropping systems, but at the cost of grain yields except in the winter wheat–summer maize–spring maize system. Net uptake of CH 4 by the soil was little affected by cropping system. Average N 2 O emission factors were only 0.17% for winter wheat and 0.53% for maize. In conclusion, the winter wheat–summer maize–spring maize system has considerable potential to decrease water and N use and decrease N 2 O emissions while maintaining high grain yields and sustainable use of groundwater. - Highlights: • Yields, resource use efficiency and N 2 O + CH 4 emission differ among cropping systems. • An

  1. Nitrous oxide and methane emissions from optimized and alternative cereal cropping systems on the North China Plain: A two-year field study

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Bing [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Ju, Xiaotang, E-mail: juxt@cau.edu.cn [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Su, Fang; Meng, Qingfeng [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Oenema, Oene [Wageningen University and Research, Alterra, Wageningen (Netherlands); Christie, Peter [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Agri-Environment Branch, Agri-Food and Biosciences Institute, Belfast BT9 5PX (United Kingdom); Chen, Xinping; Zhang, Fusuo [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China)

    2014-02-01

    The impacts of different crop rotation systems with their corresponding management practices on grain yield, greenhouse gas emissions, and fertilizer nitrogen (N) and irrigation water use efficiencies are not well documented. This holds especially for the North China Plain which provides the staple food for hundreds of millions of people and where groundwater resources are polluted with nitrate and depleted through irrigation. Here, we report on fertilizer N and irrigation water use, grain yields, and nitrous oxide (N{sub 2}O) and methane (CH{sub 4}) emissions of conventional and optimized winter wheat–summer maize double-cropping systems, and of three alternative cropping systems, namely a winter wheat–summer maize (or soybean)–spring maize system, with three harvests in two years; and a single spring maize system with one crop per year. The results of this two-year study show that the optimized double-cropping system led to a significant increase in grain yields and a significant decrease in fertilizer N use and net greenhouse gas intensity, but the net greenhouse gas N{sub 2}O emissions plus CH{sub 4} uptake and the use of irrigation water did not decrease relative to the conventional system. Compared to the conventional system the net greenhouse gas emissions, net greenhouse gas intensity and use of fertilizer N and irrigation water decreased in the three alternative cropping systems, but at the cost of grain yields except in the winter wheat–summer maize–spring maize system. Net uptake of CH{sub 4} by the soil was little affected by cropping system. Average N{sub 2}O emission factors were only 0.17% for winter wheat and 0.53% for maize. In conclusion, the winter wheat–summer maize–spring maize system has considerable potential to decrease water and N use and decrease N{sub 2}O emissions while maintaining high grain yields and sustainable use of groundwater. - Highlights: • Yields, resource use efficiency and N{sub 2}O + CH{sub 4} emission

  2. Submarine Volcanic Eruptions and Potential Analogs for Venus

    Science.gov (United States)

    Wilson, L.; Mouginismark, P. J.; Fryer, P.; Gaddis, L. R.

    1985-01-01

    As part of an analysis program to better understand the diversity of volcanic processes on the terrestrial planets, an investigation of the volcanic landforms which exist on the Earth's ocean floor was initiated. In part, this analysis is focused toward gaining a better understanding of submarine volcanic landforms in their own right, but also it is hoped that these features may show similarities to volcanic landforms on Venus, due to the high ambient water (Earth) and atmospheric (Venus) pressures. A series of numerical modelling experiments was performed to investigate the relative importance of such attributes as water pressure and temperature on the eruption process, and to determine the rate of cooling and emplacement of lava flows in the submarine environment. Investigations to date show that the confining water pressure and the buoyancy effects of the surrounding water significantly affect the styles of volcanism on the ocean floor. In the case of Venusian volcanism, confining pressures will not be as great as that found at the ocean's abyssal plains, but nevertheless the general trend toward reducing magma vesiculation will hold true for Venus as well as the ocean floor. Furthermore, other analogs may also be found between submarine volcanism and Venusian activity.

  3. Yellowstone-Snake River Plain seismic profilling experiment: Crustal structure of the eastern Snake River Plain

    International Nuclear Information System (INIS)

    Braile, L.W.; Smith, R.B.; Ansorge, J.; Baker, M.R.; Sparlin, M.A.; Prodehl, C.; Schilly, M.M.; Healy, J.H.; Mueller, S.; Olsen, K.H.

    1982-01-01

    Seismic refraction profiles recorded along the eastern Snake River Plain (ESRP) in southeastern Idaho during the 1978 Yellowstone-Snake River Plain cooperative seismic profiling experiment are interpreted to infer the crustal velocity and attenuation (Q-1) structure of the ESRP. Travel-time and synthetic seismogram modeling of a 250 km reversed refraction profile as well as a 100 km detailed profile indicate that the crust of the ESRP is highly anomalous. Approximately 3 to 6 km of volcanic rocks (with some interbedded sediments) overlie an upper-crustal layer (compressional velocity approx. =6.1 km/s) which thins southwestward along the ESRP from a thickness of 10 km near Island Park Caldera to 2 to 3 km beneath the central and southwestern portions of the ESRP. An intermediate-velocity (approx. =6.5 km/s) layer extends from approx. =10 to approx. =20 km depth. a thick (approx. =22 km) lower crust of compressional velocity 6.8 km/s, a total crustall thickness of approx. =42 km, and a P/sub n/ velocity of approx. =7.9 km/s is observed in the ESRP, similar to the western Snake River Plain and the Rocky Mountains Provinces. High attenuation is evident on the amplitude corrected seismic data due to low-Q values in the volcanic rocks (Q/sub p/ = 20 to 200) and throughout the crust (Q/sub p/ = 160 to 300). Based on these characteristics of the crustal structure and volcanic-age progression data, it is suggested that the ESRP has resulted from an intensitive period of intrusion of mantle-derived basaltic magma into the upper crust generating explosive silicic volcanism and associated regional uplift and caldera collapse. This activity began about 15 m.y. ago in southwestern Idaho and has migrated northeast to its present position at Yellowstone. Subsequent cooling of the intruded upper crust results in the 6.5 km/s velocity intermediate layer. Crustal subsidence and periodic basaltic volcanism as represented by the ESRP complete the sequence of crustal evolution

  4. Seismic and GPS constraints on the dynamics and kinematics of the Yellowstone volcanic field

    Science.gov (United States)

    Smith, R. B.; Farrell, J.; Jordan, M.; Puskas, C.; Waite, G. P.

    2007-12-01

    The seismically and volcanically Yellowstone hotspot resulted from interaction of a mantle plume with the overriding North America plate. This feature and related processes have modified continental lithosphere producing the Yellowstone-Snake River Plain-Newberry silicic volcanic field (YSRPN) system, with its NE volcanically active Yellowstone volcanic field. The size and accessibility of the Yellowstone area has allowed a range of geophysical experiments including earthquake monitoring and seismic and GPS imaging of this system. Seismicity is dominated by small-magnitude normal- to oblique-slip faulting earthquake swarms with shallow focal depths, maximum of ~5 km, restricted by high temperatures and a weak elastic layer. There is developing evidence of non-double couple events. Outside the caldera, earthquakes are deeper, ~20 km, and capable of M 7+ earthquakes. We integrate the results from a multi-institution experiment that recorded data from 110 seismic stations and 180 GPS stations for 1999-2004. The tomographic images confirm the existence of a low Vp-body beneath the Yellowstone caldera at depths greater than 8 km, possibly representing hot, crystallizing magma. A key result of our study is a volume of anomalously low Vp and Vp/Vs in the northwestern part of the volcanic field at shallow depths of stress field inverted from seismic and GPS data is dominated by regional SW extension with superimposed volumetric expansion and uplift from local volcanic sources. Mantle tomography derived from integrated inversion of teleseismic and local earthquake data constrained by geoid, crustal structure, discontinuity structure reveals an upper-mantle low P and S velocity body extends from 80 km to ~250 km directly beneath Yellowstone and then continues to 650 km with unexpected westward tilt to the west at ~60° with a 1% to 2% melt. This geometry is consistent with the ascent of the buoyant magma entrained in eastward return-flow of the upper mantle. Some remaining

  5. A Volcanic Hydrogen Habitable Zone

    International Nuclear Information System (INIS)

    Ramirez, Ramses M.; Kaltenegger, Lisa

    2017-01-01

    The classical habitable zone (HZ) is the circular region around a star in which liquid water could exist on the surface of a rocky planet. The outer edge of the traditional N_2–CO_2–H_2O HZ extends out to nearly ∼1.7 au in our solar system, beyond which condensation and scattering by CO_2 outstrips its greenhouse capacity. Here, we show that volcanic outgassing of atmospheric H_2 can extend the outer edge of the HZ to ∼2.4 au in our solar system. This wider volcanic-hydrogen HZ (N_2–CO_2–H_2O–H_2) can be sustained as long as volcanic H_2 output offsets its escape from the top of the atmosphere. We use a single-column radiative-convective climate model to compute the HZ limits of this volcanic hydrogen HZ for hydrogen concentrations between 1% and 50%, assuming diffusion-limited atmospheric escape. At a hydrogen concentration of 50%, the effective stellar flux required to support the outer edge decreases by ∼35%–60% for M–A stars. The corresponding orbital distances increase by ∼30%–60%. The inner edge of this HZ only moves out ∼0.1%–4% relative to the classical HZ because H_2 warming is reduced in dense H_2O atmospheres. The atmospheric scale heights of such volcanic H_2 atmospheres near the outer edge of the HZ also increase, facilitating remote detection of atmospheric signatures.

  6. A Volcanic Hydrogen Habitable Zone

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, Ramses M.; Kaltenegger, Lisa, E-mail: rmr277@cornell.edu [Carl Sagan Institute, Cornell University, Ithaca, NY (United States)

    2017-03-01

    The classical habitable zone (HZ) is the circular region around a star in which liquid water could exist on the surface of a rocky planet. The outer edge of the traditional N{sub 2}–CO{sub 2}–H{sub 2}O HZ extends out to nearly ∼1.7 au in our solar system, beyond which condensation and scattering by CO{sub 2} outstrips its greenhouse capacity. Here, we show that volcanic outgassing of atmospheric H{sub 2} can extend the outer edge of the HZ to ∼2.4 au in our solar system. This wider volcanic-hydrogen HZ (N{sub 2}–CO{sub 2}–H{sub 2}O–H{sub 2}) can be sustained as long as volcanic H{sub 2} output offsets its escape from the top of the atmosphere. We use a single-column radiative-convective climate model to compute the HZ limits of this volcanic hydrogen HZ for hydrogen concentrations between 1% and 50%, assuming diffusion-limited atmospheric escape. At a hydrogen concentration of 50%, the effective stellar flux required to support the outer edge decreases by ∼35%–60% for M–A stars. The corresponding orbital distances increase by ∼30%–60%. The inner edge of this HZ only moves out ∼0.1%–4% relative to the classical HZ because H{sub 2} warming is reduced in dense H{sub 2}O atmospheres. The atmospheric scale heights of such volcanic H{sub 2} atmospheres near the outer edge of the HZ also increase, facilitating remote detection of atmospheric signatures.

  7. Volcanism on Io

    Science.gov (United States)

    Davies, Ashley Gerard

    2014-03-01

    Preface; Introduction; Part I. Io, 1610 to 1995: Galileo to Galileo: 1. Io, 1610-1979; 2. Between Voyager and Galileo: 1979-95; 3. Galileo at Io; Part II. Planetary Volcanism: Evolution and Composition: 4. Io and Earth: formation, evolution, and interior structure; 5. Magmas and volatiles; Part III. Observing and Modeling Volcanic Activity: 6. Observations: thermal remote sensing of volcanic activity; 7. Models of effusive eruption processes; 8. Thermal evolution of volcanic eruptions; Part IV. Galileo at Io: the Volcanic Bestiary: 9. The view from Galileo; 10. The lava lake at Pele; 11. Pillan and Tvashtar: lava fountains and flows; 12. Prometheus and Amirani: Effusive activity and insulated flows; 13. Loki Patera: Io's powerhouse; 14. Other volcanoes and eruptions; Part V. Volcanism on Io: The Global View: 15. Geomorphology: paterae, shields, flows and mountains; 16. Volcanic plumes; 17. Hot spots; Part VI. Io after Galileo: 18. Volcanism on Io: a post-Galileo view; 19. The future of Io observations; Appendix 1; Appendix 2; References; Index.

  8. First Results from HOTSPOT: The Snake River Plain Scientific Drilling Project, Idaho, U.S.A.

    Directory of Open Access Journals (Sweden)

    John W. Shervais

    2013-03-01

    Full Text Available HOTSPOT is an international collaborative effort to understand the volcanic history of the Snake River Plain (SRP. The SRP overlies a thermal anomaly, the Yellowstone-Snake River hotspot, that is thought to represent a deep-seated mantle plume under North America. Theprimary goal of this project is to document the volcanic and stratigraphic history of the SRP, which represents the surface expression of this hotspot, and to understand how it affected the evolution of continental crust and mantle. An additional goal is to evaluate the geothermal potential of southern Idaho.Project HOTSPOT has completed three drill holes. (1 The Kimama site is located along the central volcanic axis of the SRP; our goal here was to sample a long-term record of basaltic volcanism in the wake of the SRP hotspot. (2 The Kimberly site is located near the margin of the plain; our goal here was to sample a record of high-temperaturerhyolite volcanism associated with the underlying plume. This site was chosen to form a nominally continuous record of volcanism when paired with the Kimama site. (3 The Mountain Home site is located in the western plain; our goal here was to sample the Pliocene-Pleistocene transition in lake sediments at this site and to sample older basalts that underlie the sediments.We report here on our initial results for each site, and on some of the geophysical logging studies carried out as part of this project.

  9. Synthesis of a one-part geopolymer system for soil stabilizer using fly ash and volcanic ash

    Directory of Open Access Journals (Sweden)

    Tigue April Anne S.

    2018-01-01

    Full Text Available A novel approach one-part geopolymer was employed to investigate the feasibility of enhancing the strength of in-situ soil for possible structural fill application in the construction industry. Geopolymer precursors such as fly ash and volcanic ash were utilized in this study for soil stabilization. The traditional geopolymer synthesis uses soluble alkali activators unlike in the case of ordinary Portland cement where only water is added to start the hydration process. This kind of synthesis is an impediment to geopolymer soil stabilizer commercial viability. Hence, solid alkali activators such as sodium silicate (SS, sodium hydroxide (SH, and sodium aluminate (SA were explored. The influence of amount of fly ash (15% and 25%, addition of volcanic ash (0% and 12.5%, and ratio of alkali activator SS:SH:SA (50:50:0, 33:33:33, 50:20:30 were investigated. Samples cured for 28 days were tested for unconfined compressive strength (UCS. To evaluate the durability, sample yielding highest UCS was subjected to sulfuric acid resistance test for 28 days. Analytical techniques such as X-ray fluorescence (XRF, X-ray diffraction (XRD, and scanning electron microscope/energy-dispersive X-ray spectroscopy (SEM/EDX were performed to examine the elemental composition, mineralogical properties, and microstructure of the precursors and the geopolymer stabilized soil.

  10. The chemistry and isotopic composition of waters in the low-enthalpy geothermal system of Cimino-Vico Volcanic District, Italy

    DEFF Research Database (Denmark)

    Battistel, Maria; Hurwitz, Shaul; Evans, William C.

    2016-01-01

    Geothermal energy exploration is based in part on interpretation of the chemistry, temperature, and discharge rate of thermal springs. Here we present the major element chemistry and the δD, δ18O, 87Sr/86Sr and δ11B isotopic ratio of groundwater from the low-enthalpy geothermal system near the city...... and tortuous ascent enhances extraction of boron but also promotes conductive cooling, partially masking the heat present in the reservoir. Overall data from this study is consistent with previous studies that concluded that the geothermal system has a large energy potential....... of Viterbo in the Cimino-Vico volcanic district of west-Central Italy. The geothermal system hosts many thermal springs and gas vents, but the resource is still unexploited. Water chemistry is controlled by mixing between low salinity,HCO3-rich fresh waters (

  11. The cross wavelet and wavelet coherence analysis of spatio-temporal rainfall-groundwater system in Pingtung plain, Taiwan

    Science.gov (United States)

    Lin, Yuan-Chien; Yu, Hwa-Lung

    2013-04-01

    The increasing frequency and intensity of extreme rainfall events has been observed recently in Taiwan. Particularly, Typhoon Morakot, Typhoon Fanapi, and Typhoon Megi consecutively brought record-breaking intensity and magnitude of rainfalls to different locations of Taiwan in these two years. However, records show the extreme rainfall events did not elevate the amount of annual rainfall accordingly. Conversely, the increasing frequency of droughts has also been occurring in Taiwan. The challenges have been confronted by governmental agencies and scientific communities to come up with effective adaptation strategies for natural disaster reduction and sustainable environment establishment. Groundwater has long been a reliable water source for a variety of domestic, agricultural, and industrial uses because of its stable quantity and quality. In Taiwan, groundwater accounts for the largest proportion of all water resources for about 40%. This study plans to identify and quantify the nonlinear relationship between precipitation and groundwater recharge, find the non-stationary time-frequency relations between the variations of rainfall and groundwater levels to understand the phase difference of time series. Groundwater level data and over-50-years hourly rainfall records obtained from 20 weather stations in Pingtung Plain, Taiwan has been collected. Extract the space-time pattern by EOF method, which is a decomposition of a signal or data set in terms of orthogonal basis functions determined from the data for both time series and spatial patterns, to identify the important spatial pattern of groundwater recharge and using cross wavelet and wavelet coherence method to identify the relationship between rainfall and groundwater levels. Results show that EOF method can specify the spatial-temporal patterns which represents certain geological characteristics and other mechanisms of groundwater, and the wavelet coherence method can identify general correlation between

  12. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.

    2009-08-22

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean integrates volcanic radiative cooling and responds over a wide range of time scales. The associated processes, especially ocean heat uptake, play a key role in ongoing climate change. However, they are not well constrained by observations, and attempts to simulate them in current climate models used for climate predictions yield a range of uncertainty. Volcanic impacts on the ocean provide an independent means of assessing these processes. This study focuses on quantification of the seasonal to multidecadal time scale response of the ocean to explosive volcanism. It employs the coupled climate model CM2.1, developed recently at the National Oceanic and Atmospheric Administration\\'s Geophysical Fluid Dynamics Laboratory, to simulate the response to the 1991 Pinatubo and the 1815 Tambora eruptions, which were the largest in the 20th and 19th centuries, respectively. The simulated climate perturbations compare well with available observations for the Pinatubo period. The stronger Tambora forcing produces responses with higher signal-to-noise ratio. Volcanic cooling tends to strengthen the Atlantic meridional overturning circulation. Sea ice extent appears to be sensitive to volcanic forcing, especially during the warm season. Because of the extremely long relaxation time of ocean subsurface temperature and sea level, the perturbations caused by the Tambora eruption could have lasted well into the 20th century.

  13. Geochemistry of the late Holocene rocks from the Tolbachik volcanic field, Kamchatka: Quantitative modelling of subduction-related open magmatic systems

    Science.gov (United States)

    Portnyagin, Maxim; Duggen, Svend; Hauff, Folkmar; Mironov, Nikita; Bindeman, Ilya; Thirlwall, Matthew; Hoernle, Kaj

    2015-12-01

    We present new major and trace element, high-precision Sr-Nd-Pb (double spike), and O-isotope data for the whole range of rocks from the Holocene Tolbachik volcanic field in the Central Kamchatka Depression (CKD). The Tolbachik rocks range from high-Mg basalts to low-Mg basaltic trachyandesites. The rocks considered in this paper represent mostly Late Holocene eruptions (using tephrochronological dating), including historic ones in 1941, 1975-1976 and 2012-2013. Major compositional features of the Tolbachik volcanic rocks include the prolonged predominance of one erupted magma type, close association of middle-K primitive and high-K evolved rocks, large variations in incompatible element abundances and ratios but narrow range in isotopic composition. We quantify the conditions of the Tolbachik magma origin and evolution and revise previously proposed models. We conclude that all Tolbachik rocks are genetically related by crystal fractionation of medium-K primary magmas with only a small range in trace element and isotope composition. The primary Tolbachik magmas contain 14 wt.% of MgO and 4% wt.% of H2O and originated by partial melting ( 6%) of moderately depleted mantle peridotite with Indian-MORB-type isotopic composition at temperature of 1250 °C and pressure of 2 GPa. The melting of the mantle wedge was triggered by slab-derived hydrous melts formed at 2.8 GPa and 725 °C from a mixture of sediments and MORB- and Meiji-type altered oceanic crust. The primary magmas experienced a complex open-system evolution termed Recharge-Evacuation-Fractional Crystallization (REFC). First the original primary magmas underwent open-system crystal fractionation combined with periodic recharge of the magma chamber with more primitive magma, followed by mixing of both magma types, further fractionation and finally eruption. Evolved high-K basalts, which predominate in the Tolbachik field, and basaltic trachyandesites erupted in 2012-2013 approach steady-state REFC liquid

  14. Global positioning system survey data for active seismic and volcanic areas of eastern Sicily, 1994 to 2013

    Science.gov (United States)

    Bonforte, Alessandro; Fagone, Sonia; Giardina, Carmelo; Genovese, Simone; Aiesi, Gianpiero; Calvagna, Francesco; Cantarero, Massimo; Consoli, Orazio; Consoli, Salvatore; Guglielmino, Francesco; Puglisi, Biagio; Puglisi, Giuseppe; Saraceno, Benedetto

    2016-08-01

    This work presents and describes a 20-year long database of GPS data collected by geodetic surveys over the seismically and volcanically active eastern Sicily, for a total of more than 6300 measurements. Raw data were initially collected from the various archives at the Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania—Osservatorio Etneo and organized in a single repository. Here, quality and completeness checks were performed, while all necessary supplementary information were searched, collected, validated and organized together with the relevant data. Once all data and information collections were completed, raw binary data were converted into the universal ASCII RINEX format; all data are provided in this format with the necessary information for precise processing. In order to make the data archive readily consultable, we developed software allowing the user to easily search and obtain the needed data by simple alphanumeric and geographic queries.

  15. Global positioning system survey data for active seismic and volcanic areas of eastern Sicily, 1994 to 2013.

    Science.gov (United States)

    Bonforte, Alessandro; Fagone, Sonia; Giardina, Carmelo; Genovese, Simone; Aiesi, Gianpiero; Calvagna, Francesco; Cantarero, Massimo; Consoli, Orazio; Consoli, Salvatore; Guglielmino, Francesco; Puglisi, Biagio; Puglisi, Giuseppe; Saraceno, Benedetto

    2016-08-01

    This work presents and describes a 20-year long database of GPS data collected by geodetic surveys over the seismically and volcanically active eastern Sicily, for a total of more than 6300 measurements. Raw data were initially collected from the various archives at the Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania-Osservatorio Etneo and organized in a single repository. Here, quality and completeness checks were performed, while all necessary supplementary information were searched, collected, validated and organized together with the relevant data. Once all data and information collections were completed, raw binary data were converted into the universal ASCII RINEX format; all data are provided in this format with the necessary information for precise processing. In order to make the data archive readily consultable, we developed software allowing the user to easily search and obtain the needed data by simple alphanumeric and geographic queries.

  16. The use of geographical information systems for disaster risk reduction strategies: a case study of Volcan de Colima, Mexico

    Science.gov (United States)

    Landeg, O.

    Contemporary disaster risk management requires the analysis of vulnerability and hazard exposure, which is imperative at Volcan de Colima (VdC), Mexico, due to the predicted, large-magnitude eruption forecast to occur before 2025. The methods used to gauge social vulnerability included the development and application of proxies to census records, the undertaking of a building vulnerability survey and the spatial mapping of civil and emergency infrastructure. Hazard exposure was assessed using primary modelling of laharic events and the digitalisation of secondary data sources detailing the modelled extent of pyroclastic flows and tephra deposition associated with a large-magnitude (VEI 5) eruption at VdC. The undertaking and analysis of a risk perception survey of the population enabled an understanding of the cognitive behaviour of residents towards the volcanic risk. In comparison to the published hazard map, the GIS analysis highlighted an underestimation of lahar hazard on the western flank of VdC and the regional tephra hazard. Vulnerability analysis identified three communities where social deprivation is relatively high, and those with significant elderly and transient populations near the volcano. Furthermore, recognition of the possibility of an eruption in the near future was found to be low across the study region. These results also contributed to the analysis of emergency management procedures and the preparedness of the regional authorities. This multidisciplinary research programme demonstrates the success of applying a GIS platform to varied integrative spatial and temporal analysis. Furthermore, ascertaining the impact of future activity at VdC upon its surrounding populations permits the evaluation of emergency preparedness and disaster risk reduction strategies.

  17. A field trip guide to the petrology of Quaternary volcanism on the Yellowstone Plateau

    Science.gov (United States)

    Vazquez, Jorge A.; Stelten, Mark; Bindeman, Ilya N.; Cooper, Kari

    2017-12-19

    The Yellowstone Plateau is one of the largest manifestations of silicic volcanism on Earth, and marks the youngest focus of magmatism associated with the Yellowstone Hot Spot. The earliest products of Yellowstone Hot Spot volcanism are from ~17 million years ago, but may be as old as ~32 Ma, and include contemporaneous eruption of voluminous mafic and silicic magmas, which are mostly located in the region of northwestern Nevada and southeastern Oregon. Since 17 Ma, the main locus of Yellowstone Hot Spot volcanism has migrated northeastward producing numerous silicic caldera complexes that generally remain active for ~2–4 million years, with the present-day focus being the Yellowstone Plateau. Northeastward migration of volcanism associated with the Yellowstone Hot Spot resulted in the formation of the Snake River Plain, a low relief physiographic feature extending ~750 kilometers from northern Nevada to eastern Idaho. Most of the silicic volcanic centers along the Snake River Plain have been inundated by younger basalt volcanism, but many of their ignimbrites and lava flows are exposed in the extended regions at the margins of the Snake River Plain

  18. Mountain-Plains Curriculum.

    Science.gov (United States)

    Mountain-Plains Education and Economic Development Program, Inc., Glasgow AFB, MT.

    The document lists the Mountain-Plains curriculum by job title (where applicable), including support courses. The curriculum areas covered are mathematics skills, communication skills, office education, lodging services, food services, marketing and distribution, welding support, automotive, small engines, career guidance, World of Work, health…

  19. Tietkens Plain karst - Maralinga

    International Nuclear Information System (INIS)

    James, J.M.

    1988-09-01

    The Tietkens Plain karst is located to the north of Maralinga village which is on the crest of the Ooldea Range on the north and east margin of the Nullarbor Plain in western South Australia. The geology of the carbonate rocks in the Maralinga area is summarised. On Tietkens Plain from 1955 to 1963 nuclear weapons tests dispersed radioactive materials over the Maralinga area. Six nuclear devices were detonated in the air and one was exploded a few metres below the surface. The effect such explosions have on the karst and the possible rate of recovery of its surface are discussed. This report is the record of a visit to the Maralinga area from the 15th -21st November 1986 which involved an inspection of the karst surface together with collection of water, soil and rock samples. Results of the measurements made in order to assess water quality and water contamination by radioactive nuclides are presented. The implications arising from the presence of radioactive materials on the surface and the possibility of their entering and contaminating the groundwater in the area are discussed in the context of the chemistry of uranium and plutonium. The potential for transmission of contaminants through groundwater conduits and aquifers in the dolomite is discussed. Evidence is produced to show that the caves of the Nullabor Plain are not contaminated at present and are unlikely to be so in the future. 21 refs., 2 figs. 3 tabs., ills

  20. Geology of Pine and Crater Buttes: two basaltic constructs on the far eastern Snake River Plain

    International Nuclear Information System (INIS)

    Mazierski, P.F.; King, J.S.

    1987-01-01

    The emplacement history and petrochemical evolution of the volcanics associated with Pine Butte, Crater Butte, and other nearby vents are developed and described. Four major vents were identified in the study area and their associated eruptive products were mapped. All of the vents show a marked physical elongation or linear orientation coincident with the observed rift set. Planetary exploration has revealed the importance of volcanic processes in the genesis and modification of extraterrestrial surfaces. Interpretation of surface features has identified plains-type basaltic volcanism in various mare regions of the Moon and the volcanic provinces of Mars. Identification of these areas with features that appear analogous to those observed in the Pine Butte area suggests similar styles of eruption and mode of emplacement. Such terrestrial analogies serve as a method to interpret the evolution of volcanic planetary surfaces on the inner planets

  1. Hydrochemical study of an arsenic-contaminated plain in Guandu, north Taiwan

    Science.gov (United States)

    Hsiao, Yu-Hsiang

    2015-04-01

    Arsenic pollution in Guandu Plain, north Taiwan is a critical issue due to highly developed anthropogenic activities. It was considered that arsenic was carried in by surface water system. Two major rivers, Huanggang Creek and South Huang Greek, flow through Guandu Plain. Both creeks originate from Tatung Volcano Group, which is extensively active in post-volcanic activities. In this study, the hydrochemistry along the two major rivers was studied for tracing the source of arsenic pollution in Guandu Plain. The pH values in the upstream water are in the range from 6 to 8 but dramatically decrease down to 2-4.5 in the downstream area. It can be concluded that the creeks are recharged with very low pH geothermal water. In addition, arsenic shows a different spatial distribution. In Huanggang Creek, arsenic concentration is much higher, about 200 ppb to 500 ppb, in the downstream than in the upstream while arsenic concentration is extremely low, below 1 ppb, in the downstream of South Huang Greek. The geochemical results show that rare earth elements (REEs) are depleted in the upstream both in Huanggang creek and South Huang creek, and the NASC-normalized ratios of heavy to light REE (Lu/La) in the upstream are very close to 1. This demonstrates that the upstream water is geochemically dominated by the interaction between water and sedimentary rock. In the downstream, the NASC-normalized REE pattern shows a quit different type which is depleted in light REEs (much higher Lu/La ratio). It is well known that igneous rock is depleted in light REEs; therefore, arsenic is possibly volcanic origin. In this study, PHREEQC, a thermodynamic modeling program, was also utilized to calculate the saturation index (SI) of hydrous ferric oxide (HFO), which can effectively scavenge arsenic in water. The results demonstrate that SI of HFO is mainly controlled by pH in this study. When pH is greater than 3.5, HFO start to precipitate and remove arsenic from water. Therefore, it is

  2. Volcanic Rocks and Features

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Volcanoes have contributed significantly to the formation of the surface of our planet. Volcanism produced the crust we live on and most of the air we breathe. The...

  3. The link between volcanism and plutonism in epizonal magma systems; high-precision U–Pb zircon geochronology from the Organ Mountains caldera and batholith, New Mexico

    Science.gov (United States)

    Rioux, Matthew; Farmer, Lang; Bowring, Samuel; Wooton, Kathleen M.; Amato, Jeffrey M.; Coleman, Drew S.; Verplanck, Philip L.

    2016-01-01

    final eruption. Calculated magmatic fluxes for the Organ Needle pluton range from 0.0006 to 0.0030 km3/year, in agreement with estimates from other well-studied plutons. The petrogenetic evolution proposed here may be common to many small-volume silicic volcanic systems.

  4. Volcanic Plume Measurements with UAV (Invited)

    Science.gov (United States)

    Shinohara, H.; Kaneko, T.; Ohminato, T.

    2013-12-01

    Volatiles in magmas are the driving force of volcanic eruptions and quantification of volcanic gas flux and composition is important for the volcano monitoring. Recently we developed a portable gas sensor system (Multi-GAS) to quantify the volcanic gas composition by measuring volcanic plumes and obtained volcanic gas compositions of actively degassing volcanoes. As the Multi-GAS measures variation of volcanic gas component concentrations in the pumped air (volcanic plume), we need to bring the apparatus into the volcanic plume. Commonly the observer brings the apparatus to the summit crater by himself but such measurements are not possible under conditions of high risk of volcanic eruption or difficulty to approach the summit due to topography etc. In order to overcome these difficulties, volcanic plume measurements were performed by using manned and unmanned aerial vehicles. The volcanic plume measurements by manned aerial vehicles, however, are also not possible under high risk of eruption. The strict regulation against the modification of the aircraft, such as installing sampling pipes, also causes difficulty due to the high cost. Application of the UAVs for the volcanic plume measurements has a big advantage to avoid these problems. The Multi-GAS consists of IR-CO2 and H2O gas analyzer, SO2-H2O chemical sensors and H2 semiconductor sensor and the total weight ranges 3-6 kg including batteries. The necessary conditions of the UAV for the volcanic plumes measurements with the Multi-GAS are the payloads larger than 3 kg, maximum altitude larger than the plume height and installation of the sampling pipe without contamination of the exhaust gases, as the exhaust gases contain high concentrations of H2, SO2 and CO2. Up to now, three different types of UAVs were applied for the measurements; Kite-plane (Sky Remote) at Miyakejima operated by JMA, Unmanned airplane (Air Photo Service) at Shinomoedake, Kirishima volcano, and Unmanned helicopter (Yamaha) at Sakurajima

  5. Topographic Rise in the Northern Smooth Plains of Mercury: Characteristics from Messenger Image and Altimetry Data and Candidate Modes of Origin

    Science.gov (United States)

    Dickson, James L.; Head, James W.; Whitten, Jennifer L.; Fassett, Caleb I.; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.; Phillips, Roger J.

    2012-01-01

    MESSENGER observations from orbit around Mercury have revealed that a large contiguous area of smooth plains occupies much of the high northern latitudes and covers an area in excess of approx.6% of the surface of the planet [1] (Fig. 1). Smooth surface morphology, embayment relationships, color data, candidate flow fronts, and a population of partly to wholly buried craters provide evidence for the volcanic origin of these plains and their emplacement in a flood lava mode to depths at least locally in excess of 1 km. The age of these plains is similar to that of plains associated with and postdating the Caloris impact basin, confirming that volcanism was a globally extensive process in the post-heavy bombardment history of Mercury [1]. No specific effusive vent structures, constructional volcanic edifices, or lava distributary features (leveed flow fronts or sinuous rilles) have been identified in the contiguous plains, although vent structures and evidence of high-effusion-rate flood eruptions are seen in adjacent areas [1]. Subsequent to the identification and mapping of the extensive north polar smooth plains, data from the Mercury Laser Altimeter (MLA) on MESSENGER revealed the presence of a broad topographic rise in the northern smooth plains that is 1,000 km across and rises more than 1.5 km above the surrounding smooth plains [2] (Fig. 2). The purpose of this contribution is to characterize the northern plains rise and to outline a range of hypotheses for its origin.

  6. Relation of major volcanic center concentration on Venus to global tectonic patterns

    Science.gov (United States)

    Crumpler, L. S.; Head, James W.; Aubele, Jayne C.

    1993-01-01

    Global analysis of Magellan image data indicates that a major concentration of volcanic centers covering about 40 percent of the surface of Venus occurs between the Beta, Atla, and Themis regions. Associated with this enhanced concentration are geological characteristics commonly interpreted as rifting and mantle upwelling. Interconnected low plains in an annulus around this concentration are characterized by crustal shortening and infrequent volcanic centers that may represent sites of mantle return flow and net downwelling. Together, these observations suggest the existence of relatively simple, large-scale patterns of mantle circulation similar to those associated with concentrations of intraplate volcanism on earth.

  7. Volcanic geothermal system in the Main Ethiopian Rift: insights from 3D MT finite-element inversion and other exploration methods

    Science.gov (United States)

    Samrock, F.; Grayver, A.; Eysteinsson, H.; Saar, M. O.

    2017-12-01

    In search for geothermal resources, especially in exploration for high-enthalpy systems found in regions with active volcanism, the magnetotelluric (MT) method has proven to be an efficient tool. Electrical conductivity of the subsurface, imaged by MT, is used for detecting layers of electrically highly conductive clays which form around the surrounding strata of hot circulating fluids and for delineating magmatic heat sources such as zones with partial melting. We present a case study using a novel 3-D inverse solver, based on adaptive local mesh refinement techniques, applied to decoupled forward and inverse mesh parameterizations. The flexible meshing allows accurate representation of surface topography, while keeping computational costs at a reasonable level. The MT data set we analyze was measured at 112 sites, covering an area of 18 by 11 km at a geothermal prospect in the Main Ethiopian Rift. For inverse modelling, we tested a series of different settings to ensure that the recovered structures are supported by the data. Specifically, we tested different starting models, regularization functionals, sets of transfer functions, with and without inclusion of topography. Several robust subsurface structures were revealed. These are prominent features of a high-enthalpy geothermal system: A highly conductive shallow clay cap occurs in an area with high fumarolic activity, and is underlain by a more resistive zone, which is commonly interpreted as a propylitic reservoir and is the main geothermal target for drilling. An interesting discovery is the existence of a channel-like conductor connecting the geothermal field at the surface with an off-rift conductive zone, whose existence was proposed earlier as being related to an off-rift volcanic belt along the western shoulder of the Main Ethiopian Rift. The electrical conductivity model is interpreted together with results from other geoscientific studies and outcomes from satellite remote sensing techniques.

  8. The macrofauna of the soil in systems of agricultural production: Answers to the perturbations and handling perspectives. A case of study in the Oriental Plains of Colombia

    International Nuclear Information System (INIS)

    Decaens, T; Jimenez, J J; Schneidmadl, J; Lavelle, P

    1998-01-01

    During the last 20 years, numerous investigations were dedicated to the understanding of the relationships between soil macro-invertebrates and the abiotic factors that determine soil function. Important effects of macro-fauna activities were observed in soil organic matter dynamics, cycles of assimilable nutrients, soil structure and plant growth. Actual investigation in the Eastern Plains of Colombia (Investigation Centre of Carimagua and Matazul Farm) aims to identify sustainable and macrofauna-protecting systems of production; managing savanna results in important changes in soil faunal communities. Sowing improved pastures increases the activity of local macro-invertebrates populations (especially earthworms) and conserves the initial biodiversity of the savanna. On the other hand, monocrops have a dramatic effect on the whole soil macrofauna. An appropriate management of soil tillage and plant residues may minimize the negative effects of such monocrops. Other alternative is the use of rotations and/or juxtapositions of suitable and unfavorable situations, which may facilitates macrofaunal migrations from one system to another

  9. Geographical information systems as a tool in limnological studies An applied case study in a shallow .lake of a plain area, Buenos Aires province, Argentina

    International Nuclear Information System (INIS)

    Quiroz, Orlando; Romanelli, Asuncion; Martinez, Daniel

    2009-01-01

    The understanding of the hydrological functioning and the interaction among the different water bodies in an area is essential when a sustainable use of the hydric resources is considered. The aim of the present paper is to assess both hydrological-limnological methods and GIS as an integrated methodology applied to the study of shallow lakes, and the hydrological behavior of shallow wetlands in plain areas. La Salada is an areic permanent shallow lake with an area of 5,78 km 2 located near La Dulce town (SE of Buenos Aires Province, Argentina). In this paper we applied methods and tools of the Geographical information Systems in order to assess both, the evolution and state of the wetland. Topographic profiles, showing the relationship among the lake and the other aquatic systems, and also a multi temporal assessment of the morphometric parameters were performed by using a Digital Terrain Model of the area. A sample grid was designed to obtain bathymetric, hydrogeochemical and isotopic data. The chemical water composition is homogeneous in area and depth. changes in the conductivity values along depth, the isotopic contents and the Gibbs diagram showed that the evaporation is the main process controlling the water chemistry. Physical-chemical parameters established water quality and uses of the lake.

  10. 49 CFR 215.107 - Defective plain bearing box: General.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing box: General. 215.107... Suspension System § 215.107 Defective plain bearing box: General. A railroad may not place or continue in... the bearing; or (2) Have a detrimental effect on the lubrication of the journal and the bearings. ...

  11. Local and remote infrasound from explosive volcanism

    Science.gov (United States)

    Matoza, R. S.; Fee, D.; LE Pichon, A.

