WorldWideScience

Sample records for volcano ranch evidence

  1. Fuego Volcano eruption (Guatemala, 1974): evidence of a tertiary fragmentation?

    International Nuclear Information System (INIS)

    Brenes-Andre, Jose

    2014-01-01

    Values for mode and dispersion calculated from SFT were analyzed using the SFT (Sequential Fragmentation/Transport) model to Fuego Volcano eruption (Guatemala, 1974). Analysis results have showed that the ideas initially proposed for Irazu, can be applied to Fuego Volcano. Experimental evidence was found corroborating the existence of tertiary fragmentations. (author) [es

  2. Volcanoes

    Science.gov (United States)

    ... rock, steam, poisonous gases, and ash reach the Earth's surface when a volcano erupts. An eruption can also cause earthquakes, mudflows and flash floods, rock falls and landslides, acid rain, fires, and even tsunamis. Volcanic gas ...

  3. Cyclic Activity of Mud Volcanoes: Evidences from Trinidad (SE Caribbean)

    Science.gov (United States)

    Deville, E.

    2007-12-01

    Fluid and solid transfer in mud volcanoes show different phases of activity, including catastrophic events followed by periods of relative quiescence characterized by moderate activity. This can be notably shown by historical data onshore Trinidad. Several authors have evoked a possible link between the frequencies of eruption of some mud volcanoes and seismic activity, but in Trinidad there is no direct correlation between mud eruptions and seisms. It appears that each eruptive mud volcano has its own period of catastrophic activity, and this period is highly variable from one volcano to another. The frequency of activity of mud volcanoes seems essentially controlled by local pressure regime within the sedimentary pile. At the most, a seism can, in some cases, activate an eruption close to its term. The dynamics of expulsion of the mud volcanoes during the quiescence phases has been studied notably from temperature measurements within the mud conduits. The mud temperature is concurrently controlled by, either, the gas flux (endothermic gas depressurizing induces a cooling effect), or by the mud flux (mud is a vector for convective heat transfer). Complex temperature distribution was observed in large conduits and pools. Indeed, especially in the bigger pools, the temperature distribution characterizes convective cells with an upward displacement of mud above the deep outlet, and ring-shaped rolls associated with the burial of the mud on the flanks of the pools. In simple, tube-like shaped, narrow conduits, the temperature is more regular, but we observed different types of profiles, with either downward increasing or decreasing temperatures. If the upward flow of mud would be regular, we should expect increasing temperatures and progressively decreasing gradient with depth within the conduits. However, the variable measured profiles from one place to another, as well as time-variable measured temperatures within the conduits and especially, at the base of the

  4. Using Bayesian Belief Networks To Assess Volcano State from Multiple Monitoring Timeseries And Other Evidence

    Science.gov (United States)

    Odbert, Henry; Aspinall, Willy

    2013-04-01

    When volcanoes exhibit unrest or become eruptively active, science-based decision support invariably is sought by civil authorities. Evidence available to scientists about a volcano's internal state is usually indirect, secondary or very nebulous.Advancement of volcano monitoring technology in recent decades has increased the variety and resolution of multi-parameter timeseries data recorded at volcanoes. Monitoring timeseries may be interpreted in real time by observatory staff and are often later subjected to further analytic scrutiny by the research community at large. With increasing variety and resolution of data, interpreting these multiple strands of parallel, partial evidence has become increasingly complex. In practice, interpretation of many timeseries involves familiarity with the idiosyncracies of the volcano, the monitoring techniques, the configuration of the recording instrumentation, observations from other datasets, and so on. Assimilation of this knowledge is necessary in order to select and apply the appropriate statistical techniques required to extract the required information. Bayesian Belief Networks (BBNs) use probability theory to treat and evaluate uncertainties in a rational and auditable scientific manner, but only to the extent warranted by the strength of the available evidence. The concept is a suitable framework for marshalling multiple observations, model results and interpretations - and associated uncertainties - in a methodical manner. The formulation is usually implemented in graphical form and could be developed as a tool for near real-time, ongoing use in a volcano observatory, for example. We explore the application of BBNs in analysing volcanic timeseries, the certainty with which inferences may be drawn, and how they can be updated dynamically. Such approaches provide a route to developing analytical interface(s) between volcano monitoring analyses and probabilistic hazard analysis. We discuss the use of BBNs in hazard

  5. A critical evaluation of the evidence for multiple Late Pleistocene eruptions of Laacher See Volcano

    DEFF Research Database (Denmark)

    Zernack, Anke Verena; Hoggard, Christian Steven; Sauer, Florian Rudolf

    The c. 12,900 BP Plinian eruption of Laacher See Volcano is one of the largest known volcanic events of the Late Pleistocene in the Northern Hemisphere. It buried proximal areas under tens of meters of pyroclastic flow, surge and fallout deposits and deposited a widespread tephra layer across much...... of dispersal of the products from varying eruptive stages and some sites even report two distinct Laacher See Tephra layers that have been interpreted as evidence of a precursor eruption. In order to assess the potential for multiple Late Pleistocene eruptions of Laacher See Volcano, we have compiled...

  6. Glacier melting during lava dome growth at Nevado de Toluca volcano (Mexico): Evidences of a major threat before main eruptive phases at ice-caped volcanoes

    Science.gov (United States)

    Capra, L.; Roverato, M.; Groppelli, G.; Caballero, L.; Sulpizio, R.; Norini, G.

    2015-03-01

    Nevado de Toluca volcano is one of the largest stratovolcanoes in the Trans-Mexican Volcanic Belt. During Late Pleistocene its activity was characterized by large dome growth and subsequent collapse emplacing large block and ash flow deposits, intercalated by Plinian eruptions. Morphological and paleoclimate studies at Nevado de Toluca and the surrounding area evidenced that the volcano was affected by extensive glaciation during Late Pleistocene and Holocene. During the older recognized glacial period (27-60 ka, MIS 3), the glacier was disturbed by the intense magmatic and hydrothermal activity related to two dome extrusion episodes (at 37 ka and 28 ka). Glacier reconstruction indicates maximum ice thickness of 90 m along main valleys, as at the Cano ravines, the major glacial valley on the northern slope of the volcano. Along this ravine, both 37 and 28 ka block-and-ash deposits are exposed, and they directly overlay a fluviatile sequence, up to 40 m-thick, which 14C ages clearly indicate that their emplacement occurred just before the dome collapsed. These evidences point to a clear interaction between the growing dome and its hydrothermal system with the glacier. During dome growth, a large amount of melting water was released along major glacial valleys forming thick fluvioglacial sequences that were subsequently covered by the block-and-ash flow deposits generated by the collapse of the growing dome. Even though this scenario is no longer possible at the Nevado de Toluca volcano, the data presented here indicate that special attention should be paid to the possible inundation areas from fluviatile/lahar activity prior to the main magmatic eruption at ice-capped volcanoes.

  7. Late Holocene history of Chaitén Volcano: new evidence for a 17th century eruption

    Science.gov (United States)

    Lara, Luis E.; Moreno, Rodrigo; Amigo, Álvaro; Hoblitt, Richard P.; Pierson, Thomas C.

    2013-01-01

    Prior to May 2008, it was thought that the last eruption of Chaitén Volcano occurred more than 5,000 years ago, a rather long quiescent period for a volcano in such an active arc segment. However, increasingly more Holocene eruptions are being identified. This article presents both geological and historical evidence for late Holocene eruptive activity in the 17th century (AD 1625-1658), which included an explosive rhyolitic eruption that produced pumice ash fallout east of the volcano and caused channel aggradation in the Chaitén River. The extents of tephra fall and channel aggradation were similar to those of May 2008. Fine ash, pumice and obsidian fragments in the pre-2008 deposits are unequivocally derived from Chaitén Volcano. This finding has important implications for hazards assessment in the area and suggests the eruptive frequency and magnitude should be more thoroughly studied.

  8. The Zambian wildlife ranching industry: scale, associated benefits, and limitations affecting its development.

    Science.gov (United States)

    Lindsey, Peter A; Barnes, Jonathan; Nyirenda, Vincent; Pumfrett, Belinda; Tambling, Craig J; Taylor, W Andrew; t'Sas Rolfes, Michael

    2013-01-01

    The number and area of wildlife ranches in Zambia increased from 30 and 1,420 km(2) in 1997 to 177 and ∼6,000 km(2) by 2012. Wild ungulate populations on wildlife ranches increased from 21,000 individuals in 1997 to ∼91,000 in 2012, while those in state protected areas declined steeply. Wildlife ranching and crocodile farming have a turnover of ∼USD15.7 million per annum, compared to USD16 million from the public game management areas which encompass an area 29 times larger. The wildlife ranching industry employs 1,200 people (excluding jobs created in support industries), with a further ∼1,000 individuals employed through crocodile farming. Wildlife ranches generate significant quantities of meat (295,000 kg/annum), of which 30,000 kg of meat accrues to local communities and 36,000 kg to staff. Projected economic returns from wildlife ranching ventures are high, with an estimated 20-year economic rate of return of 28%, indicating a strong case for government support for the sector. There is enormous scope for wildlife ranching in Zambia due to the availability of land, high diversity of wildlife and low potential for commercial livestock production. However, the Zambian wildlife ranching industry is small and following completion of field work for this study, there was evidence of a significant proportion of ranchers dropping out. The industry is performing poorly, due to inter alia: rampant commercial bushmeat poaching; failure of government to allocate outright ownership of wildlife to landowners; bureaucratic hurdles; perceived historical lack of support from the Zambia Wildlife Authority and government; a lack of a clear policy on wildlife ranching; and a ban on hunting on unfenced lands including game ranches. For the wildlife ranching industry to develop, these limitations need to be addressed decisively. These findings are likely to apply to other savanna countries with large areas of marginal land potentially suited to wildlife ranching.

  9. The Zambian Wildlife Ranching Industry: Scale, Associated Benefits, and Limitations Affecting Its Development

    Science.gov (United States)

    Lindsey, Peter A.; Barnes, Jonathan; Nyirenda, Vincent; Pumfrett, Belinda; Tambling, Craig J.; Taylor, W. Andrew; Rolfes, Michael t’Sas

    2013-01-01

    The number and area of wildlife ranches in Zambia increased from 30 and 1,420 km2 in 1997 to 177 and ∼6,000 km2 by 2012. Wild ungulate populations on wildlife ranches increased from 21,000 individuals in 1997 to ∼91,000 in 2012, while those in state protected areas declined steeply. Wildlife ranching and crocodile farming have a turnover of ∼USD15.7 million per annum, compared to USD16 million from the public game management areas which encompass an area 29 times larger. The wildlife ranching industry employs 1,200 people (excluding jobs created in support industries), with a further ∼1,000 individuals employed through crocodile farming. Wildlife ranches generate significant quantities of meat (295,000 kg/annum), of which 30,000 kg of meat accrues to local communities and 36,000 kg to staff. Projected economic returns from wildlife ranching ventures are high, with an estimated 20-year economic rate of return of 28%, indicating a strong case for government support for the sector. There is enormous scope for wildlife ranching in Zambia due to the availability of land, high diversity of wildlife and low potential for commercial livestock production. However, the Zambian wildlife ranching industry is small and following completion of field work for this study, there was evidence of a significant proportion of ranchers dropping out. The industry is performing poorly, due to inter alia: rampant commercial bushmeat poaching; failure of government to allocate outright ownership of wildlife to landowners; bureaucratic hurdles; perceived historical lack of support from the Zambia Wildlife Authority and government; a lack of a clear policy on wildlife ranching; and a ban on hunting on unfenced lands including game ranches. For the wildlife ranching industry to develop, these limitations need to be addressed decisively. These findings are likely to apply to other savanna countries with large areas of marginal land potentially suited to wildlife ranching. PMID:24367493

  10. The Family Partnership on the Ranch.

    Science.gov (United States)

    Stoeltje, Beverly J.

    This paper contends that women are as vital as men to the functioning of western ranches where cattle raising--or cattle culture--is central to the social system. The self-sufficient nuclear family is also emphasized, and a ranch couple is described as a business as well as a domestic partnership. Ranch women have four roles: rearing children,…

  11. Evidence of methane venting and geochemistry of brines on mud volcanoes of the eastern Mediterranean

    NARCIS (Netherlands)

    Charlou, J.-L.; Donval, J.-P.; Zitter, T.; Roy, N.; Jean Baptiste, P.; Foucher, J.P.; Woodside, J.M.; Medinaut, Party

    2003-01-01

    As a part of the Dutch-French MEDINAUT diving expedition in 1998, cold seeps and mud volcanoes were studied and sampled in two distinctive tectonic settings in the eastern Mediterranean Sea. The first setting was the Olimpi Mud Volcano field (OMV area), including Napoli, Milano, Maidstone and Moscow

  12. Economics of ocean ranching: experiences, outlook and theory

    National Research Council Canada - National Science Library

    Ragnar Arnason

    2001-01-01

    "The author distinguishes between ocean fish farming and ocean ranching. The distinguishing characteristic of ocean ranching is that the released species are unassisted once released into the ocean...

  13. The Zambian wildlife ranching industry: scale, associated benefits, and limitations affecting its development.

    Directory of Open Access Journals (Sweden)

    Peter A Lindsey

    Full Text Available The number and area of wildlife ranches in Zambia increased from 30 and 1,420 km(2 in 1997 to 177 and ∼6,000 km(2 by 2012. Wild ungulate populations on wildlife ranches increased from 21,000 individuals in 1997 to ∼91,000 in 2012, while those in state protected areas declined steeply. Wildlife ranching and crocodile farming have a turnover of ∼USD15.7 million per annum, compared to USD16 million from the public game management areas which encompass an area 29 times larger. The wildlife ranching industry employs 1,200 people (excluding jobs created in support industries, with a further ∼1,000 individuals employed through crocodile farming. Wildlife ranches generate significant quantities of meat (295,000 kg/annum, of which 30,000 kg of meat accrues to local communities and 36,000 kg to staff. Projected economic returns from wildlife ranching ventures are high, with an estimated 20-year economic rate of return of 28%, indicating a strong case for government support for the sector. There is enormous scope for wildlife ranching in Zambia due to the availability of land, high diversity of wildlife and low potential for commercial livestock production. However, the Zambian wildlife ranching industry is small and following completion of field work for this study, there was evidence of a significant proportion of ranchers dropping out. The industry is performing poorly, due to inter alia: rampant commercial bushmeat poaching; failure of government to allocate outright ownership of wildlife to landowners; bureaucratic hurdles; perceived historical lack of support from the Zambia Wildlife Authority and government; a lack of a clear policy on wildlife ranching; and a ban on hunting on unfenced lands including game ranches. For the wildlife ranching industry to develop, these limitations need to be addressed decisively. These findings are likely to apply to other savanna countries with large areas of marginal land potentially suited to wildlife

  14. Behavior of volatiles in arc volcanism : geochemical and petrologic evidence from active volcanoes in Indonesia

    NARCIS (Netherlands)

    Hoog, J.C.M. de

    2001-01-01

    Large amounts of material are recycled along subduction zones by uprising magmas, of which volcanoes are the surface expression. This thesis focuses on the behavior of volatiles elements (S, Cl, H) during these recycling processes. The study area is the Indonesian arc system, which

  15. Geochemical evidence for the existence of high-temperature hydrothermal brines at Vesuvio volcano, Italy

    Science.gov (United States)

    Chiodini, Giovanni; Marini, Luigi; Russo, Massimo

    2001-07-01

    A high-temperature hydrothermal system is present underneath the crater area of Vesuvio volcano. It is suggested that NaCl brines reside in the high-temperature reservoir and influence the chemical composition of the gases discharged by the fumaroles of the crater bottom (vents FC1, FC2, and FC5). These have typical hydrothermal compositions, with H 2O and CO 2 as major components, followed by H 2, H 2S, N 2, CH 4, and CO (in order of decreasing contents) and undetectable SO 2, HCl, and HF. Fumarolic H 2O is either meteoric water enriched in 18O through high-temperature water-rock oxygen isotope exchange or a mixture of meteoric and arc-type magmatic water. Fumarolic CO 2 is mainly generated by decarbonation reactions of marine carbonates, but the addition of small amounts of magmatic CO 2 is also possible. All investigated gas species (H 2O, CO 2, CO, CH 4, H 2, H 2S, N 2, and NH 3) equilibrate, probably in a saturated vapor phase, at temperatures of 360 to 370°C for vent FC1 and 430 to 445°C for vents FC2 and FC5. These temperatures are confirmed by the H 2-Ar geoindicator. The minimum salt content of the liquid phase coexisting with the vapor phase is ˜14.9 wt.% NaCl, whereas its maximum salinity corresponds to halite saturation (49.2-52.5 wt.% NaCl). These poorly constrained salinities of NaCl brines reflect in large uncertainties in total fluid pressures, which are estimated to be 260 to 480 bar for vents FC2 and FC5 and 130 to 220 bar for vent FC1. Pressurization in some parts of the hydrothermal system, and its subsequent discharge through hydrofracturing, could explain the relatively frequent seismic crises recorded in the Vesuvio area after the last eruption. An important heat source responsible for hydrothermal circulation is represented by the hot rocks of the eruptive conduits, which have been active from 1631 to 1944. Geochemical evidence suggests that no input of fresh magma at shallow depths took place after the end of the last eruptive period.

  16. Acorns - Spears and Didion Ranches [ds322

    Data.gov (United States)

    California Natural Resource Agency — These data are the characteristics and acorn counts from 2005 of individual live oak trees found in 0.05-ha circular habitat plots at Spears and Didion Ranches,...