    2014-12-01

    Explosive volcanic eruptions can inject large volumes of ash into heavily travelled air corridors and thus pose a significant societal and economic hazard. In remote volcanic regions, satellite data are sometimes the only technology available to observe volcanic eruptions and constrain ash-release parameters for aviation safety. Infrasound (acoustic waves ~0.01-20 Hz) data fill this critical observational gap, providing ground-based data for remote volcanic eruptions. Explosive volcanic eruptions are among the most powerful sources of infrasound observed on earth, with recordings routinely made at ranges of hundreds to thousands of kilometers. Advances in infrasound technology and the efficient propagation of infrasound in the atmosphere therefore greatly enhance our ability to monitor volcanoes in remote regions such as the North Pacific Ocean. Infrasound data can be exploited to detect, locate, and provide detailed chronologies of the timing of explosive volcanic eruptions for use in ash transport and dispersal models. We highlight results from case studies of multiple eruptions recorded by the International Monitoring System and dedicated regional infrasound networks (2008 Kasatochi, Alaska, USA; 2008 Okmok, Alaska, USA; 2009 Sarychev Peak, Kuriles, Russian Federation; 2010 Eyjafjallajökull, Icleand) and show how infrasound is currently used in volcano monitoring. We also present progress towards characterizing and modeling the variability in source mechanisms of infrasound from explosive eruptions using dedicated local infrasound field deployments at volcanoes Karymsky, Russian Federation and Sakurajima, Japan.

  12. Volcanic hazards to airports

    Science.gov (United States)

    Guffanti, M.; Mayberry, G.C.; Casadevall, T.J.; Wunderman, R.

    2009-01-01

    Volcanic activity has caused significant hazards to numerous airports worldwide, with local to far-ranging effects on travelers and commerce. Analysis of a new compilation of incidents of airports impacted by volcanic activity from 1944 through 2006 reveals that, at a minimum, 101 airports in 28 countries were affected on 171 occasions by eruptions at 46 volcanoes. Since 1980, five airports per year on average have been affected by volcanic activity, which indicates that volcanic hazards to airports are not rare on a worldwide basis. The main hazard to airports is ashfall, with accumulations of only a few millimeters sufficient to force temporary closures of some airports. A substantial portion of incidents has been caused by ash in airspace in the vicinity of airports, without accumulation of ash on the ground. On a few occasions, airports have been impacted by hazards other than ash (pyroclastic flow, lava flow, gas emission, and phreatic explosion). Several airports have been affected repeatedly by volcanic hazards. Four airports have been affected the most often and likely will continue to be among the most vulnerable owing to continued nearby volcanic activity: Fontanarossa International Airport in Catania, Italy; Ted Stevens Anchorage International Airport in Alaska, USA; Mariscal Sucre International Airport in Quito, Ecuador; and Tokua Airport in Kokopo, Papua New Guinea. The USA has the most airports affected by volcanic activity (17) on the most occasions (33) and hosts the second highest number of volcanoes that have caused the disruptions (5, after Indonesia with 7). One-fifth of the affected airports are within 30 km of the source volcanoes, approximately half are located within 150 km of the source volcanoes, and about three-quarters are within 300 km; nearly one-fifth are located more than 500 km away from the source volcanoes. The volcanoes that have caused the most impacts are Soufriere Hills on the island of Montserrat in the British West Indies

  13. Simulating the 2012 High Plains Drought Using Three Single Column Model Versions of the Community Earth System Model (SCM-CESM)

    Science.gov (United States)

    Medina, I. D.; Denning, S.

    2014-12-01

    The impact of changes in the frequency and severity of drought on fresh water sustainability is a great concern for many regions of the world. One such location is the High Plains, where the local economy is primarily driven by fresh water withdrawals from the Ogallala Aquifer, which accounts for approximately 30% of total irrigation withdrawals from all U.S. aquifers combined. Modeling studies that focus on the feedback mechanisms that control the climate and eco-hydrology during times of drought are limited in the sense that they use conventional General Circulation Models (GCMs) with grid length scales ranging from one hundred to several hundred kilometers. Additionally, these models utilize crude statistical parameterizations of cloud processes for estimating sub-grid fluxes of heat and moisture and have a poor representation of land surface heterogeneity. For this research, we focus on the 2012 High Plains drought, and will perform numerical simulations using three single column model versions of the Community Earth System Model (SCM-CESM) at multiple sites overlying the Ogallala Aquifer for the 2010-2012 period. In the first version of SCM-CESM, CESM will be used in standard mode (Community Atmospheric Model (CAM) coupled to a single instance of the Community Land Model (CLM)), secondly, CESM will be used in Super-Parameterized mode (SP-CESM), where a cloud resolving model (CRM consists of 32 atmospheric columns) replaces the standard CAM atmospheric parameterization and is coupled to a single instance of CLM, and thirdly, CESM is used in "Multi Instance" SP-CESM mode, where an instance of CLM is coupled to each CRM column of SP-CESM (32 CRM columns coupled to 32 instances of CLM). To assess the physical realism of the land-atmosphere feedbacks simulated at each site by all versions of SCM-CESM, differences in simulated energy and moisture fluxes will be computed between years for the 2010-2012 period, and will be compared to differences calculated using

  14. HYDRUS Simulation of Sustainable Brackish Water Irrigation in a Winter Wheat-Summer Maize Rotation System in the North China Plain

    Directory of Open Access Journals (Sweden)

    Kangkang He

    2017-07-01

    Full Text Available Freshwater resources in the North China Plain (NCP are near depletion due to the unceasing overexploitation of deep groundwater, by far the most significant source of freshwater in the region. To deal with the deepening freshwater crisis, brackish water (rich but largely unused water in agriculture is increasingly being used in irrigation in the region. However, inappropriate irrigation with brackish water could lead to soil salinization and cropland degradation. To evaluate such negative impacts, the HYDRUS-1D model was used to simulate soil salt transport and accumulation under 15 years of irrigation with brackish water. The irrigation scenarios included brackish water irrigation during the wintering and jointing stages of winter wheat and then freshwater irrigation just before the sowing of summer maize. Freshwater irrigation was done to leach out soil salts, which is particularly vital in dry years. For the littoral region of the plain, HYDRUS-ID was used to simulate the irrigated cropping system stated above for a total period of 15 years. The results showed that it was feasible to use brackish water twice in one year, provided freshwater irrigation was performed before sowing summer maize. Freshwater irrigation, in conjunction with precipitation, leached out soil salts from the 100 cm root-zone depth. The maximum salt accumulation was in the 160–220 cm soil layer, which ensured that root-zone soil was free of restrictive salinity for crop growth. Precipitation was a critical determinant of the rate and depth leaching of soil salt. Heavy rainfall (>100 mm caused significant leaching of soluble salts in the 0–200 cm soil profile. Salt concentration under brackish water irrigation had no significant effect on the variations in the trend of soil salt transport in the soil profile. The variations of soil salinity were mainly affected by hydrological year type, for which the buried depth of soil salt was higher in wet years than in dry years

  15. Can we develop an effective early warning system for volcanic eruptions using `off the shelf' webcams and low-light cameras?

    Science.gov (United States)

    Harrild, M.; Webley, P. W.; Dehn, J.

    2016-12-01

    An effective early warning system to detect volcanic activity is an invaluable tool, but often very expensive. Detecting and monitoring precursory events, thermal signatures, and ongoing eruptions in near real-time is essential, but conventional methods are often logistically challenging, expensive, and difficult to maintain. Our investigation explores the use of `off the shelf' webcams and low-light cameras, operating in the visible to near-infrared portions of the electromagnetic spectrum, to detect and monitor volcanic incandescent activity. Large databases of webcam imagery already exist at institutions around the world, but are often extremely underutilised and we aim to change this. We focus on the early detection of thermal signatures at volcanoes, using automated scripts to analyse individual images for changes in pixel brightness, allowing us to detect relative changes in thermally incandescent activity. Primarily, our work focuses on freely available streams of webcam images from around the world, which we can download and analyse in near real-time. When changes in activity are detected, an alert is sent to the users informing them of the changes in activity and a need for further investigation. Although relatively rudimentary, this technique provides constant monitoring for volcanoes in remote locations and developing nations, where it is not financially viable to deploy expensive equipment. We also purchased several of our own cameras, which were extensively tested in controlled laboratory settings with a black body source to determine their individual spectral response. Our aim is to deploy these cameras at active volcanoes knowing exactly how they will respond to varying levels of incandescence. They are ideal for field deployments as they are cheap (0-1,000), consume little power, are easily replaced, and can provide telemetered near real-time data. Data from Shiveluch volcano, Russia and our spectral response lab experiments are presented here.

  16. Documentation of a groundwater flow model developed to assess groundwater availability in the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to North Carolina

    Science.gov (United States)

    Masterson, John P.; Pope, Jason P.; Fienen, Michael N.; Monti, Jr., Jack; Nardi, Mark R.; Finkelstein, Jason S.

    2016-08-31

    The U.S. Geological Survey developed a groundwater flow model for the Northern Atlantic Coastal Plain aquifer system from Long Island, New York, to northeastern North Carolina as part of a detailed assessment of the groundwater availability of the area and included an evaluation of how these resources have changed over time from stresses related to human uses and climate trends. The assessment was necessary because of the substantial dependency on groundwater for agricultural, industrial, and municipal needs in this area.The three-dimensional, groundwater flow model developed for this investigation used the numerical code MODFLOW–NWT to represent changes in groundwater pumping and aquifer recharge from predevelopment (before 1900) to future conditions, from 1900 to 2058. The model was constructed using existing hydrogeologic and geospatial information to represent the aquifer system geometry, boundaries, and hydraulic properties of the 19 separate regional aquifers and confining units within the Northern Atlantic Coastal Plain aquifer system and was calibrated using an inverse modeling parameter-estimation (PEST) technique.The parameter estimation process was achieved through history matching, using observations of heads and flows for both steady-state and transient conditions. A total of 8,868 annual water-level observations from 644 wells from 1986 to 2008 were combined into 29 water-level observation groups that were chosen to focus the history matching on specific hydrogeologic units in geographic areas in which distinct geologic and hydrologic conditions were observed. In addition to absolute water-level elevations, the water-level differences between individual measurements were also included in the parameter estimation process to remove the systematic bias caused by missing hydrologic stresses prior to 1986. The total average residual of –1.7 feet was normally distributed for all head groups, indicating minimal bias. The average absolute residual value

  17. Soil and Foliar Arthropod Abundance and Diversity in Five Cropping Systems in the Coastal Plains of North Carolina.

    Science.gov (United States)

    Adams, Paul R; Orr, David B; Arellano, Consuelo; Cardoza, Yasmin J

    2017-08-01

    Soil and foliar arthropod populations in agricultural settings respond to environmental disturbance and degradation, impacting functional biodiversity in agroecosystems. The objective of this study was to evaluate system level management effects on soil and foliar arthropod abundance and diversity in corn and soybean. Our field experiment was a completely randomized block design with three replicates for five farming systems which included: Conventional clean till, conventional long rotation, conventional no-till, organic clean till, and organic reduced till. Soil arthropod sampling was accomplished by pitfall trapping. Foliar arthropod sampling was accomplished by scouting corn and sweep netting soybean. Overall soil arthropod abundance was significantly impacted by cropping in corn and for foliar arthropods in soybeans. Conventional long rotation and organic clean till systems were highest in overall soil arthropod abundance for corn while organic reduced till systems exceeded all other systems for overall foliar arthropod abundance in soybeans. Foliar arthropod abundance over sampling weeks was significantly impacted by cropping system and is suspected to be the result of in-field weed and cover crop cultivation practices. This suggests that the sum of management practices within production systems impact soil and foliar arthropod abundance and diversity and that the effects of these systems are dynamic over the cropping season. Changes in diversity may be explained by weed management practices as sources of disturbance and reduced arthropod refuges via weed reduction. Furthermore, our results suggest agricultural systems lower in management intensity, whether due to organic practices or reduced levels of disturbance, foster greater arthropod diversity. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Melt extraction during heating and cooling of felsic crystal mushes in shallow volcanic systems: An experimental study

    Science.gov (United States)

    Pistone, M.; Baumgartner, L. P.; Sisson, T. W.; Bloch, E. M.

    2017-12-01

    The dynamics and kinetics of melt extraction in near-solidus, rheologically stalled, felsic crystal mushes (> 50 vol.% crystals) are essential to feeding many volcanic eruptions. At shallow depths (volatile-saturated and may be thermally stable for long time periods (104-107 years). In absence of deformation, residual melt can segregate from the mush's crystalline framework stimulated by: 1) gas injecting from hot mafic magmas into felsic mushes (heating / partial melting scenario), and 2) gas exsolving from the crystallizing mush (cooling / crystallizing scenario). The conditions and efficiency of melt extraction from a mush in the two scenarios are not well understood. Thus, we conducted high-temperature (700 to 850 °C) and -pressure (1.1 kbar) cold seal experiments (8-day duration) on synthetic felsic mushes, composed of water-saturated (4.2 wt.%) rhyodacite melt bearing different proportions of added quartz crystals (60, 70, and 80 vol%; 68 mm average particle size). High-spatial resolution X-ray tomography of run products show: 1) in the heating scenario (> 750 °C) melt has not segregated due to coalescence of vesicles (≤ 23 vol%) and large melt connectivity (> 7 vol% glass) / low pressure gradient for melt movement up to 80 vol% crystals; 2) in the cooling scenario (≤ 750 °C) vesicle (< 11 vol%) coalescence is limited or absent and limited amount of melt (3 to 11 vol%) segregated from sample center to its outer periphery (30 to 100 mm melt-rich lenses), testifying to the efficiency of melt extraction dictated by increasing crystallinity. These results suggest that silicic melt hosted within a crystal-rich mush can accumulate rapidly due to the buildup of modest gas pressures during crystallization at temperatures near the solidus.

  19. Defining 'plain language' in contemporary South Africa

    African Journals Online (AJOL)

    Kate H

    dimensions that are “characteristically human [and take the form of] the logical, the historical, ... the philosopher Cicero (James 2008: 3), are still important in plain language work: invention ... databases, help files, content management systems, etc., that essentially serve the same ...... From a talent to a scientific discipline.

  20. Nitrogen balance and groundwater nitrate contamination: Comparison among three intensive cropping systems on the North China Plain

    Energy Technology Data Exchange (ETDEWEB)

    Ju, X.T. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Kou, C.L. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Institute of Soils and Fertilizers, Henan Academy of Agricultural Sciences, Zhengzhou 450002 (China); Zhang, F.S. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China)]. E-mail: zfs@cau.edu.cn; Christie, P. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Agricultural and Environmental Science Department, Queen' s University Belfast, Belfast BT9 5PX (United Kingdom)

    2006-09-15

    The annual nitrogen (N) budget and groundwater nitrate-N concentrations were studied in the field in three major intensive cropping systems in Shandong province, north China. In the greenhouse vegetable systems the annual N inputs from fertilizers, manures and irrigation water were 1358, 1881 and 402 kg N ha{sup -1} on average, representing 2.5, 37.5 and 83.8 times the corresponding values in wheat (Triticum aestivum L.)-maize (Zea mays L.) rotations and 2.1, 10.4 and 68.2 times the values in apple (Malus pumila Mill.) orchards. The N surplus values were 349, 3327 and 746 kg N ha{sup -1}, with residual soil nitrate-N after harvest amounting to 221-275, 1173 and 613 kg N ha{sup -1} in the top 90 cm of the soil profile and 213-242, 1032 and 976 kg N ha{sup -1} at 90-180 cm depth in wheat-maize, greenhouse vegetable and orchard systems, respectively. Nitrate leaching was evident in all three cropping systems and the groundwater in shallow wells (<15 m depth) was heavily contaminated in the greenhouse vegetable production area, where total N inputs were much higher than crop requirements and the excessive fertilizer N inputs were only about 40% of total N inputs. - Intensive greenhouse vegetable production systems may pose a greater nitrogen pollution threat than apple orchards or cereal rotations to soil and water quality in north China.

  1. Nitrogen balance and groundwater nitrate contamination: Comparison among three intensive cropping systems on the North China Plain

    International Nuclear Information System (INIS)

    Ju, X.T.; Kou, C.L.; Zhang, F.S.; Christie, P.

    2006-01-01

    The annual nitrogen (N) budget and groundwater nitrate-N concentrations were studied in the field in three major intensive cropping systems in Shandong province, north China. In the greenhouse vegetable systems the annual N inputs from fertilizers, manures and irrigation water were 1358, 1881 and 402 kg N ha -1 on average, representing 2.5, 37.5 and 83.8 times the corresponding values in wheat (Triticum aestivum L.)-maize (Zea mays L.) rotations and 2.1, 10.4 and 68.2 times the values in apple (Malus pumila Mill.) orchards. The N surplus values were 349, 3327 and 746 kg N ha -1 , with residual soil nitrate-N after harvest amounting to 221-275, 1173 and 613 kg N ha -1 in the top 90 cm of the soil profile and 213-242, 1032 and 976 kg N ha -1 at 90-180 cm depth in wheat-maize, greenhouse vegetable and orchard systems, respectively. Nitrate leaching was evident in all three cropping systems and the groundwater in shallow wells (<15 m depth) was heavily contaminated in the greenhouse vegetable production area, where total N inputs were much higher than crop requirements and the excessive fertilizer N inputs were only about 40% of total N inputs. - Intensive greenhouse vegetable production systems may pose a greater nitrogen pollution threat than apple orchards or cereal rotations to soil and water quality in north China

  2. Production of more durable and sustainable concretes using volcanic scoria as cement replacement

    International Nuclear Information System (INIS)

    Al-Swaidani, A. M.

    2017-01-01

    The objective of the study is to investigate strength and durability-related properties of volcanic scoria-based cements. Compressive and tensile strength development of mortars and concretes containing volcanic scoria with replacement levels ranging from 10 to 35% was investigated. Water permeability, chloride penetrability and porosity of concretes cured for 2, 7, 28, 90 and 180 days were also examined. Results revealed that volcanic scoria could be suitable for making blended cements. The strength of mortar/concrete containing volcanic scoria was lower than that of plain cement mortar/concrete at all ages. However, at 90 day curing, the strengths of volcanic scoria-based mortars/concretes were comparable to those of plain cement. In addition, water permeability, chloride penetrability and porosity of scoria-based concretes were much lower than those of plain concrete. Further, the results were statistically analysed and estimation equations have been developed to predict the studied properties. SEM/EDX analysis was employed, as well. [es

  3. Large-scale volcanism associated with coronae on Venus

    Science.gov (United States)

    Roberts, K. Magee; Head, James W.

    1993-01-01

    The formation and evolution of coronae on Venus are thought to be the result of mantle upwellings against the crust and lithosphere and subsequent gravitational relaxation. A variety of other features on Venus have been linked to processes associated with mantle upwelling, including shield volcanoes on large regional rises such as Beta, Atla and Western Eistla Regiones and extensive flow fields such as Mylitta and Kaiwan Fluctus near the Lada Terra/Lavinia Planitia boundary. Of these features, coronae appear to possess the smallest amounts of associated volcanism, although volcanism associated with coronae has only been qualitatively examined. An initial survey of coronae based on recent Magellan data indicated that only 9 percent of all coronae are associated with substantial amounts of volcanism, including interior calderas or edifices greater than 50 km in diameter and extensive, exterior radial flow fields. Sixty-eight percent of all coronae were found to have lesser amounts of volcanism, including interior flooding and associated volcanic domes and small shields; the remaining coronae were considered deficient in associated volcanism. It is possible that coronae are related to mantle plumes or diapirs that are lower in volume or in partial melt than those associated with the large shields or flow fields. Regional tectonics or variations in local crustal and thermal structure may also be significant in determining the amount of volcanism produced from an upwelling. It is also possible that flow fields associated with some coronae are sheet-like in nature and may not be readily identified. If coronae are associated with volcanic flow fields, then they may be a significant contributor to plains formation on Venus, as they number over 300 and are widely distributed across the planet. As a continuation of our analysis of large-scale volcanism on Venus, we have reexamined the known population of coronae and assessed quantitatively the scale of volcanism associated

  4. 41 CFR 102-2.140 - What elements of plain language appear in the FMR?

    Science.gov (United States)

    2010-07-01

    ... MANAGEMENT REGULATION SYSTEM Plain Language Regulatory Style § 102-2.140 What elements of plain language... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What elements of plain language appear in the FMR? 102-2.140 Section 102-2.140 Public Contracts and Property Management Federal...

  5. Comparison of Soil Respiration in Typical Conventional and New Alternative Cereal Cropping Systems on the North China Plain

    Science.gov (United States)

    Gao, Bing; Ju, Xiaotang; Su, Fang; Gao, Fengbin; Cao, Qingsen; Oenema, Oene; Christie, Peter; Chen, Xinping; Zhang, Fusuo

    2013-01-01

    We monitored soil respiration (Rs), soil temperature (T) and volumetric water content (VWC%) over four years in one typical conventional and four alternative cropping systems to understand Rs in different cropping systems with their respective management practices and environmental conditions. The control was conventional double-cropping system (winter wheat and summer maize in one year - Con.W/M). Four alternative cropping systems were designed with optimum water and N management, i.e. optimized winter wheat and summer maize (Opt.W/M), three harvests every two years (first year, winter wheat and summer maize or soybean; second year, fallow then spring maize - W/M-M and W/S-M), and single spring maize per year (M). Our results show that Rs responded mainly to the seasonal variation in T but was also greatly affected by straw return, root growth and soil moisture changes under different cropping systems. The mean seasonal CO2 emissions in Con.W/M were 16.8 and 15.1 Mg CO2 ha−1 for summer maize and winter wheat, respectively, without straw return. They increased significantly by 26 and 35% in Opt.W/M, respectively, with straw return. Under the new alternative cropping systems with straw return, W/M-M showed similar Rs to Opt.W/M, but total CO2 emissions of W/S-M decreased sharply relative to Opt.W/M when soybean was planted to replace summer maize. Total CO2 emissions expressed as the complete rotation cycles of W/S-M, Con.W/M and M treatments were not significantly different. Seasonal CO2 emissions were significantly correlated with the sum of carbon inputs of straw return from the previous season and the aboveground biomass in the current season, which explained 60% of seasonal CO2 emissions. T and VWC% explained up to 65% of Rs using the exponential-power and double exponential models, and the impacts of tillage and straw return must therefore be considered for accurate modeling of Rs in this geographical region. PMID:24278340

  6. Comparison of soil respiration in typical conventional and new alternative cereal cropping systems on the North China plain.

    Science.gov (United States)

    Gao, Bing; Ju, Xiaotang; Su, Fang; Gao, Fengbin; Cao, Qingsen; Oenema, Oene; Christie, Peter; Chen, Xinping; Zhang, Fusuo

    2013-01-01

    We monitored soil respiration (Rs), soil temperature (T) and volumetric water content (VWC%) over four years in one typical conventional and four alternative cropping systems to understand Rs in different cropping systems with their respective management practices and environmental conditions. The control was conventional double-cropping system (winter wheat and summer maize in one year--Con.W/M). Four alternative cropping systems were designed with optimum water and N management, i.e. optimized winter wheat and summer maize (Opt.W/M), three harvests every two years (first year, winter wheat and summer maize or soybean; second year, fallow then spring maize--W/M-M and W/S-M), and single spring maize per year (M). Our results show that Rs responded mainly to the seasonal variation in T but was also greatly affected by straw return, root growth and soil moisture changes under different cropping systems. The mean seasonal CO2 emissions in Con.W/M were 16.8 and 15.1 Mg CO2 ha(-1) for summer maize and winter wheat, respectively, without straw return. They increased significantly by 26 and 35% in Opt.W/M, respectively, with straw return. Under the new alternative cropping systems with straw return, W/M-M showed similar Rs to Opt.W/M, but total CO2 emissions of W/S-M decreased sharply relative to Opt.W/M when soybean was planted to replace summer maize. Total CO2 emissions expressed as the complete rotation cycles of W/S-M, Con.W/M and M treatments were not significantly different. Seasonal CO2 emissions were significantly correlated with the sum of carbon inputs of straw return from the previous season and the aboveground biomass in the current season, which explained 60% of seasonal CO2 emissions. T and VWC% explained up to 65% of Rs using the exponential-power and double exponential models, and the impacts of tillage and straw return must therefore be considered for accurate modeling of Rs in this geographical region.

  7. A re-appraisal of the stratigraphy and volcanology of the Cerro Galán volcanic system, NW Argentina

    Science.gov (United States)

    Folkes, Christopher B.; Wright, Heather M.; Cas, Ray A.F.; de Silva, Shanaka L.; Lesti, Chiara; Viramonte, Jose G.

    2011-01-01

    From detailed fieldwork and biotite 40Ar/39Ar dating correlated with paleomagnetic analyses of lithic clasts, we present a revision of the stratigraphy, areal extent and volume estimates of ignimbrites in the Cerro Galán volcanic complex. We find evidence for nine distinct outflow ignimbrites, including two newly identified ignimbrites in the Toconquis Group (the Pitas and Vega Ignimbrites). Toconquis Group Ignimbrites (~5.60–4.51 Ma biotite ages) have been discovered to the southwest and north of the caldera, increasing their spatial extents from previous estimates. Previously thought to be contemporaneous, we distinguish the Real Grande Ignimbrite (4.68 ± 0.07 Ma biotite age) from the Cueva Negra Ignimbrite (3.77 ± 0.08 Ma biotite age). The form and collapse processes of the Cerro Galán caldera are also reassessed. Based on re-interpretation of the margins of the caldera, we find evidence for a fault-bounded trapdoor collapse hinged along a regional N-S fault on the eastern side of the caldera and accommodated on a N-S fault on the western caldera margin. The collapsed area defines a roughly isosceles trapezoid shape elongated E-W and with maximum dimensions 27 × 16 km. The Cerro Galán Ignimbrite (CGI; 2.08 ± 0.02 Ma sanidine age) outflow sheet extends to 40 km in all directions from the inferred structural margins, with a maximum runout distance of ~80 km to the north of the caldera. New deposit volume estimates confirm an increase in eruptive volume through time, wherein the Toconquis Group Ignimbrites increase in volume from the ~10 km3 Lower Merihuaca Ignimbrite to a maximum of ~390 km3 (Dense Rock Equivalent; DRE) with the Real Grande Ignimbrite. The climactic CGI has a revised volume of ~630 km3 (DRE), approximately two thirds of the commonly quoted value.

  8. Contribution of the FUTUREVOLC project to the study of segmented lateral dyke growth in the 2014 rifting event at Bárðarbunga volcanic system, Iceland

    Science.gov (United States)

    Sigmundsson, Freysteinn; Hooper, Andrew; Hreinsdóttir, Sigrún; Vogfjörd, Kristín S.; Ófeigsson, Benedikt; Rafn Heimisson, Elías; Dumont, Stéphanie; Parks, Michelle; Spaans, Karsten; Guðmundsson, Gunnar B.; Drouin, Vincent; Árnadóttir, Thóra; Jónsdóttir, Kristín; Gudmundsson, Magnús T.; Samsonov, Sergey; Brandsdóttir, Bryndís; White, Robert S.; Ágústsdóttir, Thorbjörg; Björnsson, Helgi; Bean, Christopher J.

    2015-04-01

    The FUTUREVOLC project (a 26-partner project funded by FP7 Environment Programme of the European Commission, addressing topic "Long-term monitoring experiment in geologically active regions of Europe prone to natural hazards: the Supersite concept) set aims to (i) establish an innovative volcano monitoring system and strategy, (ii) develop new methods for near real-time integration of multi-parametric datasets, (iii) apply a seamless transdisciplinary approach to further scientific understanding of magmatic processes, and (iv) to improve delivery, quality and timeliness of transdisciplinary information from monitoring scientists to civil protection. The project duration is 1 October 2012 - 31 March 2016. Unrest and volcanic activity since August 2014 at one of the focus areas of the project in Iceland, at the Bárðarbunga volcanic system, near the middle of the project duration, has offered unique opportunities for this project. On 16 August 2014 an intense seismic swarm started in Bárðarbunga, the beginning of a major volcano-tectonic rifting event forming over 45 km long dyke extending from the caldera to Holuhraun lava field outside the northern margin of Vatnajökull. A large basaltic, effusive fissure eruption began in Holuhraun on 31 August which had by January formed a lava field with a volume in excess of one cubic kilometre. We document how the FUTUREVOLC project has contributed to the study and response to the subsurface dyke formation, through increased seismic and geodetic coverage and joint interpreation of the data. The dyke intrusion in the Bárðarbunga volcanic system, grew laterally for over 45 km at a variable rate, with an influence of topography on the direction of propagation. Barriers at the ends of each segment were overcome by the build-up of pressure in the dyke end; then a new segment formed and dyke lengthening temporarily peaked. The dyke evolution, which occurred over 14 days, was revealed by propagating seismicity, ground

  9. Assessment of six tapping systems for four Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg.,clones in the Colombian High Plains

    International Nuclear Information System (INIS)

    Quesada Mendez, Isaac; Aristizabal Gutierrez, Fabio Ancizar; Chaves Cordoba, Bernardo

    2009-01-01

    The rubber yield of four Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg. clones was evaluated on the Colombian high plains in the Meta department: IAN 873 and RRIM 600 (third year of tapping being done) and PB 260 and GT 1 (first year of tapping). Six tapping systems were used, including a combination of different tapping frequencies (d/4 and d/5), Ethephon concentrations (0%, 2.5%, 3.3% and 5%) and a number of applications per year (4 to 8) were also used depending on the clone. The production figures for one commercial year were obtained from assays, using a completely random- block design (having four repetitions) independently defined for each clone: having on average 4446 g rubber/tree of produce per year for the RRIM 600 clone within a system 1/2S, d/4, 6d/7, 10m/12, ET 2.5%, Pa 7/y; 2696 g rubber/tree for the PB 260 clone with 1/2S, d/4, 6d/7, 10m/12, ET 2.5%, Pa 5/y; 3822 g rubber/tree for the IAN 873 clone, 1/2S, d/4, 6d/7, 10m/12, ET 3.3%, Pa 8/y, and 3472 g rubber/ tree for the GT 1 clone, 1/2S, d/4, 6d/7, 10m/12, ET 2.5%, Pa 5/y. The highest produce was obtained with a four-day tapping frequency.

  10. Water Leakage and Nitrate Leaching Characteristics in the Winter Wheat–Summer Maize Rotation System in the North China Plain under Different Irrigation and Fertilization Management Practices

    Directory of Open Access Journals (Sweden)

    Shufeng Chen

    2017-02-01

    Full Text Available Field experiments were carried out in Huantai County from 2006 to 2008 to evaluate the effects of different nitrogen (N fertilization and irrigation management practices on water leakage and nitrate leaching in the dominant wheat–maize rotation system in the North China Plain (NCP. Two N fertilization (NF1, the traditional one; NF2, fertilization based on soil testing and two irrigation (IR1, the traditional one; IR2, irrigation based on real-time soil water content monitoring management practices were designed in the experiments. Water and nitrate amounts leaving the soil layer at a depth of 2.0 m below the soil surface were calculated and compared. Results showed that the IR2 effectively reduced water leakage and nitrate leaching amounts in the two-year period, especially in the winter wheat season. Less than 10 percent irrigation water could be saved in a dry winter wheat season, but about 60 percent could be saved in a wet winter wheat season. Besides, 58.8 percent nitrate under single NF2IR1 and 85.2 percent under NF2IR2 could be prevented from leaching. The IR2 should be considered as the best management practice to save groundwater resources and prevent nitrate from leaching. The amounts of N input play a great role in affecting nitrate concentrations in the soil solutions in the winter wheat–summer maize rotation system. The NF2 significantly reduced N inputs and should be encouraged in ordinary agricultural production. Thus, nitrate leaching and groundwater contamination could be alleviated, but timely N supplement might be needed under high precipitation condition.

  11. Modeling volcanic ash dispersal

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    The assessment of volcanic fallout hazard is an important scientific, economic, and political issue, especially in densely populated areas. From a scientific point of view, considerable progress has been made during the last two decades through the use of increasingly powerful computational models and capabilities. Nowadays, models are used to quantify hazard...

  12. A Study by Remote Sensing Methods of Volcanism at Craters of the Moon National Park, Idaho

    Science.gov (United States)

    Haberle, C. W.; Hughes, S. S.; Kobs-Nawotniak, S. E.; Lim, D. S. S.; Garry, B.; Sears, D. W. G.; Downs, M.; Busto, J.; Skok, J. R.; Elphic, R. C.; Kobayashi, L.; Heldmann, J. L.; Christensen, P. R.

    2014-12-01

    Craters of the Moon (COTM) National Park, on the eastern Snake River Plain, and its associated lava fields are currently a focus of the NASA SSERVI FINESSE (Field Investigations to Enable Solar System Science and Exploration) team. COTM was selected for study owing to similarities with volcanic features observed on the Moon, Mars and Vesta. The COTM basaltic lava fields emanate from an 80 km long rift zone where at least eight eruptive episodes, occurring 15,000 to 2,000 BP, have created an expansive volcanic field covering an area of approximately 1,650 km2. This polygenetic volcanic field hosts a diverse collection of basaltic volcanic edifices such as phreatic explosion craters, eruptive fissures, cinder cones, spatter cones, shield volcanoes and expansive lava flows. Engineering challenges and high cost limit the number of robotic and human field investigations of planetary bodies and, due to these constraints, exhaustive remote sensing investigations of planetary surface properties are undertaken prior to field deployment. This creates an unavoidable dependence upon remote sensing, a critical difference between field investigations of planetary bodies and most terrestrial field investigations. Studies of this nature have utility in terrestrial investigations as they can help link spatially encompassing datasets and conserve field resources. We present preliminary results utilizing Earth orbital datasets to determine the efficacy of products derived from remotely sensed data when compared to geologic field observations. Multispectral imaging data (ASTER, AVIRIS, TIMS) collected at a range of spatial and spectral resolutions are paired with high resolution imagery from both orbit and unmanned aircraft systems. This enables the creation of derived products detailing morphology, compositional variation, mineralogy, relative age and vegetation. The surface morphology of flows within COTM differs from flow to flow and observations of these properties can aid in

  13. The interplay of evolved seawater and magmatic-hydrothermal fluids in the 3.24 Ga panorama volcanic-hosted massive sulfide hydrothermal system, North Pilbara Craton, Western Australia

    Science.gov (United States)

    Drieberg, Susan L.; Hagemann, Steffen G.; Huston, David L.; Landis, Gary; Ryan, Chris G.; Van Achterbergh, Esmé; Vennemann, Torsten

    2013-01-01

    The ~3240 Ma Panorama volcanic-hosted massive sulfide (VHMS) district is unusual for its high degree of exposure and low degree of postdepositional modification. In addition to typical seafloor VHMS deposits, this district contains greisen- and vein-hosted Mo-Cu-Zn-Sn mineral occurrences that are contemporaneous with VHMS orebodies and are hosted by the Strelley granite complex, which also drove VHMS circulation. Hence the Panorama district is a natural laboratory to investigate the role of magmatic-hydrothermal fluids in VHMS hydrothermal systems. Regional and proximal high-temperature alteration zones in volcanic rocks underlying the VHMS deposits are dominated by chlorite-quartz ± albite assemblages, with lesser low-temperature sericite-quartz ± K-feldspar assemblages. These assemblages are typical of VHMS hydrothermal systems. In contrast, the alteration assemblages associated with granite-hosted greisens and veins include quartz-topaz-muscovite-fluorite and quartz-muscovite (sericite)-chlorite-ankerite. These vein systems generally do not extend into the overlying volcanic pile. Fluid inclusion and stable isotope studies suggest that the greisens were produced by high-temperature (~590°C), high-salinity (38–56 wt % NaCl equiv) fluids with high densities (>1.3 g/cm3) and high δ18O (9.3 ± 0.6‰). These fluids are compatible with the measured characteristics of magmatic fluids evolved from the Strelley granite complex. In contrast, fluids in the volcanic pile (including the VHMS ore-forming fluids) were of lower temperature (90°–270°C), lower salinity (5.0–11.2 wt % NaCl equiv), with lower densities (0.88–1.01 g/cm3) and lower δ18O (−0.8 ± 2.6‰). These fluids are compatible with evolved Paleoarchean seawater. Fluids that formed the quartz-chalcopyrite-sphalerite-cassiterite veins, which are present within the granite complex near the contact with the volcanic pile, were intermediate in temperature and isotopic composition between the greisen

  14. Volcanism Studies: Final Report for the Yucca Mountain Project

    International Nuclear Information System (INIS)

    Crowe, Bruce M.; Perry, Frank V.; Valentine, Greg A.; Bowker, Lynn M.

    1998-01-01

    This report synthesizes the results of volcanism studies conducted by scientists at the Los Alamos National Laboratory and collaborating institutions on behalf of the Department of Energy's Yucca Mountain Project. An assessment of the risk of future volcanic activity is one of many site characterization studies that must be completed to evaluate the Yucca Mountain site for potential long-term storage of high-level radioactive waste. The presence of several basaltic volcanic centers in the Yucca Mountain region of Pliocene and Quaternary age indicates that there is a finite risk of a future volcanic event occurring during the 10,000-year isolation period of a potential repository. Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The risk of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Future volcanic events cannot be predicted with certainty but instead are estimated using formal methods of probabilistic volcanic hazard assessment (PVHA). Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The distribution, eruptive history, and geochronology of Plio-Quaternary basalt centers are described by individual center emphasizing the younger postcaldera basalt ( than about 7 x 10 -8 events yr -1 . Simple probability estimates are used to assess possible implications of not drilling aeromagnetic anomalies in the Amargosa Valley. The sensitivity of the disruption probability to the location of northeast boundaries of volcanic zones near the Yucca Mountain sit

  15. Stratigraphy of the Caloris Basin, Mercury: Implications for Volcanic History and Basin Impact Melt

    Science.gov (United States)

    Ernst, Carolyn M.; Denevi, Brett W.; Barnouin, Olivier S.; Klimczak, Christian; Chabot, Nancy L.; Head, James W.; Murchie, Scott L.; Neumann, Gregory A.; Prockter, Louis M.; Robinson, Mark S.; hide

    2015-01-01

    Caloris basin, Mercury's youngest large impact basin, is filled by volcanic plains that are spectrally distinct from surrounding material. Post-plains impact craters of a variety of sizes populate the basin interior, and the spectra of the material they have excavated enable the thickness of the volcanic fill to be estimated and reveal the nature of the subsurface. The thickness of the interior volcanic plains is consistently at least 2.5 km, reaching 3.5 km in places, with thinner fill toward the edge of the basin. No systematic variations in fill thickness are observed with long-wavelength topography or azimuth. The lack of correlation between plains thickness and variations in elevation at large horizontal scales within the basin indicates that plains emplacement must have predated most, if not all, of the changes in long-wavelength topography that affected the basin. There are no embayed or unambiguously buried (ghost) craters with diameters greater than 10 km in the Caloris interior plains. The absence of such ghost craters indicates that one or more of the following scenarios must hold: the plains are sufficiently thick to have buried all evidence of craters that formed between the Caloris impact event and the emplacement of the plains; the plains were emplaced soon after basin formation; or the complex tectonic deformation of the basin interior has disguised wrinkle-ridge rings localized by buried craters. That low-reflectance material (LRM) was exposed by every impact that penetrated through the surface volcanic plains provides a means to explore near-surface stratigraphy. If all occurrences of LRM are derived from a single layer, the subsurface LRM deposit is at least 7.5-8.5 km thick and its top likely once made up the Caloris basin floor. The Caloris-forming impact would have generated a layer of impact melt 3-15 km thick; such a layer could account for the entire thickness of LRM. This material would have been derived from a combination of lower crust

  16. Volcanic Hazards in Site Evaluation for Nuclear Installations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-10-15

    This publication provides comprehensive and updated guidance for site evaluation in relation to volcanic hazards. It includes recommendations on assessing the volcanic hazards at a nuclear installation site, in order to identify and characterize, in a comprehensive manner, all potentially hazardous phenomena that may be associated with future volcanic events. It describes how some of these volcanic phenomena may affect the acceptability of the selected site, resulting in exclusion of a site or determining the corresponding design basis parameters for the installation. This Safety Guide is applicable to both existing and new sites, and a graded approach is recommended to cater for all types of nuclear installations. Contents: 1. Introduction; 2. Overview of volcanic hazard assessment; 3. General recommendations; 4. Necessary information and investigations (database); 5. Screening of volcanic hazards; 6. Site specific volcanic hazard assessment; 7. Nuclear installations other than nuclear power plants; 8. Monitoring and preparation for response; 9. Management system for volcanic hazard assessment; Annex I: Volcanic hazard scenarios; Annex II: Worldwide sources of information.

  17. Constructional Volcanic Edifices on Mercury: Candidates and Hypotheses of Formation

    Science.gov (United States)

    Wright, Jack; Rothery, David A.; Balme, Matthew R.; Conway, Susan J.