  17. LOTT RANCH 3D PROJECT

    International Nuclear Information System (INIS)

    Larry Lawrence; Bruce Miller

    2004-01-01

    The Lott Ranch 3D seismic prospect located in Garza County, Texas is a project initiated in September of 1991 by the J.M. Huber Corp., a petroleum exploration and production company. By today's standards the 126 square mile project does not seem monumental, however at the time it was conceived it was the most intensive land 3D project ever attempted. Acquisition began in September of 1991 utilizing GEO-SEISMIC, INC., a seismic data contractor. The field parameters were selected by J.M. Huber, and were of a radical design. The recording instruments used were GeoCor IV amplifiers designed by Geosystems Inc., which record the data in signed bit format. It would not have been practical, if not impossible, to have processed the entire raw volume with the tools available at that time. The end result was a dataset that was thought to have little utility due to difficulties in processing the field data. In 1997, Yates Energy Corp. located in Roswell, New Mexico, formed a partnership to further develop the project. Through discussions and meetings with Pinnacle Seismic, it was determined that the original Lott Ranch 3D volume could be vastly improved upon reprocessing. Pinnacle Seismic had shown the viability of improving field-summed signed bit data on smaller 2D and 3D projects. Yates contracted Pinnacle Seismic Ltd. to perform the reprocessing. This project was initiated with high resolution being a priority. Much of the potential resolution was lost through the initial summing of the field data. Modern computers that are now being utilized have tremendous speed and storage capacities that were cost prohibitive when this data was initially processed. Software updates and capabilities offer a variety of quality control and statics resolution, which are pertinent to the Lott Ranch project. The reprocessing effort was very successful. The resulting processed data-set was then interpreted using modern PC-based interpretation and mapping software. Production data, log data

  18. MARINE CONGLOMERATE AND REEF MEGACLASTS AT MAURITUS ISLAND: Evidences of a tsunami generated by a flank collapse of the PITON DE LA Fournaise volcano, Reunion Island?

    Directory of Open Access Journals (Sweden)

    R. Paris

    2014-05-01

    Full Text Available Tsunamis related to volcano flank collapse are typically a high-magnitude, low frequency hazard for which evaluation and mitigation are difficult to address. In this short communication, we present field evidences of a large tsunami along the southern coast of Mauritius Island ca. 4400 years ago. Tsunami deposits described include both marine conglomerates and coral boulders up to 90 m3 (> 100 tons. The most probable origin of the tsunami is a flank collapse of Piton de la Fournaise volcano, Réunion Island.

  19. Calculating stocking rates for game ranches: substitution ratios for ...

    African Journals Online (AJOL)

    Calculating stocking rates for game ranches: substitution ratios for use in the Mopani ... Reports on a study conducted to quantify the overlap in ungulate resource-use on a game ranch, and to demonstrate how ... AJOL African Journals Online.

  20. Compositional Trends in Acid Fluids of Copahue Volcano, Argentina: Evidence for a failed eruption in 2004?

    Science.gov (United States)

    Kading, T. J.; Brophy, M.; Varekamp, J. C.

    2008-12-01

    The concentrations and fluxes of major, minor, and trace elements in the crater lake, volcanic spring, and acidified watershed of Copahue Volcano, Neuquen province, Argentina, have been monitored over the last decade. The 2000 Copahue eruption resulted in enhanced S/Cl, increased concentrations and fluxes of rock forming elements (especially Mg and Na) with strongly raised Mg/Cl and Mg/K values. The degree of LREE enrichment decreased and a pronounced Eu anomaly developed in the fluids (Eu/Eu*> rock values). These patterns are explained as the result of hot acid fluid attack on newly intruded magma, with early dissolution of olivine (Mg spike) and plagioclase (Na spike, Eu anomaly). Similar compositional changes were observed in water samples taken in November, 2004, but no eruption occurred. These may be the signals of a small magmatic intrusion into the hydrothermal system, which failed to continue into an eruption. The compositional changes of Copahue volcanic fluids over the last decade will be discussed in the context of chemical signals of an actual and a suspected 'failed eruption'.

  1. Kansas Farm and Ranch Management Project.

    Science.gov (United States)

    Albracht, James, Ed.

    Thirty-four units of instruction are included in this core curriculum in farm management for postsecondary farm and ranch management programs. Units of instruction are divided into twelve instructional areas: (1) Introduction to Financial Management, (2) Farm Business Arrangement, (3) Credit Management, (4) Budgeting, (5) Record Keeping, (6)…

  2. Evidence for water influx from a caldera lake during the explosive hydromagmatic eruption of 1790, Kilauea volcano, Hawaii

    Science.gov (United States)

    Mastin, L.G.

    1997-01-01

    In 1790 a major hydromagmatic eruption at the summit of Kilauea volcano, Hawaii, deposited up to 10 m of pyroclastic fall and surge deposits and killed several dozen Hawaiian natives who were crossing the island. Previous studies have hypothesized that the explosivity of this eruption was due to the influx of groundwater into the conduit and mixing of the groundwater with ascending magma. This study proposes that surface water, not groundwater, was the agent responsible for the explosiveness of the eruption. That is, a lake or pond may have existed in the caldera in 1790 and explosions may have taken place when magma ascended into the lake from below. That assertion is based on two lines of evidence: (1) high vesicularity (averaging 73% of more than 3000 lapilli) and high vesicle number density (105-107 cm-3 melt) of pumice clasts suggest that some phases of the eruption involved vigorous, sustained magma ascent; and (2) numerical calculations suggest that under most circumstances, hydrostatic pressure would not be sufficient to drive water into the eruptive conduit during vigorous magma ascent unless the water table were above the ground surface. These results are supported by historical data on the rate of infilling of the caldera floor during the early 1800s. When extrapolated back to 1790, they suggest that the caldera floor was below the water table.

  3. New evidence of CO2 soil degassing anomalies on Piton de la Fournaise volcano and the link with volcano tectonic structures

    Science.gov (United States)

    Liuzzo, M.; Di Muro, A.; Giudice, G.; Michon, L.; Ferrazzini, V.; Gurrieri, S.

    2015-12-01

    Piton de la Fournaise (PdF) is recognized as one of the world's most active volcanoes in terms of eruptive frequency and the substantial quantity of lava produced. Yet with the sole exception of rather modest intracrateric fumarole activity, this seems to be in contrast with an apparent absence of any type of natural fluid emission during periods of quiescence. Measurement campaigns were undertaken during a long-lasting quiescent period (2012-2014) and just after a short-lived summit eruption (June 2014) in order to identify potential degassing areas in relation to the main structural features of the volcano (e.g., rift zones) with the aim of developing a broader understanding of the geometry of the plumbing and degassing system. In order to assess the possible existence of anomalous soil CO2 flux, 513 measurements were taken along transects roughly orthogonal to the known tectonic lineaments crossing PdF edifice. In addition, 53 samples of gas for C isotope analysis were taken at measurement points that showed a relatively high CO2 concentration in the soil. CO2 flux values range from 10 to 1300 g m-2 d-1 while δ13C are between -26.6 and -8‰. The results of our investigation clearly indicate that there is a strong spatial correlation between the anomalous high values of diffusive soil emissions and the main rift zones cutting the PdF massif and, moreover, that generally high soil CO2 fluxes show a δ13C signature clearly related to a magmatic origin.

  4. Agent Orange Exposure and Monoclonal Gammopathy of Undetermined Significance: An Operation Ranch Hand Veteran Cohort Study.

    Science.gov (United States)

    Landgren, Ola; Shim, Youn K; Michalek, Joel; Costello, Rene; Burton, Debra; Ketchum, Norma; Calvo, Katherine R; Caporaso, Neil; Raveche, Elizabeth; Middleton, Dan; Marti, Gerald; Vogt, Robert F

    2015-11-01

    Multiple myeloma has been classified as exhibiting "limited or suggestive evidence" of an association with exposure to herbicides in Vietnam War veterans. Occupational studies have shown that other pesticides (ie, insecticides, herbicides, fungicides) are associated with excess risk of multiple myeloma and its precursor state, monoclonal gammopathy of undetermined significance (MGUS); however, to our knowledge, no studies have uncovered such an association in Vietnam War veterans. To examine the relationship between MGUS and exposure to Agent Orange, including its contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in Vietnam War veterans. This was a prospective cohort study conducted in 2013 to 2014, testing for MGUS in serum specimens collected and stored in 2002 by the Air Force Health Study (AFHS). The relevant exposure data collected by the AFHS was also used. We tested all specimens in 2013 without knowledge of the exposure status. The AFHS included former US Air Force personnel who participated in Operation Ranch Hand (Ranch Hand veterans) and other US Air Force personnel who had similar duties in Southeast Asia during the same time period (1962 to 1971) but were not involved in herbicide spray missions (comparison veterans). Agent Orange was used by the US Air Force personnel who conducted aerial spray missions of herbicides (Operation Ranch Hand) in Vietnam from 1962 to 1971. We included 479 Ranch Hand veterans and 479 comparison veterans who participated in the 2002 follow-up examination of AFHS. Agent Orange and TCDD. Serum TCDD levels were measured in 1987, 1992, 1997, and 2002. Risk of MGUS measured by prevalence, odds ratios (ORs), and 95% CIs. The 479 Ranch Hand veterans and 479 comparison veterans had similar demographic and lifestyle characteristics and medical histories. The crude prevalence of overall MGUS was 7.1% (34 of 479) in Ranch Hand veterans and 3.1% (15 of 479) in comparison veterans. This translated into a 2.4-fold increased risk

  5. Monogenetic origin of Ubehebe Crater maar volcano, Death Valley, California: Paleomagnetic and stratigraphic evidence

    Science.gov (United States)

    Champion, Duane E.; Cyr, Andy; Fierstein, Judy; Hildreth, Wes

    2018-04-01

    Paleomagnetic data for samples collected from outcrops of basaltic spatter at the Ubehebe Crater cluster, Death Valley National Park, California, record a single direction of remanent magnetization indicating that these materials were emplaced during a short duration, monogenetic eruption sequence 2100 years ago. This conclusion is supported by geochemical data encompassing a narrow range of oxide variation, by detailed stratigraphic studies of conformable phreatomagmatic tephra deposits showing no evidence of erosion between layers, by draping of sharp rimmed craters by later tephra falls, and by oxidation of later tephra layers by the remaining heat of earlier spatter. This model is also supported through a reinterpretation and recalculation of the published 10Be age results (Sasnett et al., 2012) from an innovative and bold exposure-age study on very young materials. Their conclusion of multiple and protracted eruptions at Ubehebe Crater cluster is here modified through the understanding that some of their quartz-bearing clasts inherited 10Be from previous exposure on the fan surface (too old), and that other clasts were only exposed at the surface by wind and/or water erosion centuries after their eruption (too young). Ubehebe Crater cluster is a well preserved example of young monogenetic maar type volcanism protected within a National Park, and it represents neither a protracted eruption sequence as previously thought, nor a continuing volcanic hazard near its location.

  6. Mechanical coupling between earthquakes and volcanoes inferred from stress transfer models: evidence from Vesuvio, Etna and Alban Hills (Italy)

    Science.gov (United States)

    Cocco, M.; Feuillet, N.; Nostro, C.; Musumeci, C.

    2003-04-01

    We investigate the mechanical interactions between tectonic faults and volcanic sources through elastic stress transfer and discuss the results of several applications to Italian active volcanoes. We first present the stress modeling results that point out a two-way coupling between Vesuvius eruptions and historical earthquakes in Southern Apennines, which allow us to provide a physical interpretation of their statistical correlation. Therefore, we explore the elastic stress interaction between historical eruptions at the Etna volcano and the largest earthquakes in Eastern Sicily and Calabria. We show that the large 1693 seismic event caused an increase of compressive stress along the rift zone, which can be associated to the lack of flank eruptions of the Etna volcano for about 70 years after the earthquake. Moreover, the largest Etna eruptions preceded by few decades the large 1693 seismic event. Our modeling results clearly suggest that all these catastrophic events are tectonically coupled. We also investigate the effect of elastic stress perturbations on the instrumental seismicity caused by magma inflation at depth both at the Etna and at the Alban Hills volcanoes. In particular, we model the seismicity pattern at the Alban Hills volcano (central Italy) during a seismic swarm occurred in 1989-90 and we interpret it in terms of Coulomb stress changes caused by magmatic processes in an extensional tectonic stress field. We verify that the earthquakes occur in areas of Coulomb stress increase and that their faulting mechanisms are consistent with the stress perturbation induced by the volcanic source. Our results suggest a link between faults and volcanic sources, which we interpret as a tectonic coupling explaining the seismicity in a large area surrounding the volcanoes.

  7. Ranch business planning and resource monitoring for rangeland sustainability

    Science.gov (United States)

    Kristie A. Maczko; John A. Tanaka; Michael Smith; Cindy Garretson-Weibel; Stanley F. Hamilton; John E. Mitchell; Gene Fults; Charles Stanley; Dick Loper; Larry D. Bryant; J. K. (Rooter) Brite

    2012-01-01

    Aligning a rancher's business plan goals with the capability of the ranch's rangeland resources improves the viability and sustainability of family ranches. Strategically monitoring the condition of soil, water, vegetation, wildlife, livestock production, and economics helps inform business plan goals. Business planning and resource monitoring help keep...

  8. A Working Ranch with an Effective Medusahead Management Program

    Science.gov (United States)

    Since 2005, rancher Ben McGough, owner of the Circle Bar Ranch in Mitchell, Oregon, has been working with USDA-ARS rangeland ecologist Roger Sheley to implement EBIPM on the ranch. More than 600 acres were infested with medusahead (Taeniatherum caput-medusae) when they began working together. We de...

  9. What Are Volcano Hazards?

    Science.gov (United States)

    ... Sheet 002-97 Revised March 2008 What Are Volcano Hazards? Volcanoes give rise to numerous geologic and ... as far as 15 miles from the volcano. Volcano Landslides A landslide or debris avalanche is a ...

  10. A survey of volcano deformation in the central Andes using InSAR: Evidence for deep, slow inflation

    Science.gov (United States)

    Pritchard, M. E.; Simons, M.

    2001-12-01

    We use interferometric synthetic aperture radar (InSAR) to survey about 50 volcanos of the central Andes (15-27o S) for deformation during the 1992-2000 time interval. Because of the remote location of these volcanos, the activity of most are poorly constrained. Using the ERS-1/2 C-band radars (5.6 cm), we observe good interferometric correlation south of about 21o S, but poor correlation north of that latitude, especially in southern Peru. This variation is presumably related to regional climate variations. Our survey reveals broad (10's of km), roughly axisymmetric deformation at 2 volcanic centers with no previously documented deformation. At Uturuncu volcano, in southwestern Bolivia, the deformation rate can be constrained with radar data from several satellite tracks and is about 1 cm/year between 1992 and 2000. We find a second source of volcanic deformation located between Lastarria and Cordon del Azufre volcanos near the Chile/Argentina border. There is less radar data to constrain the deformation in this area, but the rate is also about 1 cm/yr between 1996 and 2000. While the spatial character of the deformation field appears to be affected by atmosphere at both locations, we do not think that the entire signal is atmospheric, because the signal is observed in several interferograms and nearby edifices do not show similar patterns. The deformation signal appears to be time-variable, although it is difficult to determine whether this is due to real variations in the deformation source or atmospheric effects. We model the deformation with both a uniform point-source source of inflation, and a tri-axial point-source ellipsoid, and compare both elastic half-space and layered-space models. We also explore the effects of local topography upon the deformation field using the method of Williams and Wadge (1998). We invert for source parameters using the global search Neighborhood Algorithm of Sambridge (1998). Preliminary results indicate that the sources at both

  11. Ultrastructure and potential sub-seafloor evidence of bacteriogenic iron oxides from Axial Volcano, Juan de Fuca Ridge, north-east Pacific Ocean.

    Science.gov (United States)

    Kennedy, C B; Scott, S D; Ferris, F G

    2003-03-01

    Iron oxides from the caldera of Axial Volcano, a site of hydrothermal vent activity along the Juan de Fuca Ridge, were found to consist predominantly of microbial structures in hydrated whole mounts examined using an environmental scanning electron microscope. Novel observations were made of the iron oxides revealing the spatial relationships of the bacteria within to be more consistent with microbial mats than mineral precipitates. The bacterial structures are attributed to the sheaths of Leptothrix ochracea, the stalks of Gallionella ferruginea, and the filaments of a novel iron oxidizing PV-1 strain, based on the distinctive morphological characteristics of these three bacteria. Energy dispersive X-ray spectroscopy revealed the presence and distribution of Fe, Si, and Cl on the bacterial sheaths, stalks and filaments. The iron oxides were identified by X-ray diffraction to be two-line ferrihydrite, a poorly ordered iron oxyhydroxide. Adsorption of Si in particular to two-line ferrihydrite likely contributes to its stability on the seafloor, and might also be a preservation mechanism creating microfossils of the bacterial structures encrusted with ferrihydrite. Presumptive evidence of the sub-seafloor presence of L. ochracea, G. ferruginea and PV-1 at Axial Volcano was obtained from the presence of these bacteria on a trap that had been placed within an active vent, and also in a vent fluid sample. If indeed these bacteria are present in the sub-seafloor, it may be an indication that the surface expression of iron oxide deposits at Axial Volcano is minimal in comparison to what exists beneath the seafloor.

  12. Comparative Economics of Cattle and Wildlife Ranching in the Zimbabwe Midlands

    OpenAIRE

    Kreuter, Urs P.

    1992-01-01

    The economics of ranches in the Zimbabwe Midlands, generating income from cattle, or wildlife, or both, were compared during 1989/90 to test the claim that wildlife ranching can generate greater profits than cattle ranching on semi-arid African savannas. Both financial (market) prices and economic prices (opportunity cost) were used. Financial data were obtained from 15 cattle, 7 wildlife and 13 mixed ranches in four areas with wildlife and from 15 cattle ranches in two areas with sparse w...

  13. Feasibility Study for Paragon - Bisti Solar Ranch

    Energy Technology Data Exchange (ETDEWEB)

    Benally, Thomas [Navajo Hopi Land Commission Office (NHLCO), Window Rock, AZ (United States)

    2015-06-01

    The Navajo Hopi Land Commission Office (NHLCO) and Navajo Nation (NN) plan to develop renewable energy (RE) projects on the Paragon-Bisti Ranch (PBR) lands, set aside under the Navajo Hopi Land Settlement Act (NHLSA) for the benefit of Relocatees. This feasibility study (FS), which was funded under a grant from DOE’s Tribal Energy Program (TEP), was prepared in order to explore the development of the 22,000-acre PBR in northwestern New Mexico for solar energy facilities. Topics covered include: • Site Selection • Analysis of RE, and a Preliminary Design • Transmission, Interconnection Concerns and Export Markets • Financial and Economic Analysis • Environmental Study • Socioeconomic and Cultural Factors • Next Steps.

  14. Pine Creek Ranch, FY 2001 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Mark E.

    2001-11-01

    Pine Creek Ranch was purchased in 1999 by the Confederated Tribes of Warm Springs using Bonneville Power Administration Fish and Wildlife Habitat Mitigation funds. The 25,000 acre property will be managed in perpetuity for the benefit of fish and wildlife habitat. Major issues include: (1) Restoring quality spawning and rearing habitat for stealhead. Streams are incised and fish passage barriers exist from culverts and possibly beaver dams. In addition to stealhead habitat, the Tribes are interested in overall riparian recovery in the John Day River system for wildlife habitat, watershed values and other values such as recreation. (2) Future grazing for specific management purposes. Past grazing practices undoubtedly contributed to current unacceptable conditions. The main stem of Pine Creek has already been enrolled in the CREP program administered by the USDA, Natural Resource Conservation Service in part because of the cost-share for vegetation restoration in a buffer portion of old fields and in part because of rental fees that will help the Tribes to pay the property taxes. Grazing is not allowed in the riparian buffer for the term of the contract. (3) Noxious weeds are a major concern. (4) Encroachment by western juniper throughout the watershed is a potential concern for the hydrology of the creek. Mark Berry, Habitat Manager, for the Pine Creek Ranch requested the Team to address the following objectives: (1) Introduce some of the field staff and others to Proper Functioning Condition (PFC) assessments and concepts. (2) Do a PFC assessment on approximately 10 miles of Pine Creek. (3) Offer management recommendations. (4) Provide guidelines for monitoring.

  15. Herp Coverboard Sampling - Spears and Didion Ranches [ds324

    Data.gov (United States)

    California Natural Resource Agency — These data are detections of reptiles in 2006 under 2 ft x 2 ft dimension plywood coverboards at four of the 15 sample points at Spears and Didion Ranches, Placer...

  16. 78 FR 34090 - Lois Von Morganroth; Shiloh Warm Springs Ranch, LLC; Notice of Application for Transfer of...

    Science.gov (United States)

    2013-06-06

    ... Springs Ranch, LLC (transferee) filed an application for the transfer of license for the L & M Angus Ranch..., Idaho. Applicants seek Commission approval to transfer the license for the L & M Angus Ranch Project...

  17. Vertical Motions of Oceanic Volcanoes

    Science.gov (United States)

    Clague, D. A.; Moore, J. G.

    2006-12-01

    Oceanic volcanoes offer abundant evidence of changes in their elevations through time. Their large-scale motions begin with a period of rapid subsidence lasting hundreds of thousands of years caused by isostatic compensation of the added mass of the volcano on the ocean lithosphere. The response is within thousands of years and lasts as long as the active volcano keeps adding mass on the ocean floor. Downward flexure caused by volcanic loading creates troughs around the growing volcanoes that eventually fill with sediment. Seismic surveys show that the overall depression of the old ocean floor beneath Hawaiian volcanoes such as Mauna Loa is about 10 km. This gross subsidence means that the drowned shorelines only record a small part of the total subsidence the islands experienced. In Hawaii, this history is recorded by long-term tide-gauge data, the depth in drill holes of subaerial lava flows and soil horizons, former shorelines presently located below sea level. Offshore Hawaii, a series of at least 7 drowned reefs and terraces record subsidence of about 1325 m during the last half million years. Older sequences of drowned reefs and terraces define the early rapid phase of subsidence of Maui, Molokai, Lanai, Oahu, Kauai, and Niihau. Volcanic islands, such as Maui, tip down toward the next younger volcano as it begins rapid growth and subsidence. Such tipping results in drowned reefs on Haleakala as deep as 2400 m where they are tipped towards Hawaii. Flat-topped volcanoes on submarine rift zones also record this tipping towards the next younger volcano. This early rapid subsidence phase is followed by a period of slow subsidence lasting for millions of years caused by thermal contraction of the aging ocean lithosphere beneath the volcano. The well-known evolution along the Hawaiian chain from high to low volcanic island, to coral island, and to guyot is due to this process. This history of rapid and then slow subsidence is interrupted by a period of minor uplift

  18. The 21,700 yr b.p. Lower Toluca Pumice Plinian Eruption of Nevado de Toluca Volcano (Mexico): Evidences of Magma Mixing Process as Triggering Mechanism.

    Science.gov (United States)

    Capra, L.; Arce, J.; Macias, J.

    2006-05-01

    Approximately 21,700 yr B.P., after a period of quiescence of 4800 yr, Nevado de Toluca volcano erupted, producing the Lower Toluca Pumice deposit. The activity generated a 24-km-high Plinian column that lasted ~11 h and dispersed 2.3 km3 (0.8 km3 dense rock equivalent) of tephra toward the NE, blanketing the Lerma basin, an area occupied today by the city of Toluca, with up to 5 cm of ash. Subsequent eruptive pulses were sub-Plinian in style, accompanied by phreatomagmatic explosions that emplaced surge deposits. Finally, the column collapsed toward the NE with the emplacement of a pumice flow deposit. The high vesicularity of the pumice from the basal Plinian layer, up to 83% by volume, indicates that exsolution was dominantly magmatic, and that pressurization of the magma chamber was probably due to a magma mixing process. Evidence for this includes the compositional range of juvenile products (from 55 to 65 wt% SiO2), as well as the presence of two types of plagioclase, one in equilibrium and the other one with disequilibrium textures and reverse zoning. This suggests input of an andesitic liquid into the dacitic magma chamber. Based on the eruptive record, the most likely future eruptive activity at Nevado de Toluca volcano will be Plinian. Although quiet for more than 3250 yr, Plinian activity could occur after a long period of quiescence, and it could represent a hazard for the entire Toluca basin, where more than one million people live today.

  19. Forced transport of thermal energy in magmatic and phreatomagmatic large volume ignimbrites: Paleomagnetic evidence from the Colli Albani volcano, Italy

    Science.gov (United States)

    Trolese, Matteo; Giordano, Guido; Cifelli, Francesca; Winkler, Aldo; Mattei, Massimo

    2017-11-01

    Few studies have detailed the thermal architecture of large-volume pyroclastic density current deposits, although such work has a clear importance for understanding the dynamics of eruptions of this magnitude. Here we examine the temperature of emplacement of large-volume caldera-forming ignimbrites related to magmatic and phreatomagmatic eruptions at the Colli Albani volcano, Italy, by using thermal remanent magnetization analysis on both lithic and juvenile clasts. Results show that all the magmatic ignimbrites were deposited at high temperature, between the maximum blocking temperature of the magnetic carrier (600-630 °C) and the glass transition temperature (about 710 °C). Temperature estimations for the phreatomagmatic ignimbrite range between 200 and 400 °C, with most of the clasts emplaced between 200 and 320 °C. Because all the investigated ignimbrites, magmatic and phreatomagmatic, share similar magma composition, volume and mobility, we attribute the temperature difference to magma-water interaction, highlighting its pronounced impact on thermal dissipation, even in large-volume eruptions. The homogeneity of the deposit temperature of each ignimbrite across its areal extent, which is maintained across topographic barriers, suggests that these systems are thermodynamically isolated from the external environment for several tens of kilometers. Based on these findings, we propose that these large-volume ignimbrites are dominated by the mass flux, which forces the lateral transport of mass, momentum, and thermal energy for distances up to tens of kilometers away from the vent. We conclude that spatial variation of the emplacement temperature can be used as a proxy for determining the degree of forced-convection flow.

  20. 77 FR 58181 - Power Resources, Inc., Smith Ranch Highland Uranium Project; License Renewal Request, Opportunity...

    Science.gov (United States)

    2012-09-19

    ... NUCLEAR REGULATORY COMMISSION [Docket No. 04008964, NRC-2012-0214] Power Resources, Inc., Smith... available in ADAMS) is provided the first time that a document is referenced. The Smith Ranch Highland... (Smith Ranch Technical Report); Accession No. ML12234A539 (Smith Ranch Environmental Report). In addition...

  1. Stratigraphy, distribution, and evidence for mafic triggering of the ca. 8.5 ka Driftwood Pumice eruption, Makushin Volcano, Alaska, U.S.A

    Science.gov (United States)

    Lerner, Allan H.; Crowley, Peter D.; Nicolaysen, Kirsten P.; Hazlett, Richard W.

    2018-05-01

    Makushin Volcano on Unalaska Island, Alaska, threatens the Aleutian's largest population centers (Unalaska and Dutch Harbor), yet its eruption mechanisms are poorly known. This study presents a detailed stratigraphic and geochemical investigation of Makushin's most recent highly explosive event: the ca. 8.5 ka Driftwood Pumice eruption. The Driftwood Pumice has measured thicknesses of over 2.5 m, and isopach reconstructions estimate a total deposit volume of 0.3 to 1.6 km3, indicating a VEI 4-5 eruption. Proximal deposits consist of normally-graded, tan, dacitic to andesitic pumice, capped by a thinner dark layer of lower-silica andesitic scoria mixed with abundant lithic fragments. This stratigraphy is interpreted as an initial vent-clearing eruption that strengthened into a climactic ejection of pumice and ash and concluded with vent destabilization and the eruption of somewhat more mafic, gas-poor magma. Within the pumice, geochemical trends, disequilibrium mineral populations, and mineral zonation patterns show evidence of magma mixing between a bulk silicic magma and a mafic melt. Euhedral high-Ca plagioclase (An68-91) and high-Mg olivine (Fo69-77) phenocrysts are in disequilibrium with trachydacitic glass (65-68 wt% SiO2) and more abundant sodic plagioclase (An34-55), indicating the former originally crystallized in a more mafic melt. Tephra whole rock compositions become more mafic upwards through the deposit, ranging from a basal low-silica dacite to an andesite (total range: 60.8-63.3 wt% SiO2). Collectively, these compositional variations suggest magma mixing in the Driftwood Pumice (DWP) magma reservoir, with a systematic increase in the amount of a mafic component (up to 25%) upward through the deposit. Olivine-liquid and liquid-only thermometry indicate the mafic magma intruded at temperatures 140-200 °C hotter than the silicic magma. Diffusion rates calculated for 5-7 μm thick, lower-Mg rims on the olivine phenocrysts (Fo60 rim vs Fo76 bulk) suggest

  2. Productivity of Indigenous and Exotic Cattle on Kenya Ranches ...

    African Journals Online (AJOL)

    A comparison of productivity and adaptability of indigenous (Boran and Small East African Zebu) and the exotic (Sahiwal and Ayrshire) cattle on Kenyan ranches located in semi-arid areas of the Rift Valley Provinces was done. Data sets of the cattle breeds over the 1979-1993 period on Deloraine, Elkarama, Ilkerin, ...

  3. Book Review: Game Ranch Management (Sixth Edition) | Peel ...

    African Journals Online (AJOL)

    Book Title: Game Ranch Management (Sixth Edition). Book Authors: J du P Bothma & J.G. du Toit (Eds.) 2016, Van Schaik Publishers, PO Box 12681, Hatfield 0028, Pretoria, South Africa 1012 pages, hardcover, eBook and ePub. ISBN: 9780627033469, 9780627033476 (eBook), 9780627034909 (ePub). Price R949.00 ...

  4. Cultural Resource Survey Report. Hildebrand Ranch Area: Proposed Chatfield Arboretum.

    Science.gov (United States)

    1981-05-01

    stabilization and attic re- pair General Purpose Shed X X Chicken Coop X X Carriage Shed X x Corrals and Fences X X Grape Arbor x Inventory of Buildings and Fact...area of about 350 acres and included the en- tire ranch except for the areas of ground occupied by buildings and parking lots. The area along Deer

  5. Ranch profitability given increased precipitation variability and flexible stocking

    Science.gov (United States)

    Forage and cattle performance relationships with spring precipitation, combined with cattle market price variability, were incorporated into a ranch level model to determine if addition of a yearling enterprise to the base cow-calf herd would improve profitability with increasing (25% and 50% greate...

  6. Avian response to pine restoration at Peck Ranch Conservation Area

    Science.gov (United States)

    Richard Clawson; Carrie Steen; Kim Houf; Terry Thompson

    2007-01-01

    Midco Pine Flats is a 2,223-acre region of Peck Ranch Conservation Area (CA) that is classified as a pine-oak plains land type association. Extensive logging in the early 1900s removed most overstory shortleaf pine allowing oak to become the primary overstory component. In 2000, Missouri Department of Conservation staff initiated a pineoak woodland restoration project...

  7. 78 FR 41795 - Farm, Ranch, and Rural Communities Committee Teleconference

    Science.gov (United States)

    2013-07-11

    ... Communities Committee Teleconference AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of Public..., EPA gives notice of a teleconference meeting of the Farm, Ranch, and Rural Communities Committee (FRRCC). The FRRCC is a policy-oriented committee that provides policy advice, information, and...

  8. 77 FR 71396 - Council for Native American Farming and Ranching

    Science.gov (United States)

    2012-11-30

    ... American Farming and Ranching (CNAFR) a public advisory committee of the Office of Tribal Relations (OTR... documents other than rules #0;or proposed rules that are applicable to the public. Notices of hearings #0..., filing of petitions and applications and agency #0;statements of organization and functions are examples...

  9. Relative chronology of Martian volcanoes

    International Nuclear Information System (INIS)

    Landheim, R.; Barlow, N.G.

    1991-01-01

    Impact cratering is one of the major geological processes that has affected the Martian surface throughout the planet's history. The frequency of craters within particular size ranges provides information about the formation ages and obliterative episodes of Martian geologic units. The Barlow chronology was extended by measuring small craters on the volcanoes and a number of standard terrain units. Inclusions of smaller craters in units previously analyzed by Barlow allowed for a more direct comparison between the size-frequency distribution data for volcanoes and established chronology. During this study, 11,486 craters were mapped and identified in the 1.5 to 8 km diameter range in selected regions of Mars. The results are summarized in this three page report and give a more precise estimate of the relative chronology of the Martian volcanoes. Also, the results of this study lend further support to the increasing evidence that volcanism has been a dominant geologic force throughout Martian history

  10. Nichols Ranch ISL Uranium Mine - A case history

    International Nuclear Information System (INIS)

    Catchpole, G.; Thomas, G.

    2014-01-01

    The Nichols Ranch ISL Uranium Mine is located in the Powder River Basin of Wyoming, U.S.A. The mine is owned and operated by Uranerz Energy Corporation (Uranerz), a U.S. corporation headquartered in Casper, Wyoming. Nichols Ranch started operations in February 2014 and is the newest uranium mine to go into production in the USA. The uranium being extracted is hosted in a sandstone, roll-front deposit at a depth ranging from 400 to 800 feet [~120 to ~240 m). The In-Situ Recovery (ISL) mining method is employed at the Nichols Ranch mine which is the method currently being utilized at most uranium mines in the USA. Environmental permit applications for the Nichols Ranch mine were submitted to the appropriate regulatory agencies in late 2007. It required more than three and a half years to obtain all the necessary permits and licenses to construct and operate the mine. Construction of the mining facilities and the first wellfield started in late 2011 and was completed in late 2013. Mining results to date have been better than anticipated and Uranerz expects to reach its 2014 production target. The most challenging part of getting a new uranium mine in production in the United States of America was the three plus years it took to get through the environmental permitting process. Uranerz was one of three companies in 2011 that applied for permits to construct and operate uranium mines in Wyoming at essentially the same time. The Nichols Ranch mine is licensed to produce up to two million pounds per year of uranium (as U_3O_8) [~770 tU] ready for shipment to the converter. At this time only the ion exchange portion of the central processing plant has been installed at Nichols Ranch with uranium loaded resin being shipped to Cameco’s nearby Smith Ranch – Highland ISL uranium mine for elution, precipitation, drying and packaging under a toll processing agreement. Cameco provides Uranerz with dried and drummed yellowcake that Uranerz owns which is shipped to the

  11. Global Volcano Locations Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC maintains a database of over 1,500 volcano locations obtained from the Smithsonian Institution Global Volcanism Program, Volcanoes of the World publication. The...

  12. Inferred Early Permian Arc Rifting in Bogda Mountain, Southernmost of the Central Asia Orogenic Belt: Evidence from a Peperite Bearing Volcano-Sedimentary Succession

    Science.gov (United States)

    Memtimin, M.; Guo, Z.