    2018-04-01

    Mercury, a planet with a predominantly volcanic crust, has perplexingly few, if any, constructional volcanic edifices, despite their common occurrence on other solar system bodies with volcanic histories. Using image and topographical data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, we describe two small (Earth and the Moon. Though we cannot definitively conclude that these landforms are volcanic, the paucity of constructional volcanic edifices on Mercury is intriguing in itself. We suggest that this lack is because volcanic eruptions with sufficiently low eruption volumes, rates, and flow lengths, suitable for edifice construction, were highly spatiotemporally restricted during Mercury's geological history. We suggest that volcanic edifices may preferentially occur in association with late-stage, postimpact effusive volcanic deposits. The European Space Agency/Japan Aerospace Exploration Agency BepiColombo mission to Mercury will be able to investigate further our candidate volcanic edifices; search for other, as-yet unrecognized edifices beneath the detection limits of MESSENGER data; and test our hypothesis that edifice construction is favored by late-stage, low-volume effusive eruptions.

  18. Report on achievements in fiscal 1975 in Sunshine Project. Feasibility study on a volcanic electric power generation system; 1975 nendo kazan hatsuden hoshiki ni kansuru feasibility study seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-03-01

    The survey and study activities in the second year for the feasibility study (FS) on a volcanic electric power generation system consist of the following three parts: Part I, the case study on Satsuma Iojima Island, Part II, case study on Toyohane Mine, and Part III, FS on remote measurement of volcanic fume. The Part I, which has been performed subsequently from the previous fiscal year, has carried out the following surveys at different sites: meteorological, hydrological and underground water surveys, natural earthquake survey, fume and hot spring surveys (on-shore and off-shore), heat dissipation survey, tide level survey, underground structure survey (electric exploration), natural environment (vegetation) survey, thermal image survey, and social environment survey. The part II has begun surveys starting this fiscal year, because a considerable number of high temperature portions are already known to exist in the gallery, where there is a possibility of dry and hot rocks to exist without relationship with the present volcanic activities. This fiscal year has carried out mainly putting into order and analyzing the materials having been obtained in association with mine developments. The part III has been performed succeeding the 'FS on technologies to measure volcanic fume energy' done by the Japan Mining Industry Association. Some experiments were also executed at the Aso volcano. (NEDO)

  19. Report on achievements in fiscal 1975 in Sunshine Project. Feasibility study on a volcanic electric power generation system; 1975 nendo kazan hatsuden hoshiki ni kansuru feasibility study seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-03-01

    The survey and study activities in the second year for the feasibility study (FS) on a volcanic electric power generation system consist of the following three parts: Part I, the case study on Satsuma Iojima Island, Part II, case study on Toyohane Mine, and Part III, FS on remote measurement of volcanic fume. The Part I, which has been performed subsequently from the previous fiscal year, has carried out the following surveys at different sites: meteorological, hydrological and underground water surveys, natural earthquake survey, fume and hot spring surveys (on-shore and off-shore), heat dissipation survey, tide level survey, underground structure survey (electric exploration), natural environment (vegetation) survey, thermal image survey, and social environment survey. The part II has begun surveys starting this fiscal year, because a considerable number of high temperature portions are already known to exist in the gallery, where there is a possibility of dry and hot rocks to exist without relationship with the present volcanic activities. This fiscal year has carried out mainly putting into order and analyzing the materials having been obtained in association with mine developments. The part III has been performed succeeding the 'FS on technologies to measure volcanic fume energy' done by the Japan Mining Industry Association. Some experiments were also executed at the Aso volcano. (NEDO)

  20. Timing of the volcanism of the southern Kivu province: Implications for the evolution of the western branch of the East African rift system

    International Nuclear Information System (INIS)

    Pasteels, P.

    1989-01-01

    New K-Ar datings of a large rock sampling from the South Kivu volcanic province (Zaire, Rwanda, Burundi) are reported. No ages older than 10 Ma have been obtained. This result contrasts with older assumptions and puts severe constraints on the relations between volcanism and rift evolution. From 10 to 7.5 Ma tholeiitic volcanism predominates corresponding to an episode of fissural eruptions; from 7.5 to 5 Ma alkali basalts and their differentiates are mainly erupted in localized rifts. A culmination of activity occurs between 6.0 and 5.5 Ma ago. Pleistocene alkalic volcanism is restricted to localized areas. The transition from tholeiites to alkali-basaltic volcanism dated around 7.5 Ma would correspond to a major rifting phase which corresponds with the initiation of Lake Kivu Basin formation. The distribution of tholeiitic rocks in the central part of the rift, and predominantly alkalic rocks along the western active border fault, strengthens the idea that the former are associated with tension, the latter with vertical, possibly also strike-slip movements. Volcanism in the Western Rift is restricted to areas where tension occurs in a zone which is located between two zones of strike-slip. In the South Kivu area normal faults intersect strike-slip faults and this seems to have determined the location of volcanic activity. Magma formation is considered to be related with shear heating combined with adiabatic decompression in ascending diapirs. This implies heating at the lithosphere-asthenosphere boundary as a result of extension. Generation of tholeiitic or alkalic magmas is connected with the variable ascent velocity of mantle diapirs or with variable shear heating along the shear zone. Changes in both magma composition and intensity of volcanic activity with time are considered to be related to major phases of rift evolution. (orig.)

  1. Global warming likely reduces crop yield and water availability of the dryland cropping systems in the U.S. central Great Plains

    Science.gov (United States)

    We investigated impacts of GCM-projected climate change on dryland crop rotations of wheat-fallow and wheat-corn-fallow in the Central Great Plains (Akron in Colorado, USA) using the CERES 4.0 crop modules in RZWQM2. The climate change scenarios for CO2, temperature, and precipitation were produced ...

  2. OPTIMISASI SISTEM USAHA TANI UNTUK PERTANIAN BERKELANJUTAN DI KAWASAN PESISIR BALI UTARA (Optimization of Farming System Towards Sustainable Agriculture in North Coastal Plain Bali

    Directory of Open Access Journals (Sweden)

    I Wayan Budiasa

    2007-11-01

    system development (FSD on poor fertile soil with limited water source can lead to trade-off between economic benefit in the short run and environmental problems in the long run. As environmental degradation increases and inefficient in resources allocation, farming system will become unsustainable. This study aims to optimize irrigated farming system model and to assess its sustainability. By using linear programming analysis, local farmer in north coastal plain of Bali was optimal in resources allocation indicated from optimal solution of conventional farming system model which conforms to observed behavior. By several adjustments, conventional farming system model can be extended to sustainable farming system model. It is found that the sustainable farming system is better than the conventional farming system. Since all components and indicators of sustainability were considered into model and all criteria of sustainability were fulfilled by optimal results, the extended farming system model also guarantees that irrigated farming system development at household level will become sustaipable. To make the sustainable farming system at household level, the farmer should be able to allocate the groundwater less than or equal to 8.547 Lis, to add the organic fertilizer from manure more than or equal to 5 t/ha/yr, to continue the mixed-farming system and crops rotation, to consider minimum household expenditure, and to put the sustainable value in the use of water in approximately Rp I ,218.29/CM into effect. The sustainable farming system model generated from this study passed validated process. Thus, it can be contributed to scientific development. Also, its results can become best management practices by local farmers on their farms.

  3. Geochemistry of volcanic series of Aragats province

    International Nuclear Information System (INIS)

    Meliksetyan, Kh.B.

    2012-01-01

    In this contribution we discuss geochemical and isotope characteristics of volcanism of the Aragats volcanic province and possible petrogenetical models of magma generation in collision zone of Armenian highland. We talk about combination of some specific features of collision related volcanism such as dry and high temperature conditions of magma generation, that demonstrate some similarities to intraplate-like petrogenesis and presence of mantle source enriched by earlier subductions, indicative to island-arc type magma generation models. Based on comprehensive analysis of isotope and geochemical data and some published models of magma generation beneath Aragats we lead to a petrogenetic model of origin of Aragats system to be a result of magma mixture between mantle originated mafic magma with felsic, adakite-type magmas

  4. Volcanic air pollution hazards in Hawaii

    Science.gov (United States)

    Elias, Tamar; Sutton, A. Jeff

    2017-04-20

    Noxious sulfur dioxide gas and other air pollutants emitted from Kīlauea Volcano on the Island of Hawai‘i react with oxygen, atmospheric moisture, and sunlight to produce volcanic smog (vog) and acid rain. Vog can negatively affect human health and agriculture, and acid rain can contaminate household water supplies by leaching metals from building and plumbing materials in rooftop rainwater-catchment systems. U.S. Geological Survey scientists, along with health professionals and local government officials are working together to better understand volcanic air pollution and to enhance public awareness of this hazard.

  5. Towards understanding the puzzling lack of acid geothermal springs in Tibet (China): Insight from a comparison with Yellowstone (USA) and some active volcanic hydrothermal systems

    Science.gov (United States)

    Nordstrom, D. Kirk; Guo, Qinghai; McCleskey, R. Blaine

    2014-01-01

    Explanations for the lack of acid geothermal springs in Tibet are inferred from a comprehensive hydrochemical comparison of Tibetan geothermal waters with those discharged from Yellowstone (USA) and two active volcanic areas, Nevado del Ruiz (Colombia) and Miravalles (Costa Rica) where acid springs are widely distributed and diversified in terms of geochemical characteristic and origin. For the hydrothermal areas investigated in this study, there appears to be a relationship between the depths of magma chambers and the occurrence of acid, chloride-rich springs formed via direct magmatic fluid absorption. Nevado del Ruiz and Miravalles with magma at or very close to the surface (less than 1–2 km) exhibit very acidic waters containing HCl and H2SO4. In contrast, the Tibetan hydrothermal systems, represented by Yangbajain, usually have fairly deep-seated magma chambers so that the released acid fluids are much more likely to be fully neutralized during transport to the surface. The absence of steam-heated acid waters in Tibet, however, may be primarily due to the lack of a confining layer (like young impermeable lavas at Yellowstone) to separate geothermal steam from underlying neutral chloride waters and the possible scenario that the deep geothermal fluids below Tibet carry less H2S than those below Yellowstone.

  6. Towards understanding the puzzling lack of acid geothermal springs in Tibet (China): Insight from a comparison with Yellowstone (USA) and some active volcanic hydrothermal systems

    Science.gov (United States)

    Guo, Qinghai; Kirk Nordstrom, D.; Blaine McCleskey, R.

    2014-11-01

    Explanations for the lack of acid geothermal springs in Tibet are inferred from a comprehensive hydrochemical comparison of Tibetan geothermal waters with those discharged from Yellowstone (USA) and two active volcanic areas, Nevado del Ruiz (Colombia) and Miravalles (Costa Rica) where acid springs are widely distributed and diversified in terms of geochemical characteristic and origin. For the hydrothermal areas investigated in this study, there appears to be a relationship between the depths of magma chambers and the occurrence of acid, chloride-rich springs formed via direct magmatic fluid absorption. Nevado del Ruiz and Miravalles with magma at or very close to the surface (less than 1-2 km) exhibit very acidic waters containing HCl and H2SO4. In contrast, the Tibetan hydrothermal systems, represented by Yangbajain, usually have fairly deep-seated magma chambers so that the released acid fluids are much more likely to be fully neutralized during transport to the surface. The absence of steam-heated acid waters in Tibet, however, may be primarily due to the lack of a confining layer (like young impermeable lavas at Yellowstone) to separate geothermal steam from underlying neutral chloride waters and the possible scenario that the deep geothermal fluids below Tibet carry less H2S than those below Yellowstone.

  7. Backprojection of volcanic tremor

    Science.gov (United States)

    Haney, Matthew M.

    2014-01-01

    Backprojection has become a powerful tool for imaging the rupture process of global earthquakes. We demonstrate the ability of backprojection to illuminate and track volcanic sources as well. We apply the method to the seismic network from Okmok Volcano, Alaska, at the time of an escalation in tremor during the 2008 eruption. Although we are able to focus the wavefield close to the location of the active cone, the network array response lacks sufficient resolution to reveal kilometer-scale changes in tremor location. By deconvolving the response in successive backprojection images, we enhance resolution and find that the tremor source moved toward an intracaldera lake prior to its escalation. The increased tremor therefore resulted from magma-water interaction, in agreement with the overall phreatomagmatic character of the eruption. Imaging of eruption tremor shows that time reversal methods, such as backprojection, can provide new insights into the temporal evolution of volcanic sources.

  8. The geology of Pine and Crater Buttes: Two basaltic constructs on the far eastern Snake River Plain

    Science.gov (United States)

    Mazierski, Paul F.; King, John S.

    1987-01-01

    The emplacement history and petrochemical evolution of the volcanics associated with Pine Butte, Crater Butte, and other nearby vents are developed and described. Four major vents were identified in the study area and their associated eruptive products were mapped. All of the vents show a marked physical elongation or linear orientation coincident with the observed rift set. Planetary exploration has revealed the importance of volcanic processes in the genesis and modification of extraterrestrial surfaces. Interpretation of surface features has identified plains-type basaltic volcanism in various mare regions of the Moon and the volcanic provinces of Mars. Identification of these areas with features that appear analogous to those observed in the Pine Butte area suggests similar styles of eruption and mode of emplacement. Such terrestrial analogies serve as a method to interpret the evolution of volcanic planetary surfaces on the inner planets.

  9. Developing International Guidelines on Volcanic Hazard Assessments for Nuclear Facilities

    Science.gov (United States)

    Connor, Charles

    2014-05-01

    Worldwide, tremendous progress has been made in recent decades in forecasting volcanic events, such as episodes of volcanic unrest, eruptions, and the potential impacts of eruptions. Generally these forecasts are divided into two categories. Short-term forecasts are prepared in response to unrest at volcanoes, rely on geophysical monitoring and related observations, and have the goal of forecasting events on timescales of hours to weeks to provide time for evacuation of people, shutdown of facilities, and implementation of related safety measures. Long-term forecasts are prepared to better understand the potential impacts of volcanism in the future and to plan for potential volcanic activity. Long-term forecasts are particularly useful to better understand and communicate the potential consequences of volcanic events for populated areas around volcanoes and for siting critical infrastructure, such as nuclear facilities. Recent work by an international team, through the auspices of the International Atomic Energy Agency, has focused on developing guidelines for long-term volcanic hazard assessments. These guidelines have now been implemented for hazard assessment for nuclear facilities in nations including Indonesia, the Philippines, Armenia, Chile, and the United States. One any time scale, all volcanic hazard assessments rely on a geologically reasonable conceptual model of volcanism. Such conceptual models are usually built upon years or decades of geological studies of specific volcanic systems, analogous systems, and development of a process-level understanding of volcanic activity. Conceptual models are used to bound potential rates of volcanic activity, potential magnitudes of eruptions, and to understand temporal and spatial trends in volcanic activity. It is these conceptual models that provide essential justification for assumptions made in statistical model development and the application of numerical models to generate quantitative forecasts. It is a

  10. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Geologic map analyses: Correlation of geologic and cratering histories. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    Geologic map analyses are expanded, beginning with a discussion of particular regions which may illustrate volcanic and ballistic plains emplacement on Mercury. Major attention is focused on the surface history of Mercury through discussion of the areal distribution of plains and craters and the paleogeologic maps of the first quadrant. A summary of the lunar intercrater plains formation similarly interrelates the information from the Moon's geologic and cratering histories.

  11. The relationship between carbonate facies, volcanic rocks and plant remains in a late Palaeozoic lacustrine system (San Ignacio Fm, Frontal Cordillera, San Juan province, Argentina)

    Science.gov (United States)

    Busquets, P.; Méndez-Bedia, I.; Gallastegui, G.; Colombo, F.; Cardó, R.; Limarino, O.; Heredia, N.; Césari, S. N.

    2013-07-01

    The San Ignacio Fm, a late Palaeozoic foreland basin succession that crops out in the Frontal Cordillera (Argentinean Andes), contains lacustrine microbial carbonates and volcanic rocks. Modification by extensive pedogenic processes contributed to the massive aspect of the calcareous beds. Most of the volcanic deposits in the San Ignacio Fm consist of pyroclastic rocks and resedimented volcaniclastic deposits. Less frequent lava flows produced during effusive eruptions led to the generation of tabular layers of fine-grained, greenish or grey andesites, trachytes and dacites. Pyroclastic flow deposits correspond mainly to welded ignimbrites made up of former glassy pyroclasts devitrified to microcrystalline groundmass, scarce crystals of euhedral plagioclase, quartz and K-feldspar, opaque minerals, aggregates of fine-grained phyllosilicates and fiammes defining a bedding-parallel foliation generated by welding or diagenetic compaction. Widespread silicified and silica-permineralized plant remains and carbonate mud clasts are found, usually embedded within the ignimbrites. The carbonate sequences are underlain and overlain by volcanic rocks. The carbonate sequence bottoms are mostly gradational, while their tops are usually sharp. The lower part of the carbonate sequences is made up of mud which appear progressively, filling interstices in the top of the underlying volcanic rocks. They gradually become more abundant until they form the whole of the rock fabric. Carbonate on volcanic sandstones and pyroclastic deposits occur, with the nucleation of micritic carbonate and associated production of pyrite. Cyanobacteria, which formed the locus of mineral precipitation, were related with this nucleation. The growth of some of the algal mounds was halted by the progressive accumulation of volcanic ash particles, but in most cases the upper boundary is sharp and suddenly truncated by pyroclastic flows or volcanic avalanches. These pyroclastic flows partially destroyed the

  12. Volcanic Eruptions and Climate: Outstanding Research Issues

    Science.gov (United States)

    Robock, Alan

    2016-04-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of this aerosol cloud produce responses in the climate system. Based on observations after major eruptions of the past and experiments with numerical models of the climate system, we understand much about their climatic impact, but there are also a number of unanswered questions. Volcanic eruptions produce global cooling, and are an important natural cause of interannual, interdecadal, and even centennial-scale climate change. One of the most interesting volcanic effects is the "winter warming" of Northern Hemisphere continents following major tropical eruptions. During the winter in the Northern Hemisphere following every large tropical eruption of the past century, surface air temperatures over North America, Europe, and East Asia were warmer than normal, while they were colder over Greenland and the Middle East. This pattern and the coincident atmospheric circulation correspond to the positive phase of the Arctic Oscillation. While this response is observed after recent major eruptions, most state-of-the-art climate models have trouble simulating winter warming. Why? High latitude eruptions in the Northern Hemisphere, while also producing global cooling, do not have the same impact on atmospheric dynamics. Both tropical and high latitude eruptions can weaken the Indian and African summer monsoon, and the effects can be seen in past records of flow in the Nile and Niger Rivers. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade have had a small effect on global temperature trends. Some important outstanding research questions include: How much seasonal, annual, and decadal predictability is possible following a large volcanic eruption? Do

  13. Evidence for volcanism in NW Ishtar Terra, Venus

    International Nuclear Information System (INIS)

    Gaddis, L.; Greeley, R.

    1989-01-01

    Venera 15/16 radar data for an area in NW Ishtar Terra, Venus, show an area with moderate radar return and a smooth textured surface which embays low lying areas of the surrounding mountainous terrain. Although this unit may be an extension of the lava plains of Lakshmi Planum to the southeast, detailed study suggests a separate volcanic center in NW Ishtar Terra. Lakshmi Planum, on the Ishtar Terra highland, exhibits major volcanic and tectonic features. On the Venera radar image radar brightness is influenced by slope and roughness; radar-facing slopes (east-facing) and rough surfaces (approx. 8 cm average relief) are bright, while west-facing slopes and smooth surfaces are dark. A series of semi-circular features, apparently topographic depressions, do not conform in orientation to major structural trends in this region of NW Ishtar Terra. The large depression in NW Ishtar Terra is similar to the calderas of Colette and Sacajawea Paterae, as all three structures are large irregular depressions. NW Ishtar Terra appears to be the site of a volcanic center with a complex caldera structure, possibly more than one eruptive vent, and associated lobed flows at lower elevations. The morphologic similarity between this volcanic center and those of Colette and Sacajawea suggests that centralized eruptions have been the dominant form of volcanism in Ishtar. The location of this volcanic center at the intersection of two major compressional mountain belts and the large size of the calders (with an inferred larg/deep magma source) support a crustal thickening/melting rather than a hot-spot origin for these magmas

  14. Variation of the fractal dimension anisotropy of two major Cenozoic normal fault systems over space and time around the Snake River Plain, Idaho and SW Montana

    Science.gov (United States)

    Davarpanah, A.; Babaie, H. A.

    2012-12-01

    The interaction of the thermally induced stress field of the Yellowstone hotspot (YHS) with existing Basin and Range (BR) fault blocks, over the past 17 m.y., has produced a new, spatially and temporally variable system of normal faults around the Snake River Plain (SRP) in Idaho and Wyoming-Montana area. Data about the trace of these new cross faults (CF) and older BR normal faults were acquired from a combination of satellite imageries, DEM, and USGS geological maps and databases at scales of 1:24,000, 1:100,000, 1:250,000, 1:1000, 000, and 1:2,500, 000, and classified based on their azimuth in ArcGIS 10. The box-counting fractal dimension (Db) of the BR fault traces, determined applying the Benoit software, and the anisotropy intensity (ellipticity) of the fractal dimensions, measured with the modified Cantor dust method applying the AMOCADO software, were measured in two large spatial domains (I and II). The Db and anisotropy of the cross faults were studied in five temporal domains (T1-T5) classified based on the geologic age of successive eruptive centers (12 Ma to recent) of the YHS along the eastern SRP. The fractal anisotropy of the CF system in each temporal domain was also spatially determined in the southern part (domain S1), central part (domain S2), and northern part (domain S3) of the SRP. Line (fault trace) density maps for the BR and CF polylines reveal a higher linear density (trace length per unit area) for the BR traces in the spatial domain I, and a higher linear density of the CF traces around the present Yellowstone National Park (S1T5) where most of the seismically active faults are located. Our spatio-temporal analysis reveals that the fractal dimension of the BR system in domain I (Db=1.423) is greater than that in domain II (Db=1.307). It also shows that the anisotropy of the fractal dimension in domain I is less eccentric (axial ratio: 1.242) than that in domain II (1.355), probably reflecting the greater variation in the trend of the BR

  15. Monitoring and forecasting Etna volcanic plumes

    Directory of Open Access Journals (Sweden)

    S. Scollo

    2009-09-01

    Full Text Available In this paper we describe the results of a project ongoing at the Istituto Nazionale di Geofisica e Vulcanologia (INGV. The objective is to develop and implement a system for monitoring and forecasting volcanic plumes of Etna. Monitoring is based at present by multispectral infrared measurements from the Spin Enhanced Visible and Infrared Imager on board the Meteosat Second Generation geosynchronous satellite, visual and thermal cameras, and three radar disdrometers able to detect ash dispersal and fallout. Forecasting is performed by using automatic procedures for: i downloading weather forecast data from meteorological mesoscale models; ii running models of tephra dispersal, iii plotting hazard maps of volcanic ash dispersal and deposition for certain scenarios and, iv publishing the results on a web-site dedicated to the Italian Civil Protection. Simulations are based on eruptive scenarios obtained by analysing field data collected after the end of recent Etna eruptions. Forecasting is, hence, supported by plume observations carried out by the monitoring system. The system was tested on some explosive events occurred during 2006 and 2007 successfully. The potentiality use of monitoring and forecasting Etna volcanic plumes, in a way to prevent threats to aviation from volcanic ash, is finally discussed.

  16. Hydrogeochemical characterization of the phreatic system of the coastal wetland located between Fiumi Uniti and Bevano rivers in the southern Po plain (Northern Italy).

    Science.gov (United States)

    Marconi, V.; Dinelli, E.; Antonellini, M.; Capaccioni, B.; Balugani, E.; Gabbianelli, G.

    2009-04-01

    A hydrogeochemical study has been undertaken on the phreatic system of the coastal area included between Fiumi Uniti and Bevano rivers (in the southern part of the Po plain, near the city of Ravenna) within the framework of the CIRCLE-ERANET project WATERKNOW on the effects of climate change on the mediterranean catchments. It is one of the first attempt in the area to characterize the shallow groundwater water system and to investigate if the arsenic anomaly, known in deeper groundwater (about 100 µg/l according to recent Annual Groundwater Quality Reports of Emilia-Romagna Region), occurs also in the phreatic system. The coastal part of the Po plain consists of a low-lying and mechanically-drained farmland further from the sea and of a narrow belt of dunes and pine forests in the backshore area. The study area is recognized as a protected area at european (ZPS and SIC, site code number: IT 14070009), national and regional level (Po delta Park area). As a result of an intensive exploitation of coastal aquifers for agricultural, industrial, and civil uses, both the phreatic aquifer and the surface waters (drainage ditches and ponds) have been contaminated by seawater and by deeper groundwater. Samples representative of the top of the water table were collected in Summer 2008 in 22 auger-holes and in 3 shallow piezometers (6 m deep) documenting the deeper layers of the phreatic groundwater system. Temperature, electrical conductivity, pH and Eh of the groundwater and of the surface water were measured on site using portable instruments. Samples were filtered directly in the field, an aliquot was acidified with diluted HCl for metal analysis. Cations were determined by Flame Atomic Absorption (thermo S-series spectrometer), anions by ion chromatography (Dionex ICS-90), Fe, As, Si, B by ICP-OES (Thermo iCAP6000). The data collected in the field show that a fresh groundwater lens is still present at the top of the phreatic aquifer in the backshore area and that the

  17. Screening criteria of volcanic hazards aspect in the NPP site evaluation

    International Nuclear Information System (INIS)

    Nur Siwhan

    2013-01-01

    Studies have been conducted on the completeness of regulation in Indonesia particularly on volcanic hazards aspects in the evaluation of nuclear power plant site. Volcanic hazard aspect needed to identify potential external hazards that may endanger the safety of the operation of nuclear power plants. There are four stages for evaluating volcanic hazards, which are initial assessment, characterization sources of volcanic activity in the future, screening volcanic hazards and assessment of capable volcanic hazards. This paper discuss the third stage of the general evaluation which is the screening procedure of volcanic hazards. BAPETEN Chairman Regulation No. 2 Year of 2008 has only one screening criteria for missile volcanic phenomena, so it required screening criteria for other hazard phenomena that are pyroclastic flow density; lava flows; avalanche debris materials; lava; opening hole new eruptions, volcano missile; tsunamis; ground deformation; and hydrothermal system and ground water anomaly. (author)

  18. Global time-size distribution of volcanic eruptions on Earth.

    Science.gov (United States)

    Papale, Paolo

    2018-05-01

    Volcanic eruptions differ enormously in their size and impacts, ranging from quiet lava flow effusions along the volcano flanks to colossal events with the potential to affect our entire civilization. Knowledge of the time and size distribution of volcanic eruptions is of obvious relevance for understanding the dynamics and behavior of the Earth system, as well as for defining global volcanic risk. From the analysis of recent global databases of volcanic eruptions extending back to more than 2 million years, I show here that the return times of eruptions with similar magnitude follow an exponential distribution. The associated relative frequency of eruptions with different magnitude displays a power law, scale-invariant distribution over at least six orders of magnitude. These results suggest that similar mechanisms subtend to explosive eruptions from small to colossal, raising concerns on the theoretical possibility to predict the magnitude and impact of impending volcanic eruptions.

  19. Arsenic in the water-soil-plant system and the potential health risks in the coastal part of Chianan Plain, Southwestern Taiwan

    Science.gov (United States)

    Kar, Sandeep; Das, Suvendu; Jean, Jiin-Shuh; Chakraborty, Sukalyan; Liu, Chia-Chuan

    2013-11-01

    The present study investigates the bioavailability, soil to plant transfer and health risks of arsenic (As) in the coastal part of Chianan Plain in southwestern Taiwan. Groundwater used for irrigation, surface soils from agricultural lands and locally grown foodstuffs were collected from eight locations and analyzed for As to assess the risks associated with consuming these items. The concentration of As in groundwater ranged from 13.8 to 881 μg/L, whereas surface soil showed total As content in the range of 7.92-12.7 mg/kg. The available As content in surface soil accounted for 0.06-6.71% of the total As content, and was significantly correlated with it (R2 = 0.65, p < 0.05). Among the leachable fraction, the organic matter (3.23-54.8%) and exchangeable portions of oxides (6.03-38.4%) appear to be the major binding phases of As. The average As content in fourteen studied crops and vegetables varied from 10.3 to 151 μg/kg with maximum in mustard and minimum in radish. All the plants showed considerably higher As content (21.5 ± 3.64-262 ± 36.2 μg/kg) in their roots compared to the edible parts (9.15 ± 1.44-75.8 ± 22.9 μg/kg). The bioaccumulation factor (BAF) based on total As (ranging from 0.0009 to 0.144) and available As in soil (ranging from 0.039 to 0.571) indicate that mustard, rice, amaranth and spinach are the highest accumulators of As. Although the health risk index (HRI) of the studied crops and vegetables ranged from only 0.0068-0.454, with the maximum in rice, the combined HRI indicates an alarming value of 0.88. Therefore, the possible health risks due to long-term consumption of rice and other As-rich foodstuffs could be overcome by controlling the contamination pathways in the water-soil-plant system.

  20. Geochemical features of the geothermal fluids from the Mapamyum non-volcanic geothermal system (Western Tibet, China)

    Science.gov (United States)

    Wang, Peng; Chen, Xiaohong; Shen, Licheng; Wu, Kunyu; Huang, Mingzhi; Xiao, Qiong

    2016-06-01

    Mapamyum geothermal field (MGF) in western Tibet is one of largest geothermal areas characterized by the occurrence of hydrothermal explosions on the Tibetan Plateau. The geochemical properties of hydrothermal water in the MGF system were investigated to trace the origin of the solutes and to determine the equilibrium temperatures of the feeding reservoir. The study results show that the geochemistry of hydrothermal waters in the MGF system is mainly of the Na-HCO3 type. The chemical components of hydrothermal waters are mainly derived from the minerals in the host rocks (e.g., K-feldspar, albite, Ca-montmorillonite, and Mg-montmorillonite). The hydrothermal waters are slightly supersaturated or undersaturated with respect to aragonite, calcite, dolomite, chalcedony and quartz (saturation indices close to 0), but are highly undersaturated with respect to gypsum and anhydrite (saturation indices < 0). Mixing models and Na-K-Mg ternary diagrams show that strong mixing between cold meteoric water and deeply-seated thermal fluids occurred during the upward flowing process. δD and δ18O data confirm that the meteoric water acts as the water source of the geothermal waters. An 220 °C equilibrated reservoir temperature of hydrothermal spring waters was calculated via both the Na-K-Mg ternary diagrams and the cationic chemical geothermometers. The logpCO2 of hydrothermal waters in the MGF system ranges from - 2.59 to - 0.57 and δ13C of the total dissolved inorganic carbon ranges from - 5.53‰ to - 0.94‰, suggesting that the carrier CO2 in hydrothermal water are mainly of a magmatic or metamorphic CO2 origin.

  1. Delineation of the High Enthalpy Reservoirs of the Sierra Nevada Volcanic Geothermal System, South-Central Chile

    Science.gov (United States)

    Alam, M.; Muñoz, M.; Parada, M.

    2011-12-01

    Geothermal system associated with the Pleistocene-Holocene Sierra Nevada volcano (SNVGS) in the Araucanía Region of Chile has surface manifestations from the north-western flank of the volcano, up to Manzanar and Malalcahuello. Baños del Toro, located on the northwestern flank of the volcano, has numerous fumaroles and acid pools (acid sulfate waters, T=~90°C, pH=2.1, TDS=3080 mg/L); while Aguas de la Vaca, near the base of the volcano, has a bubbling spring (chloride-sulfate waters, T=~60°C, pH=7.0, TDS=950 mg/L). Five shallow (Geotermia) of the Ministry of Energy and Mining, Government of Chile.

  2. From source to surface: Tracking magmatic boron and chlorine input into the geothermal systems of the Taupo Volcanic Zone, New Zealand

    Science.gov (United States)

    Bégué, Florence; Deering, Chad D.; Gravley, Darren M.; Chambefort, Isabelle; Kennedy, Ben M.

    2017-10-01

    The magmatic contribution into geothermal fluids in the central Taupo Volcanic Zone (TVZ), New Zealand, has been attributed to either andesitic, 'arc-type' fluids, or rhyolitic, 'rift-type' fluids to explain the compositional diversity of discharge waters. However, this model relies on outdated assumptions related to geochemical trends associated with the magma at depth of typical arc to back-arc settings. Current tectonic models have shown that the TVZ is situated within a rifting arc and hosts magmatic systems dominated by distinct rhyolite types, that are likely to have evolved under different conditions than the subordinate andesites. Therefore, a new appraisal of the existing models is required to further understand the origin of the spatial compositional diversity observed in the geothermal fluids and its relationship to the structural setting. Here, we use volatile concentrations (i.e. H2O, Cl, B) from rhyolitic and andesitic mineral-hosted melt inclusions to evaluate the magmatic contribution to the TVZ geothermal systems. The andesite and two different types of rhyolites (R1 and R2) are each distinct in Cl/H2O and B/Cl, which will affect volatile solubility and phase separation (vapor vs. hydrosaline liquid) of the exsolved volatile phase. Ultimately, these key differences in the magmatic volatile constituents will play a significant role in governing the concentration of Cl discharged into geothermal systems. We estimate bulk fluid compositions (B and Cl) in equilibrium with the different melt types to show the potential contribution of 'parent' fluids to the geothermal systems throughout the TVZ. The results of this analysis show that the variability in fluid compositions partly reflects degassing from previously unaccounted for distinct magma source compositions. We suggest the geothermal systems that appear to have an 'arc-type' andesitic fluid contribution are actually derived from a rhyolite melt in equilibrium with a highly crystalline andesite

  3. Contrasting estimates on the depth of magma storage zones in volcanic systems from mineral barometry and phase equilibrium experiments: a case study from Mount Merapi, Indonesia

    Science.gov (United States)

    Erdmann, Saskia; Martel, Caroline

    2015-04-01

    Mount Merapi, located in central Java, erupts on average every 5-10 years by discharging block-and-ash flows that pose local, but spatially restricted hazards. In 2010, however, the volcano erupted with a force that has been unprecedented in over 100 years. Its proximity to the metropolis of Yogyakarta with a population of >4 million makes short- and long-term eruption forecasting a task of vital importance. Critical to the appraisal of the volcano's hazard potential are tight constraints on its upper-crustal magma plumbing system and particularly on the location of its pre-eruptive reservoir. Previous petrological studies have estimated on the basis of amphibole and clinopyroxene barometry that the main magma storage zone below Merapi is located at depths of >10-15 km, while geophysical surveys have inferred significant magma storage zones at depths of ~5.5-9 km. We have carried out phase equilibrium experiments on basaltic andesite erupted in 2010, which indicate that the main pre-eruptive reservoir is located at a depth of ~7-8 km (~200 MPa). Our results thus corroborate the findings of earlier geophysical surveys and highlight the extreme uncertainty of mineral-based pressure estimates for volcanic magma systems. We point out that the commonly employed amphibole barometric calibrations of Ridolfi et al. (2010) and Ridolfi & Renzulli (2012) calculate low crystallization pressure for amphibole crystallized from felsic melt and high crystallization pressure for amphibole crystallized from mafic melt, and that the calculated pressure is thus largely unrelated to true values. Commonly employed clinopyroxene barometers (e.g., those of Nimis 1999; Putirka 2008) are also of limited use for estimating the location of crustal magma reservoirs, because the methods have large standard errors and are extremely temperature-sensitive. As a result, the calculated crystallization pressures inevitably indicate crystallization over a large range of depths, often from deep- to

  4. Crustal Seismicity and Geomorphic Observations of the Chiripa-Haciendas Fault System: The Guanacaste Volcanic Arc Sliver of Western Costa Rica

    Science.gov (United States)

    Lewis, J. C.; Montero Pohly, W. K.; Araya, M. C.

    2017-12-01

    It has recently been shown that contemporary northwest motion of the Nicoya Peninsula of Costa Rica reflects a tectonic sliver that includes much of the upper-plate arc, referred to as the Guanacaste Volcanic Arc Sliver (GVAS). Here we characterize historical seismicity and geomorphic expressions of faults that define the northeastern margin of the GVAS. Several crustal earthquakes and their aftershocks provide constraints on the geometry and/or kinematics of the fault system. These include the Armenia earthquake of July 12, 2011, the Bijagua earthquake of January 27, 2002, the Tilarán earthquake of April 13, 1973 and two much older events. We summarize these earthquakes in the context of recent fault mapping and focal mechanism solutions, and suggest that most of the deformation can be explained by slip on steeply dipping NW-striking fault planes accommodating dextral slip. Streams that cross the major fault traces we have mapped also show deflections consistent with dextral slip. These include map-view apparent offsets of 6.5 km for the Haciendas River, 1.0 km for the Orosi River and 0.6 km for the Pizote River. Although preservation is poor, we document stream terrace risers that reveal truncations and/or offsets consistent with dextral slip. Additional constraints on the fault system are apparent as it is traced into Lake Nicaragua. Previous workers have shown that earthquake clusters accommodate a combination of dextral slip on NW-strike faults and sinistral slip NE-strike faults, the latter described as part of a system of bookshelf fault blocks. Whether the northeastern margin of the GVAS under Lake Nicaragua is a single fault strand or an array of bookshelf blocks remains an open question. An equally important gap in our understanding is the kinematic link of the fault system to the east where the GVAS originates. Our results set the stage for expanded studies that will be essential to understanding the relative contributions of Cocos Ridge collision and

  5. Pre-eruptive volatile and erupted gas phase characterization of the 2014 basalt of Bárðarbunga volcanic system, Iceland.

    Science.gov (United States)

    Haddadi, Baptiste; Moune, Séverine; Sigmarsson, Olgeir; Gauthier, Pierre-Jean; Gouhier, Mathieu

    2015-04-01

    The 2014 Holuhraun eruption on the Bárðarbunga Volcanic System is the largest fissure eruption in Iceland since the 1783 Laki eruption. The eruption started end of August 2014 and has been characterized by large emission of SO2 into the atmosphere. It provides a rare opportunity to study in details magmatic and degassing processes during a large-volume fissure eruption. In order to characterize the pre-eruptive magmatic composition and to assess the plume chemistry at the eruption site, lava and tephra were sampled together with the eruption plume. The basalt composition is olivine tholeiite with MgO close to 7 wt%. It is phenocryst-poor with plagioclase as the dominant mineral phase but olivine and clinopyroxene are also present together with sulphide globules composed principally of pyrite and chalcopyrite. The volatile (S, Cl and F) and major element concentrations were measured by the electron microprobe in melt inclusions (MIs) trapped in plagioclase and clinopyroxene and groundmass glass. The MIs composition ranges from fairly primitive basaltic compositions (MgO: 9.03 wt%) down to evolved qz-tholeiites (MgO: 5.57 wt%), with estimated pre-eruptive S concentrations of 1500 ppm. Tephra groundmass glass contains 400 ppm S, whereas Cl and F concentrations are respectively slightly lower and indistinguishable from those in the MIs. This implies limited exsolution of halogens but 75% of the initial sulphur content. Relatively to their total iron content, MIs are sulphur saturated, and their oxygen fugacity close to the FMQ buffer. The difference between the estimated initial volatile concentrations measured in the MIs and in the tephra groundmass (i.e. the so-called petrological method) yields 7.2 Mt SO2, limited HCl and no HF atmospheric mass loading from the Holuhraun 2014 eruption. The SO2/HCl molar ratio of the gas phase, calculated from the MIs, is 13 and 14, respectively, using average and estimated pre-eruptive S and Cl concentrations in the MIs. Filter

  6. Quaternary volcanism, tectonics, and sedimentation in the Idaho National Engineering Laboratory area

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, W.R.; Smith, R.P.

    1992-09-01

    In this article, we discuss the regional context and describe localities for a two-day field excursion in the vicinity of the Idaho National Engineering Laboratory (INEL). We address several geologic themes: (1) Late Cenozoic, bimodal volcanism of the Eastern Snake River Plain (ESRP), (2) the regional tectonics and structural geology of the Basin and Range province to the northwest of the ESRP, (3) fluvial, lacustrine, and aeolian sedimentation in the INEL area, and (4) the influence of Quaternary volcanism and tectonics on sedimentation near the INEL.

  7. Quaternary volcanism, tectonics, and sedimentation in the Idaho National Engineering Laboratory area

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, W.R.; Smith, R.P.

    1992-01-01

    In this article, we discuss the regional context and describe localities for a two-day field excursion in the vicinity of the Idaho National Engineering Laboratory (INEL). We address several geologic themes: (1) Late Cenozoic, bimodal volcanism of the Eastern Snake River Plain (ESRP), (2) the regional tectonics and structural geology of the Basin and Range province to the northwest of the ESRP, (3) fluvial, lacustrine, and aeolian sedimentation in the INEL area, and (4) the influence of Quaternary volcanism and tectonics on sedimentation near the INEL.