    2017-12-01

    Late Paleozoic tectonic history, especially Carboniferous-Permian periods, of the Central Asia Orogenic Belt (CAOB) is considered to be the turning point for the termination of terrane amalgamation and closure of the Paleoasian Ocean. However, the debate about the paleoenvironment and tectonic setting of the region during the period is still not resolved. In this study, we report a set of volcano-sedimentary sequence in the Bogda Mountain of the southernmost of CAOB, which is associated with contemporaneous subaqueous emplacement of and interaction between mafic lava and carbonate sediments. The succession contains four distinct facies including closely packed pillow basalts, pillow basalts with interstitial materials, hyaloclastites and peperites. We discuss their formation and emplacement mechanism, interaction between hot magma-water/unconsolidated sediments and thermal metamorphism during the interaction. Textural features of the sequence, especially hyaloclastites and peperites, provide clear evidence for in situ autofragmentation of lava flows, synvolcanic sedimentation of carbonates, fuel coolant interaction when hot magma bulldozed into wet unconsolidated sediments, and represent autochthonous origin of the succession. Lateral transition of the lithofacies indicate a progressively deepening subaqueous environment, resembling a stepwise evolution from early stage of volcanic intrusion with lower lava flux in shallower water level to increasingly subsiding basin with more lava flux in greater depth. Previous studies determined that the mafic magma was intruded around the Carboniferous-Permian boundary ( 300Ma), and geochemical studies showed the magma was originated from dry depleted mantle with little crustal contamination. Nevertheless, the succession was thought to be fault related allochthones formation which was transferred in as part of a Carboniferous intraplate arc. Combining our findings with the previous study results, we propose a new model to

  13. A Scientific Excursion: Volcanoes.

    Science.gov (United States)

    Olds, Henry, Jr.

    1983-01-01

    Reviews an educationally valuable and reasonably well-designed simulation of volcanic activity in an imaginary land. VOLCANOES creates an excellent context for learning information about volcanoes and for developing skills and practicing methods needed to study behavior of volcanoes. (Author/JN)

  14. Volcano seismology

    Science.gov (United States)

    Chouet, B.

    2003-01-01

    A fundamental goal of volcano seismology is to understand active magmatic systems, to characterize the configuration of such systems, and to determine the extent and evolution of source regions of magmatic energy. Such understanding is critical to our assessment of eruptive behavior and its hazardous impacts. With the emergence of portable broadband seismic instrumentation, availability of digital networks with wide dynamic range, and development of new powerful analysis techniques, rapid progress is being made toward a synthesis of high-quality seismic data to develop a coherent model of eruption mechanics. Examples of recent advances are: (1) high-resolution tomography to image subsurface volcanic structures at scales of a few hundred meters; (2) use of small-aperture seismic antennas to map the spatio-temporal properties of long-period (LP) seismicity; (3) moment tensor inversions of very-long-period (VLP) data to derive the source geometry and mass-transport budget of magmatic fluids; (4) spectral analyses of LP events to determine the acoustic properties of magmatic and associated hydrothermal fluids; and (5) experimental modeling of the source dynamics of volcanic tremor. These promising advances provide new insights into the mechanical properties of volcanic fluids and subvolcanic mass-transport dynamics. As new seismic methods refine our understanding of seismic sources, and geochemical methods better constrain mass balance and magma behavior, we face new challenges in elucidating the physico-chemical processes that cause volcanic unrest and its seismic and gas-discharge manifestations. Much work remains to be done toward a synthesis of seismological, geochemical, and petrological observations into an integrated model of volcanic behavior. Future important goals must include: (1) interpreting the key types of magma movement, degassing and boiling events that produce characteristic seismic phenomena; (2) characterizing multiphase fluids in subvolcanic

  15. Caldwell Ranch Exploration and Confirmation Project, Northwest Geysers, CA

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Mark A.

    2013-04-25

    The purpose of the Caldwell Ranch Exploration and Confirmation Project was to drill, test, and confirm the present economic viability of the undeveloped geothermal reservoir in the 870 acre Caldwell Ranch area of the Northwest Geysers that included the CCPA No.1 steam field. All of the drilling, logging, and sampling challenges were met. Three abandoned wells, Prati 5, Prati 14 and Prati 38 were re-opened and recompleted to nominal depths of 10,000 feet in 2010. Two of the wells required sidetracking. The flow tests indicated Prati 5 Sidetrack 1 (P-5 St1), Prati 14 (P-14) and Prati 38 Sidetrack 2 (P-38 St2) were collectively capable of initially producing an equivalent of 12 megawatts (MWe) of steam using a conversion rate of 19,000 pounds of steam/hour

  16. Passive solar ranch house for the mass market

    Energy Technology Data Exchange (ETDEWEB)

    Albanes, M.N.

    1981-01-01

    To promote the building of passive solar housing in the Denver metropolitan area, a solar ranch style house was designed for a builder, Unique Homes, as part of a group of thirteen passive solar houses built for the mass market under SERI's Denver Metro Home Builders Program. The project, process of design, thermal performance analysis, cost and consumer/media response are reviewed. The final design was a direct gain, attached greenhouse system that used brick as interior mass.

  17. Kulanaokuaiki Tephra (ca, A.D. 400-1000): Newly recognized evidence for highly explosive eruptions at Kilauea Volcano, Hawai'i

    Science.gov (United States)

    Fiske, R.S.; Rose, T.R.; Swanson, D.A.; Champion, D.E.; McGeehin, J.P.

    2009-01-01

    K??lauea may be one of the world's most intensively monitored volcanoes, but its eruptive history over the past several thousand years remains rather poorly known. Our study has revealed the vestiges of thin basaltic tephra deposits, overlooked by previous workers, that originally blanketed wide, near-summit areas and extended more than 17 km to the south coast of Hawai'i. These deposits, correlative with parts of tephra units at the summit and at sites farther north and northwest, show that K??lauea, commonly regarded as a gentle volcano, was the site of energetic pyroclastic eruptions and indicate the volcano is significantly more hazardous than previously realized. Seventeen new calibrated accelerator mass spectrometry (AMS) radiocarbon ages suggest these deposits, here named the Kulanaokuaiki Tephra, were emplaced ca. A.D. 400-1000, a time of no previously known pyroclastic activity at the volcano. Tephra correlations are based chiefly on a marker unit that contains unusually high values of TiO2 and K2O and on paleomagnetic signatures of associated lava flows, which show that the Kulanaokuaiki deposits are the time-stratigraphic equivalent of the upper part of a newly exhumed section of the Uw??kahuna Ash in the volcano's northwest caldera wall. This section, thought to have been permanently buried by rockfalls in 1983, is thicker and more complete than the previously accepted type Uw??kahuna at the base of the caldera wall. Collectively, these findings justify the elevation of the Uw??kahuna Ash to formation status; the newly recognized Kulanaokuaiki Tephra to the south, the chief focus of this study, is defined as a member of the Uw??kahuna Ash. The Kulanaokuaiki Tephra is the product of energetic pyroclastic falls; no surge- or pyroclastic-flow deposits were identified with certainty, despite recent interpretations that Uw??kahuna surges extended 10-20 km from K??lauea's summit. ?? 2009 Geological Society of America.

  18. Volcanoes: Nature's Caldrons Challenge Geochemists.

    Science.gov (United States)

    Zurer, Pamela S.

    1984-01-01

    Reviews various topics and research studies on the geology of volcanoes. Areas examined include volcanoes and weather, plate margins, origins of magma, magma evolution, United States Geological Survey (USGS) volcano hazards program, USGS volcano observatories, volcanic gases, potassium-argon dating activities, and volcano monitoring strategies.…

  19. Volcanoes: observations and impact

    Science.gov (United States)

    Thurber, Clifford; Prejean, Stephanie G.

    2012-01-01

    Volcanoes are critical geologic hazards that challenge our ability to make long-term forecasts of their eruptive behaviors. They also have direct and indirect impacts on human lives and society. As is the case with many geologic phenomena, the time scales over which volcanoes evolve greatly exceed that of a human lifetime. On the other hand, the time scale over which a volcano can move from inactivity to eruption can be rather short: months, weeks, days, and even hours. Thus, scientific study and monitoring of volcanoes is essential to mitigate risk. There are thousands of volcanoes on Earth, and it is impractical to study and implement ground-based monitoring at them all. Fortunately, there are other effective means for volcano monitoring, including increasing capabilities for satellite-based technologies.

  20. Soufriere Hills Volcano

    Science.gov (United States)

    2002-01-01

    In this ASTER image of Soufriere Hills Volcano on Montserrat in the Caribbean, continued eruptive activity is evident by the extensive smoke and ash plume streaming towards the west-southwest. Significant eruptive activity began in 1995, forcing the authorities to evacuate more than 7,000 of the island's original population of 11,000. The primary risk now is to the northern part of the island and to the airport. Small rockfalls and pyroclastic flows (ash, rock and hot gases) are common at this time due to continued growth of the dome at the volcano's summit.This image was acquired on October 29, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. 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 satellite. 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 will provide 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 physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA

  1. Magmas with slab fluid and decompression melting signatures coexisting in the Gulf of Fonseca: Evidence from Isla El Tigre volcano (Honduras, Central America)

    Science.gov (United States)

    Mattioli, Michele; Renzulli, Alberto; Agostini, Samuele; Lucidi, Roberto

    2016-01-01

    Isla El Tigre volcano is located in the Gulf of Fonseca (Honduras) along the Central America volcanic front, where a significant change in the strike of the volcanic chain is observed. The studied samples of this poorly investigated volcano are mainly subalkaline basic to intermediate lavas (basalts and basaltic andesites) and subordinate subalkaline/alkaline transitional basalts, both having the typical mineralogical and geochemical characteristics of arc volcanic rocks. On the basis of petrographic and geochemical features, two groups of rocks have been distinguished. Lavas from the main volcanic edifice are highly porphyritic and hy-qz normative, and have lower MgO contents ( 5 wt.%), are ol-hy normative and show lower HFSE depletions relative to LILE and LREE, with lower Ba/La, Ba/Nb and Zr/Nb ratios. This suggests that mantle-derived magmas were not produced by the same process throughout the activity of the volcano. The bulk rock geochemistry and 87Sr/86Sr (0.70373-0.70382), 143Nd/144Nd (0.51298-0.51301), 206Pb/204Pb (18.55-18.58), 207Pb/204Pb (15.54-15.56) and 208Pb/204Pb (38.23-38.26) isotopic data of Isla El Tigre compared with the other volcanoes of the Gulf of Fonseca and all available literature data for Central America suggests that this stratovolcano was mainly built by mantle-derived melts driven by slab-derived fluid-flux melting, while magmas erupted through its parasitic cones have a clear signature of decompression melting with minor slab contribution. The coexistence of these two different mantle melting generation processes is likely related to the complex geodynamic setting of the Gulf of Fonseca, where the volcanic front changes direction by ca. 30° and two fundamental tectonic structures of the Chortis continental block, mainly the N-S Honduras Depression and the NE-SW Guayape Fault Zone, cross each other.

  2. Vertical distribution of major, minor and trace elements in sediments from mud volcanoes of the Gulf of Cadiz: evidence of Cd, As and Ba fronts in upper layers

    Science.gov (United States)

    Carvalho, Lina; Monteiro, Rui; Figueira, Paula; Mieiro, Cláudia; Almeida, Joana; Pereira, Eduarda; Magalhães, Vítor; Pinheiro, Luís; Vale, Carlos

    2018-01-01

    Mud volcanoes are feature of the coastal margins where anaerobic oxidation of methane triggers geochemical signals. Elemental composition, percentage of fine particles and loss on ignition were determined in sediment layers of eleven gravity cores retrieved from four mud volcanoes (Sagres, Bonjardim, Soloviev and Porto) and three undefined structures located on the deep Portuguese margin of the Gulf of Cadiz. Calcium was positively correlated to Sr and inversely to Al as well as to most of the trace elements. Vertical profiles of Ba, Cd and As concentrations, and their ratios to Al, in Porto and Soloviev showed pronounced enhancements in the top 50-cm depth. Sub-surface enhancements were less pronounced in other mud volcanoes and were absent in sediments from the structures. These profiles were interpreted as diagenetic enrichments related to the anaerobic oxidation of methane originated from upward methane-rich fluxes. The observed barium fronts were most likely caused by the presence of barite which precipitated at the sulphate-methane transition zone. Cd and As enrichments have probably resulted from successive dissolution/precipitation of sulphides in response to vertical shifts of redox boundaries.

  3. Tidal wetland vegetation and ecotone profiles: The Rush Ranch Open Space Preserve

    Science.gov (United States)

    The Rush Ranch Open Space Preserve (Rush Ranch) is a component site of the San Francisco Bay National Estuarine Research Reserve (SF Bay NERR) that includes one of the largest undiked tidal wetlands in the San Francisco Estuary. The brackish tidal wetlands grade into transitional vegetation and unde...

  4. 76 FR 77890 - Swan Ranch Railroad, L.L.C.-Operation Exemption-Swan Industrial Park

    Science.gov (United States)

    2011-12-14

    ... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. FD 35574] Swan Ranch Railroad, L.L.C.--Operation Exemption--Swan Industrial Park Swan Ranch Railroad, L.L.C. (SRR),\\1\\ a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to operate, pursuant to an agreement with Cheyenne Logistics Hub, LLC (CLH), all...

  5. Richness of mammals on the San Bernardino Ranch in the municipality of Agua Prieta, Sonora, Mexico

    Science.gov (United States)

    Mario Erandi Bonillas-Monge; Carlos Manuel Valdez-Coronel

    2013-01-01

    Historically, the San Bernardino Ranch has performed, as economical activities, livestock and farming, which has contributed to the deterioration of regional ecosystems. The ranch is ecologically important due to the diverse types of habitats of conservation interest such as the semi-desert grassland, the riparian vegetation, and a large ciénega, in which restoration...

  6. Vegetation map and plant checklist of Ol Ari Nyiro ranch and the ...

    African Journals Online (AJOL)

    Ol Ari Nyiro is a 360 km2 ranch of the Laikipia Plateau, in a semi-arid part of Kenya. The vegetation of the ranch and nearby Mukutan Gorge was mapped, and a preliminary check-list of fungi and vascular plants compiled. The vegetation was classified in 16 different types. A total of 708 species and subspecies were ...

  7. 77 FR 4290 - Conway Ranch Hydropower Project; Notice of Preliminary Permit Application Accepted for Filing and...

    Science.gov (United States)

    2012-01-27

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13089-002] Conway Ranch Hydropower Project; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments... study the feasibility of the Conway Ranch Hydropower Project to be located on Virginia Creek, near the...

  8. Traditional ranching heritage and cultural continuity in the southwestern United States

    Science.gov (United States)

    Carol Raish; Alice M. McSweeney

    2008-01-01

    This study, conducted among ranchers on the Santa Fe and Carson National Forests in the Southwestern United States, examines the role of ranching in maintaining traditional heritage and cultural continuity. The mainly Hispanic ranching families of northern New Mexico first came into the region in 1598 with Spanish colonization. Many of the villages received community...

  9. Forrest Ranch Management and Implementation, Annual Report 2002-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Brent

    2004-01-01

    Through their John Day Basin Office, the Confederated Tribes of Warm Springs Reservation of Oregon (Tribes) acquired the Forrest Ranch during July of 2002. The property consists of two parcels located in the John Day subbasin within the Columbia basin. The mainstem parcel consists of 3,503 acres and is located 1/2 mile to the east of Prairie City, Oregon on the mainstem of the John Day River. The middle fork parcel consists of 820 acres and is located one mile to the west of the town of Austin, OR on the middle fork John Day River. The Forrest Ranch Project is under a memorandum of agreement with the Bonneville Power Administration (BPA) to provide an annual written report generally describing the real property interests of the project and management activities undertaken or in progress. The Forrest Ranch acquisition was funded by BPA as part of their program to protect, mitigate, and enhance fish and wildlife habitat affected by the operation of their hydroelectric facilities on the Columbia River and its tributaries. Following lengthy negotiations with the BPA and property owner, the Tribes were able to conclude the acquisition of the Forrest Ranch in July of 2002. The intent of the acquisition project was to partially mitigate fish and wildlife impacts for the John Day Dam on the Columbia River as outlined in the Northwest Power Planning Council's Wildlife Program (NPPC 1994, section 11.1, section 7.6). While the Tribes hold fee-title to the property, the BPA has assured a level of program funding through a memorandum of agreement and annual statement of work. As early as 1997, the Tribes identified this property as a priority for restoration in the John Day basin. In 2000, the Tribes arranged an agreement with the landowner to seek funds for the acquisition of both the Middle Fork and upper Mainstem John Day River holdings of Mr. John Forrest. This property had been a priority of not only the Tribes, but of many other basin natural resource agencies. The

  10. Forrest Ranch Acquisition, Annual Report 2001-2002.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Brent

    2003-08-01

    Through their John Day Basin Office, the Confederated Tribes of Warm Springs Reservation of Oregon (Tribes) acquired the Forrest Ranch during July of 2002. The property consists of two parcels located in the John Day subbasin within the Columbia basin. The mainstem parcel consists of 3,503 acres and is located 1/2 mile to the east of Prairie City, Oregon on the mainstem of the John Day River. The middle fork parcel consists of 820 acres and is located one mile to the west of the town of Austin, OR on the middle fork John Day River. The Forrest Ranch Project is under a memorandum of agreement with the Bonneville Power Administration (BPA) to provide an annual written report generally describing the real property interests of the project and management activities undertaken or in progress. The Forrest Ranch acquisition was funded by BPA as part of their program to protect, mitigate, and enhance fish and wildlife habitat affected by the operation of their hydroelectric facilities on the Columbia River and its tributaries. Following lengthy negotiations with the BPA and property owner, the Tribes were able to conclude the acquisition of the Forrest Ranch in July of 2002. The intent of the acquisition project was to partially mitigate fish and wildlife impacts for the John Day Dam on the Columbia River as outlined in the Northwest Power Planning Council's Wildlife Program (NPPC 1994, section 11.1, section 7.6). While the Tribes hold fee-title to the property, the BPA has assured a level of program funding through a memorandum of agreement and annual statement of work. As early as 1997, the Tribes identified this property as a priority for restoration in the John Day basin. In 2000, the Tribes arranged an agreement with the landowner to seek funds for the acquisition of both the Middle Fork and upper Mainstem John Day River holdings of Mr. John Forrest. This property had been a priority of not only the Tribes, but of many other basin natural resource agencies. The

  11. Visions of Volcanoes

    Directory of Open Access Journals (Sweden)

    David M. Pyle

    2017-12-01

    Full Text Available The long nineteenth century marked an important transition in the understanding of the nature of combustion and fire, and of volcanoes and the interior of the earth. It was also a period when dramatic eruptions of Vesuvius lit up the night skies of Naples, providing ample opportunities for travellers, natural philosophers, and early geologists to get up close to the glowing lavas of an active volcano. This article explores written and visual representations of volcanoes and volcanic activity during the period, with the particular perspective of writers from the non-volcanic regions of northern Europe. I explore how the language of ‘fire’ was used in both first-hand and fictionalized accounts of peoples’ interactions with volcanoes and experiences of volcanic phenomena, and see how the routine or implicit linkage of ‘fire’ with ‘combustion’ as an explanation for the deep forces at play within and beneath volcanoes slowly changed as the formal scientific study of volcanoes developed. I show how Vesuvius was used as a ‘model’ volcano in science and literature and how, later, following devastating eruptions in Indonesia and the Caribbean, volcanoes took on a new dimension as contemporary agents of death and destruction.