  8. Volcanic risk; Risque volcanique

    Energy Technology Data Exchange (ETDEWEB)

    Rancon, J.P.; Baubron, J.C.

    1995-12-31

    This project follows the previous multi-disciplinary studies carried out by the French Bureau de Recherches Geologiques et Minieres (BRGM) on the two active volcanoes of the French lesser Antilles: Mt Pelee (Martinique) and Soufriere (Guadeloupe) for which geological maps and volcanic risk studies have been achieved. The research program comprises 5 parts: the study of pyroclastic deposits from recent eruptions of the two volcanoes for a better characterization of their eruptive phenomenology and a better definition of crisis scenarios; the study of deposits and structures of active volcanoes from Central America and the study of eruptive dynamics of andesite volcanoes for a transposition to Antilles` volcanoes; the starting of a methodological multi-disciplinary research (volcanology, geography, sociology...) on the volcanic risk analysis and on the management of a future crisis; and finally, the development of geochemical survey techniques (radon, CO{sub 2}, H{sub 2}O) on active volcanoes of Costa-Rica and Europe (Fournaise, Furnas, Etna) and their application to the Soufriere. (J.S.). 9 refs., 3 figs.

  9. Friction in volcanic environments

    Science.gov (United States)

    Kendrick, Jackie E.; Lavallée, Yan

    2016-04-01

    Volcanic landscapes are amongst the most dynamic on Earth and, as such, are particularly susceptible to failure and frictional processes. In rocks, damage accumulation is frequently accompanied by the release of seismic energy, which has been shown to accelerate in the approach to failure on both a field and laboratory scale. The point at which failure occurs is highly dependent upon strain-rate, which also dictates the slip-zone properties that pertain beyond failure, in scenarios such as sector collapse and pyroclastic flows as well as the ascent of viscous magma. High-velocity rotary shear (HVR) experiments have provided new opportunities to overcome the grand challenge of understanding faulting processes during volcanic phenomena. Work on granular ash material demonstrates that at ambient temperatures, ash gouge behaves according to Byerlee's rule at low slip velocities, but is slip-weakening, becoming increasingly lubricating as slip ensues. In absence of ash along a slip plane, rock-rock friction induces cataclasis and heating which, if sufficient, may induce melting (producing pseudotachylyte) and importantly, vesiculation. The viscosity of the melt, so generated, controls the subsequent lubrication or resistance to slip along the fault plane thanks to non-Newtonian suspension rheology. The shear-thinning behaviour and viscoelasticity of frictional melts yield a tendency for extremely unstable slip, and occurrence of frictional melt fragmentation. This velocity-dependence acts as an important feedback mechanism on the slip plane, in addition to the bulk composition, mineralogy and glass content of the magma, that all influence frictional behaviour. During sector collapse events and in pyroclastic density currents it is the frictional properties of the rocks and ash that, in-part, control the run-out distance and associated risk. In addition, friction plays an important role in the eruption of viscous magmas: In the conduit, the rheology of magma is integral

  10. Microphysical Properties of Alaskan Volcanic Ash

    Science.gov (United States)

    Puthukkudy, A.; Espinosa, R.; Rocha Lima, A.; Remer, L.; Colarco, P. R.; Whelley, P.; Krotkov, N. A.; Young, K.; Dubovik, O.; Wallace, K.; Martins, J. V.

    2017-12-01

    Volcanic ash has the potential to cause a variety of severe problems for human health and the environment. Therefore, effective monitoring of the dispersion and fallout from volcanic ash clouds and characterization of the aerosol particle properties are essential. One way to acquire information from volcanic clouds is through satellite remote sensing: such images have greater coverage than ground-based observations and can present a "big picture" perspective. A challenge of remote sensing is that assumptions of certain properties of the target are often a pre-requisite for making accurate and quantitative retrievals. For example, detailed information about size distribution, sphericity, and optical properties of the constituent matter is needed or must be assumed. The same kind of information is also needed for atmospheric transport models to properly simulate the dispersion and fallout of volcanic ash. Presented here is a laboratory method to determine the microphysical and optical properties of volcanic ash samples collected from two Alaskan volcanoes with markedly different compositions. Our method uses a Polarized Imaging Nephelometer (PI-Neph) and a system that re-suspends the particles in an air flow. The PI-Neph measures angular light scattering and polarization of the re-suspended particles from 3o to 175o in scattering angle, with an angular resolution of 1o . Primary measurements include phase function and polarized phase function at three wavelengths (445nm, 532nm, and 661nm). Size distribution, sphericity, and complex refractive index are retrieved indirectly from the PI-Neph measurements using the GRASP (Generalized Retrieval of Aerosol and Surface Properties) inversion algorithm. We report the results of this method applied to samples from the Mt. Okmok (2008) and Mt. Katmai (1912) volcanic eruptions. To our knowledge, this is the first time direct measurements of phase matrix elements of ash from Mt. Okmok and Mt. Katmai have been reported. Retrieved

  11. Volcanism Studies: Final Report for the Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Bruce M. Crowe; Frank V. Perry; Greg A. Valentine; Lynn M. Bowker

    1998-12-01

    This report synthesizes the results of volcanism studies conducted by scientists at the Los Alamos National Laboratory and collaborating institutions on behalf of the Department of Energy's Yucca Mountain Project. An assessment of the risk of future volcanic activity is one of many site characterization studies that must be completed to evaluate the Yucca Mountain site for potential long-term storage of high-level radioactive waste. The presence of several basaltic volcanic centers in the Yucca Mountain region of Pliocene and Quaternary age indicates that there is a finite risk of a future volcanic event occurring during the 10,000-year isolation period of a potential repository. Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The risk of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Future volcanic events cannot be predicted with certainty but instead are estimated using formal methods of probabilistic volcanic hazard assessment (PVHA). Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The distribution, eruptive history, and geochronology of Plio-Quaternary basalt centers are described by individual center emphasizing the younger postcaldera basalt (<5 Ma). The Lathrop Wells volcanic center is described in detail because it is the youngest basalt center in the YMR. The age of the Lathrop Wells center is now confidently determined to be about 75 thousand years old. Chapter 3 describes the tectonic setting of the YMR and presents and assesses the significance of multiple alternative tectonic models. The Crater Flat volcanic zone is

  12. The Role of Volcanic Activity in Climate and Global Change

    KAUST Repository

    Stenchikov, Georgiy L.

    2015-09-23

    Explosive volcanic eruptions are magnificent events that in many ways affect the Earth\\'s natural processes and climate. They cause sporadic perturbations of the planet\\'s energy balance, activating complex climate feedbacks and providing unique opportunities to better quantify those processes. We know that explosive eruptions cause cooling in the atmosphere for a few years, but we have just recently realized that volcanic signals can be seen in the subsurface ocean for decades. The volcanic forcing of the previous two centuries offsets the ocean heat uptake and diminishes global warming by about 30%. The explosive volcanism of the twenty-first century is unlikely to either cause any significant climate signal or to delay the pace of global warming. The recent interest in dynamic, microphysical, chemical, and climate impacts of volcanic eruptions is also excited by the fact that these impacts provide a natural analogue for climate geoengineering schemes involving deliberate development of an artificial aerosol layer in the lower stratosphere to counteract global warming. In this chapter we aim to discuss these recently discovered volcanic effects and specifically pay attention to how we can learn about the hidden Earth-system mechanisms activated by explosive volcanic eruptions. To demonstrate these effects we use our own model results when possible along with available observations, as well as review closely related recent publications.

  13. Geophysical expression of caldera related volcanism, structures and mineralization in the McDermitt volcanic field

    Science.gov (United States)

    Rytuba, J. J.; Blakely, R. J.; Moring, B.; Miller, R.

    2013-12-01

    The High Rock, Lake Owyhee, and McDermitt volcanic fields, consisting of regionally extensive ash flow tuffs and associated calderas, developed in NW Nevada and SE Oregon following eruption of the ca. 16.7 Ma Steens flood basalt. The first ash flow, the Tuff of Oregon Canyon, erupted from the McDermitt volcanic field at 16.5Ma. It is chemically zoned from peralkaline rhyolite to dacite with trace element ratios that distinguish it from other ash flow tuffs. The source caldera, based on tuff distribution, thickness, and size of lithic fragments, is in the area in which the McDermitt caldera (16.3 Ma) subsequently formed. Gravity and magnetic anomalies are associated with some but not all of the calderas. The White Horse caldera (15.6 Ma), the youngest caldera in the McDermitt volcanic field has the best geophysical expression, with both aeromagnetic and gravity lows coinciding with the caldera. Detailed aeromagnetic and gravity surveys of the McDermitt caldera, combined with geology and radiometric surveys, provides insight into the complexities of caldera collapse, resurgence, post collapse volcanism, and hydrothermal mineralization. The McDermitt caldera is among the most mineralized calderas in the world, whereas other calderas in these three Mid Miocene volcanic fields do not contain important hydrothermal ore deposits, despite having similar age and chemistry. The McDermitt caldera is host to Hg, U, and Li deposits and potentially significant resources of Ga, Sb, and REE. The geophysical data indicate that post-caldera collapse intrusions were important in formation of the hydrothermal systems. An aeromagnetic low along the E caldera margin reflects an intrusion at a depth of 2 km associated with the near-surface McDermitt-hot-spring-type Hg-Sb deposit, and the deeper level, high-sulfidation Ga-REE occurrence. The Li deposits on the W side of the caldera are associated with a series of low amplitude, small diameter aeromagnetic anomalies that form a continuous

  14. Long term volcanic hazard analysis in the Canary Islands

    Science.gov (United States)

    Becerril, L.; Galindo, I.; Laín, L.; Llorente, M.; Mancebo, M. J.

    2009-04-01

    Historic volcanism in Spain is restricted to the Canary Islands, a volcanic archipelago formed by seven volcanic islands. Several historic eruptions have been registered in the last five hundred years. However, and despite the huge amount of citizens and tourist in the archipelago, only a few volcanic hazard studies have been carried out. These studies are mainly focused in the developing of hazard maps in Lanzarote and Tenerife islands, especially for land use planning. The main handicap for these studies in the Canary Islands is the lack of well reported historical eruptions, but also the lack of data such as geochronological, geochemical or structural. In recent years, the use of Geographical Information Systems (GIS) and the improvement in the volcanic processes modelling has provided an important tool for volcanic hazard assessment. Although this sophisticated programs are really useful they need to be fed by a huge amount of data that sometimes, such in the case of the Canary Islands, are not available. For this reason, the Spanish Geological Survey (IGME) is developing a complete geo-referenced database for long term volcanic analysis in the Canary Islands. The Canarian Volcanic Hazard Database (HADA) is based on a GIS helping to organize and manage volcanic information efficiently. HADA includes the following groups of information: (1) 1:25.000 scale geologic maps, (2) 1:25.000 topographic maps, (3) geochronologic data, (4) geochemical data, (5) structural information, (6) climatic data. Data must pass a quality control before they are included in the database. New data are easily integrated in the database. With the HADA database the IGME has started a systematic organization of the existing data. In the near future, the IGME will generate new information to be included in HADA, such as volcanological maps of the islands, structural information, geochronological data and other information to assess long term volcanic hazard analysis. HADA will permit

  15. Deep Geothermal Reservoir Temperatures in the Eastern Snake River Plain, Idaho using Multicomponent Geothermometry

    Energy Technology Data Exchange (ETDEWEB)

    Ghanashyam Neupane; Earl D. Mattson; Travis L. McLing; Carl D. Palmer; Robert W. Smith; Thomas R. Wood

    2014-02-01

    The U.S. Geological survey has estimated that there are up to 4,900 MWe of undiscovered geothermal resources and 92,000 MWe of enhanced geothermal potential within the state of Idaho. Of particular interest are the resources of the Eastern Snake River Plain (ESRP) which was formed by volcanic activity associated with the relative movement of the Yellowstone Hot Spot across the state of Idaho. This region is characterized by a high geothermal gradient and thermal springs occurring along the margins of the ESRP. Masking much of the deep thermal potential of the ESRP is a regionally extensive and productive cold-water aquifer. We have undertaken a study to infer the temperature of the geothermal system hidden beneath the cold-water aquifer of the ESRP. Our approach is to estimate reservoir temperatures from measured water compositions using an inverse modeling technique (RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. In the initial stages of this study, we apply the RTEst model to water compositions measured from a limited number of wells and thermal springs to estimate the regionally extensive geothermal system in the ESRP.

  16. Mainshock-Aftershocks Clustering Detection in Volcanic Regions

    Science.gov (United States)

    Garza Giron, R.; Brodsky, E. E.; Prejean, S. G.

    2017-12-01

    Crustal earthquakes tend to break their general Poissonean process behavior by gathering into two main kinds of seismic bursts: swarms and mainshock-aftershocks sequences. The former is commonly related to volcanic or geothermal processes whereas the latter is a characteristic feature of tectonically driven seismicity. We explore the mainshock-aftershock clustering behavior of different active volcanic regions in Japan and its comparison to non-volcanic regions. We find that aftershock production in volcanoes shows mainshock-aftershocks clustering similar to what is observed in non-volcanic areas. The ratio of volanic areas that cluster in mainshock-aftershocks sequences vs the areas that do not is comparable to the ratio of non-volcanic regions that show clustering vs the ones that do not. Furthermore, the level of production of aftershocks for most volcanic areas where clustering is present seems to be of the same order of magnitude, or slightly higher, as the median of the non-volcanic regions. An interesting example of highly aftershock-productive volcanoes emerges from the 2000 Miyakejima dike intrusion. A big seismic cluster started to build up rapidly in the south-west flank of Miyakejima to later propagate to the north-west towards the Kozushima and Niijima volcanoes. In Miyakejima the seismicity showed a swarm-like signature with a constant earthquake rate, whereas Kozushima and Niijima both had expressions of highly productive mainshock-aftershocks sequences. These findings are surprising given the alternative mechanisms available in volcanic systems for releasing deviatoric strain. We speculate that aftershock behavior might hold a relationship with the rheological properties of the rocks of each system and with the capacity of a system to accumulate or release the internal pressures caused by magmatic or hydrothermal systems.

  17. Closer look at lunar volcanism

    International Nuclear Information System (INIS)

    Vaniman, D.T.; Heiken, G.; Taylor, G.J.

    1984-01-01

    Although the American Apollo and Soviet Luna missions concentrated on mare basalt samples, major questions remain about lunar volcanism. Lunar field work will be indispensable for resolving the scientific questions about ages, compositions, and eruption processes of lunar volcanism. From a utilitarian standpoint, a better knowledge of lunar volcanism will also yield profitable returns in lunar base construction (e.g., exploitation of rille or lava-tube structures) and in access to materials such as volatile elements, pure glass, or ilmenite for lunar industry

  18. Components for containment enclosures - Part 3: Transfer systems such as plain doors, airlock chambers, double door transfer systems, leaktight connections for waste drums. 1. ed.

    International Nuclear Information System (INIS)

    1998-01-01

    This part of ISO 11933 specifies requirements for the selection, construction and use of the following leak tight components: doors, airlock chambers, double door transfer systems, leaktight connections for waste drums. Some of the elements, double doors or airlock chambers are described in ISO 11933-1 and ISO 11933-2 as well. Doors having bigger dimensions used for personnel od larger objects are not covered by this document

  19. On the plumbing system of volcanic complexes: field constraints from the Isle of Skye (UK) and FEM elasto-plastic modelling including gravity and tectonics.

    Science.gov (United States)

    Bistacchi, A.; Pisterna, R.; Romano, V.; Rust, D.; Tibaldi, A.

    2009-04-01

    The plumbing system that connects a sub-volcanic magma reservoir to the surface has been the object of field characterization and mechanical modelling efforts since the pioneering work by Anderson (1936), who produced a detailed account of the spectacular Cullin Cone-sheet Complex (Isle of Skye, UK) and a geometrical and mechanical model aimed at defining the depth to the magma chamber. Since this work, the definition of the stress state in the half space comprised between the magma reservoir and the surface (modelled either as a flat surface or a surface comprising a volcanic edifice) was considered the key point in reconstructing dike propagation paths from the magma chamber. In fact, this process is generally seen as the propagation in an elastic media of purely tensional joints (mode I or opening mode propagation), which follow trajectories perpendicular to the least compressive principal stress axis. Later works generally used different continuum mechanics methodologies (analytic, BEM, FEM) to solve the problem of a pressure source (the magma chamber, either a point source or a finite volume) in an elastic (in some cases heterogeneous) half space (bounded by a flat topography or topped by a "volcano"). All these models (with a few limited exceptions) disregard the effect of the regional stress field, which is caused by tectonic boundary forces and gravitational body load, and consider only the pressure source represented by the magma chamber (review in Gudmundsson, 2006). However, this is only a (sometimes subordinate) component of the total stress field. Grosfils (2007) first introduced the gravitational load (but not tectonic stresses) in an elastic model solved with FEM in a 2D axisymmetric half-space, showing that "failure to incorporate gravitational loading correctly" affect the calculated stress pattern and many of the predictions that can be drawn from the models. In this contribution we report on modelling results that include: 2D axisymmetric or true

  20. Volcanic ash impacts on critical infrastructure

    Science.gov (United States)

    Wilson, Thomas M.; Stewart, Carol; Sword-Daniels, Victoria; Leonard, Graham S.; Johnston, David M.; Cole, Jim W.; Wardman, Johnny; Wilson, Grant; Barnard, Scott T.

    2012-01-01

    supply managers include: monitoring turbidity levels in raw water intakes, and if necessary increasing chlorination to compensate for higher turbidity; managing water demand; and communicating monitoring results with the public to allay fears of contamination. Ash can cause major damage to wastewater disposal systems. Ash deposited onto impervious surfaces such as roads and car parks is very easily washed into storm drains, where it can form intractable masses and lead to long-term flooding problems. It can also enter wastewater treatment plants (WWTPs), both through sewer lines and by direct fallout. Damage to modern WWTPs can run into millions of dollars. Ash falls reduce visibility creating hazards for ground transportation. Dry ash is also readily remobilised by vehicle traffic and wind, and dry and wet ash deposits will reduce traction on paved surfaces, including airport runways. Ash cleanup from road and airports is commonly necessary, but the large volumes make it logistically challenging. Vehicles are vulnerable to ash; it will clog filters and brake systems and abrade moving parts within engines. Lastly, modern telecommunications networks appear to be relatively resilient to volcanic ash fall. Signal attenuation and interference during ash falls has not been reported in eruptions over the past 20 years, with the exception of interference from ash plume-generated lightning. However, some telecommunications equipment is vulnerable to airborne ash, in particular heating, ventilation and air-conditioning (HVAC) systems which may become blocked from ash ingestion leading to overheating. This summary of volcanic ash impacts on critical infrastructure provides insight into the relative vulnerability of infrastructure under a range of different ashfall scenarios. Identifying and quantifying these impacts is an essential step in building resilience within these critical systems. We have attempted to consider interdependencies between sectors in a holistic way using

  1. Volcanology: Volcanic bipolar disorder explained

    Science.gov (United States)

    Jellinek, Mark

    2014-02-01

    Eruptions come in a range of magnitudes. Numerical simulations and laboratory experiments show that rare, giant super-eruptions and smaller, more frequent events reflect a transition in the essential driving forces for volcanism.

  2. Observations of volcanic plumes using small balloon soundings

    Science.gov (United States)

    Voemel, H.

    2015-12-01

    Eruptions of volcanoes are very difficult to predict and for practical purposes may occur at any time. Any observing system intending to observe volcanic eruptions has to be ready at any time. Due to transport time scales, emissions of large volcanic eruptions, in particular injections into the stratosphere, may be detected at locations far from the volcano within days to weeks after the eruption. These emissions may be observed using small balloon soundings at dedicated sites. Here we present observations of particles of the Icelandic Grimsvotn eruption at the Meteorological Observatory Lindenberg, Germany in the months following the eruption and observations of opportunity of other volcanic particle events. We also present observations of the emissions of SO2 from the Turrialba volcano at San Jose, Costa Rica. We argue that dedicated sites for routine observations of the clean and perturbed atmosphere using small sounding balloons are an important element in the detection and quantification of emissions from future volcanic eruptions.

  3. Volcanic hazards and aviation safety

    Science.gov (United States)

    Casadevall, Thomas J.; Thompson, Theodore B.; Ewert, John W.; ,

    1996-01-01

    An aeronautical chart was developed to determine the relative proximity of volcanoes or ash clouds to the airports and flight corridors that may be affected by volcanic debris. The map aims to inform and increase awareness about the close spatial relationship between volcanoes and aviation operations. It shows the locations of the active volcanoes together with selected aeronautical navigation aids and great-circle routes. The map mitigates the threat that volcanic hazards pose to aircraft and improves aviation safety.

  4. Volcanic crisis in

    Directory of Open Access Journals (Sweden)

    Mgs. Víctor Manuel Pérez Martínez

    2007-01-01

    Full Text Available The article is the result of an investigation which is focussed on some deontological aspects of the scientificjournalism. In the first place it gives a theoretical vision about science, journalism, internet and including some reflectionsabout the deontological principles in handling the information about science and technology. This focus is useful as it formsthe base of an investigation where we deal with the information about a possible ”volcanic crisis” in El Teide during the years2004-2005 done by the digital newspaper” El Dïa” a canarian newspaper from Tenerife. The work required the revision of theinformation which was published and a followed analysis of its context. It was used the digital version with the purpose ofvisualizing the news which was published. It was also compared with a printed version, with local cover but divulged theinformation to the public who was most affected by this particular news. The results give rise to some questions regardinghow the information is given to a topic which is of local interest as well as national and international interest due to therepercussions in the social, economical and tourist field (the tourist field is the main industrial sector in Tenerife by receivingthis type of news.

  5. Plain film diagnosis of the liver

    International Nuclear Information System (INIS)

    Rogers, J.V. Jr.; Torres, W.E.; Clements, J.L. Jr.; Gedgaudas-McClees, R.K.

    1985-01-01

    One of the first examinations obtained routinely in abdominal radiography is the plain radiograph of the abdomen. The liver occupies anywhere from 15 to 30 percent of the area on such examinations. Thus, it is important to pay particular attention to the region of the liver and obtain as much information as possible from these films. The purpose of this chapter is to review the normal radiographic anatomy and pathology. Also, pathologic calcifications, gas collections, unusual collections of fat, and the systemic manifestations of hepatic disease are discussed within this chapter

  6. Scaling properties of planetary calderas and terrestrial volcanic eruptions

    Directory of Open Access Journals (Sweden)

    L. Sanchez

    2012-11-01

    Full Text Available Volcanism plays an important role in transporting internal heat of planetary bodies to their surface. Therefore, volcanoes are a manifestation of the planet's past and present internal dynamics. Volcanic eruptions as well as caldera forming processes are the direct manifestation of complex interactions between the rising magma and the surrounding host rock in the crust of terrestrial planetary bodies. Attempts have been made to compare volcanic landforms throughout the solar system. Different stochastic models have been proposed to describe the temporal sequences of eruptions on individual or groups of volcanoes. However, comprehensive understanding of the physical mechanisms responsible for volcano formation and eruption and more specifically caldera formation remains elusive. In this work, we propose a scaling law to quantify the distribution of caldera sizes on Earth, Mars, Venus, and Io, as well as the distribution of calderas on Earth depending on their surrounding crustal properties. We also apply the same scaling analysis to the distribution of interevent times between eruptions for volcanoes that have the largest eruptive history as well as groups of volcanoes on Earth. We find that when rescaled with their respective sample averages, the distributions considered show a similar functional form. This result implies that similar processes are responsible for caldera formation throughout the solar system and for different crustal settings on Earth. This result emphasizes the importance of comparative planetology to understand planetary volcanism. Similarly, the processes responsible for volcanic eruptions are independent of the type of volcanism or geographical location.

  7. Gas measurements from the Costa Rica-Nicaragua volcanic segment suggest possible along-arc variations in volcanic gas chemistry

    Science.gov (United States)

    Aiuppa, A.; Robidoux, P.; Tamburello, G.; Conde, V.; Galle, B.; Avard, G.; Bagnato, E.; De Moor, J. M.; Martínez, M.; Muñóz, A.

    2014-12-01

    Obtaining accurate estimates of the CO2 output from arc volcanism requires a precise understanding of the potential along-arc variations in volcanic gas chemistry, and ultimately of the magmatic gas signature of each individual arc segment. In an attempt to more fully constrain the magmatic gas signature of the Central America Volcanic Arc (CAVA), we present here the results of a volcanic gas survey performed during March and April 2013 at five degassing volcanoes within the Costa Rica-Nicaragua volcanic segment (CNVS). Observations of the volcanic gas plume made with a multicomponent gas analyzer system (Multi-GAS) have allowed characterization of the CO2/SO2-ratio signature of the plumes at Poás (0.30±0.06, mean ± SD), Rincón de la Vieja (27.0±15.3), and Turrialba (2.2±0.8) in Costa Rica, and at Telica (3.0±0.9) and San Cristóbal (4.2±1.3) in Nicaragua (all ratios on molar basis). By scaling these plume compositions to simultaneously measured SO2 fluxes, we estimate that the CO2 outputs at CNVS volcanoes range from low (25.5±11.0 tons/day at Poás) to moderate (918 to 1270 tons/day at Turrialba). These results add a new information to the still fragmentary volcanic CO2 output data set, and allow estimating the total CO2 output from the CNVS at 2835±1364 tons/day. Our novel results, with previously available information about gas emissions in Central America, are suggestive of distinct volcanic gas CO2/ST (= SO2 + H2S)-ratio signature for magmatic volatiles in Nicaragua (∼3) relative to Costa Rica (∼0.5-1.0). We also provide additional evidence for the earlier theory relating the CO2-richer signature of Nicaragua volcanism to increased contributions from slab-derived fluids, relative to more-MORB-like volcanism in Costa Rica. The sizeable along-arc variations in magmatic gas chemistry that the present study has suggested indicate that additional gas observations are urgently needed to more-precisely confine the volcanic CO2 from the CAVA, and from

  8. Late Hesperian plains formation and degradation in a low sedimentation zone of the northern lowlands of Mars

    Science.gov (United States)

    Rodriguez, J.A.P.; Tanaka, K.L.; Berman, D.C.; Kargel, J.S.

    2010-01-01

    The plains materials that form the martian northern lowlands suggest large-scale sedimentation in this part of the planet. The general view is that these sedimentary materials were transported from zones of highland erosion via outflow channels and other fluvial systems. The study region, the northern circum-polar plains south of Gemini Scopuli on Planum Boreum, comprises the only extensive zone in the martian northern lowlands that does not include sub-basin floors nor is downstream from outflow channel systems. Therefore, within this zone, the ponding of fluids and fluidized sediments associated with outflow channel discharges is less likely to have taken place relative to sub-basin areas that form the other northern circum-polar plains surrounding Planum Boreum. Our findings indicate that during the Late Hesperian sedimentary deposits produced by the erosion of an ancient cratered landscape, as well as via sedimentary volcanism, were regionally emplaced to form extensive plains materials within the study region. The distribution and magnitude of surface degradation suggest that groundwater emergence from an aquifer that extended from the Arabia Terra cratered highlands to the northern lowlands took place non-catastrophically and regionally within the study region through faulted upper crustal materials. In our model the margin of the Utopia basin adjacent to the study region may have acted as a boundary to this aquifer. Partial destruction and dehydration of these Late Hesperian plains, perhaps induced by high thermal anomalies resulting from the low thermal conductivity of these materials, led to the formation of extensive knobby fields and pedestal craters. During the Early Amazonian, the rates of regional resurfacing within the study region decreased significantly; perhaps because the knobby ridges forming the eroded impact crater rims and contractional ridges consisted of thermally conductive indurated materials, thereby inducing freezing of the tectonically

  9. 49 CFR 229.64 - Plain bearings.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to the...

  10. Geochronology and Geomorphology of the Pioneer Archaeological Site (10BT676), Upper Snake River Plain, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Keene, Joshua L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-01

    The Pioneer site in southeastern Idaho, an open-air, stratified, multi-component archaeological locality on the upper Snake River Plain, provides an ideal situation for understanding the geomorphic history of the Big Lost River drainage system. We conducted a block excavation with the goal of understanding the geochronological context of both cultural and geomorphological components at the site. The results of this study show a sequence of five soil formation episodes forming three terraces beginning prior to 7200 cal yr BP and lasting until the historic period, preserving one cultural component dated to ~3800 cal yr BP and multiple components dating to the last 800 cal yr BP. In addition, periods of deposition and stability at Pioneer indicate climate fluctuation during the middle Holocene (~7200-3800 cal yr BP), minimal deposition during the late Holocene, and a period of increased deposition potentially linked to the Little Ice Age. In addition, evidence for a high-energy erosion event dated to ~3800 cal yr BP suggest a catastrophic flood event during the middle Holocene that may correlate with volcanic activity at the Craters of the Moon lava fields to the northwest. This study provides a model for the study of alluvial terrace formations in arid environments and their potential to preserve stratified archaeological deposits.

  11. Plain packaging of cigarettes: do we have sufficient evidence?

    Directory of Open Access Journals (Sweden)

    Smith CN

    2015-04-01

    Full Text Available Collin N Smith,1 John D Kraemer,2 Andrea C Johnson,1 Darren Mays1 1Department of Oncology, Georgetown University Medical Center, Lombardi Comprehensive Cancer Center, Washington, DC, USA; 2Department of Health Systems Administration, School of Nursing and Health Studies, Georgetown University, Washington, DC, USA Abstract: Tobacco industry marketing is a primary factor influencing cigarette smoking behavior and the cigarette pack has become an important marketing vehicle for tobacco companies. Standardized “plain” cigarette packaging is advocated as a public health policy to prevent and reduce morbidity and mortality caused by smoking by reducing youth smoking initiation and promoting cessation among smokers. Plain packaging was implemented in Australia in December 2012, and several other countries are considering doing so, but each faces foreseeable legal resistance from opponents to such measures. Tobacco companies have challenged these public health policies, citing international trade agreements and intellectual property laws. Decision-making in these court cases will hinge in part on whether the evidence indicates the public health benefits of plain packaging outweigh any potential harm to tobacco manufacturers’ interests. We reviewed the available evidence in support of plain packaging, finding evidence from observational, experimental, and population-based studies. Results indicate that plain packaging can reduce positive perceptions of smoking and dissuade tobacco use. Governments deciding to implement plain cigarette packaging measures can rely on this evidence to help make a strong case that plain packaging plays an important role in the context of comprehensive smoking prevention efforts. Keywords: cigarette smoking, tobacco, plain packaging, regulation, policy

  12. Geothermal and volcanism in west Java

    Science.gov (United States)

    Setiawan, I.; Indarto, S.; Sudarsono; Fauzi I, A.; Yuliyanti, A.; Lintjewas, L.; Alkausar, A.; Jakah

    2018-02-01

    Indonesian active volcanoes extend from Sumatra, Jawa, Bali, Lombok, Flores, North Sulawesi, and Halmahera. The volcanic arc hosts 276 volcanoes with 29 GWe of geothermal resources. Considering a wide distribution of geothermal potency, geothermal research is very important to be carried out especially to tackle high energy demand in Indonesia as an alternative energy sources aside from fossil fuel. Geothermal potency associated with volcanoes-hosted in West Java can be found in the West Java segment of Sunda Arc that is parallel with the subduction. The subduction of Indo-Australian oceanic plate beneath the Eurasian continental plate results in various volcanic products in a wide range of geochemical and mineralogical characteristics. The geochemical and mineralogical characteristics of volcanic and magmatic rocks associated with geothermal systems are ill-defined. Comprehensive study of geochemical signatures, mineralogical properties, and isotopes analysis might lead to the understanding of how large geothermal fields are found in West Java compared to ones in Central and East Java. The result can also provoke some valuable impacts on Java tectonic evolution and can suggest the key information for geothermal exploration enhancement.

  13. Self-potential anomalies in some Italian volcanic areas

    Directory of Open Access Journals (Sweden)

    C. Silenziario

    1996-06-01

    Full Text Available The study of Self-Potential (SP space and time variations in volcanic areas may provide useful information on both the geometrical structure of the volcanic apparatuses and the dynamical behaviour of the feeding and uprising systems. In this paper, the results obtained on the islands of Vulcano (Eolian arc and Ponza (Pontine archipelago and on the Mt. Somma-Vesuvius complex are shown. On the island of Vulcano and on the Mt. Somma-Vesuvius apparatus areal SP surveys were performed with the aim of evidencing anomalies closely associated to the zones of major volcanic activity. On the island of Vulcano a profile across the fumaroles along the crater rim of the Fossa Cone was also carried out in order to have a direct relationship between fumarolic fracture migration and flow rate and SP anomaly space and time variations. The areal survey on the island of Ponza, which is considered an inactive area, is assumed as a reference test with which to compare the amplitude and pattern of the anomalies in the active areas. A tentative interpretation of the SP anomalies in volcanic areas is suggested in terms of electrokinetic phenomena, related to the movement of fluids of both volcanic and non-volcanic origin.

  14. Radon gas as a tracer for volcanic processes

    International Nuclear Information System (INIS)

    Thomas, D.M.

    1990-01-01

    Radon emissions from volcanic systems have been under investigation for several decades. Soil gas and groundwater radon activities have been used to map faults and to characterize geothermal systems, and measurements of atmospheric radon and radon daughter concentrations have been used to estimate the volume of magma chambers feeding active eruptions. Several studies have also shown that temporal variations in radon concentration have been associated with the onset of volcanic eruptions or changes in the rates or character of an eruption. Some of these studies have been able to clearly define the cause of the radon anomalies but others have proposed models of radon emission and transport that are not well supported by the known physical and chemical processes that occur in a volcanic system. In order to better characterize the processes that control radon activities in volcanic systems, it is recommended that future radon monitoring programs attempt to maintain continuous recording of radon activities; individual radon measurements should be made over the shortest time intervals possible that are consistent with acceptable counting statistics and geophysical, meteorological, and hydrological parameters should be measured in order to better define the physical processes that affect radon activities in volcanic systems. (author). 63 refs

  15. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Chronology of surface history of the Moon. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    The sequence of events is described that occurred from the time that the ancient lunar crust solidified (about 4.4. billion years ago) and anorthositic high lands dominated the surface, until the global contraction (cooling) that began around 3.3 billion years ago when late stage basalts were emplaced at basin margins where fractures penetrated to subsurface tensional zones. The lunar intercrater plains may be linked with early KREEP volcanism, the LKFM basalt source region, and the first stages of mare volcanism. Ages of KREEP bracket the possible ages of the pre-Imbrian plains, and overlap the initial stages of mare basalt emplacement. Both plains are extruded under the same tensional tectonic regime.

  16. Climatic impact of volcanic eruptions

    Science.gov (United States)

    Rampino, Michael R.

    1991-01-01

    Studies have attempted to 'isolate' the volcanic signal in noisy temperature data. This assumes that it is possible to isolate a distinct volcanic signal in a record that may have a combination of forcings (ENSO, solar variability, random fluctuations, volcanism) that all interact. The key to discovering the greatest effects of volcanoes on short-term climate may be to concentrate on temperatures in regions where the effects of aerosol clouds may be amplified by perturbed atmospheric circulation patterns. This is especially true in subpolar and midlatitude areas affected by changes in the position of the polar front. Such climatic perturbation can be detected in proxy evidence such as decrease in tree-ring widths and frost rings, changes in the treeline, weather anomalies, severity of sea-ice in polar and subpolar regions, and poor grain yields and crop failures. In low latitudes, sudden temperature drops were correlated with the passage overhead of the volcanic dust cloud (Stothers, 1984). For some eruptions, such as Tambora, 1815, these kinds of proxy and anectdotal information were summarized in great detail in a number of papers and books (e.g., Post, 1978; Stothers, 1984; Stommel and Stommel, 1986; C. R. Harrington, in press). These studies lead to the general conclusion that regional effects on climate, sometimes quite severe, may be the major impact of large historical volcanic aerosol clouds.

  17. Rate of volcanism on Venus

    International Nuclear Information System (INIS)

    Fegley, B. Jr.; Prinn, R.G.

    1988-07-01

    The maintenance of the global H 2 SO 4 clouds on Venus requires volcanism to replenish the atmospheric SO 2 which is continually being removed from the atmosphere by reaction with calcium minerals on the surface of Venus. The first laboratory measurements of the rate of one such reaction, between SO 2 and calcite (CaCO 3 ) to form anhydrite (CaSO 4 ), are reported. If the rate of this reaction is representative of the SO 2 reaction rate at the Venus surface, then we estimate that all SO 2 in the Venus atmosphere (and thus the H 2 SO 4 clouds) will be removed in 1.9 million years unless the lost SO 2 is replenished by volcanism. The required rate of volcanism ranges from about 0.4 to about 11 cu km of magma erupted per year, depending on the assumed sulfur content of the erupted material. If this material has the same composition as the Venus surface at the Venera 13, 14 and Vega 2 landing sites, then the required rate of volcanism is about 1 cu km per year. This independent geochemically estimated rate can be used to determine if either (or neither) of the two discordant (2 cu km/year vs. 200 to 300 cu km/year) geophysically estimated rates is correct. The geochemically estimated rate also suggests that Venus is less volcanically active than the Earth

  18. Changes in plain bearing technology

    CERN Document Server

    Koring, Rolf

    2012-01-01

    A unique fusion of theoretical and practical knowledge, Changes in Plain Bearing Technology, by Rolf Koring, covers a meaningful range of expertise in this field.Drawing from years of experience in design development, materials selection, and their correlation to real-life part failure, this title, co-published by SAE International and expert Verlag (Germany), concentrates on hydrodynamic bearings lined with white metals, also known as Babbits.Written under the assumption that even the most mature body of knowledge can be revisited and improved, Changes in Plain Bearing Technology is a courageous and focused approach to questioning accepted test results and looking at alternative material compounds, and their application suitability.The process, which leads to innovative answers on how the technology is transforming itself to respond to new market requirements, shows how interdisciplinary thinking can recognize new potential in long-established industrial modus operandi.Tackling the highly complex issue of co...

  19. Structural control of monogenetic volcanism in the Garrotxa volcanic field (Northeastern Spain) from gravity and self-potential measurements

    Science.gov (United States)

    Barde-Cabusson, S.; Gottsmann, J.; Martí, J.; Bolós, X.; Camacho, A. G.; Geyer, A.; Planagumà, Ll.; Ronchin, E.; Sánchez, A.

    2014-01-01

    We report new geophysical observations on the distribution of subsurface structures associated with monogenetic volcanism in the Garrotxa volcanic field (Northern Spain). As part of the Catalan Volcanic Zone, this Quaternary volcanic field is associated with the European rifts system. It contains the most recent and best preserved volcanic edifices of the Catalan Volcanic Zone with 38 monogenetic volcanoes identified in the Garrotxa Natural Park. We conducted new gravimetric and self-potential surveys to enhance our understanding of the relationship between the local geology and the spatial distribution of the monogenetic volcanoes. The main finding of this study is that the central part of the volcanic field is dominated by a broad negative Bouguer anomaly of around -0.5 mGal, within which a series of gravity minima are found with amplitudes of up to -2.3 mGal. Inverse modelling of the Bouguer data suggests that surficial low-density material dominates the volcanic field, most likely associated with effusive and explosive surface deposits. In contrast, an arcuate cluster of gravity minima to the NW of the Croscat volcano, the youngest volcano of this zone, is modelled by vertically extended low-density bodies, which we interpret as a complex ensemble of fault damage zones and the roots of young scoria cones. A ground-water infiltration zone identified by a self-potential anomaly is associated with a steep horizontal Bouguer gravity gradient and interpreted as a fault zone and/or magmatic fissure, which fed the most recent volcanic activity in the Garrotxa. Gravimetric and self-potential data are well correlated and indicate a control on the locations of scoria cones by NNE-SSW and NNW-SSE striking tectonic features, which intersect the main structural boundaries of the study area to the north and south. Our interpretation of the data is that faults facilitated magma ascent to the surface. Our findings have major implications for understanding the relationship

  20. Southern Great Plains Safety Orientation

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, John

    2014-05-01

    Welcome to the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARM) Southern Great Plains (SGP) site. This U.S. Department of Energy (DOE) site is managed by Argonne National Laboratory (ANL). It is very important that all visitors comply with all DOE and ANL safety requirements, as well as those of the Occupational Safety and Health Administration (OSHA), the National Fire Protection Association, and the U.S. Environmental Protection Agency, and with other requirements as applicable.

  1. Volcanic Eruptions in Kamchatka

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Sheveluch Stratovolcano Click on the image for full resolution TIFF Klyuchevskoy Stratovolcano Click on the image for full resolution TIFF One of the most volcanically active regions of the world is the Kamchatka Peninsula in eastern Siberia, Russia. It is not uncommon for several volcanoes to be erupting at the same time. On April 26, 2007, the Advanced Spaceborne Thermal Emission and Reflection Radioneter (ASTER) on NASA's Terra spacecraft captured these images of the Klyuchevskoy and Sheveluch stratovolcanoes, erupting simultaneously, and 80 kilometers (50 miles) apart. Over Klyuchevskoy, the thermal infrared data (overlaid in red) indicates that two open-channel lava flows are descending the northwest flank of the volcano. Also visible is an ash-and-water plume extending to the east. Sheveluch volcano is partially cloud-covered. The hot flows highlighted in red come from a lava dome at the summit. They are avalanches of material from the dome, and pyroclastic flows. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra spacecraft. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and

  2. Status of volcanism studies for the Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.; Perry, F.; Murrell, M.; Poths, J.; Valentine, G.A. [Los Alamos National Lab., NM (United States); Wells, S. [Univ. of California, Riverside, CA (United States); Bowker, L.; Finnegan, K. [Univ. of Nevada, Las Vegas, NV (United States); Geissman, J.; McFadden, L.

    1995-02-01

    Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The risk of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The Lathrop Wells volcanic center is described in detail because it is the youngest basalt center in the YMR. Chapter 3 describes the tectonic setting of the YMR and presents and assesses the significance of multiple alternative tectonic models. Geophysical data are described for the YMR and are used as an aid to understand the distribution of basaltic volcanic centers. Chapter 4 discusses the petrologic and geochemical features of basaltic volcanism in the YMR, the southern Great Basin and the Basin and Range province. The long time of activity and characteristic small volume of the Postcaldera basalt of the YMR result in one of the lowest eruptive rates in a volcanic field in the southwest United States. Chapter 5 summarizes current concepts of the segregation, ascent, and eruption of basalt magma. Chapter 6 summarizes the history of volcanism studies (1979 through early 1994), including work for the Yucca Mountain Site Characterization Project and overview studies by the state of Nevada and the Nuclear Regulatory Commission. Chapter 7 summarizes probabilistic volcanic hazard assessment using a three-part conditional probability model. Chapter 8 describes remaining volcanism work judged to be needed to complete characterization studies for the YMR. Chapter 9 summarizes the conclusions of this volcanism status report.

  3. Status of volcanism studies for the Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    Crowe, B.; Perry, F.; Murrell, M.; Poths, J.; Valentine, G.A.; Wells, S.; Bowker, L.; Finnegan, K.; Geissman, J.; McFadden, L.

    1995-02-01

    Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The risk of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The Lathrop Wells volcanic center is described in detail because it is the youngest basalt center in the YMR. Chapter 3 describes the tectonic setting of the YMR and presents and assesses the significance of multiple alternative tectonic models. Geophysical data are described for the YMR and are used as an aid to understand the distribution of basaltic volcanic centers. Chapter 4 discusses the petrologic and geochemical features of basaltic volcanism in the YMR, the southern Great Basin and the Basin and Range province. The long time of activity and characteristic small volume of the Postcaldera basalt of the YMR result in one of the lowest eruptive rates in a volcanic field in the southwest United States. Chapter 5 summarizes current concepts of the segregation, ascent, and eruption of basalt magma. Chapter 6 summarizes the history of volcanism studies (1979 through early 1994), including work for the Yucca Mountain Site Characterization Project and overview studies by the state of Nevada and the Nuclear Regulatory Commission. Chapter 7 summarizes probabilistic volcanic hazard assessment using a three-part conditional probability model. Chapter 8 describes remaining volcanism work judged to be needed to complete characterization studies for the YMR. Chapter 9 summarizes the conclusions of this volcanism status report

  4. Long-term Agroecosystem Research in the Northern Great Plains.

    Science.gov (United States)

    Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.

    2015-12-01

    The Northern Great Plains is the bread basket of the United States, accounting for a substantial portion of U.S. agricultural production. This region faces critical challenges regarding balancing food needs, resource conservation (e.g Ogallala aquifer), environmental concerns, and rural economy development. Developing transformative, multifunctional systems will require equally imaginative and efficient tools to help farmers manage complex agroecosystems in a rapidly changing climate. The Northern Plains long-term agroecosystem research (LTAR) site at Mandan, ND and the Platte River High Plains LTAR (ARS/University of Nebraska-Lincoln) at Lincoln, NE in collaboration with USDA-ARS research units in Brookings, SD and Fargo, ND are collaborating to address the grand challenge of providing and sustaining multiple service provisions from Northern Great Plains agroecosystems. We propose to attain these goals through sustainable intensification based on the adoption of conservation agriculture principles including reduced soil disturbance, livestock integration, and greater complexity and diversity in the cropping system. Here, we summarize new concepts these locations have pioneered in dynamic cropping systems, resource use efficiency, and agricultural management technologies. As part of the LTAR network, we will conduct long-term cross-site research to design and assess new agricultural practices and systems aimed at improving our understanding of decision making processes and outcomes across an array of agricultural systems.

  5. Scale Effects of Water Saving on Irrigation Efficiency: Case Study of a Rice-Based Groundwater Irrigation System on the Sanjiang Plain, Northeast China

    Directory of Open Access Journals (Sweden)

    Haorui Chen

    2017-12-01

    Full Text Available This research analyzed the scale effect of water saving in Bielahonghe (BLH Basin, a rice-cultivating district on the Sanjiang Plain, Northeast China. Water budgets with different surface irrigation water supply ratios and water-saving measures were simulated with a semi-distributed water balance model. PFnws, representing the ratio of rice evapotranspiration to net water supply (the total amount of irrigation and precipitation minus the amount of water reused, was employed to assess the water use efficiency. Seven spatial scales (noted from S1 to S7, ranging from a single field (317.87 ha to the whole basin (about 100,800 ha were determined. PFnws values were quantified across scales and several water-saving measures, including water-saving irrigation regimes, canal lining, and a reduction of the surface water supply ratio (SWSR. The results indicated that PFnws increased with scale and could be calculated by a fitted power function (PFnws = 0.736Area0.033, R2 = 0.58. Furthermore, PFnws increased most prominently when the scale increased from S1 to S2. The water-saving irrigation regime (WSIR had the most substantial water-saving effect (WSE at S1. Specifically, PFnws improved by 21.2% at S1 when high-intensity WSIR was applied. Additionally, the WSE values of S3 and S5 were slightly higher than at other scales when the branch canal water delivery coefficient increased from 0.65 to 0.80 through canal lining. Furthermore, the PFnws at each scale varied with SWSR. Specifically, PFnws from S3 to S7 improved as SWSR decreased from 0.4 to 0.3 but remained approximately constant when SWSR decreased from 0.3 to 0.

  6. Volcanic eruptions and solar activity

    Science.gov (United States)

    Stothers, Richard B.

    1989-01-01

    The historical record of large volcanic eruptions from 1500 to 1980 is subjected to detailed time series analysis. In two weak but probably statistically significant periodicities of about 11 and 80 yr, the frequency of volcanic eruptions increases (decreases) slightly around the times of solar minimum (maximum). Time series analysis of the volcanogenic acidities in a deep ice core from Greenland reveals several very long periods ranging from about 80 to about 350 yr which are similar to the very slow solar cycles previously detected in auroral and C-14 records. Solar flares may cause changes in atmospheric circulation patterns that abruptly alter the earth's spin. The resulting jolt probably triggers small earthquakes which affect volcanism.

  7. The Lathrop Wells volcanic center

    International Nuclear Information System (INIS)

    Crowe, B.; Morley, R.

    1992-01-01

    The Lathrop Wells volcanic center is located 20 km south of the potential Yucca Mountain site, at the south end of the Yucca Mountain range. This paper discusses a detailed Study Plan which was prepared describing planned geochronology and field studies to assess the chronology of the Lathrop Wells volcanic center and other Quaternary volcanic centers in the region. A paper was published discussing the geomorphic and soil evidence for a late Pleistocene or Holoceno age for the main cone of the center. The purpose of this paper was to expose the ideas concerning the age of the Lathrop Wells center to scientific scrutiny. Additionally, field evidence was described suggesting the Lathrop Wells center may have formed from multiple eruptive events with significant intervals of no activity between events. This interpretation breaks with established convention in the volcanological literature that small volume basalt centers are monogenetic

  8. The geothermal system of Caviahue-Copahue Volcanic Complex (Chile-Argentina): New insights from self-potential, soil CO2 degassing, temperature measurements and helium isotopes, with structural and fluid circulation implications.

    Science.gov (United States)

    Roulleau, Emilie; Bravo, Francisco; Barde-Cabusson, Stephanie; Pizarro, Marcela; Muños, Carlos; Sanchez, Juan; Tardani, Daniele; Sano, Yuji; Takahata, Naoto; de Cal, Federico; Esteban, Carlos

    2016-04-01

    Geothermal systems represent natural heat transfer engines in a confined volume of rock which are strongly influenced by the regional volcano-tectonic setting controlling the formation of shallow magmatic reservoirs, and by the local faults/fracture network, that permits the development of hydrothermal circulation cells and promote the vertical migration of fluids and heat. In the Southern Volcanic Zone of Chile-Argentina, geothermal resources occur in close spatial relationship with active volcanism along the Cordillera which is primarily controlled by the 1000 km long, NNE Liquiñe-Ofqui Fault Zone (LOFZ), an intra-arc dextral strike-slip fault system, associated with second-order intra-arc anisotropy of overall NE-SW (extensional) and NW-SE orientation (compressional). However there is still a lack of information on how fault network (NE and WNW strinking faults) and lithology control the fluid circulation. In this study, we propose new data of dense self-potential (SP), soil CO2 emanation and temperature (T) measurements within the geothermal area from Caviahue-Copahue Volcanic Complex (CCVC), coupled with helium isotopes ratios measured in fumaroles and thermal springs. We observe that inside the geothermal system the NE-striking faults, characterized by a combination of SP-CO2 and T maxima with high 3He/4He ratios (7.86Ra), promote the formation of high vertical permeability pathways for fluid circulation. Whereas, the WNW-striking faults represent low permeability pathways for hydrothermal fluids ascent associated with moderate 3He/4He ratios (5.34Ra), promoting the infiltration of meteoric water at shallow depth. These active zones are interspersed by SP-CO2- T minima, which represent self-sealed zones (e.g. impermeable altered rocks) at depth, creating a barrier inhibiting fluids rise. The NE-striking faults seem to be associated with the upflow zones of the geothermal system, where the boiling process produces a high vapor-dominated zone close to the

  9. On a Possible Unified Scaling Law for Volcanic Eruption Durations.

    Science.gov (United States)

    Cannavò, Flavio; Nunnari, Giuseppe

    2016-03-01

    Volcanoes constitute dissipative systems with many degrees of freedom. Their eruptions are the result of complex processes that involve interacting chemical-physical systems. At present, due to the complexity of involved phenomena and to the lack of precise measurements, both analytical and numerical models are unable to simultaneously include the main processes involved in eruptions thus making forecasts of volcanic dynamics rather unreliable. On the other hand, accurate forecasts of some eruption parameters, such as the duration, could be a key factor in natural hazard estimation and mitigation. Analyzing a large database with most of all the known volcanic eruptions, we have determined that the duration of eruptions seems to be described by a universal distribution which characterizes eruption duration dynamics. In particular, this paper presents a plausible global power-law distribution of durations of volcanic eruptions that holds worldwide for different volcanic environments. We also introduce a new, simple and realistic pipe model that can follow the same found empirical distribution. Since the proposed model belongs to the family of the self-organized systems it may support the hypothesis that simple mechanisms can lead naturally to the emergent complexity in volcanic behaviour.

  10. Impact of major volcanic eruptions on stratospheric water vapour

    Directory of Open Access Journals (Sweden)

    M. Löffler

    2016-05-01

    Full Text Available Volcanic eruptions can have a significant impact on the Earth's weather and climate system. Besides the subsequent tropospheric changes, the stratosphere is also influenced by large eruptions. Here changes in stratospheric water vapour after the two major volcanic eruptions of El Chichón in Mexico in 1982 and Mount Pinatubo on the Philippines in 1991 are investigated with chemistry–climate model simulations. This study is based on two simulations with specified dynamics of the European Centre for Medium-Range Weather Forecasts Hamburg – Modular Earth Submodel System (ECHAM/MESSy Atmospheric Chemistry (EMAC model, performed within the Earth System Chemistry integrated Modelling (ESCiMo project, of which only one includes the long-wave volcanic forcing through prescribed aerosol optical properties. The results show a significant increase in stratospheric water vapour induced by the eruptions, resulting from increased heating rates and the subsequent changes in stratospheric and tropopause temperatures in the tropics. The tropical vertical advection and the South Asian summer monsoon are identified as sources for the additional water vapour in the stratosphere. Additionally, volcanic influences on tropospheric water vapour and El Niño–Southern Oscillation (ENSO are evident, if the long-wave forcing is strong enough. Our results are corroborated by additional sensitivity simulations of the Mount Pinatubo period with reduced nudging and reduced volcanic aerosol extinction.

  11. The Surface of Venus is Saturated With Ancient Impact Structures, and its Plains are Marine Sediments

    Science.gov (United States)

    Hamilton, W. B.

    2009-05-01

    Conventional interpretations of Venus are forced to fit dubious pre-Magellan conjectures that the planet is as active internally as Earth and preserves no ancient surface features. Plate tectonics obviously does not operate, so it is commonly assumed that the surface must record other endogenic processes, mostly unique to Venus. Imaginative systems of hundreds of tiny to huge rising and sinking plumes and diapirs are invoked. That much of the surface in fact is saturated with overlapping large circular depressions with the morphology of impact structures is obscured by postulating plume origins for selected structures and disregarding the rest. Typical structures are rimmed circular depressions, often multiring, with lobate debris aprons; central peaks are common. Marine-sedimentation features are overlooked because dogma deems the plains to be basalt flows despite their lack of source volcanoes and fissures. The unearthly close correlation between geoid and topography at long to moderate wavelengths requires, in conventional terms, dynamic maintenance of topography by up and down plumes of long-sustained precise shapes and buoyancy. A venusian upper mantle much stronger than that of Earth, because it is cooler or poorer in volatiles, is not considered. (The unearthly large so-called volcanoes and tessera plateaus often are related to rimmed circular depressions and likely are products of impact fluidization and melting.) Plains-saturating impact structures (mostly more obvious in altimetry than backscatter) with diameters of hundreds of km are superimposed as cookie-cutter bites, are variably smoothed and smeared by apparent submarine impact and erosion, and are differentially buried by sediments compacted into them. Marine- sedimentation evidence includes this compaction; long sinuous channels and distributaries with turbidite- channel characteristics and turbidite-like lobate flows (Jones and Pickering, JGSL 2003); radar-smooth surfaces and laminated aspect in

  12. Huygens Crater: Insights into Noachian Volcanism, Stratigraphy, and Aqueous Processes

    Science.gov (United States)

    Ackiss, S. E.; Wray, J. J.; Seelos, K. D.; Niles, P. B.

    2015-01-01

    Huygens crater is a well preserved peak ring structure on Mars centered at 13.5 deg S, 55.5 deg E in the Noachian highlands between Terras Tyrrhena and Sabaea near the NW rim of Hellas basin. With a diameter of approximately 470 km, it uplifted and exhumed pre-Noachian crustal materials from depths greater than 25 km, penetrating below the thick, ubiquitous layer of Hellas ejecta. In addition, Huygens served as a basin for subsequent aqueous activity, including erosion/deposition by fluvial valley networks and subsurface alteration that is now exposed by smaller impacts. Younger mafic-bearing plains that partially cover the basin floor and surrounding intercrater areas were likely emplaced by later volcanism.

  13. Recurrence models of volcanic events: Applications to volcanic risk assessment

    International Nuclear Information System (INIS)

    Crowe, B.M.; Picard, R.; Valentine, G.; Perry, F.V.

    1992-01-01

    An assessment of the risk of future volcanism has been conducted for isolation of high-level radioactive waste at the potential Yucca Mountain site in southern Nevada. Risk used in this context refers to a combined assessment of the probability and consequences of future volcanic activity. Past studies established bounds on the probability of magmatic disruption of a repository. These bounds were revised as additional data were gathered from site characterization studies. The probability of direct intersection of a potential repository located in an eight km 2 area of Yucca Mountain by ascending basalt magma was bounded by the range of 10 -8 to 10 -10 yr -1 2 . The consequences of magmatic disruption of a repository were estimated in previous studies to be limited. The exact releases from such an event are dependent on the strike of an intruding basalt dike relative to the repository geometry, the timing of the basaltic event relative to the age of the radioactive waste and the mechanisms of release and dispersal of the waste radionuclides in the accessible environment. The combined low probability of repository disruption and the limited releases associated with this event established the basis for the judgement that the risk of future volcanism was relatively low. It was reasoned that that risk of future volcanism was not likely to result in disqualification of the potential Yucca Mountain site

  14. 129I in volcanic fluids: Testing for the presence of marine sediments in the Central American volcanic arc

    International Nuclear Information System (INIS)

    Snyder, Glen; Fehn, Udo

    2000-01-01

    The long half-life and the geochemical behavior of the 129 I system suggest that this cosmogenic radioisotope can contribute significantly to the understanding of processes associated with subduction zones and volcanic arc systems. Because iodine is not incorporated into igneous rocks, the age-signal associated with 129 I permits the determination of the origin of volatiles within arc volcanic systems. We report here results of a study to test the application of 129 I in fluids collected from hotsprings, crater lakes, fumaroles and geothermal wells from the Central American volcanic arc. Both the Momotombo geothermal field in Nicaragua and the Miravalles geothermal field in Costa Rica show 129 I/I ratios consistent with magmatic contributions from subducted marine pelagic sediments (minimum iodine ages of 25-30 Ma). In addition, several wells provide iodine isotopic ratios indicative of an older end-member, presumably located in the shallow crust (minimum iodine age = 65 Ma)

  15. Global volcanic aerosol properties derived from emissions, 1990-2014, using CESM1(WACCM): VOLCANIC AEROSOLS DERIVED FROM EMISSIONS

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Michael J. [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Schmidt, Anja [School of Earth and Environment, University of Leeds, Leeds UK; Easter, Richard [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Solomon, Susan [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge Massachusetts USA; Kinnison, Douglas E. [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Ghan, Steven J. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Neely, Ryan R. [School of Earth and Environment, University of Leeds, Leeds UK; National Centre for Atmospheric Science, University of Leeds, Leeds UK; Marsh, Daniel R. [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Conley, Andrew [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Bardeen, Charles G. [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA; Gettelman, Andrew [Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder Colorado USA

    2016-03-06

    Accurate representation of global stratospheric aerosol properties from volcanic and non-volcanic sulfur emissions is key to understanding the cooling effects and ozone-loss enhancements of recent volcanic activity. Attribution of climate and ozone variability to volcanic activity is of particular interest in relation to the post-2000 slowing in the apparent rate of global average temperature increases, and variable recovery of the Antarctic ozone hole. We have developed a climatology of global aerosol properties from 1990 to 2014 calculated based on volcanic and non-volcanic emissions of sulfur sources. We have complied a database of volcanic SO2 emissions and plume altitudes for eruptions between 1990 and 2014, and a new prognostic capability for simulating stratospheric sulfate aerosols in version 5 of the Whole Atmosphere Community Climate Model, a component of the Community Earth System Model. Our climatology shows remarkable agreement with ground-based lidar observations of stratospheric aerosol optical depth (SAOD), and with in situ measurements of aerosol surface area density (SAD). These properties are key parameters in calculating the radiative and chemical effects of stratospheric aerosols. Our SAOD climatology represents a significant improvement over satellite-based analyses, which ignore aerosol extinction below 15 km, a region that can contain the vast majority of stratospheric aerosol extinction at mid- and high-latitudes. Our SAD climatology significantly improves on that provided for the Chemistry-Climate Model Initiative, which misses 60% of the SAD measured in situ. Our climatology of aerosol properties is publicly available on the Earth System Grid.

  16. Disruptive event analysis: volcanism and igneous intrusion

    International Nuclear Information System (INIS)

    Crowe, B.M.

    1979-01-01

    Three basic topics are addressed for the disruptive event analysis: first, the range of disruptive consequences of a radioactive waste repository by volcanic activity; second, the possible reduction of the risk of disruption by volcanic activity through selective siting of a repository; and third, the quantification of the probability of repository disruption by volcanic activity

  17. How Did Climate and Humans Respond to Past Volcanic Eruptions?

    Science.gov (United States)

    Toohey, Matthew; Ludlow, Francis; Legrande, Allegra N.

    2016-01-01

    To predict and prepare for future climate change, scientists are striving to understand how global-scale climatic change manifests itself on regional scales and also how societies adapt or don't to sometimes subtle and complex climatic changes. In this regard, the strongest volcanic eruptions of the past are powerful test cases, showcasing how the broad climate system responds to sudden changes in radiative forcing and how societies have responded to the resulting climatic shocks. These issues were at the heart of the inaugural workshop of the Volcanic Impacts on Climate and Society (VICS) Working Group, convened in June 2016 at the Lamont-Doherty Earth Observatory of Columbia University in Palisades, N.Y. The 3-day meeting gathered approximately 50 researchers, who presented work intertwining the history of volcanic eruptions and the physical processes that connect eruptions with human and natural systems on a global scale.

  18. Groundwater characteristics and problems in volcanic rock terrains

    International Nuclear Information System (INIS)

    Custodio, E.

    1989-01-01

    Volcanic rock formations, each with their own particular hydrogeological characteristics, occur in circumstances that cover a multiplicity of situations. These range from permeable porous rock formations to permeable fissured formations and include all types of intermediate situation between the two. The type of volcanism, distance from the source of emission, age, alteration processes and tectonics are all factors which determine their behaviour. Volcanic formations usually constitute a single aquifer system, even though this may be very heterogeneous and may locally be separated into clearly defined subunits. At times, formations may be hundreds of metres thick and are fairly permeable almost throughout. As a rule, volcanic material does not yield directly soluble salts to the water that flows through it. Mineralization of the water is due to the concentration of rainfall and the hydrolysis of silicates as a result of CO 2 being absorbed from the atmosphere and the ground, or as a result of volcanism itself. Cationic grouping is usually closely correlated to that of the rock formation in which the chemical composition is formed. Most environmental isotope and radioisotope techniques may be used, and at times are of unquestionable value. However, the existence of evaporation in the soil with possible isotopic fractionation, the effects of marked relief, the dilution of dissolved carbon by volcanic carbon and isotopic exchange brought about by volcanic carbon, etc., should be taken into account before valid conclusions are drawn. The paper uses examples taken from existing studies, mainly those being carried out in the Canary Islands (Spain). (author). 98 refs, 18 figs, 4 tabs

  19. The "Escarot" gas seep, French Massif Central: CO2 discharge from a quiescent volcanic system - Characterization and quantification of gas emissions

    Science.gov (United States)

    Gal, F.; Leconte, S.; Gadalia, A.

    2018-03-01

    Natural CO2 emissions from the volcanic rocks of the French Massif Central are poorly constrained. It is of interest better to assess the emission of such non-anthropogenic gases that may significantly contribute to the global carbon budget. We quantified the CO2 emissions to the atmosphere in a small area (0.052 km2) located in the Massif Central close to Lake Pavin, the most recent volcanic edifice in metropolitan France. The specific character of this area, known as the Escarot mofette, was earlier studied for soil-gas concentrations only. In June 2017, we used the accumulation chamber method for measuring CO2 flux and related O2 depletion in the gases emitted at the soil/atmosphere interface, resulting in 176 data acquisitions over four days. In addition, 44 soil-gas concentration measurements were made at selected locations. CO2 emission rates are estimated at 8100 ± 1800 tons/year of deep-seated CO2 and at 660 ± 440 tons/year of biologically produced CO2. The uncertainty on these evaluations comes from the high-frequency variability of CO2 efflux in the more emissive areas and from the occurrence of heavy precipitation events. Though unexpected, these events were used for quantifying the decreases in CO2 efflux, which were as high as 500% over a few hours or even days in some locations. However, repeat acquisitions performed under more favourable weather conditions showed errors of commonly accepted amplitude (±15%). The area showed several degassing centres aligned along a NNW-SSE direction that correlates well with known geological structures, proving the ability of soil-gas methods to map hidden faults. The whole area is characterized by strong CO2 enrichment and related O2 depletion, but it is nonetheless possible to detect areas influenced by the rise of deep-seated gases and a few peripheral areas where biological processes dominate (CO2 up to 10% vol.). This study of gas emissions in a non-urban area also provides complementary information that is

  20. Model-based aviation advice on distal volcanic ash clouds by assimilating aircraft in situ measurements

    Directory of Open Access Journals (Sweden)

    G. Fu

    2016-07-01

    Full Text Available The forecast accuracy of distal volcanic ash clouds is important for providing valid aviation advice during volcanic ash eruption. However, because the distal part of volcanic ash plume is far from the volcano, the influence of eruption information on this part becomes rather indirect and uncertain, resulting in inaccurate volcanic ash forecasts in these distal areas. In our approach, we use real-life aircraft in situ observations, measured in the northwestern part of Germany during the 2010 Eyjafjallajökull eruption, in an ensemble-based data assimilation system combined with a volcanic ash transport model to investigate the potential improvement on the forecast accuracy with regard to the distal volcanic ash plume. We show that the error of the analyzed volcanic ash state can be significantly reduced through assimilating real-life in situ measurements. After a continuous assimilation, it is shown that the aviation advice for Germany, the Netherlands and Luxembourg can be significantly improved. We suggest that with suitable aircrafts measuring once per day across the distal volcanic ash plume, the description and prediction of volcanic ash clouds in these areas can be greatly improved.

  1. The InVEST Volcanic Concept Survey: Exploring Student Understanding about Volcanoes

    Science.gov (United States)

    Parham, Thomas L., Jr.; Cervato, Cinzia; Gallus, William A., Jr.; Larsen, Michael; Hobbs, Jon; Stelling, Pete; Greenbowe, Thomas; Gupta, Tanya; Knox, John A.; Gill, Thomas E.

    2010-01-01

    Results from the Volcanic Concept Survey (VCS) indicated that many undergraduates do not fully understand volcanic systems and plate tectonics. During the 2006 academic year, a ten-item conceptual survey was distributed to undergraduate students enrolled in Earth science courses at five U.S. colleges and universities. A trained team of graders…

  2. Deep long-period earthquakes west of the volcanic arc in Oregon: evidence of serpentine dehydration in the fore-arc mantle wedge

    Science.gov (United States)

    Vidale, John E.; Schmidt, David A.; Malone, Stephen D.; Hotovec-Ellis, Alicia J.; Moran, Seth C.; Creager, Kenneth C.; Houston, Heidi

    2014-01-01

    Here we report on deep long-period earthquakes (DLPs) newly observed in four places in western Oregon. The DLPs are noteworthy for their location within the subduction fore arc: 40–80 km west of the volcanic arc, well above the slab, and near the Moho. These “offset DLPs” occur near the top of the inferred stagnant mantle wedge, which is likely to be serpentinized and cold. The lack of fore-arc DLPs elsewhere along the arc suggests that localized heating may be dehydrating the serpentinized mantle wedge at these latitudes and causing DLPs by dehydration embrittlement. Higher heat flow in this region could be introduced by anomalously hot mantle, associated with the western migration of volcanism across the High Lava Plains of eastern Oregon, entrained in the corner flow proximal to the mantle wedge. Alternatively, fluids rising from the subducting slab through the mantle wedge may be the source of offset DLPs. As far as we know, these are among the first DLPs to be observed in the fore arc of a subduction-zone system.

  3. Plain Language to Communicate Physical Activity Information: A Website Content Analysis.

    Science.gov (United States)

    Paige, Samantha R; Black, David R; Mattson, Marifran; Coster, Daniel C; Stellefson, Michael

    2018-04-01

    Plain language techniques are health literacy universal precautions intended to enhance health care system navigation and health outcomes. Physical activity (PA) is a popular topic on the Internet, yet it is unknown if information is communicated in plain language. This study examined how plain language techniques are included in PA websites, and if the use of plain language techniques varies according to search procedures (keyword, search engine) and website host source (government, commercial, educational/organizational). Three keywords ("physical activity," "fitness," and "exercise") were independently entered into three search engines (Google, Bing, and Yahoo) to locate a nonprobability sample of websites ( N = 61). Fourteen plain language techniques were coded within each website to examine content formatting, clarity and conciseness, and multimedia use. Approximately half ( M = 6.59; SD = 1.68) of the plain language techniques were included in each website. Keyword physical activity resulted in websites with fewer clear and concise plain language techniques ( p websites with more clear and concise techniques ( p language techniques did not vary by search engine or the website host source. Accessing PA information that is easy to understand and behaviorally oriented may remain a challenge for users. Transdisciplinary collaborations are needed to optimize plain language techniques while communicating online PA information.

  4. Assessment of hydraulic properties of sedimentary and volcanic aquifer systems under arid conditions in the Republic of Djibouti (Horn of Africa)

    Science.gov (United States)

    Jalludin, Mohamed; Razack, Moumtaz

    The Republic of Djibouti (23,000 km2 500,000 inhabitants), located within the Horn of Africa, undergoes an arid climate with an average annual rainfall less than 150 mm. Water resources are provided up to 98% by groundwater. Two types of aquifers are encountered: volcanic and sedimentary aquifers. This paper focuses on the assessment of their hydraulic properties, which is necessary for future tasks regarding the management of these aquifers. To this end, a data base consisting of all available pumping test data obtained since the 1960s was compiled. Pumping tests have been interpreted to determine transmissivity. Solely for volcanic aquifers, transmissivity also has been estimated through an empirical relationship using specific capacity corrected for turbulent well losses. The transmissivity of each type of aquifer can span up to four orders of magnitude, pointing out their strong heterogeneity. For the various volcanic rocks, the younger the rock, the higher the transmissivity. The transmissivity of volcanic rocks has therefore decreased in the course of geological time. At present, a much better understanding of the hydraulic properties of these complex aquifers has been obtained, which should enable optimal management of their groundwater resources through the use of numerical modeling. La République de Djibouti (23,000 km2 500,000 habitants), située dans la Corne de l'Afrique, subit un climat aride avec une pluviométrie moyenne annuelle inférieure à 150 mm. Les ressources en eau sont fournies à plus de 98% par les eaux souterraines contenues dans des aquifères sédimentaires ou volcaniques. Cet article a pour objectif l'évaluation des propriétés hydrauliques de ces aquifères, étape indispensable pour entreprendre par la suite des études en vue de la gestion de ces aquifères. Une base rassemblant les données d'essais par pompage disponibles depuis les années Soixante a d'abord été établie. Les essais par pompage ont été interprétés pour

  5. The volcaniclastic sequence of Aranzazu: Record of the impact of volcanism on Neogene fluvial system in the middle part of the Central Cordillera, Colombia

    International Nuclear Information System (INIS)

    Borrero Pena, Carlos Alberto; Rosero Cespedes, Juan Sebastian; Valencia M, Julian David; Pardo Trujillo, Andres

    2008-01-01

    The volcaniclastic sequence of Aranzazu (VSA, late Pliocene - early Pleistocene?) was sourced from the northernmost sector of the Machin - Cerro Bravo volcanic complex. The volcaniclastic accumulations filled the pre-existing fault-bend depressions in the surroundings of Aranzazu town (Caldas department, Colombia). A new classification of volcaniclastic deposits is proposed, in which the lahars are defined as volcaniclastic resedimented deposits, and differentiated from the primary volcaniclastic and epiclastic deposits. The updating the sedimentology and rheology of the deposits related with the laharic events is aimed. The VSA stratigraphy is based on the lithofacies identification and the definition of the architectural elements for syn- and inter-eruptive periods. The VSA lower member corresponds to the successive aggradation of syneruptive lahars (SV and SB elements) resulted from re-sedimentation of pumice-rich pyroclastic deposits and transported as debris and hyperconcentrated stream/flood flows. The VSA middle and upper members defined by coal contents were formed during the dominion of inter-eruptive (FF element) over the syn-eruptive (SV and SB elements) periods. They were formed during the reestablishment of the fluvial condition after the syn-eruptive laharic activity. Once the fluvial deposition was strengthened, the necessary conditions for the peat formation were propitious and the coal-bearing bed sets were developed.

  6. Months between rejuvenation and volcanic eruption at Yellowstone caldera, Wyoming

    Science.gov (United States)

    Till, Christy B.; Vazquez, Jorge A.; Boyce, Jeremy W

    2015-01-01

    Rejuvenation of previously intruded silicic magma is an important process leading to effusive rhyolite, which is the most common product of volcanism at calderas with protracted histories of eruption and unrest such as Yellowstone, Long Valley, and Valles, USA. Although orders of magnitude smaller in volume than rare caldera-forming super-eruptions, these relatively frequent effusions of rhyolite are comparable to the largest eruptions of the 20th century and pose a considerable volcanic hazard. However, the physical pathway from rejuvenation to eruption of silicic magma is unclear particularly because the time between reheating of a subvolcanic intrusion and eruption is poorly quantified. This study uses geospeedometry of trace element profiles with nanometer resolution in sanidine crystals to reveal that Yellowstone’s most recent volcanic cycle began when remobilization of a near- or sub-solidus silicic magma occurred less than 10 months prior to eruption, following a 220,000 year period of volcanic repose. Our results reveal a geologically rapid timescale for rejuvenation and effusion of ~3 km3 of high-silica rhyolite lava even after protracted cooling of the subvolcanic system, which is consistent with recent physical modeling that predict a timescale of several years or less. Future renewal of rhyolitic volcanism at Yellowstone is likely to require an energetic intrusion of mafic or silicic magma into the shallow subvolcanic reservoir and could rapidly generate an eruptible rhyolite on timescales similar to those documented here.

  7. Global monsoon precipitation responses to large volcanic eruptions

    Science.gov (United States)

    Liu, Fei; Chai, Jing; Wang, Bin; Liu, Jian; Zhang, Xiao; Wang, Zhiyuan

    2016-01-01

    Climate variation of global monsoon (GM) precipitation involves both internal feedback and external forcing. Here, we focus on strong volcanic forcing since large eruptions are known to be a dominant mechanism in natural climate change. It is not known whether large volcanoes erupted at different latitudes have distinctive effects on the monsoon in the Northern Hemisphere (NH) and the Southern Hemisphere (SH). We address this issue using a 1500-year volcanic sensitivity simulation by the Community Earth System Model version 1.0 (CESM1). Volcanoes are classified into three types based on their meridional aerosol distributions: NH volcanoes, SH volcanoes and equatorial volcanoes. Using the model simulation, we discover that the GM precipitation in one hemisphere is enhanced significantly by the remote volcanic forcing occurring in the other hemisphere. This remote volcanic forcing-induced intensification is mainly through circulation change rather than moisture content change. In addition, the NH volcanic eruptions are more efficient in reducing the NH monsoon precipitation than the equatorial ones, and so do the SH eruptions in weakening the SH monsoon, because the equatorial eruptions, despite reducing moisture content, have weaker effects in weakening the off-equatorial monsoon circulation than the subtropical-extratropical volcanoes do. PMID:27063141

  8. Global monsoon precipitation responses to large volcanic eruptions.

    Science.gov (United States)

    Liu, Fei; Chai, Jing; Wang, Bin; Liu, Jian; Zhang, Xiao; Wang, Zhiyuan

    2016-04-11

    Climate variation of global monsoon (GM) precipitation involves both internal feedback and external forcing. Here, we focus on strong volcanic forcing since large eruptions are known to be a dominant mechanism in natural climate change. It is not known whether large volcanoes erupted at different latitudes have distinctive effects on the monsoon in the Northern Hemisphere (NH) and the Southern Hemisphere (SH). We address this issue using a 1500-year volcanic sensitivity simulation by the Community Earth System Model version 1.0 (CESM1). Volcanoes are classified into three types based on their meridional aerosol distributions: NH volcanoes, SH volcanoes and equatorial volcanoes. Using the model simulation, we discover that the GM precipitation in one hemisphere is enhanced significantly by the remote volcanic forcing occurring in the other hemisphere. This remote volcanic forcing-induced intensification is mainly through circulation change rather than moisture content change. In addition, the NH volcanic eruptions are more efficient in reducing the NH monsoon precipitation than the equatorial ones, and so do the SH eruptions in weakening the SH monsoon, because the equatorial eruptions, despite reducing moisture content, have weaker effects in weakening the off-equatorial monsoon circulation than the subtropical-extratropical volcanoes do.

  9. Io - One of at Least Four Simultaneous Erupting Volcanic Eruptions

    Science.gov (United States)

    1979-01-01

    This photo of an active volcanic eruption on Jupiter's satellite Io was taken 1 hour, 52 minutes after the accompanying picture, late in the evening of March 4, 1979, Pacific time. On the limb of the satellite can be seen one of at least four simultaneous volcanic eruptions -- the first such activity ever observed on another celestial body. Seen against the limb are plume-like structures rising more than 60 miles (100 kilometers) above the surface. Several eruptions have been identified with volcanic structures on the surface of Io, which have also been identified by Voyager 1's infrared instrument as being abnormally hot -- several hundred degrees warmer than surrounding terrain. The fact that several eruptions appear to be occurring at the same time suggests that Io has the most active surface in the solar system and that volcanism is going on there essentially continuously. Another characteristic of the observed volcanism is that it appears to be extremely explosive, with velocities more than 2,000 miles an hour (at least 1 kilometer per second). That is more violent than terrestrial volcanoes like Etna, Vesuvius or Krakatoa.

  10. Uncertainties in Integrated Climate Change Impact Assessments by Sub-setting GCMs Based on Annual as well as Crop Growing Period under Rice Based Farming System of Indo-Gangetic Plains of India

    Science.gov (United States)

    Pillai, S. N.; Singh, H.; Panwar, A. S.; Meena, M. S.; Singh, S. V.; Singh, B.; Paudel, G. P.; Baigorria, G. A.; Ruane, A. C.; McDermid, S.; Boote, K. J.; Porter, C.; Valdivia, R. O.

    2016-12-01

    Integrated assessment of climate change impact on agricultural productivity is a challenge to the scientific community due to uncertainties of input data, particularly the climate, soil, crop calibration and socio-economic dataset. However, the uncertainty due to selection of GCMs is the major source due to complex underlying processes involved in initial as well as the boundary conditions dealt in solving the air-sea interactions. Under Agricultural Modeling Intercomparison and Improvement Project (AgMIP), the Indo-Gangetic Plains Regional Research Team investigated the uncertainties caused due to selection of GCMs through sub-setting based on annual as well as crop-growth period of rice-wheat systems in AgMIP Integrated Assessment methodology. The AgMIP Phase II protocols were used to study the linking of climate-crop-economic models for two study sites Meerut and Karnal to analyse the sensitivity of current production systems to climate change. Climate Change Projections were made using 29 CMIP5 GCMs under RCP4.5 and RCP 8.5 during mid-century period (2040-2069). Two crop models (APSIM & DSSAT) were used. TOA-MD economic model was used for integrated assessment. Based on RAPs (Representative Agricultural Pathways), some of the parameters, which are not possible to get through modeling, derived from literature and interactions with stakeholders incorporated into the TOA-MD model for integrated assessment.

  11. Mass movement processes associated with volcanic structures in Mexico City

    Directory of Open Access Journals (Sweden)

    Víctor Carlos Valerio

    2012-11-01

    Full Text Available Mexico City, one of the most populated areas of the world, has been affected by various hazards of natural origin, such as subsidence and cracking of the soil, seismicity, floods and mass movement processes (MMPs. Owing to the lack of space on the plain, in recent years urban growth has been concentrated particularly on the slopes of the surrounding mountain ranges, and this has significantly modified the dynamics of the relief as well as the hydrogeological conditions. The specific character of natural susceptibility to mass movements is strongly dependent on the geological–structural and morphological characteristics of the volcanic bodies that form the mountainous relief. This natural susceptibility, combined with the characteristics of vulnerability of the society, creates risk conditions that can generate severe consequences for the population and the economy. Hence, based on an inventory of mass movement processes comprising 95 data points, the present study aimed to achieve a zoning of the areas susceptible to these processes, as well as to characterize the mechanisms of instability in the volcanic structures that form the relief of the area in question. The results of this work clearly show the role of the lithology, the mode of emplacement and the morpho–structural characteristics of the volcanic structures, in the types of mass movement processes. In addition, it identifies the diverse activities of anthropogenic origin that favour slope instability in the zone: deforestation and burning of rubbish, felling of timber on the slopes for building infrastructure and dwellings, leakages of water, vibrations of vehicles, rotating machinery and the use of explosives in mining works, overloading the heads of the slopes, disturbance of the geohydrological regime, generation of rubbish tips, terracing of the slopes for cultivation, inadequate building regulations, and the use of counterproductive or ineffectual stabilization measures.