  12. The expansion of intensive agriculture and ranching in Brazilian Amazonia

    Science.gov (United States)

    Walker, Robert; DeFries, Ruth; del Carmen Vera-Diaz, Maria; Shimabukuro, Yosio; Venturieri, Adriano

    Agriculture in Amazonia has often provoked controversy, given the tremendous ecological value of the region's environment. First with ranching, and now with the soybean boom, tractors and cattle have marched across lands that for millennia supported only closed moist forest, resident ecosystems, and dispersed indigenous peoples. The present chapter considers this expansion, focusing on the Brazilian portion of the basin. Its premise is that effective Amazonian policy must be grounded on an understanding of the region's agriculture. The chapter pursues its objectives by first addressing the development initiatives that created the preconditions for Amazonia's current agricultural economy. The region is remote and has therefore required sustained government intervention to release its potential. The policy discussion is followed by descriptions of cattle ranching and soy farming. For each, market settings and trajectories of expansion are presented. Although these sectoral descriptions are data rich, they do not provide a conceptual framework for analyzing the environmental impacts of evolving market conditions. To accomplish this, the chapter invokes the classical land use model of von Thünen to explain Amazonian land cover dynamics in relation to soy-cattle linkages. It addresses these dynamics with remote sensing data from Mato Grosso, Pará, and Rondônia, and then discusses scenarios of agricultural advances on the forest. Conclusions follow, considering possible policy responses to deforestation, and the social context of agricultural intensification, with special attention to the issues of land tenure security and distributional equity.

  13. Determinants of elephant distribution at Nazinga Game Ranch, Burkina Faso

    Science.gov (United States)

    Jenks, Jonathan A.; Klaver, Robert W.; Wicks, Zeno W.

    2007-01-01

    We used seasonal ground total counts and remote sensing and GIS technology to relate elephant (Loxodonta africana africana) distribution at Nazinga Game Ranch to environmental and anthropogenic factors. Variables used in analyses were normalized difference vegetation index, elevation, stream density, density of poaching and human illegal activities, distance to dams, distance to rivers, distance to roads, and distance to poaching risk. Contrary to our expectation, road traffic did not disturb elephants. Strong negative relationships were documented between elephant abundance and stream density, distance to dams, and poaching density. Density of poaching and other human illegal activities explained 81%, vegetation greenness 6%, and stream density 3% of the variation in elephant density. Elephant distribution represented a survival strategy affected by poaching, food quality and abundance, and water availability. 

  14. Field studies of game and livestock under African ranching conditions

    International Nuclear Information System (INIS)

    King, J.M.

    1982-01-01

    A model was used to integrate the results of tritiated-water studies on game and livestock under African ranching conditions. The model illustrated the two main functions of water in a tropical herbivore, i.e. as a medium for intermediary metabolism and for evaporative cooling. The close relationship between water and nutrition in the ecosystem is reflected in the water and energy conservation mechanisms which operate concomitantly in the animal. Arid-adapted animals can maintain productivity, albeit low, on a limited water intake despite high environmental heat loads. This is achieved because of a number of physical as well as physiological attributes, which can reduce the effect of the environmental heat load without affecting the intake of food and its utilization. (author)

  15. The 2014-15 eruption and the short-term geochemical evolution of the Fogo volcano (Cape Verde): Evidence for small-scale mantle heterogeneity

    Science.gov (United States)

    Mata, J.; Martins, S.; Mattielli, N.; Madeira, J.; Faria, B.; Ramalho, R. S.; Silva, P.; Moreira, M.; Caldeira, R.; Moreira, M.; Rodrigues, J.; Martins, L.

    2017-09-01

    Recurrent eruptions at very active ocean island volcanoes provide the ideal means to gain insight on the scale of spatial variations at the mantle source and on temporal changes of magma genesis and evolution processes. In 2014, after 19 years of quiescence, Fogo volcano (Cape Verde Archipelago) experienced a new eruption, with the vents located 200 m from those of the 1995 eruption, and less than 2000 m from those of the 1951 event. This offered a unique opportunity to investigate the existence of small-scale mantle heterogeneities and the short-term compositional evolution of magmas erupted by a very active oceanic volcano like Fogo. Here we present petrological and geochemical data from the early stages of the Fogo's most recent eruption - started on November 23, 2014 - and compare them with the signature of previous eruptions (particularly those of 1995 and 1951). The magmas erupted in 2014 are alkaline (up to 23.4% and 0.94% of normative ne and lc, respectively) with somewhat evolved compositions (Mg # < 56), ranging from tephrites to phonotephrites. The eruption of phonotephritic lavas preceded the effusion of tephritic ones. Lavas carried to the surface clinopyroxene and kaersutite phenocrysts and cognate megacrysts, which indicate that the main stages of magma evolution occurred in magma chambers most probably located at mantle depths (25.6 ± 5.5 km below sea level). This was followed by a shallower (< 1.5 km below sea level) and shorter (≈ 50 days) magma stagnation before the eruption. 2014 magmas have more unradiogenic Sr and more radiogenic Nd compositions than those of the previous 1951 and 1995 eruptions, which generally have less radiogenic Pb ratios. These isotopic differences - coming from quasi-coeval materials erupted almost in the same place - are remarkable and reflect the small-scale heterogeneity of the underlying mantle source. Moreover, they reflect the limited isotopic averaging of the source composition during partial melting events as

  16. Pine Creek Ranch, FY 2001 annual report; ANNUAL

    International Nuclear Information System (INIS)

    Berry, Mark E.

    2001-01-01

    Pine Creek Ranch was purchased in 1999 by the Confederated Tribes of Warm Springs using Bonneville Power Administration Fish and Wildlife Habitat Mitigation funds. The 25,000 acre property will be managed in perpetuity for the benefit of fish and wildlife habitat. Major issues include: (1) Restoring quality spawning and rearing habitat for stealhead. Streams are incised and fish passage barriers exist from culverts and possibly beaver dams. In addition to stealhead habitat, the Tribes are interested in overall riparian recovery in the John Day River system for wildlife habitat, watershed values and other values such as recreation. (2) Future grazing for specific management purposes. Past grazing practices undoubtedly contributed to current unacceptable conditions. The main stem of Pine Creek has already been enrolled in the CREP program administered by the USDA, Natural Resource Conservation Service in part because of the cost-share for vegetation restoration in a buffer portion of old fields and in part because of rental fees that will help the Tribes to pay the property taxes. Grazing is not allowed in the riparian buffer for the term of the contract. (3) Noxious weeds are a major concern. (4) Encroachment by western juniper throughout the watershed is a potential concern for the hydrology of the creek. Mark Berry, Habitat Manager, for the Pine Creek Ranch requested the Team to address the following objectives: (1) Introduce some of the field staff and others to Proper Functioning Condition (PFC) assessments and concepts. (2) Do a PFC assessment on approximately 10 miles of Pine Creek. (3) Offer management recommendations. (4) Provide guidelines for monitoring

  17. Evidence of episodic long-lived eruptions in the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes, Gulf of Cádiz

    Science.gov (United States)

    Toyos, María H.; Medialdea, Teresa; León, Ricardo; Somoza, Luis; González, Francisco Javier; Meléndez, Nieves

    2016-06-01

    High-resolution single channel and multichannel seismic reflection profiles and multibeam bathymetric and backscatter data collected during several cruises over the period 1999 to 2007 have enabled characterising not only the seabed morphology but also the subsurface structural elements of the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes (MVs) in the Gulf of Cádiz at 1,050-1,250 m water depth. These MVs vary strongly in morphology and size. The data reveal elongated cone-shaped edifices, rimmed depressions, and scarps interpreted as flank failures developed by collapse, faulting, compaction and gravitational processes. MV architecture is characterised by both extrusive and intrusive complexes, comprising stacked edifices (including seabed cones and up to four buried bicones) underlain by chaotic vertical zones and downward-tapering cones suggesting feeder systems. These intrusive structures represent the upper layer of the feeder system linking the fluid mud sources with the constructional edifices. The overall architecture is interpreted to be the result of successive events of mud extrusion and outbuilding alternating with periods of dormancy. Each mud extrusion phase is connected with the development of an edifice, represented by a seabed cone or a buried bicone. In all four MVs, the stacked edifices and the intrusive complexes penetrate Late Miocene-Quaternary units and are rooted in the Gulf of Cádiz wedge emplaced during the late Tortonian. Major phases of mud extrusion and outbuilding took place since the Late Pliocene, even though in the Yuma and Jesús Baraza MVs mud volcanism started in the Late Miocene shortly after the emplacement of the Gulf of Cádiz wedge. This study shows that fluid venting in the eastern sector of the Gulf of Cádiz promoted the outbuilding of large long-lived mud volcanoes active since the Late Miocene, and which have been reactivated repeatedly until recent times.

  18. Deep Structure of the Zone of Tolbachik Fissure Eruptions (Kamchatka, Klyuchevskoy Volcano Group): Evidence from a Complex of Geological and Geophysical Data

    Science.gov (United States)

    Kugaenko, Yu. A.; Saltykov, V. A.; Gorvatikov, A. V.; Stepanova, M. Yu.

    2018-05-01

    With the use of the method of low-frequency microseismic sounding, the configuration of the magmatic feeding system of the Tolbachinsky Dol—a regional zone of areal basaltic volcanism in the southern part of the Klyuchevskoy volcano group in Kamchatka—is studied. The initial data are obtained by a stepby-step recording of the background microseismic noise in 2010-2015 within a thoroughly marked-out survey area covering the zones of fissure eruptions in 1975-1976 and 2012-2013 and, partly, the edifice of the Ploskii (flat) Tolbachik volcano. The depth sections reflecting the distributions of the relative velocities of seismic waves in the Earth's crust are constructed. For a more reliable interpretation of the revealed deep anomalies, the results of independent geological and geophysical studies are used. The ascertained low-velocity structures are closely correlated to the manifestations of present-day volcanism. It is shown that the feeding structure of the Tolbachinsky Dol is spatially heterogeneous, incorporating subvertical and lateral pipeshaped magma conduits, closely spaced magma feeding channels, and shallow magma reservoirs. A longlived local transcrustal magma conducting zone is revealed, and regularities in the deep structure of the feeding systems of fissure eruptions are identified. The configuration of the established subvertical magma conduits permits basalts moving to rise to the surface by different paths, which, inter alia, explains the contrasting magma compositions observed during a single eruption. Thus, based on the instrumental data, it is shown that the magmatic feeding structure of the Tolbachinsky Dol has a number of specific peculiarities and is significantly more complicated than has been previously thought about the areal volcanic fields.

  19. Salt shell fallout during the ash eruption at the Nakadake crater, Aso volcano, Japan: evidence of an underground hydrothermal system surrounding the erupting vent

    Science.gov (United States)

    Shinohara, Hiroshi; Geshi, Nobuo; Yokoo, Akihiko; Ohkura, Takahiro; Terada, Akihiko

    2018-03-01

    A hot and acid crater lake is located in the Nakadake crater, Aso volcano, Japan. The volume of water in the lake decreases with increasing activity, drying out prior to the magmatic eruptions. Salt-rich materials of various shapes were observed, falling from the volcanic plume during the active periods. In May 2011, salt flakes fell from the gas plume emitted from an intense fumarole when the acid crater lake was almost dry. The chemical composition of these salt flakes was similar to those of the salts formed by the drying of the crater lake waters, suggesting that they originated from the crater lake water. The salt flakes are likely formed by the drying up of the crater lake water droplets sprayed into the plume by the fumarolic gas jet. In late 2014, the crater lake dried completely, followed by the magmatic eruptions with continuous ash eruptions and intermittent Strombolian explosions. Spherical hollow salt shells were observed on several occasions during and shortly after the weak ash eruptions. The chemical composition of the salt shells was similar to the salts formed by the drying of the crater lake water. The hollow structure of the shells suggests that they were formed by the heating of hydrothermal solution droplets suspended by a mixed stream of gas and ash in the plume. The salt shells suggest the existence of a hydrothermal system beneath the crater floor, even during the course of magmatic eruptions. Instability of the magmatic-hydrothermal interface can cause phreatomagmatic explosions, which often occur at the end of the eruptive phase of this volcano.

  20. Power in the pasture: Energy and the history of ranching in western South Dakota

    Science.gov (United States)

    Howe, Jenika

    Transitions in the use of energy transformed the landscape, labor, and domestic life of cattle ranching in western South Dakota from the late-nineteenth to the middle of the twentieth centuries. The introduction of new energy sources to the Black Hills spurred the expansion of European Americans into the region, while helping to displace native peoples like the Lakotas. Changing energy use also intensified ranch labor in the pastures and in the household, drawing individual ranches into new connections with their surroundings. Examining cattle ranching through the lens of energy provides new insights into the momentum of energetic systems in societies, affording historians a way to understand past energy use as they consider present and future environmental concerns.

  1. 2006 Southwest Florida Water Management District (SWFWMD) Lidar: Rutland Ranch District

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Light Detection and Ranging (LiDAR) LAS dataset is a survey of select areas within Rutland Ranch. This data falls in Manatee County. These data were produced for...

  2. A Critique of the Green Economy: Approach in the Wildlife Ranching ...

    African Journals Online (AJOL)

    AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... wildlife ranching in South Africa are socially constructed through language. Discourses of game farmers' identity and practice illustrate that they use language as a critical ...

  3. An investigation into beef calf mortality on five high-altitude ranches that selected sires with low pulmonary arterial pressures for over 20 years.

    Science.gov (United States)

    Neary, Joseph M; Gould, Daniel H; Garry, Franklyn B; Knight, Anthony P; Dargatz, David A; Holt, Timothy N

    2013-03-01

    Producer reports from ranches over 2,438 meters in southwest Colorado suggest that the mortality of preweaned beef calves may be substantially higher than the national average despite the selection of low pulmonary pressure herd sires for over 20 years. Diagnostic investigations of this death loss problem have been limited due to the extensive mountainous terrain over which these calves are grazed with their dams. The objective of the current study was to determine the causes of calf mortality on 5 high-altitude ranches in Colorado that have been selectively breeding sires with low pulmonary pressure (branding (6 weeks of age) in the spring to weaning in the fall (7 months of age). Clinical signs were recorded, and blood samples were taken from sick calves. Postmortem examinations were performed, and select tissue samples were submitted for aerobic culture and/or histopathology. On the principal study ranch, 9.6% (59/612) of the calves that were branded in the spring either died or were presumed dead by weaning in the fall. In total, 28 necropsies were performed: 14 calves (50%) had lesions consistent with pulmonary hypertension and right-sided heart failure, and 14 calves (50%) died from bronchopneumonia. Remodeling of the pulmonary arterial system, indicative of pulmonary hypertension, was evident in the former and to varying degrees in the latter. There is a need to better characterize the additional risk factors that complicate pulmonary arterial pressure testing of herd sires as a strategy to control pulmonary hypertension.

  4. Stakeholder Theory and Rangeland Management: The Importance of Ranch Income Dependence

    Science.gov (United States)

    Elias, S.; Roche, L. M.; Elias, E.