  12. Reduced cooling following future volcanic eruptions

    Science.gov (United States)

    Hopcroft, Peter O.; Kandlbauer, Jessy; Valdes, Paul J.; Sparks, R. Stephen J.

    2017-11-01

    Volcanic eruptions are an important influence on decadal to centennial climate variability. Large eruptions lead to the formation of a stratospheric sulphate aerosol layer which can cause short-term global cooling. This response is modulated by feedback processes in the earth system, but the influence from future warming has not been assessed before. Using earth system model simulations we find that the eruption-induced cooling is significantly weaker in the future state. This is predominantly due to an increase in planetary albedo caused by increased tropospheric aerosol loading with a contribution from associated changes in cloud properties. The increased albedo of the troposphere reduces the effective volcanic aerosol radiative forcing. Reduced sea-ice coverage and hence feedbacks also contribute over high-latitudes, and an enhanced winter warming signal emerges in the future eruption ensemble. These findings show that the eruption response is a complex function of the environmental conditions, which has implications for the role of eruptions in climate variability in the future and potentially in the past.

  13. SYSTHESIS OF VOLCANISM STUDIES FOR THE YUCCA MOUNTAIN SITE CHARACTERIZATION PROJECT

    International Nuclear Information System (INIS)

    FV PERRY; GA CROWE; GA VALENTINE; LM BOWKER

    1997-01-01

    This report synthesizes the results of volcanism studies conducted by scientists at the Los Alamos National Laboratory and collaborating institutions on behalf of the Department of Energy's Yucca Mountain Project. Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The hazard of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Future volcanic events cannot be predicted with certainty but instead are estimated using formal methods of probabilistic volcanic hazard assessment (PVHA). Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The distribution, eruptive history, and geochronology of Plio-Quaternary basalt centers are described by individual center emphasizing the younger postcaldera basalt ( -7 events per year. Bounding probability estimates are used to assess possible implications of not drilling aeromagnetic anomalies in the Arnargosa Valley and Crater Flat. The results of simulation modeling are used to assess the sensitivity of the disruption probability for the location of northeast boundaries of volcanic zones near the Yucca Mountain site. A new section on modeling of radiological releases associated with surface and subsurface magmatic activity has been added to chapter 6. The modeling results are consistent with past total system performance assessments that show future volcanic and magmatic events are not significant components of repository performance and volcanism is not a priority issue for performance assessment studies

  14. VOLCANIC RISK ASSESSMENT - PROBABILITY AND CONSEQUENCES

    International Nuclear Information System (INIS)

    G.A. Valentine; F.V. Perry; S. Dartevelle

    2005-01-01

    framework is an important way to focus research in the most critical areas as well as providing an integrated approach to a range of complex processes. Uncertainty in both event probability and consequences can formally be accounted for within a decision framework and therefore is explicitly communicated to decision makers. Such an approach also tends to open new questions about volcanic systems and their interactions with humans and infrastructure, thereby driving new basic research

  15. Holocene volcanic geology, volcanic hazard, and risk on Taveuni, Fiji

    International Nuclear Information System (INIS)

    Cronin, S.J.; Neall, V.E.

    2001-01-01

    The Holocene volcanic geology of Taveuni has been mapped in order to produce a volcanic hazard and risk assessment for the island. Taveuni is the third-largest island of the Fiji group and home to 14,500 people. At least cubic km 2.7 of olivine-alkali-basalt magma was erupted from over 100 events throughout the Holocene. Vents are concentrated along a northeast-striking rift zone that is parallel to other regional structural trends. There is an overall trend of younging southward along the rift. Holocene lavas and tephras are grouped within six newly defined eruptive periods, established on a basis of radiocarbon dating. Within these periods, 14 tephra layers, useful as local marker horizons, are recognised. At least 58% of Holocene eruptions produced lava flows, while almost all produced some tephra. Individual eruption event volumes ranged between 0.001 and cubic km 0.20 (dense rock equivalent). Many eruptions involved at least some phases of phreatic and/or phreato-magmatic activity, although dominant hydrovolcanic activity was limited to only a few events. A volcanic hazard map is presented, based on the Holocene geology map and statistical analyses of eruption recurrence. The highest levels of ground-based and near-vent hazards are concentrated along the southern portion of the island's rift axis, with the paths of initial lava flows predicted from present topography. Tephra fall hazards are based on eruption parameters interpreted from mapped Holocene tephra layers. Hawaiian explosive-style eruptions appear to be a dominant eruptive process, with prevailing low-level (<3 km) southeasterly winds dispersing most tephra to the northwestern quadrant. Vulnerable elements (population centres, infrastructure, and economy) on Taveuni have been considered in deriving a volcanic risk assessment for the island. A number of infrastructural and subdivision developments are either under way or planned for the island, driven by its highly fertile soils and availability of

  16. Wind measurement on the Linth plain; Windmessung in der Linthebene

    Energy Technology Data Exchange (ETDEWEB)

    Langraf, B.

    2003-07-01

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of wind measurements made on the Linth plain, a flat alluvial plain in eastern Switzerland located between mountain ranges. The data, which were collected using temporary measurement masts at two locations are presented in the form of tables, diagrams and maps showing the wind-energy potential of various areas of the plain. The actual measurements are compared with prognoses from a geo-information system. The wind measurement equipment and installations are described, as are the software models for the calculation of wind direction, wind intensity and of a prognosis for energy production. Particular attention was also paid to the question of wind turbulence. Further factors investigated included the possibility of icing-up in winter and the choice of a meteorological station in the neighbourhood with similar characteristics that could be used as a reference station. The report also presents the results of the evaluation of various possible locations for wind turbines on the Linth plain. Visual, noise and shadow-casing factors are considered.

  17. Can rain cause volcanic eruptions?

    Science.gov (United States)

    Mastin, Larry G.

    1993-01-01

    Volcanic eruptions are renowned for their violence and destructive power. This power comes ultimately from the heat and pressure of molten rock and its contained gases. Therefore we rarely consider the possibility that meteoric phenomena, like rainfall, could promote or inhibit their occurrence. Yet from time to time observers have suggested that weather may affect volcanic activity. In the late 1800's, for example, one of the first geologists to visit the island of Hawaii, J.D. Dana, speculated that rainfall influenced the occurrence of eruptions there. In the early 1900's, volcanologists suggested that some eruptions from Mount Lassen, Calif., were caused by the infiltration of snowmelt into the volcano's hot summit. Most such associations have not been provable because of lack of information; others have been dismissed after careful evaluation of the evidence.

  18. Source mechanisms of volcanic tsunamis.

    Science.gov (United States)

    Paris, Raphaël

    2015-10-28

    Volcanic tsunamis are generated by a variety of mechanisms, including volcano-tectonic earthquakes, slope instabilities, pyroclastic flows, underwater explosions, shock waves and caldera collapse. In this review, we focus on the lessons that can be learnt from past events and address the influence of parameters such as volume flux of mass flows, explosion energy or duration of caldera collapse on tsunami generation. The diversity of waves in terms of amplitude, period, form, dispersion, etc. poses difficulties for integration and harmonization of sources to be used for numerical models and probabilistic tsunami hazard maps. In many cases, monitoring and warning of volcanic tsunamis remain challenging (further technical and scientific developments being necessary) and must be coupled with policies of population preparedness. © 2015 The Author(s).

  19. Volcanic hazards in Central America

    Science.gov (United States)

    Rose, William I.; Bluth, Gregg J.S.; Carr, Michael J.; Ewert, John W.; Patino, Lina C.; Vallance, James W.

    2006-01-01

    This volume is a sampling of current scientific work about volcanoes in Central America with specific application to hazards. The papers reflect a variety of international and interdisciplinary collaborations and employ new methods. The book will be of interest to a broad cross section of scientists, especially volcanologists. The volume also will interest students who aspire to work in the field of volcano hazards mitigation or who may want to work in one of Earth’s most volcanically active areas.

  20. Implication of climate change on urban drainage systems of Chicago and Mainstream and DesPlaines (MS/DP) Tunnel and Reservoir Plan (TARP)

    Science.gov (United States)

    Luo, H.; Schmidt, A.; Garcia, M. H.; Oberg, N.

    2016-12-01

    The impact of changing climate patterns and rainfall extremes on sewer system and river basin has been brought to attention to the researchers worldwide. In 1972, the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) adopted the Tunnel and Reservoir Plan (TARP) to address combined sewer overflow (CSO) pollution and flooding problems in the Chicago land area. The hydrosystem laboratory in University of Illinois at Urbana-Champaign developed a series of numerical models accordingly to analyze the complex hydraulic behavior of the as-built TARP system. Due to the interconnected nature of City of Chicago sewer network and MS/DP TARP system, a tightly coupled hydrological and hydraulic model MetroFlow was developed to facilitate such analysis by integrating previous developed models. This study utilized MetroFlow to predict the hydrologic/hydraulic response of the system for a set of pre-determined design and historical storm events. Accordingly, combined sewer overflows (CSO) of Chicago combined sewer system and MS/DP TARP system were evaluated under current and future weather scenarios. The total CSOs from TARP system can be considered as urban point pollution source to the surrounding receiving bodies, hence the potential impact of climate change on CSO fluxes is essential reference to wastewater infrastructure design and operations of the hydraulic regulating structures under storm events to mitigate predicted risks.

  1. Improving global detection of volcanic eruptions using the Ozone Monitoring Instrument (OMI

    Directory of Open Access Journals (Sweden)

    V. J. B. Flower

    2016-11-01

    Full Text Available Volcanic eruptions pose an ever-present threat to human populations around the globe, but many active volcanoes remain poorly monitored. In regions where ground-based monitoring is present the effects of volcanic eruptions can be moderated through observational alerts to both local populations and service providers, such as air traffic control. However, in regions where volcano monitoring is limited satellite-based remote sensing provides a global data source that can be utilised to provide near-real-time identification of volcanic activity. This paper details a volcanic plume detection method capable of identifying smaller eruptions than is currently feasible, which could potentially be incorporated into automated volcanic alert systems. This method utilises daily, global observations of sulfur dioxide (SO2 by the Ozone Monitoring Instrument (OMI on NASA's Aura satellite. Following identification and classification of known volcanic eruptions in 2005–2009, the OMI SO2 data, analysed using a logistic regression analysis, permitted the correct classification of volcanic events with an overall accuracy of over 80 %. Accurate volcanic plume identification was possible when lower-tropospheric SO2 loading exceeded ∼ 400 t. The accuracy and minimal user input requirements of the developed procedure provide a basis for incorporation into automated SO2 alert systems.

  2. Volcanic deformation in the Andes

    Science.gov (United States)

    Riddick, S.; Fournier, T.; Pritchard, M.

    2009-05-01

    We present the results from an InSAR survey of volcanic activity in South America. We use data from the Japanese Space Agency's ALOS L-band radar satellite from 2006-2009. The L-band instrument provides better coherence in densely vegetated regions, compared to the shorter wave length C-band data. The survey reveals volcano related deformation in regions, north, central and southern, of the Andes volcanic arc. Since observations are limited to the austral summer, comprehensive coverage of all volcanoes is not possible. Yet, our combined observations reveal volcanic/hydrothermal deformation at Lonquimay, Llaima, Laguna del Maule, and Chaitén volcanoes, extend deformation measurements at Copahue, and illustrate temporal complexity to the previously described deformation at Cerro Hudson and Cordón Caulle. No precursory deformation is apparent before the large Chaitén eruption (VEI_5) of 2 May 2008, (at least before 16 April) suggesting rapid magma movement from depth at this long dormant volcano. Subsidence at Ticsani Volcano occurred coincident with an earthquake swarm in the same region.

  3. Volcanic mercury in Pinus canariensis

    Science.gov (United States)

    Rodríguez Martín, José Antonio; Nanos, Nikos; Miranda, José Carlos; Carbonell, Gregoria; Gil, Luis

    2013-08-01

    Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 μg kg-1) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 μg kg-1). Thus, mercury emissions originating from the eruption remained only as a mark—in pyroclastic wounds—and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 μg kg-1) and bark (6.0 μg kg-1) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species.

  4. Source mechanism of volcanic tremor

    Energy Technology Data Exchange (ETDEWEB)

    Ferrick, M.G.; Qamar, A.; St. Lawrence, W.F.

    1982-10-10

    Low-frequency (<10 Hz) volcanic earthquakes originate at a wide range of depths and occur before, during, and after magmatic eruptions. The characteristics of these earthquakes suggest that they are not typical tectonic events. Physically analogous processes occur in hydraulic fracturing of rock formations, low-frequency icequakes in temperate glaciers, and autoresonance in hydroelectric power stations. We propose that unsteady fluid flow in volcanic conduits is the common source mechanism of low-frequency volcanic earthquakes (tremor). The fluid dynamic source mechanism explains low-frequency earthquakes of arbitrary duration, magnitude, and depth of origin, as unsteady flow is independent of physical properties of the fluid and conduit. Fluid transients occur in both low-viscosity gases and high-viscosity liquids. A fluid transient analysis can be formulated as generally as is warranted by knowledge of the composition and physical properties of the fluid, material properties, geometry and roughness of the conduit, and boundary conditions. To demonstrate the analytical potential of the fluid dynamic theory, we consider a single-phase fluid, a melt of Mount Hood andesite at 1250/sup 0/C, in which significant pressure and velocity variations occur only in the longitudinal direction. Further simplification of the conservation of mass and momentum equations presents an eigenvalue problem that is solved to determine the natural frequencies and associated damping of flow and pressure oscillations.

  5. Volcanic mercury in Pinus canariensis.

    Science.gov (United States)

    Rodríguez Martín, José Antonio; Nanos, Nikos; Miranda, José Carlos; Carbonell, Gregoria; Gil, Luis

    2013-08-01

    Mercury (Hg) is a toxic element that is emitted to the atmosphere by both human activities and natural processes. Volcanic emissions are considered a natural source of mercury in the environment. In some cases, tree ring records taken close to volcanoes and their relation to volcanic activity over time are contradictory. In 1949, the Hoyo Negro volcano (La Palma-Canary Islands) produced significant pyroclastic flows that damaged the nearby stand of Pinus canariensis. Recently, 60 years after the eruption, we assessed mercury concentrations in the stem of a pine which survived volcano formation, located at a distance of 50 m from the crater. We show that Hg content in a wound caused by pyroclastic impacts (22.3 μg kg(-1)) is an order of magnitude higher than the Hg concentrations measured in the xylem before and after the eruption (2.3 μg kg(-1)). Thus, mercury emissions originating from the eruption remained only as a mark-in pyroclastic wounds-and can be considered a sporadic and very high mercury input that did not affect the overall Hg input in the xylem. In addition, mercury contents recorded in the phloem (9.5 μg kg(-1)) and bark (6.0 μg kg(-1)) suggest that mercury shifts towards non-living tissues of the pine, an aspect that can be related to detoxification in volcanism-adapted species.

  6. Disruptive event analysis: volcanism and igneous intrusion

    International Nuclear Information System (INIS)

    Crowe, B.M.

    1980-08-01

    An evaluation is made of the disruptive effects of volcanic activity with respect to long term isolation of radioactive waste through deep geologic storage. Three major questions are considered. First, what is the range of disruption effects of a radioactive waste repository by volcanic activity. Second, is it possible, by selective siting of a repository, to reduce the risk of disruption by future volcanic activity. And third, can the probability of repository disruption by volcanic activity be quantified. The main variables involved in the evaluation of the consequences of repository disruption by volcanic activity are the geometry of the magma-repository intersection (partly controlled by depth of burial) and the nature of volcanism. Potential radionuclide dispersal by volcanic transport within the biosphere ranges in distance from several kilometers to global. Risk from the most catastrophic types of eruptions can be reduced by careful site selection to maximize lag time prior to the onset of activity. Certain areas or volcanic provinces within the western United States have been sites of significant volcanism and should be avoided as potential sites for a radioactive waste repository. Examples of projection of future sites of active volcanism are discussed for three areas of the western United States. Probability calculations require two types of data: a numerical rate or frequency of volcanic activity and a numerical evaluation of the areal extent of volcanic disruption for a designated region. The former is clearly beyond the current state of art in volcanology. The latter can be approximated with a reasonable degree of satisfaction. In this report, simplified probability calculations are attempted for areas of past volcanic activity

  7. Effects of volcanic deposit disaggregation on exposed water composition

    Science.gov (United States)

    Back, W. E.; Genareau, K. D.

    2016-12-01

    Explosive volcanic eruptions produce a variety of hazards. Pyroclastic material can be introduced to water through ash fallout, pyroclastic flows entering water bodies, and/or lahars. Remobilization of tephras can occur soon after eruption or centuries later, introducing additional pyroclastic material into the environment. Introduction of pyroclastic material may alter the dissolved element concentration and pH of exposed waters, potentially impacting drinking water supplies, agriculture, and ecology. This study focuses on the long-term impacts of volcanic deposits on water composition due to the mechanical breakup of volcanic deposits over time. Preliminary work has shown that mechanical milling of volcanic deposits will cause significant increases in dissolved element concentrations, conductivity, and pH of aqueous solutions. Pyroclastic material from seven eruptions sites was collected, mechanically milled to produce grain sizes Soufriere Hills, Ruapehu), mafic (Lathrop Wells) and ultramafic (mantle xenoliths) volcanic deposits. Lathrop Wells has an average bulk concentration of 49.15 wt.% SiO2, 6.11 wt. % MgO, and 8.39 wt. % CaO and produces leachate concentrations of 85.69 mg/kg for Ca and 37.22 mg/kg for Mg. Taupo and Valles Caldera samples have a bulk concentration of 72.9 wt.% SiO2, 0.59 wt. % MgO, and 1.48 wt. % CaO, and produces leachate concentrations of 4.08 mg/kg for Ca and 1.56 mg/kg for Mg. Similar testing will be conducted on the intermediate and ultramafic samples to test the hypothesis that bulk magma composition and mineralogy will directly relate to the increased dissolved element concentration of exposed waters. The measured effects on aqueous solutions will aid in evaluation of impacts to marine and freshwater systems exposed to volcanic deposits.

  8. Progress in Near Real-Time Volcanic Cloud Observations Using Satellite UV Instruments

    Science.gov (United States)

    Krotkov, N. A.; Yang, K.; Vicente, G.; Hughes, E. J.; Carn, S. A.; Krueger, A. J.

    2011-12-01

    Volcanic clouds from explosive eruptions can wreak havoc in many parts of the world, as exemplified by the 2010 eruption at the Eyjafjöll volcano in Iceland, which caused widespread disruption to air traffic and resulted in economic impacts across the globe. A suite of satellite-based systems offer the most effective means to monitor active volcanoes and to track the movement of volcanic clouds globally, providing critical information for aviation hazard mitigation. Satellite UV sensors, as part of this suite, have a long history of making unique near-real time (NRT) measurements of sulfur dioxide (SO2) and ash (aerosol Index) in volcanic clouds to supplement operational volcanic ash monitoring. Recently a NASA application project has shown that the use of near real-time (NRT,i.e., not older than 3 h) Aura/OMI satellite data produces a marked improvement in volcanic cloud detection using SO2 combined with Aerosol Index (AI) as a marker for ash. An operational online NRT OMI AI and SO2 image and data product distribution system was developed in collaboration with the NOAA Office of Satellite Data Processing and Distribution. Automated volcanic eruption alarms, and the production of volcanic cloud subsets for multiple regions are provided through the NOAA website. The data provide valuable information in support of the U.S. Federal Aviation Administration goal of a safe and efficient National Air Space. In this presentation, we will highlight the advantages of UV techniques and describe the advances in volcanic SO2 plume height estimation and enhanced volcanic ash detection using hyper-spectral UV measurements, illustrated with Aura/OMI observations of recent eruptions. We will share our plan to provide near-real-time volcanic cloud monitoring service using the Ozone Mapping and Profiler Suite (OMPS) on the Joint Polar Satellite System (JPSS).

  9. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Alternative thermal histories. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    Interpretations supporting a differentiated, once active Mercury are listed. Alternative scenarios of the planet's thermal history involve: different distributions of accreted materials, including uranium and thorium-rich materials; variations of early melting; and different modes of plains and scarp formation. Arguments are advanced which strongly favor plains formation by volcanism, lack of a primordial surface, and possible identification of remnant tensional features. Studies of remotely sensed data which strongly suggest a modestly homogeneous surface of silicates imply core separation. Reasons for accepting or rejecting various hypotheses for thermal histories of the planet are mentioned.

  10. Local to global: a collaborative approach to volcanic risk assessment

    Science.gov (United States)

    Calder, Eliza; Loughlin, Sue; Barsotti, Sara; Bonadonna, Costanza; Jenkins, Susanna

    2017-04-01

    -economic conditions tending to influence longer term well-being and recovery. The volcanological community includes almost 100 Volcano Observatories worldwide, the official institutions responsible for monitoring volcanoes. They may be dedicated institutions, or operate from national institutions (geological surveys, universities, met agencies). They have a key role in early warning, forecasting and long term hazard assessment (often in the form of volcanic hazards maps). The complexity of volcanic systems means that once unrest begins there are multiple potential eruptive outcomes and short term forecasts can change rapidly. This local knowledge of individual volcanoes underpins hazard and risk assessments developed at national, regional and global scales. Combining this local expertise with the knowledge of the international research community (including interdisciplinary perspectives) creates a powerful partnership. A collaborative approach is therefore needed to develop effective volcanic risk assessments at regional to global scale. The World Organisation of Volcano Observatories is a Commission of IAVCEI, alongside other Commissions such as 'Hazard and Risk' (with an active working group on volcanic hazards maps) and the 'Cities and Volcanoes' Commission. The Global Volcano Model network is a collaborative initiative developing hazards and risk information at national to global scales, underpinned by local expertise. Partners include IAVCEI, Smithsonian Institution, International Volcanic Health Hazard Network, VHub and other initiatives and institutions.

  11. Climate variability and Great Plains agriculture

    International Nuclear Information System (INIS)

    Rosenberg, N.J.; Katz, L.A.

    1991-01-01

    The ways in which inhabitants of the Great Plains, including Indians, early settlers, and 20th century farmers, have adapted to climate changes on the Great Plains are explored. The climate of the Great Plains, because of its variability and extremes, can be very stressful to plants, animals and people. It is suggested that agriculture and society on the Great Plains have, during the last century, become less vulnerable to the stresses imposed by climate. Opinions as to the sustainability of agriculture on the Great Plains vary substantially. Lockeretz (1981) suggests that large scale, high cost technologies have stressed farmers by creating surpluses and by requiring large investments. Opie (1989) sees irrigation as a climate substitute, however he stresses that the Ogallala aquifer must inevitably become depleted. Deborah and Frank Popper (1987) believe that farming on the Plains is unsustainable, and destruction of shelterbelts, out-migration of the rural population and environmental problems will lead to total collapse. With global warming, water in the Great Plains is expected to become scarcer, and although improvements in irrigation efficiency may slow depletion of the Ogallala aquifer, ultimately the acreage under irrigation must decrease to levels that can be sustained by natural recharge and reliable surface flows. 23 refs., 2 figs

  12. Systematic assessment of constipation on plain abdominal radiographs in children

    International Nuclear Information System (INIS)

    Bosch, Maurice van den; Graafmans, Doortje; Nievelstein, Rutger; Beek, Erik

    2006-01-01

    Constipation in childhood is common and its clinical assessment is often difficult. Plain abdominal radiography is simple and used to quantify constipation. Three scoring systems, those of Barr et al., Leech et al. and Blethyn et al., have been developed to quantify fecal loading on the abdominal radiograph. In order to determine which method is the most useful in clinical practice, we assessed the reproducibility of the three scoring systems. Plain abdominal radiographs from 40 clinically constipated children were retrospectively reviewed by two paediatric radiologists on two separate occasions. The radiographs were scored according to three different systems developed by Barr et al., Leech et al., Blethyn et al. Intraobserver variability and interobserver reproducibility were determined for each system. Kappa coefficients were calculated as indicators of inter- and intraobserver agreement for categorical outcome variables. The Leech score showed the highest reproducibility: the intraobserver agreement was high for both observers (κ values of 0.88 and 1.00, respectively, P<0.05). Furthermore, the interobserver agreement was also high: κ 0.91 in the first round and 0.84 in the second. The Leech score proved to be a highly reproducible tool for assessment of childhood constipation and is of value in clinical practice for systematic assessment of constipation on plain abdominal radiographs in children. (orig.)

  13. The characteristics of hydrogeochemical zonation of groundwater in inland plain

    Science.gov (United States)

    Xin-yu, HOU; Li-ting, XING; Yi, YANG; Wen-jing, ZHANG; Guang-yao, CHI

    2018-05-01

    To find out the hydrochemical zoning of groundwaterin the inland plain, taking Jiyang plain as an example, based on mathematical statistics, ion ratio coefficient and isotopic analysis method, the characteristics of water chemical composition and its zoning at different depths of 500m were studied. The result shows: ①The groundwater flow system in the study area can be divided into local flow system, intermediate flow system and regional flow system. ②The hydrochemical type of shallow groundwater is complex. The hydrochemical types of middle confined water are mainly ClṡSO4—MgṡNa and SO4ṡCl—NaṡMg. The deep confined water is mainly HCO3. ③The TDS of shallow groundwater increases gradually along the direction of groundwater flow. ④The shallow saltwater and freshwater are alternately distributed in horizontal direction, and saltwater is distributed sporadically in the interfluve area with sporadic punctate or banded, and hydrochemical types are mainly ClṡSO4—NaṡMgṡCa. Conclusion: Groundwater in the study area is affected by complicated hydrogeochemical action, mainly in the form of filtration, cation exchange and evaporation. The inland plain area is characterized by hydrogeochemical zonation in horizontal and vertical.

  14. Systematic assessment of constipation on plain abdominal radiographs in children

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, Maurice van den; Graafmans, Doortje [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Nievelstein, Rutger; Beek, Erik [Wilhelmina Children' s Hospital, Department of Paediatric Radiology, Utrecht (Netherlands)

    2006-03-15

    Constipation in childhood is common and its clinical assessment is often difficult. Plain abdominal radiography is simple and used to quantify constipation. Three scoring systems, those of Barr et al., Leech et al. and Blethyn et al., have been developed to quantify fecal loading on the abdominal radiograph. In order to determine which method is the most useful in clinical practice, we assessed the reproducibility of the three scoring systems. Plain abdominal radiographs from 40 clinically constipated children were retrospectively reviewed by two paediatric radiologists on two separate occasions. The radiographs were scored according to three different systems developed by Barr et al., Leech et al., Blethyn et al. Intraobserver variability and interobserver reproducibility were determined for each system. Kappa coefficients were calculated as indicators of inter- and intraobserver agreement for categorical outcome variables. The Leech score showed the highest reproducibility: the intraobserver agreement was high for both observers ({kappa} values of 0.88 and 1.00, respectively, P<0.05). Furthermore, the interobserver agreement was also high: {kappa} 0.91 in the first round and 0.84 in the second. The Leech score proved to be a highly reproducible tool for assessment of childhood constipation and is of value in clinical practice for systematic assessment of constipation on plain abdominal radiographs in children. (orig.)

  15. Simulating the lava flow formed during the 2014-2015 Holuhraun eruption (Bardarbunga volcanic system, Iceland) by using the new F-L probabilistic code

    Science.gov (United States)

    Tarquini, Simone; de'Michieli Vitturi, Mattia; Jensen, Esther H.; Barsotti, Sara; Pedersen, Gro B. M.; Coppola, Diego

    2015-04-01

    The 2014-2015 fissure eruption in Holuhraun started when a new code (named F-L) was being developed. The availability of several digital Elevation Models of the area inundated by the lava and the availability of continuously updated maps of the flow (collected in the field and through remote sensing imagery) provided an excellent opportunity for testing and calibrating the new code against an evolving flow field. Remote sensing data also provided a constrain on the effusion rate. Existing numerical codes for the simulation of lava flow emplacement are based either on the solution of some simplification of the physical governing equations of this phenomenon (the so-called "deterministic codes" - e.g. Hidaka et al. 2005; Crisci et al. 2010), or, instead, on the evidence that lava flows tend to follow the steepest descent path from the vent downhill (the so-called "probabilistic codes" - e.g. Favalli et al. 2005). F-L is a new code for the simulation of lava flows, which rests on an approach similar to the one introduced by Glaze and Baloga (2013), and can be ascribed to the "probabilistic family" of lava flow simulation codes. Nevertheless, in contrast with other probabilistic codes (e.g. Favalli et al. 2005), this code explicitly tackles not only the direction of expansion of the growing flow and the area covered, but also the volume of the emplaced lava over time, and hence the supply rate. As a result, this approach bridges the stochastic point of view of a plain probabilistic code with one of the most critical among the input parameters considered by deterministic codes, which is the effusion rate during the course of an eruption. As such, a similar code, in principle, can tackle several aspects which were previously not addressed within the probabilistic approach, which are: (i) the 3D morphology of the flow field (i.e. thickness), (ii) the implications of the effusion rate in the growth of the flow field, and (iii) the evolution of the lava coverage over time

  16. Permeability of volcanic rocks to gas and water

    Science.gov (United States)

    Heap, M. J.; Reuschlé, T.; Farquharson, J. I.; Baud, P.

    2018-04-01

    The phase (gas or liquid) of the fluids within a porous volcanic system varies in both time and space. Laboratory experiments have shown that gas and water permeabilities can differ for the same rock sample, but experiments are biased towards rocks that contain minerals that are expected react with the pore fluid (such as the reaction between liquid water and clay). We present here the first study that systematically compares the gas and water permeability of volcanic rocks. Our data show that permeabilities to argon gas and deionised water can differ by a factor between two and five in two volcanic rocks (basalt and andesite) over a confining pressure range from 2 to 50 MPa. We suggest here that the microstructural elements that offer the shortest route through the sample-estimated to have an average radius 0.1-0.5 μm using the Klinkenberg slip factor-are accessible to gas, but restricted or inaccessible to water. We speculate that water adsorption on the surface of these thin microstructural elements, assumed here to be tortuous/rough microcracks, reduces their effective radius and/or prevents access. These data have important implications for fluid flow and therefore the distribution and build-up of pore pressure within volcanic systems.

  17. Volcanic Eruptions as the Cause of the Little Ice Age

    Science.gov (United States)

    Zambri, B.; Robock, A.

    2017-12-01

    Both external forcing (solar radiation, volcanic eruptions) and internal fluctuations have been proposed to explain such multi-centennial perturbations as the Little Ice Age. Confidence in these hypotheses is limited due to the limited number of proxies, as well as only one observed realization of the Last Millennium. Here, we evaluate different hypotheses on the origin of Little Ice Age-like anomalies, focusing in particular on the long-term response of North Atlantic and Arctic climate perturbations to solar and volcanic perturbations. For that, we conduct a range of sensitivity tests carried out with the Community Earth System Model (CESM) at the National Center for Atmospheric Research, focusing in particular on the sensitivity to initial conditions and the strength of solar and volcanic forcing. By comparing the climate response to various combinations of external perturbations, we demonstrate nonlinear interactions that are necessary to explain trends observed in the fully coupled system and discuss physical mechanisms through which these external forcings can trigger multidecadal modes of the Atlantic Multidecadal Oscillation and subsequently lead to a Little-Ice-Age-like regime. For that, we capture and compare patterns of the coupled atmosphere-sea-ice-ocean response as revealed through a range of data analysis techniques. We show that the large 1257 Samalas, 1452 Kuwae, and 1600 Huaynaputina volcanic eruptions were the main causes of the multi-centennial glaciation associated with the Little Ice Age.

  18. An evolving magmatic-hydrothermal system in the formation of the Mesozoic Meishan magnetite-apatite deposit in the Ningwu volcanic basin, eastern China

    Science.gov (United States)

    Liu, Wen-Hao; Jiang, Man-Rong; Zhang, Xiao-Jun; Xia, Yan; Algeo, Thomas J.; Li, Huan

    2018-06-01

    , which could have generated an iron-rich melt, and is thus inconsistent with an iron-oxide melt origin for the Meishan iron deposit. The δ34S values of pyrite (6.6-15.1‰) and anhydrite (15.6-16.9‰) in the deposit and the occurrence of evaporites under the volcanic rocks likely indicate that the iron ores and alteration rocks of the Meishan deposit were formed by the circulation of fluids of evaporitic origin driven by heat from the hypabyssal gabbro-diorite intrusives. In the late magmatic stage, oxygen fugacity decreased to a reducing range, triggering the reduction of sulfate to reduced sulfur and leading to local gold and pyrite mineralization.

  19. Peripheral Faulting of Eden Patera: Potential Evidence in Support of a New Volcanic Construct on Mars

    Science.gov (United States)

    Harlow, J.

    2016-12-01

    Arabia Terra's (AT) pock-marked topography in the expansive upland region of Mars Northern Hemisphere has been assumed to be the result of impact crater bombardment. However, examination of several craters by researchers revealed morphologies inconsistent with neighboring craters of similar size and age. These 'craters' share features with terrestrial super-eruption calderas, and are considered a new volcanic construct on Mars called `plains-style' caldera complexes. Eden Patera (EP), located on the northern boundary of AT is a reference type for these calderas. EP lacks well-preserved impact crater morphologies, including a decreasing depth to diameter ratio. Conversely, Eden shares geomorphological attributes with terrestrial caldera complexes such as Valles Caldera (New Mexico): arcuate caldera walls, concentric fracturing/faulting, flat-topped benches, irregular geometric circumferences, etc. This study focuses on peripheral fractures surrounding EP to provide further evidence of calderas within the AT region. Scaled balloon experiments mimicking terrestrial caldera analogs have showcased fracturing/faulting patterns and relationships of caldera systems. These experiments show: 1) radial fracturing (perpendicular to caldera rim) upon inflation, 2) concentric faulting (parallel to sub-parallel to caldera rim) during evacuation, and 3) intersecting radial and concentric peripheral faulting from resurgence. Utilizing Mars Reconnaissance Orbiter Context Camera (CTX) imagery, peripheral fracturing is analyzed using GIS to study variations in peripheral fracture geometries relative to the caldera rim. Visually, concentric fractures dominate within 20 km, radial fractures prevail between 20 and 50 km, followed by gradation into randomly oriented and highly angular intersections in the fretted terrain region. Rose diagrams of orientation relative to north expose uniformly oriented mean regional stresses, but do not illuminate localized caldera stresses. Further

  20. Volcanic hazards and public response

    Science.gov (United States)

    Peterson, Donald W.

    1988-05-01

    Although scientific understanding of volcanoes is advancing, eruptions continue to take a substantial toll of life and property. Some of these losses could be reduced by better advance preparation, more effective flow of information between scientists and public officials, and better understanding of volcanic behavior by all segments of the public. The greatest losses generally occur at volcanoes that erupt infrequently where people are not accustomed to dealing with them. Scientists sometimes tend to feel that the blame for poor decisions in emergency management lies chiefly with officials or journalists because of their failure to understand the threat. However, the underlying problem embraces a set of more complex issues comprising three pervasive factors. The first factor is the volcano: signals given by restless volcanoes are often ambiguous and difficult to interpret, especially at long-quiescent volcanoes. The second factor is people: people confront hazardous volcanoes in widely divergent ways, and many have difficulty in dealing with the uncertainties inherent in volcanic unrest. The third factor is the scientists: volcanologists correctly place their highest priority on monitoring and hazard assessment, but they sometimes fail to explain clearly their conclusions to responsible officials and the public, which may lead to inadequate public response. Of all groups in society, volcanologists have the clearest understanding of the hazards and vagaries of volcanic activity; they thereby assume an ethical obligation to convey effectively their knowledge to benefit all of society. If society resists, their obligation nevertheless remains. They must use the same ingenuity and creativity in dealing with information for the public that they use in solving scientific problems. When this falls short, even excellent scientific results may be nullified.

  1. Thermal vesiculation during volcanic eruptions.

    Science.gov (United States)

    Lavallée, Yan; Dingwell, Donald B; Johnson, Jeffrey B; Cimarelli, Corrado; Hornby, Adrian J; Kendrick, Jackie E; von Aulock, Felix W; Kennedy, Ben M; Andrews, Benjamin J; Wadsworth, Fabian B; Rhodes, Emma; Chigna, Gustavo

    2015-12-24

    Terrestrial volcanic eruptions are the consequence of magmas ascending to the surface of the Earth. This ascent is driven by buoyancy forces, which are enhanced by bubble nucleation and growth (vesiculation) that reduce the density of magma. The development of vesicularity also greatly reduces the 'strength' of magma, a material parameter controlling fragmentation and thus the explosive potential of the liquid rock. The development of vesicularity in magmas has until now been viewed (both thermodynamically and kinetically) in terms of the pressure dependence of the solubility of water in the magma, and its role in driving gas saturation, exsolution and expansion during decompression. In contrast, the possible effects of the well documented negative temperature dependence of solubility of water in magma has largely been ignored. Recently, petrological constraints have demonstrated that considerable heating of magma may indeed be a common result of the latent heat of crystallization as well as viscous and frictional heating in areas of strain localization. Here we present field and experimental observations of magma vesiculation and fragmentation resulting from heating (rather than decompression). Textural analysis of volcanic ash from Santiaguito volcano in Guatemala reveals the presence of chemically heterogeneous filaments hosting micrometre-scale vesicles. The textures mirror those developed by disequilibrium melting induced via rapid heating during fault friction experiments, demonstrating that friction can generate sufficient heat to induce melting and vesiculation of hydrated silicic magma. Consideration of the experimentally determined temperature and pressure dependence of water solubility in magma reveals that, for many ascent paths, exsolution may be more efficiently achieved by heating than by decompression. We conclude that the thermal path experienced by magma during ascent strongly controls degassing, vesiculation, magma strength and the effusive

  2. Great Plains Wind Energy Transmission Development Project

    Energy Technology Data Exchange (ETDEWEB)

    Brad G. Stevens, P.E.; Troy K. Simonsen; Kerryanne M. Leroux

    2012-06-09

    In fiscal year 2005, the Energy & Environmental Research Center (EERC) received funding from the U.S. Department of Energy (DOE) to undertake a broad array of tasks to either directly or indirectly address the barriers that faced much of the Great Plains states and their efforts to produce and transmit wind energy at the time. This program, entitled Great Plains Wind Energy Transmission Development Project, was focused on the central goal of stimulating wind energy development through expansion of new transmission capacity or development of new wind energy capacity through alternative market development. The original task structure was as follows: Task 1 - Regional Renewable Credit Tracking System (later rescoped to Small Wind Turbine Training Center); Task 2 - Multistate Transmission Collaborative; Task 3 - Wind Energy Forecasting System; and Task 4 - Analysis of the Long-Term Role of Hydrogen in the Region. As carried out, Task 1 involved the creation of the Small Wind Turbine Training Center (SWTTC). The SWTTC, located Grand Forks, North Dakota, consists of a single wind turbine, the Endurance S-250, on a 105-foot tilt-up guyed tower. The S-250 is connected to the electrical grid on the 'load side' of the electric meter, and the power produced by the wind turbine is consumed locally on the property. Establishment of the SWTTC will allow EERC personnel to provide educational opportunities to a wide range of participants, including grade school through college-level students and the general public. In addition, the facility will allow the EERC to provide technical training workshops related to the installation, operation, and maintenance of small wind turbines. In addition, under Task 1, the EERC hosted two small wind turbine workshops on May 18, 2010, and March 8, 2011, at the EERC in Grand Forks, North Dakota. Task 2 involved the EERC cosponsoring and aiding in the planning of three transmission workshops in the midwest and western regions. Under Task

  3. Environmental and anthropogenic factors affecting the respiratory toxicity of volcanic ash in vitro

    Science.gov (United States)

    Tomašek, Ines; Horwell, Claire J.; Damby, David E.; Ayris, Paul M.; Barošová, Hana; Geers, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara; Clift, Martin J. D.

    2016-04-01

    Human exposure to inhalable volcanic ash particles following an eruption is a health concern, as respirable-sized particles can potentially contribute towards adverse respiratory health effects, such as the onset or exacerbation of respiratory and cardiovascular diseases. Although there is substantial information on the mineralogical properties of volcanic ash that may influence its biological reactivity, knowledge as to how external factors, such as air pollution, contribute to and augment the potential reactivity is limited. To determine the respiratory effects of volcanic particle interactions with anthropogenic pollution and volcanic gases we will experimentally assess: (i) physicochemical characteristics of volcanic ash relevant to respiratory toxicity; (ii) the effects of simultaneously inhaling anthropogenic pollution (i.e. diesel exhaust particles (DEP)) and volcanic ash (of different origins); (iii) alteration of volcanic ash toxicity following interaction with volcanic gases. In order to gain a first understanding of the biological impact of the respirable fraction of volcanic ash when inhaled with DEP in vitro, we used a sophisticated 3D triple cell co-culture model of the human alveolar epithelial tissue barrier. The multi-cellular system was exposed to DEP [0.02 mg/mL] and then exposed to either a single or repeated dose of well-characterised respirable volcanic ash (0.26 ± 0.09 or 0.89 ± 0.29 μg/cm2, respectively) from the Soufrière Hills volcano, Montserrat for a period of 24 hours using a pseudo-air liquid interface approach. Cultures were subsequently assessed for adverse biological endpoints including cytotoxicity, oxidative stress and (pro)-inflammatory responses. Results indicated that the combination of DEP and respirable volcanic ash at sub-lethal concentrations incited a significant release of pro-inflammatory markers that was greater than the response for either DEP or volcanic ash, independently. Further work is planned, to determine if

  4. Changes in the soil environment from excessive application of fertilizers and manures to two contrasting intensive cropping systems on the North China Plain

    International Nuclear Information System (INIS)

    Ju, X.T.; Kou, C.L.; Christie, P.; Dou, Z.X.; Zhang, F.S.

    2007-01-01

    Effects of excessive fertilizer and manure applications on the soil environment were compared in greenhouse vegetable systems shifted from wheat-maize rotations 5-15 years previously and in wheat-maize rotations. N, P and K surpluses to the greenhouses were 4328, 1337 and 1466 kg ha -1 year -1 , respectively compared to 346, 65 and -163 kg ha -1 year -1 to wheat-maize fields. Subsequently, substantial mineral N and available P and K accumulated in the soil and leaching occurred down the soil profile in the greenhouses. Soil pH under vegetables was significantly lower than in the wheat-maize fields, while the EC was significantly higher in the vegetable soils. The mean Cd concentration in the vegetable soils was 2.8 times that in the wheat-maize rotations. Due to excessive fertilizer application in greenhouse vegetable production in northeast China, excessive salt and nitrate concentrations may accumulate and soil quality may deteriorate faster than in conventional wheat-maize rotations. - Extremely high nutrient inputs to intensively managed vegetable crops in northeast China may lead to very serious degradation of soil and water quality

  5. Changes in the soil environment from excessive application of fertilizers and manures to two contrasting intensive cropping systems on the North China Plain

    Energy Technology Data Exchange (ETDEWEB)

    Ju, X.T. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China)]. E-mail: juxt@cau.edu.cn; Kou, C.L. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Institute of Soil and Fertilization, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 (China); Christie, P. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Agricultural and Environmental Science Department, Queen' s University Belfast, Newforge Lane, Belfast BT9 5PX (United Kingdom); Dou, Z.X. [Center for Animal Health and Productivity, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 382 West Street Road, Kennett Square, PA 19348 (United States); Zhang, F.S. [Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Agricultural Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China)

    2007-01-15

    Effects of excessive fertilizer and manure applications on the soil environment were compared in greenhouse vegetable systems shifted from wheat-maize rotations 5-15 years previously and in wheat-maize rotations. N, P and K surpluses to the greenhouses were 4328, 1337 and 1466 kg ha{sup -1} year{sup -1}, respectively compared to 346, 65 and -163 kg ha{sup -1} year{sup -1} to wheat-maize fields. Subsequently, substantial mineral N and available P and K accumulated in the soil and leaching occurred down the soil profile in the greenhouses. Soil pH under vegetables was significantly lower than in the wheat-maize fields, while the EC was significantly higher in the vegetable soils. The mean Cd concentration in the vegetable soils was 2.8 times that in the wheat-maize rotations. Due to excessive fertilizer application in greenhouse vegetable production in northeast China, excessive salt and nitrate concentrations may accumulate and soil quality may deteriorate faster than in conventional wheat-maize rotations. - Extremely high nutrient inputs to intensively managed vegetable crops in northeast China may lead to very serious degradation of soil and water quality.

  6. Seismic echo character northern Hatteras Abyssal Plain

    International Nuclear Information System (INIS)

    McCreery, C.J.; Laine, E.P.

    1985-01-01

    Latest efforts in echo-character mapping of the northern Hatteras Abyssal Plain have discerned variations in thickness in a near-surface sedimentary sequence which has been designated seismic unit A. This unit probably represents the last episode of progradation of the Hatteras Deep Sea Fan in the southern part of the study area, and has infilled probable paleochannels from the Wilmington Canyon and Sohm Gap in the north. Unit A thins to a minimum in the central part of the plain, where older sediments come within 1 meter of the surface. Variations in the character of the surface reflector probably represent differing degrees of microtopography developed on a Late Pleistocene surface overlain by Holocene sediments. With the exception of one area identified as a relict surface outcropping in the western plain, this microtopography seems related to present-day thalweg locations on the abyssal plain. 11 references, 13 figures

  7. Southern Great Plains Atmospheric Radiation Measurement Site

    Data.gov (United States)

    Federal Laboratory Consortium — The Southern Great Plains Atmospheric Radiation Measurement Site (SGP-ARM) is the oldest and largest of DOE's Arm sites. It was established in 1992. It consists of...

  8. flexural improvement of plain concrete beams strengthened

    African Journals Online (AJOL)

    Muhammad Nura Isa

    Results show significant improvement in both stiffness and load bearing capacity of plain concrete ... Various methods have been developed to increase their strength capacity by using .... obtained by carrying out uniaxial direct tensile strength.

  9. Electromagnetic exploration in high-salinity groundwater zones: case studies from volcanic and soft sedimentary sites in coastal Japan

    Science.gov (United States)

    Suzuki, Koichi; Kusano, Yukiko; Ochi, Ryota; Nishiyama, Nariaki; Tokunaga, Tomochika; Tanaka, Kazuhiro

    2017-01-01

    Estimating the spatial distribution of groundwater salinity in coastal plain regions is becoming increasingly important for site characterisation and the prediction of hydrogeological environmental conditions resulting from radioactive waste disposal and underground CO2 storage. In previous studies of the freshwater-saltwater interface, electromagnetic methods were used for sites characterised by unconsolidated deposits or Neocene soft sedimentary rocks. However, investigating the freshwater-saltwater interface in hard rock sites (e.g. igneous areas) is more complex, with the permeability of the rocks greatly influenced by fractures. In this study, we investigated the distribution of high-salinity groundwater at two volcanic rock sites and one sedimentary rock site, each characterised by different hydrogeological features. Our investigations included (1) applying the controlled source audio-frequency magnetotelluric (CSAMT) method and (2) conducting laboratory tests to measure the electrical properties of rock core samples. We interpreted the 2D resistivity sections by referring to previous data on geology and geochemistry of groundwater. At the Tokusa site, an area of inland volcanic rocks, low resistivity zones were detected along a fault running through volcanic rocks and shallow sediments. The results suggest that fluids rise through the Tokusa-Jifuku Fault to penetrate shallow sediments in a direction parallel to the river, and some fluids are diluted by rainwater. At the Oki site, a volcanic island on a continental shelf, four resistivity zones (in upward succession: low, high, low and high) were detected. The results suggest that these four zones were formed during a transgression-regression cycle caused by the last glacial period. At the Saijo site, located on a coastal plain composed of thick sediments, we observed a deep low resistivity zone, indicative of fossil seawater remnant from a transgression after the last glacial period. The current coastal

  10. Defining 'plain language' in contemporary South Africa | Cornelius ...

    African Journals Online (AJOL)

    Defining the concept 'plain language' has been hugely problematic since the origins of the socalled Plain Language Movement in the 1970s in the United States and elsewhere in the world. Definitions of 'plain language' abound, yet James (2008: 6) warns, in relation to plain language practitioners, that “we can't yet call ...

  11. 44 CFR 10.14 - Flood plains and wetlands.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plains and wetlands. 10... Flood plains and wetlands. For any action taken by FEMA in a flood plain or wetland, the provisions of... Executive Order 11988, Flood Plain Management, and Executive Order 11990, Protection of Wetlands (44 CFR...

  12. K-Ar age of the Tertiary volcanic rocks in the Tohoku area, Japan

    International Nuclear Information System (INIS)

    Konda, Tadashi; Ueda, Yoshio.

    1980-01-01

    The absolute age of the Tertiary volcanic rocks in Tohoku area has been estimated by K-Ar method. The results are: (1) in case of the volcanic rocks of Monzen-Aikawa stage, 32.8 - 38.5 m.y.B.P., (2) in case of the volcanic rocks of Nozaki-Daijima stage, 22.0 - 25.1 m.y.B.P., (3) in case of the volcanic rocks of Nishikurosawa stage, 15.5 - 16.5 m.y.B.P., (4) in case of the volcanic rocks of Onnagawa stage, 12.6 - 14.8 m.y.B.P., (5) in case of the volcanic rocks of Funakawa stage, 9.6 - 11.3 m.y.B.P., and (6) in case of the volcanic rocks of Kitaura stage, 6.9 - 9.0 m.y.B.P. The samples used are such as biotite and whole rocks. The eruption periods in Tertiary volcanic activities presumed by K-Ar method are geologically significant. In the measurements made on the same system of samples under same conditions, there was difference in the K-Ar ages between the Monzen-Aikawa and the Nozaki-Daijima stages, and it was significantly noteworthy. It is indicated that the volcanic rock activities in the former stage had took place before those in the latter stage. In the Tohoku arc of northern Japan, the simultaneity in initial volcanic activities is not seen in the direction across the arc. (J.P.N.)

  13. Status of volcanic hazard studies for the Nevada Nuclear Waste Storage Investigations. Volume II

    International Nuclear Information System (INIS)

    Crowe, B.M.; Wohletz, K.H.; Vaniman, D.T.; Gladney, E.; Bower, N.

    1986-01-01

    Volcanic hazard investigations during FY 1984 focused on five topics: the emplacement mechanism of shallow basalt intrusions, geochemical trends through time for volcanic fields of the Death Valley-Pancake Range volcanic zone, the possibility of bimodal basalt-rhyolite volcanism, the age and process of enrichment for incompatible elements in young basalts of the Nevada Test Site (NTS) region, and the possibility of hydrovolcanic activity. The stress regime of Yucca Mountain may favor formation of shallow basalt intrusions. However, combined field and drill-hole studies suggest shallow basalt intrusions are rare in the geologic record of the southern Great Basin. The geochemical patterns of basaltic volcanism through time in the NTS region provide no evidence for evolution toward a large-volume volcanic field or increases in future rates of volcanism. Existing data are consistent with a declining volcanic system comparable to the late stages of the southern Death Valley volcanic field. The hazards of bimodal volcanism in this area are judged to be low. The source of a 6-Myr pumice discovered in alluvial deposits of Crater Flat has not been found. Geochemical studies show that the enrichment of trace elements in the younger rift basalts must be related to an enrichment of their mantle source rocks. This geochemical enrichment event, which may have been metasomatic alteration, predates the basalts of the silicic episode and is, therefore, not a young event. Studies of crater dimensions of hydrovolcanic landforms indicate that the worst case scenario (exhumation of a repository at Yucca Mountain by hydrovolcanic explosions) is unlikely. Theoretical models of melt-water vapor explosions, particularly the thermal detonation model, suggest hydrovolcanic explosion are possible at Yucca Mountain. 80 refs., 21 figs., 5 tabs

  14. Detecting Volcanic Ash Plumes with GNSS Signals

    Science.gov (United States)

    Rainville, N.; Larson, K. M.; Palo, S. E.; Mattia, M.; Rossi, M.; Coltelli, M.; Roesler, C.; Fee, D.

    2016-12-01

    Global Navigation Satellite Systems (GNSS) receivers are commonly placed near volcanic sites to measure ground deformation. In addition to the carrier phase data used to measure ground position, these receivers also record Signal to Noise ratio (SNR) data. Larson (2013) showed that attenuations in SNR data strongly correlate with ash emissions at a series of eruptions of Redoubt Volcano. This finding has been confirmed at eruptions for Tongariro, Mt Etna, Mt Shindake, and Sakurajima. In each of these detections, very expensive geodetic quality GNSS receivers were used. If low-cost GNSS instruments could be used instead, a networked array could be deployed and optimized for plume detection and tomography. The outputs of this sensor array could then be used by both local volcanic observatories and Volcano Ash Advisory Centers. Here we will describe progress in developing such an array. The sensors we are working with are intended for navigation use, and thus lack the supporting power and communications equipment necessary for a networked system. Reliably providing those features is major challenge for the overall sensor design. We have built prototypes of our Volcano Ash Plume Receiver (VAPR), with solar panels, lithium-ion batteries and onboard data storage for preliminary testing. We will present results of our field tests of both receivers and antennas. A second critical need for our array is a reliable detection algorithm. We have tested our algorithm on data from recent eruptions and have incorporated the noise characteristics of the low-cost GNSS receiver. We have also developed a simulation capability so that the receivers can be deployed to optimize vent crossing GNSS signals.

  15. Influence of organic and inorganic sources of nutrients on the functional diversity of microbial communities in the vegetable cropping system of the Indo-Gangetic plains.

    Science.gov (United States)

    Manjunath, Mallappa; Kumar, Upendra; Yadava, Raj Bahadur; Rai, Awadhesh Bahadur; Singh, Bijendra

    2018-05-31

    The aim of the present study was to assess the effects of different organic and inorganic fertilizers on the functional diversity of soil microbial community under a vegetable production system. The Biolog ® Eco-plate technique and indices, such as average well-colour development (AWCD), McIntosh and Shannon diversity were employed to study the diversity of soil microorganisms. The AWCD, i.e. overall utilization of carbon sources, suggested that different organic treatments had a significant impact on the metabolic activity of soil microorganisms. After 120h, the highest AWCD values were observed in poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (0.63) and farm yard manure (FYM) (10 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (0.61). After 72h, the highest value of the McIntosh diversity index was recorded in poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) (3.87), followed by poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 )+biofertilizers (Azotobacter 500 g·ha -1 applied as seed treatment) (3.12). In the case of the Shannon diversity index, the highest values were noticed in organic treatments; however, there was no significant differences between organic and inorganic treatments. Biplot analysis showed a clear differentiation of organic treatments from the inorganic control. The amino acids, phenolics and polymer utilizing microorganisms were dominant in organic treatments. Inorganic control recorded the lowest values of the microbial diversity indices. Through this study, we have identified the best combination of organic nutrients, i.e. poultry manure (2.5 t·ha -1 )+vermicompost (3.5 t·ha -1 ) for the stimulation of metabolically active soil microbial communities. Copyright © 2018 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  16. Oligocene paleogeography of the northern Great Plains and adjacent mountains

    International Nuclear Information System (INIS)

    Seeland, D.

    1985-01-01

    Early Oligocene paleogeography of the northern Great Plains and adjacent mountains is inferred in part from published surface and subsurface studies of the pre-Oligocene surface. These studies are combined with published and unpublished information on clast provenance, crossbedding orientation, and Eocene paleogeography. The Oligocene Arctic Ocean-Gulf of Mexico continental divide extended from the southern Absaroka Mountains east along the Owl Creek Mountains, across the southern Powder River Basin, through the northern Black Hills, and eastward across South Dakota. Streams north of the divide flowed northeastward. The Olligocene White River Group contains 50 to 90 percent airfall pyroclastic debris from a northern Great Basin source. Most of the uranium deposits of the region in pre-Oligocene rocks can be related to a uranium source in the volcanic ash of the White River; in many places the pre-Oligocene deposits can be related to specific Oligocene channels. Uranium deposits in sandstones of major Oligocene rivers are an important new type of deposit. The Oligocene channel sandstones also contain small quantities of gold, molybdenum, gas, and oil

  17. Electrostatic phenomena in volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Lane, S J; James, M R; Gilbert, J S, E-mail: s.lane@lancaster.ac.uk [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2011-06-23

    Electrostatic phenomena have long been associated with the explosive eruption of volcanoes. Lightning generated in volcanic plumes is a spectacular atmospheric electrical event that requires development of large potential gradients over distances of up to kilometres. This process begins as hydrated liquid rock (magma) ascends towards Earth's surface. Pressure reduction causes water supersaturation in the magma and the development of bubbles of supercritical water, where deeper than c. 1000 m, and water vapour at shallower depths that drives flow expansion. The generation of high strain rates in the expanding bubbly magma can cause it to fracture in a brittle manner, as deformation relaxation timescales are exceeded. The brittle fracture provides the initial charge separation mechanism, known as fractoemission. The resulting mixture of charged silicate particles and ions evolves over time, generating macro-scale potential gradients in the atmosphere and driving processes such as particle aggregation. For the silicate particles, aggregation driven by electrostatic effects is most significant for particles smaller than c. 100 {mu}m. Aggregation acts to change the effective aerodynamic behaviour of silicate particles, thus altering the sedimentation rates of particles from volcanic plumes from the atmosphere. The presence of liquid phases also promotes aggregation processes and lightning.

  18. A submarine volcanic eruption leads to a novel microbial habitat.

    Science.gov (United States)

    Danovaro, Roberto; Canals, Miquel; Tangherlini, Michael; Dell'Anno, Antonio; Gambi, Cristina; Lastras, Galderic; Amblas, David; Sanchez-Vidal, Anna; Frigola, Jaime; Calafat, Antoni M; Pedrosa-Pàmies, Rut; Rivera, Jesus; Rayo, Xavier; Corinaldesi, Cinzia

    2017-04-24

    Submarine volcanic eruptions are major catastrophic events that allow investigation of the colonization mechanisms of newly formed seabed. We explored the seafloor after the eruption of the Tagoro submarine volcano off El Hierro Island, Canary Archipelago. Near the summit of the volcanic cone, at about 130 m depth, we found massive mats of long, white filaments that we named Venus's hair. Microscopic and molecular analyses revealed that these filaments are made of bacterial trichomes enveloped within a sheath and colonized by epibiotic bacteria. Metagenomic analyses of the filaments identified a new genus and species of the order Thiotrichales, Thiolava veneris. Venus's hair shows an unprecedented array of metabolic pathways, spanning from the exploitation of organic and inorganic carbon released by volcanic degassing to the uptake of sulfur and nitrogen compounds. This unique metabolic plasticity provides key competitive advantages for the colonization of the new habitat created by the submarine eruption. A specialized and highly diverse food web thrives on the complex three-dimensional habitat formed by these microorganisms, providing evidence that Venus's hair can drive the restart of biological systems after submarine volcanic eruptions.

  19. Volcanics of the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D

    stream_size 2 stream_content_type text/plain stream_name J_Geol_Soc_India_70_883.pdf.txt stream_source_info J_Geol_Soc_India_70_883.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  20. [Effects of volcanic eruptions on environment and health].

    Science.gov (United States)

    Zuskin, Eugenija; Mustajbegović, Jadranka; Doko Jelinić, Jagoda; Pucarin-Cvetković, Jasna; Milosević, Milan

    2007-12-01

    Volcanoes pose a threat to almost half a billion people; today there are approximately 500 active volcanoes on Earth, and every year there are 10 to 40 volcanic eruptions. Volcanic eruptions produce hazardous effects for the environment, climate, and the health of the exposed persons, and are associated with the deterioration of social and economic conditions. Along with magma and steam (H2O), the following gases surface in the environment: carbon dioxide (CO2) and sulphur dioxide (SO2), carbon monoxide (CO), hydrogen sulphide (H2S), carbon sulphide (CS), carbon disulfide (CS2), hydrogen chloride (HCl), hydrogen (H2), methane (CH4), hydrogen fluoride (HF), hydrogen bromide (HBr) and various organic compounds, as well as heavy metals (mercury, lead, gold).Their unfavourable effects depend on the distance from a volcano, on magma viscosity, and on gas concentrations. The hazards closer to the volcano include pyroclastic flows, flows of mud, gases and steam, earthquakes, blasts of air, and tsunamis. Among the hazards in distant areas are the effects of toxic volcanic ashes and problems of the respiratory system, eyes and skin, as well as psychological effects, injuries, transport and communication problems, waste disposal and water supplies issues, collapse of buildings and power outage. Further effects are the deterioration of water quality, fewer periods of rain, crop damages, and the destruction of vegetation. During volcanic eruptions and their immediate aftermath, increased respiratory system morbidity has been observed as well as mortality among those affected by volcanic eruptions. Unfavourable health effects could partly be prevented by timely application of safety measures.

  1. Review of the petrology of the Auckland Volcanic Field

    International Nuclear Information System (INIS)

    Smith, I.E.M.; McGee, L.E.; Lindsay, J.M.

    2009-01-01

    Research has long shown that the petrology of suites of volcanic rock can be used to define and understand the fundamental parameters of the magmatic systems that feed volcanoes. The geochemistry of volcanic rocks provides information about the nature of the source rocks, depths and amounts of melting, the processes that act on magmas as they rise to the surface and, most importantly, the rates of these processes. In turn, the answers to fundamental petrological questions can provide input to important questions concerning volcano hazard scenarios and hazard mitigation challenges. The multi-disciplinary DEVORA research programme, launched in 2008, is a GNS Science-University of Auckland collaboration with the aim of DEtermining VOlcanic Risk in Auckland. One of its main themes is the development of an integrated geological model for the Auckland Volcanic Field (AVF) by investigating the physical controls on magma generation, ascent and eruption though detailed structural and petrological investigations. A key data set underpinning this theme is a comprehensive geochemical database for the rocks of the AVF. This report, Review of the Petrology of the Auckland Volcanic Field, is a synthesis and commentary of all petrological and geochemical data currently available for the AVF. It represents one of several reports carried out as part of the 'synthesis' phase of DEVORA, whereby existing data from previous work is collated and summarised, so that gaps in current knowledge can be appropriately addressed. In this report we utilise published and unpublished sources to summarise the petrological data available up to May 2009, and identify where new data and approaches will improve our understanding of the magmatic system which feeds the field. (author). 53 refs., 7 figs., 2 tabs.

  2. DECOVALEX-THMC Task D: Long-Term Permeability/Porosity Changes in the EDZ and Near Field due to THM and THC Processes in Volcanic and Crystalline-Bentonite Systems, Status Report October 2005

    International Nuclear Information System (INIS)

    Birkholzer, J.; Rutqvist, J.; Sonnenthal, E.; Barr, D.

    2005-01-01

    The DECOVALEX project is an international cooperative project initiated by SKI, the Swedish Nuclear Power Inspectorate, with participation of about 10 international organizations. The name DECOVALEX stands for DEvelopment of COupled models and their VALidation against Experiments. The general goal of this project is to encourage multidisciplinary interactive and cooperative research on modeling coupled processes in geologic formations in support of the performance assessment for underground storage of radioactive waste. Three multi-year project stages of DECOVALEX have been completed in the past decade, mainly focusing on coupled thermal-hydrological-mechanical processes. Currently, a fourth three-year project stage of DECOVALEX is under way, referred to as DECOVALEX-THMC. THMC stands for Thermal, Hydrological, Mechanical, and Chemical processes. The new project stage aims at expanding the traditional geomechanical scope of the previous DECOVALEX project stages by incorporating geochemical processes important for repository performance. The U.S. Department of Energy (DOE) leads Task D of the new DECOVALEX phase, entitled ''Long-term Permeability/Porosity Changes in the EDZ and Near Field due to THC and THM Processes for Volcanic and Crystalline-Bentonite Systems''. In its leadership role for Task D, DOE coordinates and sets the direction for the cooperative research activities of the international research teams engaged in Task D

  3. Volcanism at 1.45 Ma within the Yellowstone Volcanic Field, United States

    Science.gov (United States)

    Rivera, Tiffany A.; Furlong, Ryan; Vincent, Jaime; Gardiner, Stephanie; Jicha, Brian R.; Schmitz, Mark D.; Lippert, Peter C.

    2018-05-01

    Rhyolitic volcanism in the Yellowstone Volcanic Field has spanned over two million years and consisted of both explosive caldera-forming eruptions and smaller effusive flows and domes. Effusive eruptions have been documented preceding and following caldera-forming eruptions, however the temporal and petrogenetic relationships of these magmas to the caldera-forming eruptions are relatively unknown. Here we present new 40Ar/39Ar dates for four small-volume eruptions located on the western rim of the second-cycle caldera, the source of the 1.300 ± 0.001 Ma Mesa Falls Tuff. We supplement our new eruption ages with whole rock major and trace element chemistry, Pb isotopic ratios of feldspar, and paleomagnetic and rock magnetic analyses. Eruption ages for the effusive Green Canyon Flow (1.299 ± 0.002 Ma) and Moonshine Mountain Dome (1.302 ± 0.003 Ma) are in close temporal proximity to the eruption age of the Mesa Falls Tuff. In contrast, our results indicate a period of volcanism at ca 1.45 Ma within the Yellowstone Volcanic Field, including the eruption of the Bishop Mountain Flow (1.458 ± 0.002 Ma) and Tuff of Lyle Spring (1.450 ± 0.003 Ma). These high-silica rhyolites are chemically and isotopically distinct from the Mesa Falls Tuff and related 1.3 Ma effusive eruptions. The 40Ar/39Ar data from the Tuff of Lyle Spring demonstrate significant antecrystic inheritance, prevalent within the upper welded ash-flow tuff matrix, and minimal within individual pumice. Antecrysts are up to 20 kyr older than the eruption, with subpopulations of grains occurring every few thousand years. We interpret these results as an indicator for the timing of magmatic pulses into a growing magmatic system that would ultimately erupt the Tuff of Lyle Spring, and which we more broadly interpret as the tempo of crustal accumulation associated with bimodal magmatism. We propose a system whereby chemically, isotopically, and temporally distinct, isolated small-volume magma batches are

  4. Diffuse Helium Emission as a Precursory Sign of Volcanic Unrest

    Science.gov (United States)

    Padron, E.; Perez, N.; Hernandez Perez, P. A.; Sumino, H.; Melian Rodriguez, G.; Barrancos, J.; Nolasco, D.; Padilla, G.; Dionis, S.; Rodriguez, F.; Hernandez, I.; Calvo, D.; Peraza, M.; Nagao, K.

    2012-12-01

    Since July 16, 2011, an anomalous seismicity at El Hierro island, the youngest and smallest of the Canary Islands, was recorded by IGN seismic network. After the occurrence of more than 10,000 seismic events, volcanic tremor was recorded since 05:15 of the October 10, by all of the seismic stations on the island, with highest amplitudes recorded in the southernmost station. During the afternoon of October 12 a large light-green coloured area was observed in the sea to the souht of La Restinga village (at the southernmost part of El Hierro island), suggesting the existence of a submarine eruption. Since October 12, frequent episodes of, turbulent gas emission and foaming, and the appearance of steamy lava fragments has been observed on the sea surface. As part of the volcanic surveillance of the island, the Instituto Volcanologico de Canarias (INVOLCAN) geochemical monitoring program is carrying out diffuse helium surveys on the surface environment of El Hierro (soil atmosphere). This nobel gas has been investigated because it has been considered an almost ideal geochemical indicator because it is chemically inert, physically stable, nonbiogenic, sparingly soluble in water under ambient conditions and almost non-adsorbable. At each survey, 600 sampling sites covering the whole island and following an homogeneous distribution are selected for helium measurements in the soil gases, The helium concentration gradients with respect to its value on air (5.24 ppm) allow us to estimate a pure diffusive emission rate of helium throughout the island. The first survey was carried out on the summer of 2003, when the island was on a quiescence period. At this survey, the amount of helium released by the volcanic system of El Hierro was estimated in 6 kg/d. Since the beginning of the seismic unrest, 13 helium emission surveys have been carried out. The helium emission rate has shown an excellent agreement with the evolution of the volcanic crisis of the island, reaching 30 kg

  5. Role of Atmospheric Chemistry in the Climate Impacts of Stratospheric Volcanic Injections

    Science.gov (United States)

    Legrande, Allegra N.; Tsigaridis, Kostas; Bauer, Susanne E.

    2016-01-01

    The climate impact of a volcanic eruption is known to be dependent on the size, location and timing of the eruption. However, the chemistry and composition of the volcanic plume also control its impact on climate. It is not just sulfur dioxide gas, but also the coincident emissions of water, halogens and ash that influence the radiative and climate forcing of an eruption. Improvements in the capability of models to capture aerosol microphysics, and the inclusion of chemistry and aerosol microphysics modules in Earth system models, allow us to evaluate the interaction of composition and chemistry within volcanic plumes in a new way. These modeling efforts also illustrate the role of water vapor in controlling the chemical evolution, and hence climate impacts, of the plume. A growing realization of the importance of the chemical composition of volcanic plumes is leading to a more sophisticated and realistic representation of volcanic forcing in climate simulations, which in turn aids in reconciling simulations and proxy reconstructions of the climate impacts of past volcanic eruptions. More sophisticated simulations are expected to help, eventually, with predictions of the impact on the Earth system of any future large volcanic eruptions.

  6. Cenozoic volcanic rocks of Saudi Arabia

    Science.gov (United States)

    Coleman, R.G.; Gregory, R.T.; Brown, G.F.

    2016-01-01

    The Cenozoic volcanic rocks of Saudi Arabia cover about 90,000 km2, one of the largest areas of alkali olivine basalt in the world. These volcanic rocks are in 13 separate fields near the eastern coast of the Red Sea and in the western Arabian Peninsula highlands from Syria southward to the Yemen Arab Republic.

  7. Field-trip guide to Columbia River flood basalts, associated rhyolites, and diverse post-plume volcanism in eastern Oregon

    Science.gov (United States)

    Ferns, Mark L.; Streck, Martin J.; McClaughry, Jason D.

    2017-08-09

    The Miocene Columbia River Basalt Group (CRBG) is the youngest and best preserved continental flood basalt province on Earth, linked in space and time with a compositionally diverse succession of volcanic rocks that partially record the apparent emergence and passage of the Yellowstone plume head through eastern Oregon during the late Cenozoic. This compositionally diverse suite of volcanic rocks are considered part of the La Grande-Owyhee eruptive axis (LOEA), an approximately 300-kilometer-long (185 mile), north-northwest-trending, middle Miocene to Pliocene volcanic belt located along the eastern margin of the Columbia River flood basalt province. Volcanic rocks erupted from and preserved within the LOEA form an important regional stratigraphic link between the (1) flood basalt-dominated Columbia Plateau on the north, (2) bimodal basalt-rhyolite vent complexes of the Owyhee Plateau on the south, (3) bimodal basalt-rhyolite and time-transgressive rhyolitic volcanic fields of the Snake River Plain-Yellowstone Plateau, and (4) the High Lava Plains of central Oregon.This field-trip guide describes a 4-day geologic excursion that will explore the stratigraphic and geochemical relationships among mafic rocks of the Columbia River Basalt Group and coeval and compositionally diverse volcanic rocks associated with the early “Yellowstone track” and High Lava Plains in eastern Oregon. Beginning in Portland, the Day 1 log traverses the Columbia River gorge eastward to Baker City, focusing on prominent outcrops that reveal a distal succession of laterally extensive, large-volume tholeiitic flood lavas of the Grande Ronde, Wanapum, and Saddle Mountains Basalt formations of the CRBG. These “great flows” are typical of the well-studied flood basalt-dominated Columbia Plateau, where interbedded silicic and calc-alkaline lavas are conspicuously absent. The latter part of Day 1 will highlight exposures of middle to late Miocene silicic ash-flow tuffs, rhyolite domes, and

  8. Volcanic sulfur degassing and the role of sulfides in controlling volcanic metal emissions

    Science.gov (United States)

    Edmonds, M.; Liu, E.

    2017-12-01

    Volcanoes emit prodigious quantities of sulfur and metals, their behaviour inextricably linked through pre-eruptive sulfide systematics and through degassing and speciation in the volcanic plume. Fundamental differences exist in the metal output of ocean island versus arc volcanoes, with volcanoes in Hawaii and Iceland outgassing large fluxes of gaseous and particulate chalcophiles; and arc volcanoes' plumes, in contrast, enriched in Zn, Cu, Tl and Pb. Metals and metalloids partition into a magmatic vapor phase from silicate melt at crustal pressures. Their abundance in magmatic vapor is influenced strongly by sulfide saturation and by the composition of the magmatic vapor phase, particularly with respect to chloride. These factors are highly dependent on tectonic setting. Metal outgassing is controlled by magma water content and redox: deep saturation in vapor and minimal sulfide in arc basalts yields metal-rich vapor; shallow degassing and resorption of sulfides feeds the metal content of volcanic gas in ocean islands. We present a detailed study of the sulfide systematics of the products of the 2014-2015 Holuhraun basaltic fissure eruption (Bárðarbunga volcanic system, Iceland) to illustrate the interplay between late water and sulfur outgassing; sulfide saturation and breakdown; and metal partitioning into a vapor phase. Sulfide globules, representing quenched droplets of an immiscible sulfide liquid, are preserved within erupted tephra. Sulfide globules in rapidly quenched tephra are preserved within both matrix glass and as inclusions in crystals. The stereologically-corrected 3D size distribution of sulfide globules ranges from importance in supplying sulfur and metals to the atmosphere during eruption.

  9. Quaternary basaltic volcanism in the Payenia volcanic province, Argentina

    DEFF Research Database (Denmark)

    Søager, Nina

    primitive basalts and trachybasalts but also more evolved samples from the retroarc region and the larger volcanoes Payún Matrú and Payún Liso are presented. The samples cover a broad range of compositions from intraplate lavas similar to ocean island basalts to arc andesites. A common feature found...... are isotopically similar to the Andean Southern Volcanic Zone arc rocks and their mantle source possibly resembled the source of South Atlantic N-MORB prior to addition of fluids and melts from the subduction channel. However, it must have been more enriched than the estimates of depleted upper mantle from...... the lithosphere is thinnest and possibly in areas of elevated mantle temperatures. The pyroxenite melts formed at deeper levels react with the surrounding peridotite and thereby changes composition leading to eruption of melts which experienced variable degrees of melt-peridotite interaction. This can presumably...

  10. Monitoring diffuse volcanic degassing during volcanic unrests: the case of Campi Flegrei (Italy).

    Science.gov (United States)

    Cardellini, C; Chiodini, G; Frondini, F; Avino, R; Bagnato, E; Caliro, S; Lelli, M; Rosiello, A

    2017-07-28

    In volcanoes with active hydrothermal systems, diffuse CO 2 degassing may constitute the primary mode of volcanic degassing. The monitoring of CO 2 emissions can provide important clues in understanding the evolution of volcanic activity especially at calderas where the interpretation of unrest signals is often complex. Here, we report eighteen years of CO 2 fluxes from the soil at Solfatara of Pozzuoli, located in the restless Campi Flegrei caldera. The entire dataset, one of the largest of diffuse CO 2 degassing ever produced, is made available for the scientific community. We show that, from 2003 to 2016, the area releasing deep-sourced CO 2 tripled its extent. This expansion was accompanied by an increase of the background CO 2 flux, over most of the surveyed area (1.4 km 2 ), with increased contributions from non-biogenic source. Concurrently, the amount of diffusively released CO 2 increased up to values typical of persistently degassing active volcanoes (up to 3000 t d -1 ). These variations are consistent with the increase in the flux of magmatic fluids injected into the hydrothermal system, which cause pressure increase and, in turn, condensation within the vapor plume feeding the Solfatara emission.

  11. Experimental study on the effect of calcination on the volcanic ash activity of diatomite

    Science.gov (United States)

    Xiao, Liguang; Pang, Bo

    2017-09-01

    The volcanic ash activity of diatomite was studied under the conditions of aerobic calcination and vacuum calcination by the combined water rate method, it was characterized by XRD, BET and SEM. The results showed that the volcanic ash activity of diatomite under vacuum conditions was higher than that of aerobic calcination, 600°C vacuum calcination 2h, the combined water rate of diatomite-Ca(OH)2-H2O system was increased from 6.24% to 71.43%, the volcanic ash activity reached the maximum value, the specific surface

  12. 2015 Volcanic activity in Alaska—Summary of events and response of the Alaska Volcano Observatory

    Science.gov (United States)

    Dixon, James P.; Cameron, Cheryl E.; Iezzi, Alexandra M.; Wallace, Kristi

    2017-09-28

    The Alaska Volcano Observatory (AVO) responded to eruptions, volcanic unrest or suspected unrest, and seismic events at 14 volcanic centers in Alaska during 2015. The most notable volcanic activity consisted of continuing intermittent ash eruptions from Cleveland and Shishaldin volcanoes in the Aleutian Islands. Two eruptive episodes, at Veniaminof and Pavlof, on the Alaska Peninsula ended in 2015. During 2015, AVO re-established the seismograph network at Aniakchak, installed six new broadband seismometers throughout the Aleutian Islands, and added a Multiple component Gas Analyzer System (MultiGAS) station on Augustine.

  13. Effects of plain packaging on decision-making and reward for nicotine cigarettes

    Directory of Open Access Journals (Sweden)

    Martin LE

    2014-05-01

    Full Text Available Laura E Martin1,21Hoglund Brain Imaging Center, 2Department of Preventive Medicine and Public Health, University of Kansas Medical Center, Kansas City, KS, USAAbstract: Cigarette smoking remains the leading preventable cause of death worldwide. Efforts to reduce smoking prevalence include changes to policies that are expected to have impacts on smoking behaviors. Plain packaging has been introduced as a method to reduce the appeal of smoking by removing such branding information as pack colors and brand logos from cigarette packages. Behavioral studies of plain packaging demonstrate reductions in the appeal of cigarette packages, changes in smoking behaviors, and expected reductions in smoking initiation. Neuroimaging studies of branding demonstrate that the neural systems of rewards and cognitive control are associated with processing brand information (eg, logos. Neuroimaging studies in smokers demonstrate that the neural systems of reward respond to images of cigarettes and are associated with reductions in cognitive control responses. The current review discusses the state of research on plain packaging in terms of a biopsychosocial model of addiction in which behavioral studies of plain packaging can identify psychological and social changes related to packaging, whereas neuroimaging studies can identify biological changes underlying the psychological and social impacts of packaging. Together, these studies show that plain packaging may reduce positive perceptions of smoking by reducing related reward responses in the brain, thus increasing the likelihood that smokers will be able to resist the urge to smoke, and perhaps quit smoking altogether.Keywords: smoking, plain packaging, neuroimaging, branding, reward

  14. Large Volcanic Rises on Venus

    Science.gov (United States)

    Smrekar, Suzanne E.; Kiefer, Walter S.; Stofan, Ellen R.