    2016-12-01

    The California drought beginning in 2012 has been driven by reduced precipitation and record high temperatures. Hydrologic drought in the Southwest United States is projected to become the new climatology of the region. While ranchers are considered naturally adaptive, often adeptly altering management based upon conditions, the projected increased aridity may challenge rangeland management. Certain rancher characteristics are likely to impact how well ranchers adapt. Based on Stakeholder Theory (ST), we hypothesize that the extent to which ranchers are dependent on their ranches as a source of income would serve as a predictor of several key variables related to ranching adaptation and success. Data were obtained from 507 ranchers throughout the State of California via the Rangeland Decision-Making Survey implemented by University of California, Davis in 2010, just prior to the unprecedented California drought. Consistent with the ST urgency facet, results of linear regression analyses indicate the more dependent ranchers are on their ranches for their income, the more aware they are of USDA ranching initiatives (β = 0.19, p < .001) and state ranching initiatives (β = 0.10, p < .05). In addition, more dependent ranchers are more likely to use multiple and diverse sources of information about ranching (β = 0.18, p < .001), are more likely to realize the severity and extent of the most recent drought's impacts (β = 0.18, p < .001), and were more likely to have a drought management plan in place during the most recent drought (β = 0.18, p < .001). These findings are important in relation to both outreach/extension efforts and rangeland research. Outreach/extension efforts should take into account that people less dependent on their ranches are less aware of resources, as well as, less prepared to adapt to drought. Researchers should control for the extent to which ranchers are dependent on their ranches for income in order to ensure more accurate findings.

  5. Cook Inlet and Kenai Peninsula, Alaska ESI: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the locations of volcanos in Cook Inlet and Kenai Peninsula, Alaska. Vector points in the data set represent the location of the volcanos....

  6. Crustal contamination and crystal entrapment during polybaric magma evolution at Mt. Somma-Vesuvius volcano, Italy: Geochemical and Sr isotope evidence

    Science.gov (United States)

    Piochi, M.; Ayuso, R.A.; de Vivo, B.; Somma, R.

    2006-01-01

    New major and trace element analyses and Sr-isotope determinations of rocks from Mt. Somma-Vesuvius volcano produced from 25 ky BP to 1944 AD are part of an extensive database documenting the geochemical evolution of this classic region. Volcanic rocks include silica undersaturated, potassic and ultrapotassic lavas and tephras characterized by variable mineralogy and different crystal abundance, as well as by wide ranges of trace element contents and a wide span of initial Sr-isotopic compositions. Both the degree of undersaturation in silica and the crystal content increase through time, being higher in rocks produced after the eruption at 472 AD (Pollena eruption). Compositional variations have been generally thought to reflect contributions from diverse types of mantle and crust. Magma mixing is commonly invoked as a fundamental process affecting the magmas, in addition to crystal fractionation. Our assessment of geochemical and Sr-isotopic data indicates that compositional variability also reflects the influence of crustal contamination during magma evolution during upward migration to shallow crustal levels and/or by entrapment of crystal mush generated during previous magma storage in the crust. Using a variant of the assimilation fractional crystallization model (Energy Conservation-Assimilation Fractional Crystallization; [Spera and Bohrson, 2001. Energy-constrained open-system magmatic processes I: General model and energy-constrained assimilation and fractional crystallization (EC-AFC) formulation. J. Petrol. 999-1018]; [Bohrson, W.A. and Spera, F.J., 2001. Energy-constrained open-system magmatic process II: application of energy-constrained assimilation-fractional crystallization (EC-AFC) model to magmatic systems. J. Petrol. 1019-1041]) we estimated the contributions from the crust and suggest that contamination by carbonate rocks that underlie the volcano (2 km down to 9-10 km) is a fundamental process controlling magma compositions at Mt. Somma

  7. Volatile-induced magma differentiation in the plumbing system of Mt. Etna volcano (Italy): evidence from glass in tephra of the 2001 eruption

    Science.gov (United States)

    Ferlito, Carmelo; Viccaro, Marco; Cristofolini, Renato

    2008-02-01

    Mount Etna volcano was shaken during the summer 2001 by one of the most singular eruptive episodes of the last centuries. For about 3 weeks, several eruptive fractures developed, emitting lava flows and tephra that significantly modified the landscape of the southern flank of the volcano. This event stimulated the attention of the scientific community especially for the simultaneous emission of petrologically distinct magmas, recognized as coming from different segments of the plumbing system. A stratigraphically controlled sampling of tephra layers was performed at the most active vents of the eruption, in particular at the 2,100 m (CAL) and at the 2,550 m (LAG) scoria cones. Detailed scanning electron microscope and energy dispersive x-ray spectrometer (SEM-EDS) analyses performed on glasses found in tephra and comparison with lava whole rock compositions indicate an anomalous increase in Ti, Fe, P, and particularly of K and Cl in the upper layers of the LAG sequence. Mass balance and thermodynamic calculations have shown that this enrichment cannot be accounted for by “classical” differentiation processes, such as crystal fractionation and magma mixing. The analysis of petrological features of the magmas involved in the event, integrated with the volcanological evolution, has evidenced the role played by volatiles in controlling the magmatic evolution within the crustal portion of the plumbing system. Volatiles, constituted of H2O, CO2, and Cl-complexes, originated from a deeply seated magma body (DBM). Their upward migration occurred through a fracture network possibly developed by the seismic swarms during the period preceding the event. In the upper portion of the plumbing system, a shallower residing magma body (ABT) had chemical and physical conditions to receive migrating volatiles, which hence dissolved the mobilized elements producing the observed selective enrichment. This volatile-induced differentiation involved exclusively the lowest erupted

  8. Global Volcano Model

    Science.gov (United States)

    Sparks, R. S. J.; Loughlin, S. C.; Cottrell, E.; Valentine, G.; Newhall, C.; Jolly, G.; Papale, P.; Takarada, S.; Crosweller, S.; Nayembil, M.; Arora, B.; Lowndes, J.; Connor, C.; Eichelberger, J.; Nadim, F.; Smolka, A.; Michel, G.; Muir-Wood, R.; Horwell, C.

    2012-04-01

    Over 600 million people live close enough to active volcanoes to be affected when they erupt. Volcanic eruptions cause loss of life, significant economic losses and severe disruption to people's lives, as highlighted by the recent eruption of Mount Merapi in Indonesia. The eruption of Eyjafjallajökull, Iceland in 2010 illustrated the potential of even small eruptions to have major impact on the modern world through disruption of complex critical infrastructure and business. The effects in the developing world on economic growth and development can be severe. There is evidence that large eruptions can cause a change in the earth's climate for several years afterwards. Aside from meteor impact and possibly an extreme solar event, very large magnitude explosive volcanic eruptions may be the only natural hazard that could cause a global catastrophe. GVM is a growing international collaboration that aims to create a sustainable, accessible information platform on volcanic hazard and risk. We are designing and developing an integrated database system of volcanic hazards, vulnerability and exposure with internationally agreed metadata standards. GVM will establish methodologies for analysis of the data (eg vulnerability indices) to inform risk assessment, develop complementary hazards models and create relevant hazards and risk assessment tools. GVM will develop the capability to anticipate future volcanism and its consequences. NERC is funding the start-up of this initiative for three years from November 2011. GVM builds directly on the VOGRIPA project started as part of the GRIP (Global Risk Identification Programme) in 2004 under the auspices of the World Bank and UN. Major international initiatives and partners such as the Smithsonian Institution - Global Volcanism Program, State University of New York at Buffalo - VHub, Earth Observatory of Singapore - WOVOdat and many others underpin GVM.

  9. Volcanoes: Coming Up from Under.

    Science.gov (United States)

    Science and Children, 1980

    1980-01-01

    Provides specific information about the eruption of Mt. St. Helens in March 1980. Also discusses how volcanoes are formed and how they are monitored. Words associated with volcanoes are listed and defined. (CS)

  10. Sem Analysis of particles from the 28, 000 B.P El Zaguan debris avalanche deposit, Nevado de Toluca volcano, Central Mexico: evidences of flow behavior during emplacement

    Science.gov (United States)

    Caballero, L.; Capra, L.

    2008-12-01

    The Zaguan deposit originated at 28, 000 yr. B.P from the flank collapse of the Nevado de Toluca volcano, a dacitic stratovolcano of the Transmexican Volcanic Belt. A Scanning Electron Microprobe analysis (SEM) was made to some clasts of this deposit to observe microtextures produced during transport and emplacement of the debris avalanche flow. Particles from 2, 0 and -2 Φ granulometric classes were randomly selected and their surface textures were described. The textures observed were divided in two groups, collision and shear structures indicating different clast interaction. Shear textures were observed predominantly on the basal part of the deposit and consisted of parallel ridges, parallel grooves, scratches and lips. Collision textures were mainly present in the upper part of the deposit and consisted of fractures, percussion marks, and broken or grinded crystals. These characteristics, coupled with field observation, like the presence of clast dikes and deformed lacustrine megaclasts, indicate that the basal part of the debris avalanche was moving in a partially liquefied state, were particles were not able to move freely because of the confinement exerted by the upper part of the flow, so shear stresses dominated. On the contrary, the particles in the upper part were able to move freely so the principal mechanism of interaction between particles was collision. These microscopic textures are in agreement with previously described behavior of emplacement of debris avalanches of volcanic origin, that suggest a stratified flow dominated by different transport and depositional mechanism depending on flow depth and possible fluid content at their base.

  11. Organizational changes at Earthquakes & Volcanoes

    Science.gov (United States)

    Gordon, David W.

    1992-01-01

    Primary responsibility for the preparation of Earthquakes & Volcanoes within the Geological Survey has shifted from the Office of Scientific Publications to the Office of Earthquakes, Volcanoes, and Engineering (OEVE). As a consequence of this reorganization, Henry Spall has stepepd down as Science Editor for Earthquakes & Volcanoes(E&V).

  12. Hawaii's volcanoes revealed

    Science.gov (United States)

    Eakins, Barry W.; Robinson, Joel E.; Kanamatsu, Toshiya; Naka, Jiro; Smith, John R.; Takahashi, Eiichi; Clague, David A.

    2003-01-01

    Hawaiian volcanoes typically evolve in four stages as volcanism waxes and wanes: (1) early alkalic, when volcanism originates on the deep sea floor; (2) shield, when roughly 95 percent of a volcano's volume is emplaced; (3) post-shield alkalic, when small-volume eruptions build scattered cones that thinly cap the shield-stage lavas; and (4) rejuvenated, when lavas of distinct chemistry erupt following a lengthy period of erosion and volcanic quiescence. During the early alkalic and shield stages, two or more elongate rift zones may develop as flanks of the volcano separate. Mantle-derived magma rises through a vertical conduit and is temporarily stored in a shallow summit reservoir from which magma may erupt within the summit region or be injected laterally into the rift zones. The ongoing activity at Kilauea's Pu?u ?O?o cone that began in January 1983 is one such rift-zone eruption. The rift zones commonly extend deep underwater, producing submarine eruptions of bulbous pillow lava. Once a volcano has grown above sea level, subaerial eruptions produce lava flows of jagged, clinkery ?a?a or smooth, ropy pahoehoe. If the flows reach the ocean they are rapidly quenched by seawater and shatter, producing a steep blanket of unstable volcanic sediment that mantles the upper submarine slopes. Above sea level then, the volcanoes develop the classic shield profile of gentle lava-flow slopes, whereas below sea level slopes are substantially steeper. While the volcanoes grow rapidly during the shield stage, they may also collapse catastrophically, generating giant landslides and tsunami, or fail more gradually, forming slumps. Deformation and seismicity along Kilauea's south flank indicate that slumping is occurring there today. Loading of the underlying Pacific Plate by the growing volcanic edifices causes subsidence, forming deep basins at the base of the volcanoes. Once volcanism wanes and lava flows no longer reach the ocean, the volcano continues to submerge, while

  13. Micro-textures in plagioclase from 1994–1995 eruption, Barren Island Volcano: Evidence of dynamic magma plumbing system in the Andaman subduction zone

    Directory of Open Access Journals (Sweden)

    M.L. Renjith

    2014-01-01

    Full Text Available A systematic account of micro-textures and a few compositional profiles of plagioclase from high-alumina basaltic aa lava erupted during the year 1994–1995, from Barren Island Volcano, NE India ocean, are presented for the first time. The identified micro-textures can be grouped into two categories: (i Growth related textures in the form of coarse/fine-sieve morphology, fine-scale oscillatory zoning and resorption surfaces resulted when the equilibrium at the crystal-melt interface was fluctuated due to change in temperature or H2O or pressure or composition of the crystallizing melt; and (ii morphological texture, like glomerocryst, synneusis, swallow-tailed crystal, microlite and broken crystals, formed by the influence of dynamic behavior of the crystallizing magma (convection, turbulence, degassing, etc.. Each micro-texture has developed in a specific magmatic environment, accordingly, a first order magma plumbing model and crystallization dynamics are envisaged for the studied lava unit. Magma generated has undergone extensive fractional crystallization of An-rich plagioclase in stable magmatic environment at a deeper depth. Subsequently they ascend to a shallow chamber where the newly brought crystals and pre-existing crystals have undergone dynamic crystallization via dissolution-regrowth processes in a convective self-mixing environment. Such repeated recharge-recycling processes have produced various populations of plagioclase with different micro-textural stratigraphy in the studied lava unit. Intermittent degassing and eruption related decompression have also played a major role in the final stage of crystallization dynamics.

  14. Acoustic Conditioning System Development and Conditioning Experiments on Black Seabreams in the Xiangshan Bay Sea Ranch

    Science.gov (United States)

    Hu, Qingsong; Rahman, Hafiz Abd ur; Jiang, Yazhou; Zhang, Shouyu; Shentu, Jikang

    2018-06-01

    Attracting released hatchery-reared fish to designated areas during the growth process is vital to realize the objectives of sea ranching. Based on the bottom artificial reefs and surface kelp culture facilities in the Xiangshan Bay sea ranch, we proposed systematic techniques related to acoustic conditioning of the black seabream ( Sparus macrocephalus). Experiments conducted in 12 m × 10 m × 1.6 m ponds on Xixuan Island showed that black seabream was positively sensitive to 500-600 Hz periodic signals. Conditioned responses were apparent after 8 d. Two to three days were required for recovery of the memory of a conditioned response after a 20-day interval. According to the practical application requirements in the open sea, unattended acoustic conditioning equipment was developed. The ranching equipment was used in 12 m × 12 m × 2.5 m cages, and the behavior of black seabream juveniles was successfully guided after 7 days. Of the 16000 released fish, 82.5% of them were conditioned with a flexible grading net. To avoid inducing a stress response, the juveniles were released into the sea ranch in situ from the net cage. The acoustic conditioning equipments were moved into the open sea and the aggregation phenomenon of the released fish was observed when the sound was played. After 6 months of investigation and based on Sr+ marking, only one acoustically conditioned fish was found outside the 3.5-km2 sea ranch area, thereby reached the goal of guiding activity. The practical effect in the Xiangshan Bay sea ranch showed the validity of the acoustic conditioning system, which may contribute to improve the operation of the sea ranches in the East China Sea.

  15. Estimates of elastic plate thicknesses beneath large volcanos on Venus

    Science.gov (United States)

    Mcgovern, Patrick J.; Solomon, Sean C.

    1992-01-01

    Megellan radar imaging and topography data are now available for a number of volcanos on Venus greater than 100 km in radius. These data can be examined to reveal evidence of the flexural response of the lithosphere to the volcanic load. On Earth, flexure beneath large hotspot volcanos results in an annual topographic moat that is partially to completely filled in by sedimentation and mass wasting from the volcano's flanks. On Venus, erosion and sediment deposition are considered to be negligible at the resolution of Magellan images. Thus, it may be possible to observe evidence of flexure by the ponding of recent volcanic flows in the moat. We also might expect to find topographic signals from unfilled moats surrounding large volcanos on Venus, although these signals may be partially obscured by regional topography. Also, in the absence of sedimentation, tectonic evidence of deformation around large volcanos should be evident except where buried by very young flows. We use analytic solutions in axisymmetric geometry for deflections and stresses resulting from loading of a plate overlying an inviscid fluid. Solutions for a set of disk loads are superimposed to obtain a solution for a conical volcano. The deflection of the lithosphere produces an annular depression or moat, the extent of which can be estimated by measuring the distance from the volcano's edge to the first zero crossing or to the peak of the flexural arch. Magellan altimetry data records (ARCDRs) from data cycle 1 are processed using the GMT mapping and graphics software to produce topographic contour maps of the volcanos. We then take topographic profiles that cut across the annular and ponded flows seen on the radar images. By comparing the locations of these flows to the predicted moat locations from a range of models, we estimate the elastic plate thickness that best fits the observations, together with the uncertainty in that estimate.

  16. Anatomy of a volcano

    NARCIS (Netherlands)

    Hooper, A.; Wassink, J.

    2011-01-01

    The Icelandic volcano Eyjafjallajökull caused major disruption in European airspace last year. According to his co-author, Freysteinn Sigmundsson, the reconstruction published in Nature six months later by aerospace engineering researcher, Dr Andy Hooper, opens up a new direction in volcanology. “We

  17. Spying on volcanoes

    Science.gov (United States)

    Watson, Matthew

    2017-07-01

    Active volcanoes can be incredibly dangerous, especially to those who live nearby, but how do you get close enough to observe one in action? Matthew Watson explains how artificial drones are providing volcanologists with insights that could one day save human lives

  18. Geology of kilauea volcano

    Science.gov (United States)

    Moore, R.B.; Trusdell, F.A.

    1993-01-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower cast rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. ?? 1993.

  19. Geodetic evidence for en echelon dike emplacement and concurrent slow slip during the June 2007 intrusion and eruption at Kīlauea volcano, Hawaii

    Science.gov (United States)

    Montgomery-Brown, E. K.; Sinnett, D.K.; Poland, M.; Segall, P.; Orr, T.; Zebker, H.; Miklius, Asta

    2010-01-01

    A series of complex events at Kīlauea Volcano, Hawaii, 17 June to 19 June 2007, began with an intrusion in the upper east rift zone (ERZ) and culminated with a small eruption (1500 m3). Surface deformation due to the intrusion was recorded in unprecedented detail by Global Positioning System (GPS) and tilt networks as well as interferometric synthetic aperture radar (InSAR) data acquired by the ENVISAT and ALOS satellites. A joint nonlinear inversion of GPS, tilt, and InSAR data yields a deflationary source beneath the summit caldera and an ENE-striking uniform-opening dislocation with ~2 m opening, a dip of ∼80° to the south, and extending from the surface to ~2 km depth. This simple model reasonably fits the overall pattern of deformation but significantly misfits data near the western end of an inferred dike-like source. Three more complex dike models are tested that allow for distributed opening including (1) a dike that follows the surface trace of the active rift zone, (2) a dike that follows the symmetry axis of InSAR deformation, and (3) two en echelon dike segments beneath mapped surface cracks and newly formed steaming areas. The en echelon dike model best fits near-field GPS and tilt data. Maximum opening of 2.4 m occurred on the eastern segment beneath the eruptive vent. Although this model represents the best fit to the ERZ data, it still fails to explain data from a coastal tiltmeter and GPS sites on Kīlauea's southwestern flank. The southwest flank GPS sites and the coastal tiltmeter exhibit deformation consistent with observations of previous slow slip events beneath Kīlauea's south flank, but inconsistent with observations of previous intrusions. Slow slip events at Kīlauea and elsewhere are thought to occur in a transition zone between locked and stably sliding zones of a fault. An inversion including slip on a basal decollement improves fit to these data and suggests a maximum of ~15 cm of seaward fault motion, comparable to previous slow

  20. Agua Caliente Wind/Solar Project at Whitewater Ranch

    Energy Technology Data Exchange (ETDEWEB)

    Hooks, Todd [Agua Caliente Band of Cahuilla Indians, Palm Springs, CA (United States); Stewart, Royce [Red Mountain Energy Partners, Sante Fe, NM (United States)

    2014-12-16

    Agua Caliente Band of Cahuilla Indians (ACBCI) was awarded a grant by the Department of Energy (DOE) to study the feasibility of a wind and/or solar renewable energy project at the Whitewater Ranch (WWR) property of ACBCI. Red Mountain Energy Partners (RMEP) was engaged to conduct the study. The ACBCI tribal lands in the Coachella Valley have very rich renewable energy resources. The tribe has undertaken several studies to more fully understand the options available to them if they were to move forward with one or more renewable energy projects. With respect to the resources, the WWR property clearly has excellent wind and solar resources. The DOE National Renewable Energy Laboratory (NREL) has continued to upgrade and refine their library of resource maps. The newer, more precise maps quantify the resources as among the best in the world. The wind and solar technology available for deployment is also being improved. Both are reducing their costs to the point of being at or below the costs of fossil fuels. Technologies for energy storage and microgrids are also improving quickly and present additional ways to increase the wind and/or solar energy retained for later use with the network management flexibility to provide power to the appropriate locations when needed. As a result, renewable resources continue to gain more market share. The transitioning to renewables as the major resources for power will take some time as the conversion is complex and can have negative impacts if not managed well. While the economics for wind and solar systems continue to improve, the robustness of the WWR site was validated by the repeated queries of developers to place wind and/or solar there. The robust resources and improving technologies portends toward WWR land as a renewable energy site. The business case, however, is not so clear, especially when the potential investment portfolio for ACBCI has several very beneficial and profitable alternatives.

  1. 77 FR 70428 - Bar None Ranch LLC; Notice of Declaration of Intention and Soliciting Comments, Protests, and/or...

    Science.gov (United States)

    2012-11-26

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. DI13-2-000] Bar None Ranch LLC; Notice of Declaration of Intention and Soliciting Comments, Protests, and/or Motions To Intervene...: November 2, 2012. d. Applicant: Bar None Ranch LLC. e. Name of Project: Snodgrass Springs Micro Hydro...

  2. 77 FR 60981 - TGP Granada, LLC and Roosevelt Wind Ranch, LLC v. Public Service Company of New Mexico, Tortoise...

    Science.gov (United States)

    2012-10-05

    ...; EL12-43-000, EL12-43-001 TGP Granada, LLC and Roosevelt Wind Ranch, LLC v. Public Service Company of New Mexico, Tortoise Capital Resources Corp.; TGP Granada, LLC and Roosevelt Wind Ranch, LLC; Notice... over capacity on the Eastern Interconnection Project. \\1\\ TGP Granada, LLC v. Pub. Serv. Co. of New...

  3. 76 FR 45602 - Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis...

    Science.gov (United States)

    2011-07-29

    ... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R8-ES-2011-N144; 81440-1113-0000-F3] Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis Obispo... Ranch in San Luis Obispo County, California. Within the 620 acres of land comprising the Enrolled...

  4. The South African wildlife ranching sector: A Social Accounting Matrix Leontief multiplier analysis

    Directory of Open Access Journals (Sweden)

    Philippus C. Cloete

    2014-10-01

    Research purpose: The purpose of this article is to put into context the relative economic contribution of the wildlife ranching sector, as opposed to other land-use options in South Africa. Motivation for the study: Growth in the wildlife ranching sector at the cost of other traditional farming practices resulted in disagreements amongst various role players about the impact thereof on the national economy. The controversy can most probably be explained by different beliefs, coupled with the lack of a proper understanding and quantification of the wildlife ranching sector’s contribution toward the economy. Research methodology: The study employed a Social Accounting Matrix-based Leontief multiplier analysis for South Africa. Main findings: Results from the multiplier analysis revealed that developments within the wildlife ranching sector are likely to make a relatively more superior contribution towards the economy, especially when compared to similar land-use options such as extensive livestock production. Practical/managerial implications: It has been acknowledged by both academia and private sector that a major need exists for more research on the South African wildlife ranching industry, specifically looking at issues such as the industries, economic and social contributions, potentials and constraints. The research, therefore, contributes toward the depth of economic information and research regarding the South African wildlife sector. Contribution/value added: The research provides valuable information in dealing with the ‘popular belief’, especially amongst some of South Africa’s decision makers, namely, that growth in the wildlife ranching sector is not or does not have the ability to contribute significantly toward economic and socioeconomic factors.

  5. Geology of Kilauea volcano

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.B. (Geological Survey, Denver, CO (United States). Federal Center); Trusdell, F.A. (Geological Survey, Hawaii National Park, HI (United States). Hawaiian Volcano Observatory)

    1993-08-01

    This paper summarizes studies of the structure, stratigraphy, petrology, drill holes, eruption frequency, and volcanic and seismic hazards of Kilauea volcano. All the volcano is discussed, but the focus is on its lower east rift zone (LERZ) because active exploration for geothermal energy is concentrated in that area. Kilauea probably has several separate hydrothermal-convection systems that develop in response to the dynamic behavior of the volcano and the influx of abundant meteoric water. Important features of some of these hydrothermal-convection systems are known through studies of surface geology and drill holes. Observations of eruptions during the past two centuries, detailed geologic mapping, radiocarbon dating, and paleomagnetic secular-variation studies indicate that Kilauea has erupted frequently from its summit and two radial rift zones during Quaternary time. Petrologic studies have established that Kilauea erupts only tholeiitic basalt. Extensive ash deposits at Kilauea's summit and on its LERZ record locally violent, but temporary, disruptions of local hydrothermal-convection systems during the interaction of water or steam with magma. Recent drill holes on the LERZ provide data on the temperatures of the hydrothermal-convection systems, intensity of dike intrusion, porosity and permeability, and an increasing amount of hydrothermal alteration with depth. The prehistoric and historic record of volcanic and seismic activity indicates that magma will continue to be supplied to deep and shallow reservoirs beneath Kilauea's summit and rift zones and that the volcano will be affected by eruptions and earthquakes for many thousands of years. 71 refs., 2 figs.

  6. Catalogue of Icelandic Volcanoes

    Science.gov (United States)

    Ilyinskaya, Evgenia; Larsen, Gudrún; Gudmundsson, Magnús T.; Vogfjörd, Kristin; Jonsson, Trausti; Oddsson, Björn; Reynisson, Vidir; Pagneux, Emmanuel; Barsotti, Sara; Karlsdóttir, Sigrún; Bergsveinsson, Sölvi; Oddsdóttir, Thorarna

    2017-04-01

    The Catalogue of Icelandic Volcanoes (CIV) is a newly developed open-access web resource (http://icelandicvolcanoes.is) intended to serve as an official source of information about volcanoes in Iceland for the public and decision makers. CIV contains text and graphic information on all 32 active volcanic systems in Iceland, as well as real-time data from monitoring systems in a format that enables non-specialists to understand the volcanic activity status. The CIV data portal contains scientific data on all eruptions since Eyjafjallajökull 2010 and is an unprecedented endeavour in making volcanological data open and easy to access. CIV forms a part of an integrated volcanic risk assessment project in Iceland GOSVÁ (commenced in 2012), as well as being part of the European Union funded effort FUTUREVOLC (2012-2016) on establishing an Icelandic volcano supersite. The supersite concept implies integration of space and ground based observations for improved monitoring and evaluation of volcanic hazards, and open data policy. This work is a collaboration of the Icelandic Meteorological Office, the Institute of Earth Sciences at the University of Iceland, and the Civil Protection Department of the National Commissioner of the Iceland Police, with contributions from a large number of specialists in Iceland and elsewhere.

  7. Bird list of San Bernardino Ranch in Agua Prieta, Sonora, Mexico

    Science.gov (United States)

    Melinda Cardenas-Garcia; Monica C. Olguin-Villa

    2013-01-01

    Interest and investigation of birds has been increasing over the last decades due to the loss of their habitats, and declination and fragmentation of their populations. San Bernardino Ranch is located in the desert grassland region of northeastern Sonora, México. Over the last decade, restoration efforts have tried to address the effects of long deteriorating economic...

  8. Introduction to in situ leaching technique and facility at Smith Ranch uranium project in USA

    International Nuclear Information System (INIS)

    Xu Lechang; Wang Delin; Sun Xianrong; Gao Shangxiong

    2005-01-01

    The history of in situ leaching of uranium in USA is reviewed. Some techniques and parameters of alkaline in situ leach at Smith Ranch uranium project are introduced, including well field, sorption, elution, precipitation, filter and drying, automatic control, radiation protection, safety and environmental protection. (authors)

  9. Farm Management Basic Core Curriculum. Kansas Postsecondary Farm and Ranch Management Project.

    Science.gov (United States)

    Albracht, James, Ed.

    Thirty-five units of instruction are included in this core curriculum in farm management for postsecondary farm and ranch management programs. Units of instruction are divided into 12 instructional areas: (1) Introduction to Financial Management, (2) Farm Business Arrangement, (3) Credit Management, (4) Budgeting, (5) Recordkeeping, (6) Record…

  10. Habitat characteristic of two selected locations for sea cucumber ranching purposes

    Science.gov (United States)

    Hartati, Retno; Trianto, Agus; Widianingsih

    2017-02-01

    Sea cucumbers face heavily overfished because of their high prices and very strong market demand. One effort suggested to overcome this problem is sea ranching. The objectives of present works were to determine biological, physical, and chemical characteristics of prospective location for sea ranching of sea cucumber Holothuria atra. Two location at Jepara Waters (Teluk Awur and Bandengan WateRs of Jepara Regency) were selected. The determination of chemical (salinity, temperature, dissolved oxygen of water, phosphate, nitrate, nitrite and ammonium of water and sediment, organic matters of sediment), physical (transparancy, sedimen grains size, water current direction and its velocity), biologycal characteristic (coverage of seagrass and its macroalgae associated, phytoplankton as well as chlorophyl-a and phaeopytin of water and sediment) ware determined. The result of present work showed that some characteristic were matched with requirement as sea ranching location of sea cucumber because the density of sea cucumber in the sea is a function of habitat features. For sediment feeding holothurians of the family Aspidochirotida, the biologycal characteristic act as very important considerations by providing sea cucumber food. High cholophyl-a and phaeopytin in sediment also represent a prosperous habitat for sea cucumber ranching.

  11. Shortleaf pine natural community restoration on Peck Ranch Conservation Area in the Missouri Ozarks

    Science.gov (United States)

    John G. Tuttle; Kim J. Houf

    2007-01-01

    Oak decline has become a significantly increasing problem on Peck Ranch Conservation Area over the last several years. Most of the oak decline problems exist on past shortleaf pine sites. To address this issue, the area managers wrote a natural community restoration plan for 2,233 acres located on the Current-Eleven Point Oak-Pine Woodland Dissected Plain land type...

  12. Coiled-tubing fracturing of coal seams on the Vermejo Park Ranch

    Energy Technology Data Exchange (ETDEWEB)

    Bybee, K.

    2003-06-01

    Coiled-tubing (CT) fracturing currently is used to stimulate the Vermejo and Raton coal seams on the Vermejo Park Ranch in northern New Mexico. The CT fracturing process increased the number of stimulation stages from 4 to 18 per well. CT fracturing results in more accurate proppant placement and more effective stimulation of the producing zones.

  13. Ruiz Volcano: Preliminary report

    Science.gov (United States)

    Ruiz Volcano, Colombia (4.88°N, 75.32°W). All times are local (= GMT -5 hours).An explosive eruption on November 13, 1985, melted ice and snow in the summit area, generating lahars that flowed tens of kilometers down flank river valleys, killing more than 20,000 people. This is history's fourth largest single-eruption death toll, behind only Tambora in 1815 (92,000), Krakatau in 1883 (36,000), and Mount Pelée in May 1902 (28,000). The following briefly summarizes the very preliminary and inevitably conflicting information that had been received by press time.

  14. Continuous monitoring of volcanoes with borehole strainmeters

    Science.gov (United States)

    Linde, Alan T.; Sacks, Selwyn

    Monitoring of volcanoes using various physical techniques has the potential to provide important information about the shape, size and location of the underlying magma bodies. Volcanoes erupt when the pressure in a magma chamber some kilometers below the surface overcomes the strength of the intervening rock, resulting in detectable deformations of the surrounding crust. Seismic activity may accompany and precede eruptions and, from the patterns of earthquake locations, inferences may be made about the location of magma and its movement. Ground deformation near volcanoes provides more direct evidence on these, but continuous monitoring of such deformation is necessary for all the important aspects of an eruption to be recorded. Sacks-Evertson borehole strainmeters have recorded strain changes associated with eruptions of Hekla, Iceland and Izu-Oshima, Japan. Those data have made possible well-constrained models of the geometry of the magma reservoirs and of the changes in their geometry during the eruption. The Hekla eruption produced clear changes in strain at the nearest instrument (15 km from the volcano) starting about 30 minutes before the surface breakout. The borehole instrument on Oshima showed an unequivocal increase in the amplitude of the solid earth tides beginning some years before the eruption. Deformational changes, detected by a borehole strainmeter and a very long baseline tiltmeter, and corresponding to the remote triggered seismicity at Long Valley, California in the several days immediately following the Landers earthquake are indicative of pressure changes in the magma body under Long Valley, raising the question of whether such transients are of more general importance in the eruption process. We extrapolate the experience with borehole strainmeters to estimate what could be learned from an installation of a small network of such instruments on Mauna Loa. Since the process of conduit formation from the magma sources in Mauna Loa and other

  15. Decision Analysis Tools for Volcano Observatories

    Science.gov (United States)

    Hincks, T. H.; Aspinall, W.; Woo, G.

    2005-12-01

    Staff at volcano observatories are predominantly engaged in scientific activities related to volcano monitoring and instrumentation, data acquisition and analysis. Accordingly, the academic education and professional training of observatory staff tend to focus on these scientific functions. From time to time, however, staff may be called upon to provide decision support to government officials responsible for civil protection. Recognizing that Earth scientists may have limited technical familiarity with formal decision analysis methods, specialist software tools that assist decision support in a crisis should be welcome. A review is given of two software tools that have been under development recently. The first is for probabilistic risk assessment of human and economic loss from volcanic eruptions, and is of practical use in short and medium-term risk-informed planning of exclusion zones, post-disaster response, etc. A multiple branch event-tree architecture for the software, together with a formalism for ascribing probabilities to branches, have been developed within the context of the European Community EXPLORIS project. The second software tool utilizes the principles of the Bayesian Belief Network (BBN) for evidence-based assessment of volcanic state and probabilistic threat evaluation. This is of practical application in short-term volcano hazard forecasting and real-time crisis management, including the difficult challenge of deciding when an eruption is over. An open-source BBN library is the software foundation for this tool, which is capable of combining synoptically different strands of observational data from diverse monitoring sources. A conceptual vision is presented of the practical deployment of these decision analysis tools in a future volcano observatory environment. Summary retrospective analyses are given of previous volcanic crises to illustrate the hazard and risk insights gained from use of these tools.

  16. Eruptive viscosity and volcano morphology

    International Nuclear Information System (INIS)

    Posin, S.B.; Greeley, R.