    1997-01-01

    Large volcanic rises on Venus have been interpreted as hotspots, or the surface manifestation of mantle upwelling, on the basis of their broad topographic rises, abundant volcanism, and large positive gravity anomalies. Hotspots offer an important opportunity to study the behavior of the lithosphere in response to mantle forces. In addition to the four previously known hotspots, Atla, Bell, Beta, and western Eistla Regiones, five new probable hotspots, Dione, central Eistla, eastern Eistla, Imdr, and Themis, have been identified in the Magellan radar, gravity and topography data. These nine regions exhibit a wider range of volcano-tectonic characteristics than previously recognized for venusian hotspots, and have been classified as rift-dominated (Atla, Beta), coronae-dominated (central and eastern Eistla, Themis), or volcano-dominated (Bell, Dione, western Eistla, Imdr). The apparent depths of compensation for these regions ranges from 65 to 260 km. New estimates of the elastic thickness, using the 90 deg and order spherical harmonic field, are 15-40 km at Bell Regio, and 25 km at western Eistla Regio. Phillips et al. find a value of 30 km at Atla Regio. Numerous models of lithospheric and mantle behavior have been proposed to interpret the gravity and topography signature of the hotspots, with most studies focusing on Atla or Beta Regiones. Convective models with Earth-like parameters result in estimates of the thickness of the thermal lithosphere of approximately 100 km. Models of stagnant lid convection or thermal thinning infer the thickness of the thermal lithosphere to be 300 km or more. Without additional constraints, any of the model fits are equally valid. The thinner thermal lithosphere estimates are most consistent with the volcanic and tectonic characteristics of the hotspots. Estimates of the thermal gradient based on estimates of the elastic thickness also support a relatively thin lithosphere (Phillips et al.). The advantage of larger estimates of

  15. Handbook for Volcanic Risk Management: an outcome from MIAVITA project

    Science.gov (United States)

    Bignami, Christian; Bosi, Vittorio; Costantini, Licia; Cristiani, Chiara; Lavigne, Franck; Thierry, Pierre

    2013-04-01

    Volcanic eruptions are one of the most impressive, violent and dramatic agents of change on Earth, threatening hundreds of millions of people. The crises management implies a strong cooperation among the main stakeholders (e.g., civil protection authorities, scientific institutions, operational forces). Considering the great amount of different actions required during the whole volcanic cycle (e.g., preparedness, unrest phase, crisis management, resilience), the role and responsibilities of stakeholders should be clarified in advance. In particular, the role of scientists, fundamental in all the phases, should be well discussed with the other stakeholders and well defined, for every country. This will allow a better management and response, and contribute to avoid misunderstanding. The new "Handbook for Volcanic Risk Management" issued by the MIAVITA European project, funded by the European Commission (Mitigate and Assess risk from Volcanic Impact on Terrain and human Activities) gives a contribution to that. Indeed, this handbook aims at synthesizing the acquired knowledge on volcanic risk management, such as prevention, preparedness, mitigation, intervention, crisis management and resilience, in a practical and useful way. It promotes the creation of an ideal bridge between different actors involved in risk management, improving and facilitating interactions among authorities and scientists. This work is based on current scientific research and the shared experience of the different MIAVITA project partners as well as on international good practices previously recommended. The handbook is composed of six sections. The first one briefly explains the global volcanic context and the principles of corresponding risk management. Section 2 contains a description of volcanic phenomena, damage and understanding size and effects that can be expected. Sections 3, 4 and 5 meet preparation and prevention issues and describe actions to be undertaken during the response phase

  16. Agricultural Fragility Estimates Subjected to Volcanic Ash Fall Hazards

    Science.gov (United States)

    Ham, H. J.; Lee, S.; Choi, S. H.; Yun, W. S.

    2015-12-01

    Agricultural Fragility Estimates Subjected to Volcanic Ash Fall Hazards Hee Jung Ham1, Seung-Hun Choi1, Woo-Seok Yun1, Sungsu Lee2 1Department of Architectural Engineering, Kangwon National University, Korea 2Division of Civil Engineering, Chungbuk National University, Korea ABSTRACT In this study, fragility functions are developed to estimate expected volcanic ash damages of the agricultural sector in Korea. The fragility functions are derived from two approaches: 1) empirical approach based on field observations of impacts to agriculture from the 2006 eruption of Merapi volcano in Indonesia and 2) the FOSM (first-order second-moment) analytical approach based on distribution and thickness of volcanic ash observed from the 1980 eruption of Mt. Saint Helens and agricultural facility specifications in Korea. Fragility function to each agricultural commodity class is presented by a cumulative distribution function of the generalized extreme value distribution. Different functions are developed to estimate production losses from outdoor and greenhouse farming. Seasonal climate influences vulnerability of each agricultural crop and is found to be a crucial component in determining fragility of agricultural commodities to an ash fall. In the study, the seasonality coefficient is established as a multiplier of fragility function to consider the seasonal vulnerability. Yields of the different agricultural commodities are obtained from Korean Statistical Information Service to create a baseline for future agricultural volcanic loss estimation. Numerically simulated examples of scenario ash fall events at Mt. Baekdu volcano are utilized to illustrate the application of the developed fragility functions. Acknowledgements This research was supported by a grant 'Development of Advanced Volcanic Disaster Response System considering Potential Volcanic Risk around Korea' [MPSS-NH-2015-81] from the Natural Hazard Mitigation Research Group, Ministry of Public Safety and Security of

  17. Open system magnetic evolution of the taos plateau volcanic field, Northern New Mexico. I - The petrology and geochemistry of the servilleta basalt

    Science.gov (United States)

    Dungan, M. A.; Lindstrom, M. M.; Mcmillan, N. J.; Moorbath, S.; Hoefs, J.

    1986-01-01

    MULTIFIT, an embodiment of the conceptual structure needed in modeling multisource and multiprocess magmatic systems, is described. This program, which uses familiar materials balance methodology and the equilibrium form of the Rayleigh equations, links evolutionary arrays, which is turn collectively relate the starting and final compositions of a given magmatic system. Moreover, MULTIFIT incorporates variations within major element data arrays; the linkage between them can be tested using an extension of the least squares algorithm, which selects the best branch point according to the minimum-sum-of-squared-residuals criterion. Advantages and disadvantages of the materials balance approach used in this program are discussed, an example is provided, and equations utilized by MULTIFIT are summarized. While MULTIFIT may not be the best approach for poorly constrained models involving partial melting for complex mixing, it may ultimately prove useful for ascertaining trace element partition coefficients in magnetic systems.

  18. Nonlinear Dynamical Analysis for a Plain Bearing

    Directory of Open Access Journals (Sweden)

    Ali Belhamra

    2014-03-01

    Full Text Available This paper investigates the nonlinear dynamic behavior for a plain classic bearing (fluid bearing lubricated by a non-Newtonian fluid of a turbo machine rotating with high speed; this type of fluid contains additives viscosity (couple-stress fluid film. The solution of the nonlinear dynamic problem of this type of bearing is determined with a spatial discretisation of the modified Reynolds' equation written in dynamic mode by using the optimized short bearing theory and a temporal discretisation for equations of rotor motion by the help of Euler's explicit diagram. This study analyzes the dynamic behavior of a rotor supported by two couple-stress fluid film journal lubricant enhances the dynamic stability of the rotor-bearing system considerably compared to that obtained when using a traditional Newtonian lubricant. The analysis shows that the dynamic behavior of a shaft which turns with high velocities is strongly nonlinear even for poor eccentricities of unbalance; the presence of parameters of couple stress allows strongly attenuating the will synchrony (unbalance and asynchrony (whipping amplitudes of vibrations of the shaft which supports more severe conditions (large unbalances.

  19. Scientific Drilling in a Central Italian Volcanic District

    Directory of Open Access Journals (Sweden)

    Paola Montone

    2007-09-01

    Full Text Available The Colli Albani Volcanic District, located 15 km SE of Rome (Fig. 1, is part of the Roman Magmatic Province, a belt of potassic to ultra-potassic volcanic districts that developed along the Tyrrhenian Sea margin since Middle Pleistocene time (Conticelli and Peccerillo, 1992; Marra et al., 2004; Giordano et al., 2006 and references therein. Eruption centers are aligned along NW-SE oriented majorextensional structures guiding the dislocation of Meso-Cenozoic siliceous-carbonate sedimentary successions at the rear of the Apennine belt. Volcanic districts developed in structural sectors with most favorable conditions for magma uprise. In particular, the Colli Albani volcanism is located in a N-S shear zone where it intersects the extensional NW- and NE-trending fault systems. In the last decade, geochronological measurements allowed for reconstructions of the eruptive history and led to the classification as "dormant" volcano. The volcanic history may be roughly subdivided into three main phases marked by different eruptive mechanisms andmagma volumes. The early Tuscolano-Artemisio Phase (ca. 561–351 ky, the most explosive and voluminous one, is characterized by five large pyroclastic flow-forming eruptions. After a ~40-ky-long dormancy, a lesser energetic phase of activity took place (Faete Phase; ca. 308–250 ky, which started with peripheral effusive eruptions coupled with subordinate hydromagmatic activity. A new ~50-ky-long dormancypreceded the start of the late hydromagmatic phase (ca. 200–36 ky, which was dominated by pyroclastic-surge eruptions, with formation of several monogenetic or multiple maars and/or tuff rings.

  20. Dinasour extinction and volcanic activity

    Science.gov (United States)

    Gledhill, J. A.

    There is at present some controversy about the reason for the mass extinction of dinosaurs and other forms of life at the end of the Cretaceous. A suggestion by Alvarez et al. [1980] that this was due to the collision of the earth with a meteorite 10 km or so in diameter has excited considerable interest [Silver and Schultz, 1982] and also some criticism [Stanley, 1984]. A recent publication [Wood, 1984] describing the catastrophic effects of a relatively minor lava flow in Iceland suggests that intense volcanic activity could have played a large part in the extinctions. In this letter it is pointed out that the Deccan lava flows in India took place in the appropriate time and may well have been of sufficient magnitude to be a major factor in the Cretaceous-Tertiary (C-T) boundary catastrophe.

  1. Noble Gas Signatures in Groundwater and Rainwater on the Island of Maui, Hawaii - Developing a New Noble Gas Application in Fractured, Volcanic Systems

    Science.gov (United States)

    Castro, M. C.; Niu, Y.; Warrier, R. B.; Hall, C. M.; Gingerich, S. B.; Scholl, M. A.; Bouvier, L.

    2014-12-01

    Recent work in the Galapagos Islands suggests that noble gas temperatures (NGTs) in fractured groundwater systems reflect the temperature of the ground surface at the time of infiltration rather than the mean annual air temperature (MAAT) value as commonly assumed in sedimentary systems where NGTs are typically used as indicators of past climate. This suggests that noble gases in fractured areas may record seasonality, and thus, provide information about timing of recharge in addition to location. Calculation of NGTs assumes that rain-derived recharge at the water table is in equilibrium with ground air. Lack of noble gas equilibration with respect to surface conditions, however, was observed in high-altitude springs in the Galapagos Islands and in a rainwater pilot study in Michigan, supporting the NGT seasonality hypothesis. Developing this new NGT application will lead to a better understanding of fractured groundwater flow systems and will contribute to improved water resource management plans. This study, carried out on Maui, Hawaii, is meant to test these hypotheses while improving knowledge of this island's groundwater flow system where limited hydrologic data are available. Here, we present the first results of noble gas analyses from samples collected in springs, groundwater wells and rainwater on northeast Maui. Results show that like most Michigan rainwater samples, rainwater from Maui is in disequilibrium with surface conditions and follows a mass-dependent pattern. Spring samples follow a similar pattern to that of rainwater and suggest that spring water originates directly from rainfall. These findings further support the hypothesis of NGT seasonality. However, while the atmospheric composition of noble gases points to direct supply from rainfall to spring aquifer systems, a direct connection between spring water and deeper aquifer levels or the mantle is apparent from He isotopic ratios which display an almost pure He mantle component in some springs.

  2. Atmospheric dispersion simulations of volcanic gas from Miyake Island by SPEEDI

    International Nuclear Information System (INIS)

    Nagai, Haruyasu; Furuno, Akiko; Terada, Hiroaki; Umeyama, Nobuaki; Yamazawa, Hiromi; Chino, Masamichi

    2001-03-01

    Japan Atomic Energy Research Institute is advancing the study for prediction of material circulation in the environment to cope with environmental pollution, based on SPEEDI (System for Prediction of Environmental Emergency Dose Information) and WSPEEDI (Worldwide version of SPEEDI), which are originally developed aiming at real-time prediction of atmospheric dispersion of radioactive substances accidentally released from nuclear facility. As a part of this study, dispersion simulation of volcanic gas erupted from Miyake Island is put into practice. After the stench incident at the west Kanto District on 28 August 2000 caused by volcanic gas from Miyake Island, the following simulations dealing with atmospheric dispersion of volcanic gas from Miyake Island have been carried out. (1) Retrospective simulation to analyze examine the mechanism of the transport of high concentration volcanic gas to the west Kanto District on 28 August and to estimate the release amount of volcanic gas. (2) Retrospective simulation to analyze the mechanism of the transport of volcanic gas to Tokai and Kansai districts in a case of stench incident on 13 September. (3) Automated real-time simulation from the acquisition of meteorological data to the output of figures for operational prediction of the transport of volcanic gas to Tokai and Kanto districts. This report describes the details of these studies. (author)

  3. Pannonian plain as a morphostructural unit of Serbia

    Directory of Open Access Journals (Sweden)

    Ćalić Jelena

    2012-01-01

    Full Text Available Differentiation between the terms “Pannonian Basin” and “Pannonian Plain” is not clear enough in geographical literature. The paper discusses the usage of the term “plain” in geomorphology, as well as the usage of a quantitative method for plain delineation, through calculation of relief roughness coefficient (using a digital elevation model. Qualitative analysis, which includes the definition of dominant geomorphological processes and the distribution of Quaternary sediments, is an addition to the quantitative analysis. In the Republic of Serbia, the area of the Pannonian plain defined in this way is 24,448 km2, which is 27.5% of the total territory of the country. The paper gives the overview of the geotectonic structure and evolution of the Pannonian Basin System, with special stress on the territory of Serbia, as well as the chronology of the Pannonian sedimentation area in Serbia from the Lower Miocene till present. In order to explain the status of the Pannonian plain as one of the morphostructural units of Serbia, the theoretical basics of morphostructures are discussed, as well as the principles of their spatial definition and the relation to the notion of a geological structure. [Projekat Ministarstva nauke Republike Srbije, br. 47007

  4. Carpal pseudoerosions: a plain X-ray interpretation pitfall

    Energy Technology Data Exchange (ETDEWEB)

    Wawer, Richard [Univ. Catholique de Lille (France). Service d' Imagerie Medicale; Budzik, Jean Francois [Univ. Catholique de Lille (France). Service d' Imagerie Medicale; Univ. Nord de France, Boulogne sur Mer (France). Unite de Recherche EA 4490, Physiopathologie des Maladies Osseuses Inflammatoires; Demondion, Xavier [Univ. Lille 2 (France). Service d' Imagerie Musculosquelettique; CHRU Lille (France). Lab. d' Anatomie; Forzy, Gerard [Univ. Catholique de Lille, Lomme (France). Lab. de Biologie; Cotten, Anne [Univ. Lille 2 (France). Service d' Imagerie Musculosquelettique; Univ. Nord de France, Boulogne sur Mer (France). Unite de Recherche EA 4490, Physiopathologie des Maladies Osseuses Inflammatoires

    2014-10-15

    To examine in detail images of pseudoerosion of the wrist and hand on plain radiographs. The study was conducted with 28 cadaver wrists. During a single imaging session three techniques - plain radiography, tomosynthesis, and computed tomography - were used to visualize the wrist and hand specimens. For each technique, 20 radio-ulno-carpo-metacarpal sites known to present bone erosions in rheumatoid arthritis were analyzed by two radiologists using a standard system to score the cortical bone: normal, pseudoerosion, true erosion, or other pathology. Cohen's concordance analysis was performed to determine inter-observer and intra-observer (for the senior radiologist) agreement by site and by technique. Serial sections of two cadaver specimens were examined to determine the anatomical correlation of the pseudoerosions. On the plain radiographs, the radiologists scored many images as pseudoerosion (7.3 %), particularly in the distal ulnar portion of the capitate, the distal radial portion of the hamate, the proximal ulnar portion of the base of the third metacarpal, the proximal radial portion of the base of the fourth metacarpal, the distal ulnar portion of the hamate, and the proximal portion of the base of the fifth metacarpal. The computed tomography scan revealed that none of these doubtful images corresponded to true erosions. The anatomical correlation study showed that these images could probably be attributed to ligament insertions, thinner lamina, and enhanced cortical bone transparency. Knowledge of the anatomical carpal localizations where pseudoerosions commonly occur is a necessary prerequisite for analysis of plain radiographs performed to diagnose or monitor rheumatoid arthritis. (orig.)

  5. Deriving spatial patterns from a novel database of volcanic rock geochemistry in the Virunga Volcanic Province, East African Rift

    Science.gov (United States)

    Poppe, Sam; Barette, Florian; Smets, Benoît; Benbakkar, Mhammed; Kervyn, Matthieu

    2016-04-01

    eruption of 1957 belongs to these primitive clusters and is the only known to have erupted outside the current rift valley in historical times. We thus infer there is a distributed hazard of vent opening susceptibility additional to the susceptibility associated with the main Virunga edifices. This study suggests that the statistical analysis of such geochemical database may help to understand complex volcanic plumbing systems and the spatial distribution of volcanic hazards in active and poorly known volcanic areas such as the Virunga Volcanic Province.

  6. First volcanic CO2 budget estimate for three actively degassing volcanoes in the Central American Volcanic Arc

    Science.gov (United States)

    Robidoux, Philippe; Aiuppa, Alessandro; Conde, Vladimir; Galle, Bo; Giudice, Gaetano; Avard, Geoffroy; Muñoz, Angélica

    2014-05-01

    CO2 is a key chemical tracer for exploring volcanic degassing mechanisms of basaltic magmatic systems (1). The rate of CO2 release from sub-aerial volcanism is monitored via studies on volcanic plumes and fumaroles, but information is still sparse and incomplete for many regions of the globe, including the majority of the volcanoes in the Central American Volcanic Arc (2). Here, we use a combination of remote sensing techniques and in-situ measurements of volcanic gas plumes to provide a first estimate of the CO2 output from three degassing volcanoes in Central America: Turrialba, in Costa Rica, and Telica and San Cristobal, in Nicaragua. During a field campaign in March-April 2013, we obtained (for the three volcanoes) a simultaneous record of SO2 fluxes (from the NOVAC network (3)) and CO2 vs. SO2 concentrations in the near-vent plumes (obtained via a temporary installed fully-automated Multi-GAS instrument (4)). The Multi-GAS time-series allowed to calculate the plume CO2/SO2 ratios for different intervals of time, showing relatively stable gas compositions. Distinct CO2 - SO2 - H2O proportions were observed at the three volcanoes, but still within the range of volcanic arc gas (5). The CO2/SO2 ratios were then multiplied by the SO2 flux in order to derive the CO2 output. At Turrialba, CO2/SO2 ratios fluctuated, between March 12 and 19, between 1.1 and 5.7, and the CO2flux was evaluated at ~1000-1350 t/d (6). At Telica, between March 23 and April 8, a somewhat higher CO2/SO2 ratio was observed (3.3 ± 1.0), although the CO2 flux was evaluated at only ~100-500 t/d (6). At San Cristobal, where observations were taken between April 11 and 15, the CO2/SO2 ratio ranged between 1.8 and 7.4, with a mean CO2 flux of 753 t/d. These measurements contribute refining the current estimates of the total CO2 output from the Central American Volcanic Arc (7). Symonds, R.B. et al., (2001). J. Volcanol. Geotherm. Res., 108, 303-341 Burton, M. R. et al. (2013). Reviews in

  7. Volcanic Plume Impact on the Atmosphere and Climate: O- and S-Isotope Insight into Sulfate Aerosol Formation

    Directory of Open Access Journals (Sweden)

    Erwan Martin

    2018-05-01

    Full Text Available The impact of volcanic eruptions on the climate has been studied over the last decades and the role played by sulfate aerosols appears to be major. S-bearing volcanic gases are oxidized in the atmosphere into sulfate aerosols that disturb the radiative balance on earth at regional to global scales. This paper discusses the use of the oxygen and sulfur multi-isotope systematics on volcanic sulfates to understand their formation and fate in more or less diluted volcanic plumes. The study of volcanic aerosols collected from air sampling and ash deposits at different distances from the volcanic systems (from volcanic vents to the Earth poles is discussed. It appears possible to distinguish between the different S-bearing oxidation pathways to generate volcanic sulfate aerosols whether the oxidation occurs in magmatic, tropospheric, or stratospheric conditions. This multi-isotopic approach represents an additional constraint on atmospheric and climatic models and it shows how sulfates from volcanic deposits could represent a large and under-exploited archive that, over time, have recorded atmospheric conditions on human to geological timescales.

  8. Gravity study of the Central African Rift system: a model of continental disruption 2. The Darfur domal uplift and associated Cainozoic volcanism

    Science.gov (United States)

    Bermingham, P. M.; Fairhead, J. D.; Stuart, G. W.

    1983-05-01

    Gravity studies of the Darfur uplift, Western Sudan, show it to be associated with a circular negative Bouguer anomaly, 50 mGal in amplitude and 700 km across. A three-dimensional model interpretation of the Darfur anomaly, using constraints deduced from geophysical studies of similar but more evolved Kenya and Ethiopia domes, suggests either a low-density laccolithic body at mid-lithospheric depth (~ 60 km) or a thinned lithosphere with emplacement at high level of low-density asthenospheric material. The regional setting of the Darfur uplift is described in terms of it being an integral part of the Central African Rift System which is shown to be broadly equivalent to the early to middle Miocene stage in the development of the Afro-Arabian Rift System. Comparisons between these rift systems suggest that extensional tectonics and passive rifting, resulting in the subsiding sedimentary rift basins associated with the Ngaoundere, Abu Gabra, Red Sea and Gulf of Aden rifts, are more typical of the early stage development of passive continental margins than the active domal uplift and development of rifted features associated with the Darfur, Kenya and Ethiopia domes.

  9. SYSTHESIS OF VOLCANISM STUDIES FOR THE YUCCA MOUNTAIN SITE CHARACTERIZATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Perry, F. V.; Crowe, G. A.; Valentine, G. A.; Bowker, L. M.

    1997-09-23

    This report synthesizes the results of volcanism studies conducted by scientists at the Los Alamos National Laboratory and collaborating institutions on behalf of the Department of Energy's Yucca Mountain Project. Chapter 1 introduces the volcanism issue for the Yucca Mountain site and provides the reader with an overview of the organization, content, and significant conclusions of this report. The hazard of future basaltic volcanism is the primary topic of concern including both events that intersect a potential repository and events that occur near or within the waste isolation system of a repository. Future volcanic events cannot be predicted with certainty but instead are estimated using formal methods of probabilistic volcanic hazard assessment (PVHA). Chapter 2 describes the volcanic history of the Yucca Mountain region (YMR) and emphasizes the Pliocene and Quaternary volcanic record, the interval of primary concern for volcanic risk assessment. The distribution, eruptive history, and geochronology of Plio-Quaternary basalt centers are described by individual center emphasizing the younger postcaldera basalt (<5 Ma). The Lathrop Wells volcanic center is described in detail because it is the youngest basalt center in the YMR. The age of the Lathrop Wells center is now confidently determined to be about 75 thousand years old. Chapter 3 describes the tectonic setting of the YMR and presents and assesses the significance of multiple alternative tectonic models. The distribution of Pliocene and Quaternary basaltic volcanic centers is evaluated with respect to tectonic models for detachment, caldera, regional and local rifting, and the Walker Lane structural zone. Geophysical data are described for the YMR and are used as an aid to understand the distribution of past basaltic volcanic centers and possible future magmatic processes. Chapter 4 discusses the petrologic and geochemical features of basaltic volcanism in the YMR, the southern Great Basin and the

  10. Miocene volcanism in the Oaş-Gutâi Volcanic Zone, Eastern Carpathians, Romania: Relationship to geodynamic processes in the Transcarpathian Basin

    Science.gov (United States)

    Kovacs, Marinel; Seghedi, Ioan; Yamamoto, Masatsugu; Fülöp, Alexandrina; Pécskay, Zoltán; Jurje, Maria

    2017-12-01

    We present the first comprehensive study of Miocene volcanic rocks of the Oaş-Gutâi Volcanic Zone (OGVZ), Romania, which are exposed in the eastern Transcarpathian Basin (TB), within the Eastern Alpine-Western Carpathian-Northern Pannonian (ALCAPA) block. Collision between the ALCAPA block and Europe at 18-16 Ma produced the Carpathian fold-and-thrust belt. This was followed by clockwise rotation and an extensional regime forming core complexes of the separated TB fragment. Based on petrographic and geochemical data, including Srsbnd Nd isotopic compositions and Ksbnd Ar ages, we distinguish three types of volcanic activity in the OGVZ: (1) early Miocene felsic volcanism that produced caldera-related ignimbrites in the Gutâi Mountains (15.4-14.8 Ma); (2) widespread middle-late Miocene intermediate/andesitic volcanism (13.4-7.0 Ma); and (3) minor late Miocene andesitic/rhyolitic volcanism comprising the Oraşu Nou rhyolitic volcano and several andesitic-dacitic domes in the Oaş Mountains (11.3-9.5 Ma). We show that magma evolution in the OGVZ was controlled by assimilation-fractional crystallization and magma-mixing processes within an interconnected multi-level crustal magmatic reservoir. The evolution of volcanic activity within the OGVZ was controlled by the geodynamics of the Transcarpathian Basin. The early felsic and late intermediate Miocene magmas were emplaced in a post-collisional setting and were derived from a mantle source region that was modified by subduction components (dominantly sediment melts) and lower crust. The style of volcanism within the eastern TB system exhibits spatial variations, with andesitic composite volcanoes (Gutâi Mountains) observed at the margins, and isolated andesitic-rhyolitic monogenetic volcanoes (Oaş Mountains) in the center of the basin.

  11. Recent advances in ground-based ultraviolet remote sensing of volcanic SO2 fluxes

    Directory of Open Access Journals (Sweden)

    Euripides P. Kantzas

    2011-06-01

    Full Text Available Measurements of volcanic SO2 emission rates have been the mainstay of remote-sensing volcanic gas geochemistry for almost four decades, and they have contributed significantly to our understanding of volcanic systems and their impact upon the atmosphere. The last ten years have brought step-change improvements in the instrumentation applied to these observations, which began with the application of miniature ultraviolet spectrometers that were deployed in scanning and traverse configurations, with differential optical absorption spectroscopy evaluation routines. This study catalogs the more recent empirical developments, including: ultraviolet cameras; wide-angle field-of-view differential optical absorption spectroscopy systems; advances in scanning operations, including tomography; and improved understanding of errors, in particular concerning radiative transfer. Furthermore, the outcomes of field deployments of sensors during the last decade are documented, with respect to improving our understanding of volcanic dynamics and degassing into the atmosphere.

  12. Volcanic unrest and hazard communication in Long Valley Volcanic Region, California

    Science.gov (United States)

    Hill, David P.; Mangan, Margaret T.; McNutt, Stephen R.

    2017-01-01

    emissions. Initial response plans developed by county and state agencies in response to the volcanic unrest began with “The Mono County Volcano Contingency Plan” and “Plan Caldera” by the California Office of Emergency Services in 1982–84. They subsequently became integrated in the regularly updated County Emergency Operation Plan. The alert level system employed by the USGS also evolved from the three-level “Notice-Watch-Warning” system of the early 1980s through a five level color-code to the current “Normal-Advisory-Watch-Warning” ground-based system in conjunction with the international 4-level aviation color-code for volcanic ash hazards. Field trips led by the scientists proved to be a particularly effective means of acquainting local residents and officials with the geologically active environment in which they reside. Relative caldera quiescence from 2000 through 2011 required continued efforts to remind an evolving population that the hazards posed by the 1980–2000 unrest persisted. Renewed uplift of the resurgent dome from 2011 to 2014 was accompanied by an increase in low-level earthquake activity in the caldera and beneath Mammoth Mountain and continues through May 2016. As unrest levels continue to wax and wane, so will the communication challenges.

  13. Melt zones beneath five volcanic complexes in California: an assessment of shallow magma occurrences

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, N.E.; Flexser, S.

    1984-12-01

    Recent geological and geophysical data for five magma-hydrothermal systems were studied for the purpose of developing estimates for the depth, volume and location of magma beneath each area. The areas studied were: (1) Salton Trough, (2) The Geysers-Clear Lake, (3) Long Valley caldera, (4) Coso volcanic field, and (5) Medicine Lake volcano, all located in California and all selected on the basis of recent volcanic activity and published indications of crustal melt zones. 23 figs.

  14. PLAINS CO2 REDUCTION (PCOR) PARTNERSHIP

    Energy Technology Data Exchange (ETDEWEB)

    Edward N. Steadman; Daniel J. Daly; Lynette L. de Silva; John A. Harju; Melanie D. Jensen; Erin M. O' Leary; Wesley D. Peck; Steven A. Smith; James A. Sorensen

    2006-01-01

    During the period of October 1, 2003, through September 30, 2005, the Plains CO2 Reduction (PCOR) Partnership, identified geologic and terrestrial candidates for near-term practical and environmentally sound carbon dioxide (CO2) sequestration demonstrations in the heartland of North America. The PCOR Partnership region covered nine states and three Canadian provinces. The validation test candidates were further vetted to ensure that they represented projects with (1) commercial potential and (2) a mix that would support future projects both dependent and independent of CO2 monetization. This report uses the findings contained in the PCOR Partnership's two dozen topical reports and half-dozen fact sheets as well as the capabilities of its geographic information system-based Decision Support System to provide a concise picture of the sequestration potential for both terrestrial and geologic sequestration in the PCOR Partnership region based on assessments of sources, sinks, regulations, deployment issues, transportation, and capture and separation. The report also includes concise action plans for deployment and public education and outreach as well as a brief overview of the structure, development, and capabilities of the PCOR Partnership. The PCOR Partnership is one of seven regional partnerships under Phase I of the U.S. Department of Energy National Energy Technology Laboratory's Regional Carbon Sequestration Partnership program. The PCOR Partnership, comprising 49 public and private sector members, is led by the Energy & Environmental Research Center at the University of North Dakota. The international PCOR Partnership region includes the Canadian provinces of Alberta, Saskatchewan, and Manitoba and the states of Montana (part), Wyoming (part), North Dakota, South Dakota, Nebraska, Missouri, Iowa, Minnesota, and Wisconsin.

  15. Fluid volcanism on Miranda and Ariel - Flow morphology and composition

    Science.gov (United States)

    Schenk, Paul M.

    1991-01-01

    Several types of volcanic units have been recognized on the icy Uranian satellites Miranda and Ariel. On Miranda, ridges characterized by crest grooves are up to 10 km wide and 500 m high. A continuous flat-topped flow band also 10 km wide and 500 m high forms the outer southern margin of Elsinore Corona, which appears to comprise coalesced flow bands and ridges. On Ariel, in addition to at least one ridge unit similar to those on Miranda, flood plains material has covered the floors of deep chasmata (grabens) and an irregular depression. Flows on both satellites are characterized by linear vent geometries and distinct topographic margins, which indicate extrusion of a relatively viscous material. The topography of the flows can be used to estimate flow viscosity or yield strength using a Bingham plastic model. Extrusion viscosity estimates, incorporating plausible volcanologically based emplacement time scales and a rigid crust correction, range from 10 MP to 1 GP (10 TP in the unlikely absence of a chilled crust). Viscosity estimates are dependent on the assumed emplacement time scale, however, and could be as high as 10 PP, if a solid-state-based time scale is assumed.

  16. Rock- and Paleomagnetic Properties and Modeling of a Deep Crustal Volcanic System, the Reinfjord Ultramafic Complex, Seiland Igneous Province, Northern Norway

    Science.gov (United States)

    ter Maat, G. W.; Pastore, Z.; Michels, A.; Church, N. S.; McEnroe, S. A.; Larsen, R. B.

    2017-12-01

    The Reinfjord Ultramafic Complex is part of the 5000 km2 Seiland Igneous Province (SIP) in Northern Norway. The SIP is argued to be the deep-seated conduit system of a Large Igneous Province and was emplaced at 25-35 km depth in less than 10 Ma (570-560 Ma). The Reinfjord Ultramafic Complex was emplaced during three major successive events at 22-28km depth at pressures of 6-8kb, with associated temperatures 1450-1500°C (Roberts, 2006). The rocks are divided into three formations: the central series (CS) consisting of mainly dunites, upper layered series (ULS) consisting of dunites and wehrlites, a lower layered series (LLS) containing most pyroxene-rich rocks and a marginal zone (MZ) which formed where the ultramafic melts intruded the gabbro-norite and metasedimentary gneisses. Deep exposures such as the Reinfjord Ultramafic Complex are rare, therefore this study gives a unique insight in the rock magnetic properties of a deep ultramafic system. Localised serpentinised zones provide an opportunity to observe the effect of this alteration process on the magnetic properties of deep-seated rocks. Here, we present the results from the rock magnetic properties, a paleomagnetic study and combined potential-fields modeling. The study of the rock magnetic properties provides insight in primary processes associated with the intrusion, and later serpentinization. The paleomagnetic data yields two distinct directions. One direction corresponds to a Laurentia pole at ≈ 532 Ma while the other, though younger, is not yet fully understood. Rock magnetic properties were measured on > 700 specimens and used to constrain the modelling of gravity, high-resolution helicopter, and ground magnetic data. The intrusion is modelled as a cylindrically shaped complex with a dunite core surrounded by wehrlite and gabbro. The ultramafic part of the complex dips to the NE and its maximum vertical extent is modelled to 1400m. Furthermore, modelling allows estimation of relative volumes of

  17. [Ichthyofauna and its community diversity in volcanic barrier lakes of Northeast China].

    Science.gov (United States)

    Yang, Fu-Yi; Lü, Xian-Guo; Lou, Yan-Jing; Lou, Xiao-Nan; Xue, Bin; Yao, Shu-Chun; Xiao, Hai-Feng

    2012-12-01

    Based on the investigations of fish resources in Jingpo Lake and Wudalianchi Lakes in 2008-2011 and the historical data, this paper analyzed the characteristics of ichthyofauna and its community diversity in volcanic barrier lakes of Northeast China. The ichthyofauna in the volcanic barrier lakes of Northeast China was consisted of 64 native species, belonging to 47 genera, 16 families, and 9 orders, among which, one species was the second class National protected wild animal, four species were Chinese endemic species, and five species were Chinese vulnerable species. In the 64 recorded species, there were 44 species of Cypriniformes order and 37 species of Cyprinidae family dominated, respectively. The ichthyofauna in the volcanic barrier lakes of Northeast China was formed by 7 fauna complexes, among which, the eastern plain fauna complex was dominant, the common species from the South and the North occupied 53.1%, and the northern endemic species took up 46.9%. The Shannon, Fisher-alpha, Pielou, Margalef, and Simpson indices of the ichthyofauna were 2.078, 4.536, 0.575, 3.723, and 0.269, respectively, and the abundance distribution pattern of native species accorded with lognormal model. The Bray-Curtis, Morisita-Horn, Ochiai, Sørensen, and Whittaker indices between the communities of ichthyofauna in the volcanic barrier lakes of Northeast China and the Jingpo Lake were 0.820, 0.992, 0.870, 0.862 and 0.138, respectively, and those between the communities of ichthyofauna in the volcanic barrier lakes and the Wudalianchi Lakes were 0.210, 0.516, 0.838, 0.825, and 0.175, respectively. The ichthyofauna in volcanic barrier lakes of Northeast China was characterized by the mutual infiltration between the South and the North, and the overlap and transition between the Palaeoarctic realm and the Oricetal realm. It was suggested that the ichthyofauna community species diversity in the volcanic barrier lakes of Northeast China was higher, the species structure was more

  18. The Variable Climate Impact of Volcanic Eruptions

    Science.gov (United States)

    Graf, H.

    2011-12-01

    The main effect of big volcanic eruptions in the climate system is due to their efficient transport of condensable gases and their precursors into the stratosphere. There the formation of aerosols leads to effects on atmospheric radiation transfer inducing a reduction of incoming solar radiation by reflection (i.e. cooling of the Earth surface) and absorption of near infrared radiation (i.e. heating) in the aerosol laden layers. In the talk processes determining the climate effect of an eruption will be illustrated by examples, mainly from numerical modelling. The amount of gases released from a magma during an eruption and the efficiency of their transport into very high altitudes depends on the geological setting (magma type) and eruption style. While mid-sized eruption plumes of Plinian style quickly can develop buoyancy by entrainment of ambient air, very large eruptions with high magma flux rates often tend to collapsing plumes and co-ignimbrite style. These cover much bigger areas and are less efficient in entraining ambient air. Vertical transport in these plumes is chaotic and less efficient, leading to lower neutral buoyancy height and less gas and particles reaching high stratospheric altitudes. Explosive energy and amount of released condensable gases are not the only determinants for the climatic effect of an eruption. The effect on shortwave radiation is not linear with the amount of aerosols formed since according to the Lambert-Beer Law atmospheric optical depth reaches a saturation limit with increased absorber concentration. In addition, if more condensable gas is available for aerosol growth, particles become larger and this affects their optical properties to less reflection and more absorption. Larger particles settle out faster, thus reducing the life time of the aerosol disturbance. Especially for big tropical eruptions the strong heating of the stratosphere in low latitudes leads to changes in atmospheric wave propagation by strengthened

  19. Coastal geomorphology of the Martian northern plains

    Science.gov (United States)

    Parker, Timothy J.; Gorsline, Donn S.; Saunders, Stephen R.; Pieri, David C.; Schneeberger, Dale M.

    1993-01-01

    The paper considers the question of the formation of the outflow channels and valley networks discovered on the Martian northern plains during the Mariner 9 mission. Parker and Saunders (1987) and Parker et al. (1987, 1989) data are used to describe key features common both in the lower reaches of the outflow channels and within and along the margins of the entire northern plains. It is suggested, that of the geological processes capable of producing similar morphologies on earth, lacustrine or marine deposition and subsequent periglacial modification offer the simplest and most consistent explanation for the suit of features found on Mars.

  20. The Lanzarote Geodynamic Laboratory: new capabilities for monitoring of volcanic activity at Canary Islands

    Science.gov (United States)

    Arnoso, J.; Vélez, E. J.; Soler, V.; Montesinos, F. G.; Benavent, M.

    2012-04-01

    The volcanic island of Lanzarote is located at the northeastern end of the Canary Islands. Together with Fuerteventura Island, Lanzarote constitutes the emergent part of the East Canary Ridge, which presents a NNE-SSW volcanic alignment. Last eruptive events took place in 1824 and during the period 1730-1736, which is the largest to occur in the archipelago and throw out about 1.3 km3 of volcanic materials. The Lanzarote Geodynamic Laboratory (LGL) was created in 1986 with the idea of making Lanzarote as a natural laboratory to carry out studies in order to acquire more knowledge about its origin, present status and evolution (Vieira et al., 1991; 2006). The LGL has a multidisciplinary scientific purpose and, among others, various objectives are devoted to investigate mass distribution in the Earth system and surface displacements associated to volcanic and/or seismic activity in the island. The influence of LGL is extended throughout the whole geographical area of Lanzarote, including small islands located at the north. The laboratory has 3 observing modules distributed along the island according to its infrastructure and scientific objectives, where more than 70 sensors are recording continuously gravity variations, ground deformations, sea level, seismic activity, meteorological parameters, etc. All these observations are supplemented by periodic measurement of geodetic and geophysical networks that allow us to make studies at local, insular and regional scales. The application of geodetic and geophysical techniques to identify geodynamic signals related to volcanic processes is then a permanent research activity of the laboratory. Nowadays, this fact becomes more interesting due to the ongoing volcanic eruption that is taking place in other island of the Canary Archipelago, El Hierro, since past July 2011. That is, the multidisciplinary research carry on up to now at the LGL allow us to apply multiparameter observations of different kinds of volcanic

  1. Volcanic Ash Advisory Database, 1983-2003

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Volcanic ash is a significant hazard to aviation and can also affect global climate patterns. To ensure safe navigation and monitor possible climatic impact, the...

  2. Age of the Auckland Volcanic Field

    International Nuclear Information System (INIS)

    Lindsay, J.; Leonard, G.S.

    2009-01-01

    In 2008 a multi-disciplinary research programme was launched, a GNS Science-University of Auckland collaboration with the aim of DEtermining VOlcanic Risk in Auckland (DEVORA). A major aspiration of DEVORA is development of a probabilistic hazard model for the Auckland Volcanic Field (AVF). This will be achieved by investigating past eruption magnitude-frequency relationships and comparing these with similar data from analogous volcanic fields. A key data set underpinning this is an age database for the AVF. To this end a comprehensive dating campaign is planned as part of DEVORA. This report, Age of the Auckland Volcanic Field, is a synthesis of all currently available age data for the AVF. It represents one of several reports carried out as part of the 'synthesis' phase of DEVORA, whereby existing data from all previous work is collated and summarised, so that gaps in current knowledge can be identified and addressed. (author). 60 refs., 7 figs., 31 tabs.

  3. Volcanic eruptions are cooling the earth

    International Nuclear Information System (INIS)

    Groenaas, Sigbjoern

    2005-01-01

    The article discusses how volcanic eruptions may influence the climate. The environmental impacts both on the earth surface and the atmosphere are surveyed. Some major eruptions in modern times are mentioned

  4. Stochastic Modeling of Past Volcanic Crises

    Science.gov (United States)

    Woo, Gordon

    2018-01-01

    The statistical foundation of disaster risk analysis is past experience. From a scientific perspective, history is just one realization of what might have happened, given the randomness and chaotic dynamics of Nature. Stochastic analysis of the past is an exploratory exercise in counterfactual history, considering alternative possible scenarios. In particular, the dynamic perturbations that might have transitioned a volcano from an unrest to an eruptive state need to be considered. The stochastic modeling of past volcanic crises leads to estimates of eruption probability that can illuminate historic