    1988-01-01

    Terrestrial central volcanoes formed predominantly from lava flows were classified as shields, stratovolcanoes, and domes. Shield volcanoes tend to be large in areal extent, have convex slopes, and are characterized by their resemblance to inverted hellenic war shields. Stratovolcanoes have concave slopes, whereas domes are smaller and have gentle convex slopes near the vent that increase near the perimeter. In addition to these differences in morphology, several other variations were observed. The most important is composition: shield volcanoes tend to be basaltic, stratovolcanoes tend to be andesitic, and domes tend to be dacitic. However, important exceptions include Fuji, Pico, Mayon, Izalco, and Fuego which have stratovolcano morphologies but are composed of basaltic lavas. Similarly, Ribkwo is a Kenyan shield volcano composed of trachyte and Suswa and Kilombe are shields composed of phonolite. These exceptions indicate that eruptive conditions, rather than composition, may be the primary factors that determine volcano morphology. The objective of this study is to determine the relationships, if any, between eruptive conditions (viscosity, erupted volume, and effusion rate) and effusive volcano morphology. Moreover, it is the goal of this study to incorporate these relationships into a model to predict the eruptive conditions of extraterrestrial (Martian) volcanoes based on their morphology

  17. Biomarker and 16S rDNA evidence for anaerobic oxidation of methane and related carbonate precipitation in deep-sea mud volcanoes of the Sorokin Trough, Black Sea

    NARCIS (Netherlands)

    Stadnitskaia, A.; Muyzer, G.; Abbas, B.; Coolen, M.J.L.; Hopmans, E.C.; Baas, M.; Weering, T.C.E. van; Ivanov, M.K.; Poludetkina, E.; Sinninghe Damsté, J.S.

    2005-01-01

    Many mud volcanoes were recently discovered in the euxinic bottom waters of the Sorokin Trough (NE Black Sea). Three of them, i.e., NIOZ, Odessa, and Kazakov, were selected for a detailed biogeochemical investigation. Four methane-related carbonate crusts covered with microbial mats, and sediments

  18. Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    Founded in 1912 at the edge of the caldera of Kīlauea Volcano, HVO was the vision of Thomas A. Jaggar, Jr., a geologist from the Massachusetts Institute of Technology, whose studies of natural disasters around the world had convinced him that systematic, continuous observations of seismic and volcanic activity were needed to better understand—and potentially predict—earthquakes and volcanic eruptions. Jaggar summarized the aim of HVO by stating that “the work should be humanitarian” and have the goals of developing “prediction and methods of protecting life and property on the basis of sound scientific achievement.” These goals align well with those of the USGS, whose mission is to serve the Nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage natural resources; and enhance and protect our quality of life.

  19. Volcanoes, Third Edition

    Science.gov (United States)

    Nye, Christopher J.

    It takes confidence to title a smallish book merely “Volcanoes” because of the impliction that the myriad facets of volcanism—chemistry, physics, geology, meteorology, hazard mitigation, and more—have been identified and addressed to some nontrivial level of detail. Robert and Barbara Decker have visited these different facets seamlessly in Volcanoes, Third Edition. The seamlessness comes from a broad overarching, interdisciplinary, professional understanding of volcanism combined with an exceptionally smooth translation of scientific jargon into plain language.The result is a book which will be informative to a very broad audience, from reasonably educated nongeologists (my mother loves it) to geology undergraduates through professional volcanologists. I bet that even the most senior professional volcanologists will learn at least a few things from this book and will find at least a few provocative discussions of subjects they know.

  20. Final environmental statement related to the United Nuclear Corporation, Morton Ranch, Wyoming Uranium Mill (Converse County, Wyoming)

    Energy Technology Data Exchange (ETDEWEB)

    1979-02-01

    Impacts from Morton Ranch Uranium Mill will result in: alterations of up to 270 acres occupied by the mill facilities; increase in the existing background radiation levels; socioeconomic effects on Glenrock and Douglas, Wyoming. Solid waste material (tailings solids) from the mill will be deposited onsite in exhausted surface mine pits. Any license issued for the Morton Ranch mill will be subject to conditions for the protection of the environment.

  1. Improving water quality for human and livestock consumption on cattle ranches in Lincoln and Socorro Counties New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Teich-McGoldrick, Stephanie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ilgen, Anastasia Gennadyevna [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dwyer, Brian P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rigali, Mark J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stewart, Thomas Austin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-12-01

    This report summarizes the assistance provided to Shafer Ranches, Inc., Hightower Ranch, and Western Environmental by Sandia National Laboratories under a Leveraged New Mexico Small Business Assistance grant. The work was conducted between April to November, 2014. Therefore, Sandia National Laboratories has been asked to investigate and develop a water treatment system that would result in reduced cost associated with infrastructure, maintenance, elimination of importing water, and improved cattle health.

  2. Final environmental statement related to the United Nuclear Corporation, Morton Ranch, Wyoming Uranium Mill (Converse County, Wyoming)

    International Nuclear Information System (INIS)

    1979-02-01

    Impacts from Morton Ranch Uranium Mill will result in: alterations of up to 270 acres occupied by the mill facilities; increase in the existing background radiation levels; socioeconomic effects on Glenrock and Douglas, Wyoming. Solid waste material (tailings solids) from the mill will be deposited onsite in exhausted surface mine pits. Any license issued for the Morton Ranch mill will be subject to conditions for the protection of the environment

  3. Volcanoes in Eruption - Set 1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain...

  4. Volcanoes in Eruption - Set 2

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The word volcano is used to refer to the opening from which molten rock and gas issue from Earth's interior onto the surface, and also to the cone, hill, or mountain...

  5. Volcano warning systems: Chapter 67

    Science.gov (United States)

    Gregg, Chris E.; Houghton, Bruce F.; Ewert, John W.

    2015-01-01

    Messages conveying volcano alert level such as Watches and Warnings are designed to provide people with risk information before, during, and after eruptions. Information is communicated to people from volcano observatories and emergency management agencies and from informal sources and social and environmental cues. Any individual or agency can be both a message sender and a recipient and multiple messages received from multiple sources is the norm in a volcanic crisis. Significant challenges to developing effective warning systems for volcanic hazards stem from the great diversity in unrest, eruption, and post-eruption processes and the rapidly advancing digital technologies that people use to seek real-time risk information. Challenges also involve the need to invest resources before unrest to help people develop shared mental models of important risk factors. Two populations of people are the target of volcano notifications–ground- and aviation-based populations, and volcano warning systems must address both distinctly different populations.

  6. Volcano-tectonic interactions at Sabancaya and other Peruvian volcanoes revealed by InSAR and seismicity

    Science.gov (United States)

    Jay, J.; Pritchard, M. E.; Aron, F.; Delgado, F.; Macedo, O.; Aguilar, V.

    2013-12-01

    An InSAR survey of all 13 Holocene volcanoes in the Andean Central Volcanic Zone of Peru reveals previously undocumented surface deformation that is occasionally accompanied by seismic activity. Our survey utilizes SAR data spanning from 1992 to the present from the ERS-1, ERS-2, and Envisat satellites, as well as selected data from the TerraSAR-X satellite. We find that the recent unrest at Sabancaya volcano (heightened seismicity since 22 February 2013 and increased fumarolic output) has been accompanied by surface deformation. We also find two distinct deformation episodes near Sabancaya that are likely associated with an earthquake swarm in February 2013 and a M6 normal fault earthquake that occurred on 17 July 2013. Preliminary modeling suggests that faulting from the observed seismic moment can account for nearly all of the observed deformation and thus we have not yet found clear evidence for recent magma intrusion. We also document an earlier episode of deformation that occurred between December 2002 and September 2003 which may be associated with a M5.3 earthquake that occurred on 13 December 2002 on the Solarpampa fault, a large EW-striking normal fault located about 25 km northwest of Sabancaya volcano. All of the deformation episodes between 2002 and 2013 are spatially distinct from the inflation seen near Sabancaya from 1992 to 1997. In addition to the activity at Sabancaya, we also observe deformation near Coropuna volcano, in the Andagua Valley, and in the region between Ticsani and Tutupaca volcanoes. InSAR images reveal surface deformation that is possibly related to an earthquake swarm near Coropuna and Sabancaya volcanoes in December 2001. We also find persistent deformation in the scoria cone and lava field along the Andagua Valley, located 40 km east of Corpuna. An earthquake swarm near Ticsani volcano in 2005 produced surface deformation centered northwest of the volcano and was accompanied by a north-south elongated subsidence signal to the

  7. GLACIERS OF THE KORYAK VOLCANO

    Directory of Open Access Journals (Sweden)

    T. M. Manevich

    2012-01-01

    Full Text Available The paper presents main glaciological characteristics of present-day glaciers located on the Koryaksky volcano. The results of fieldwork (2008–2009 and high-resolution satellite image analysis let us to specify and complete information on modern glacial complex of Koryaksky volcano. Now there are seven glaciers with total area 8.36 km2. Three of them advance, two are in stationary state and one degrades. Moreover, the paper describes the new crater glacier.

  8. Radon emanometry in active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M. (CNRS, IN2P3, BP45/F63170 Aubiere (France)); Cejudo, J. (Instituto Nacional de Investigaciones Nucleares, Mexico City)

    1984-01-01

    Radon emission measurements from active volcanoes has, since 1981, been continuously measured at monitoring stations in Mexico and in Costa Rica. Counting of etched alpha tracks on cellulose nitrate LR-115 detectors give varying results at the several stations. Radon emanation at Chichon, where an explosive eruption occurred in 1982, fell down. Radon detection at the active volcano in Colima shows a pattern of very low emission. At the Costa Rica stations located at Poas, Arenal and Irazu, the radon emanation shows regularity.

  9. Long-term surveillance plan for the Collins Ranch Disposal Site, Lakeview, Oregon

    International Nuclear Information System (INIS)

    1993-12-01

    This long-term surveillance plan (LTSP) for the Lakeview, Oregon, Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site describes the surveillance activities for the Lakeview (Collins Ranch) disposal cell, which will be referred to as the Collins Ranch disposal cell throughout this document. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States or an Indian tribe, and details how the long-term care of the disposal site will be carried out. It is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a)

  10. Chiliques volcano, Chile

    Science.gov (United States)

    2002-01-01

    A January 6, 2002 ASTER nighttime thermal infrared image of Chiliques volcano in Chile shows a hot spot in the summit crater and several others along the upper flanks of the edifice, indicating new volcanic activity. Examination of an earlier nighttime thermal infrared image from May 24,2000 showed no thermal anomaly. Chiliques volcano was previously thought to be dormant. Rising to an elevation of 5778 m, Chiliques is a simple stratovolcano with a 500-m-diameter circular summit crater. This mountain is one of the most important high altitude ceremonial centers of the Incas. It is rarely visited due to its difficult accessibility. Climbing to the summit along Inca trails, numerous ruins are encountered; at the summit there are a series of constructions used for rituals. There is a beautiful lagoon in the crater that is almost always frozen.The daytime image was acquired on November 19, 2000 and was created by displaying ASTER bands 1,2 and 3 in blue, green and red. The nighttime image was acquired January 6, 2002, and is a color-coded display of a single thermal infrared band. The hottest areas are white, and colder areas are darker shades of red. Both images cover an area of 7.5 x 7.5 km, and are centered at 23.6 degrees south latitude, 67.6 degrees west longitude.Both images cover an area of 7.5 x 7.5 km, and are centered at 23.6 degrees south latitude, 67.6 degrees west longitude.These images were acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14spectral 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 will image Earth for the next 6 years 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 satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U

  11. A porous flow model for the geometrical form of volcanoes - Critical comments

    Science.gov (United States)

    Wadge, G.; Francis, P.

    1982-01-01

    A critical evaluation is presented of the assumptions on which the mathematical model for the geometrical form of a volcano arising from the flow of magma in a porous medium of Lacey et al. (1981) is based. The lack of evidence for an equipotential surface or its equivalent in volcanoes prior to eruption is pointed out, and the preference of volcanic eruptions for low ground is attributed to the local stress field produced by topographic loading rather than a rising magma table. Other difficulties with the model involve the neglect of the surface flow of lava under gravity away from the vent, and the use of the Dupuit approximation for unconfined flow and the assumption of essentially horizontal magma flow. Comparisons of model predictions with the shapes of actual volcanoes reveal the model not to fit lava shield volcanoes, for which the cone represents the solidification of small lava flows, and to provide a poor fit to composite central volcanoes.

  12. Rifts of deeply eroded Hawaiian basaltic shields: A structural analog for large Martian volcanoes

    Science.gov (United States)

    Knight, Michael D.; Walker, G. P. L.; Mouginis-Mark, P. J.; Rowland, Scott K.

    1988-01-01

    Recently derived morphologic evidence suggests that intrusive events have not only influenced the growth of young shield volcanoes on Mars but also the distribution of volatiles surrounding these volcanoes: in addition to rift zones and flank eruptions on Arsia Mons and Pavonis Mons, melt water channels were identified to the northwest of Hecates Tholus, to the south of Hadriaca Patera, and to the SE of Olympus Mons. Melt water release could be the surface expression of tectonic deformation of the region or, potentially, intrusive events associated with dike emplacement from each of these volcanoes. In this study the structural properties of Hawaiian shield volcanoes were studied where subaerial erosion has removed a sufficient amount of the surface to enable a direct investigation of the internal structure of the volcanoes. The field investigation of dike morphology and magma flow characteristics for several volcanoes in Hawaii is reported. A comprehensive investigation was made of the Koolau dike complex that passes through the summit caldera. A study of two other dissected Hawaiian volcanoes, namely Waianae and East Molokai, was commenced. The goal is not only to understand the emplacement process and magma flow within these terrestrial dikes, but also to explore the possible role that intrusive events may have played in volcano growth and the distribution of melt water release on Mars.

  13. Rifts of deeply eroded Hawaiian basaltic shields: a structural analog for large Martian volcanoes

    International Nuclear Information System (INIS)

    Knight, M.D.; Walker, G.P.L.; Mouginis-Mark, P.J.; Rowland, S.K.

    1988-01-01

    Recently derived morphologic evidence suggests that intrusive events have not only influenced the growth of young shield volcanoes on Mars but also the distribution of volatiles surrounding these volcanoes: in addition to rift zones and flank eruptions on Arsia Mons and Pavonis Mons, melt water channels were identified to the northwest of Hecates Tholus, to the south of Hadriaca Patera, and to the SE of Olympus Mons. Melt water release could be the surface expression of tectonic deformation of the region or, potentially, intrusive events associated with dike emplacement from each of these volcanoes. In this study the structural properties of Hawaiian shield volcanoes were studied where subaerial erosion has removed a sufficient amount of the surface to enable a direct investigation of the internal structure of the volcanoes. The field investigation of dike morphology and magma flow characteristics for several volcanoes in Hawaii is reported. A comprehensive investigation was made of the Koolau dike complex that passes through the summit caldera. A study of two other dissected Hawaiian volcanoes, namely Waianae and East Molokai, was commenced. The goal is not only to understand the emplacement process and magma flow within these terrestrial dikes, but also to explore the possible role that intrusive events may have played in volcano growth and the distribution of melt water release on Mars

  14. Global Volcano Mortality Risks and Distribution

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Volcano Mortality Risks and Distribution is a 2.5 minute grid representing global volcano mortality risks. The data set was constructed using historical...

  15. Evident?

    DEFF Research Database (Denmark)

    Plant, Peter

    2012-01-01

    Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind......Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind...

  16. Copahue volcano and its regional magmatic setting

    Science.gov (United States)

    Varekamp, J C; Zareski, J E; Camfield, L M; Todd, Erin

    2016-01-01

    Copahue volcano (Province of Neuquen, Argentina) has produced lavas and strombolian deposits over several 100,000s of years, building a rounded volcano with a 3 km elevation. The products are mainly basaltic andesites, with the 2000–2012 eruptive products the most mafic. The geochemistry of Copahue products is compared with those of the main Andes arc (Llaima, Callaqui, Tolhuaca), the older Caviahue volcano directly east of Copahue, and the back arc volcanics of the Loncopue graben. The Caviahue rocks resemble the main Andes arc suite, whereas the Copahue rocks are characterized by lower Fe and Ti contents and higher incompatible element concentrations. The rocks have negative Nb-Ta anomalies, modest enrichments in radiogenic Sr and Pb isotope ratios and slightly depleted Nd isotope ratios. The combined trace element and isotopic data indicate that Copahue magmas formed in a relatively dry mantle environment, with melting of a subducted sediment residue. The back arc basalts show a wide variation in isotopic composition, have similar water contents as the Copahue magmas and show evidence for a subducted sedimentary component in their source regions. The low 206Pb/204Pb of some backarc lava flows suggests the presence of a second endmember with an EM1 flavor in its source. The overall magma genesis is explained within the context of a subducted slab with sediment that gradually looses water, water-mobile elements, and then switches to sediment melt extracts deeper down in the subduction zone. With the change in element extraction mechanism with depth comes a depletion and fractionation of the subducted complex that is reflected in the isotope and trace element signatures of the products from the main arc to Copahue to the back arc basalts.

  17. Systematic radon survey over active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, J.L.; Monnin, M.; Garcia Vindas, J.R. [Centre National de la Recherche Cientifique, Montpellier (France). Lab. GBE; Ricard, L.P.; Staudacher, T. [Observatoire Volcanologique Du Pitou de la Fournaise, La Plaine des Cafres (France)

    1999-08-01

    Data obtained since 1993 on Costa Rica volcanos are presented and radon anomalies recorded before the eruption of the Irazu volcano (December 8, 1994) are discussed. The Piton de la Fournaise volcano is inactive since mid 1992. The influence of the external parameters on the radon behaviour is studied and the type of perturbations induced on short-term measurements are individuate.

  18. Multiphase modelling of mud volcanoes

    Science.gov (United States)

    Colucci, Simone; de'Michieli Vitturi, Mattia; Clarke, Amanda B.

    2015-04-01

    Mud volcanism is a worldwide phenomenon, classically considered as the surface expression of piercement structures rooted in deep-seated over-pressured sediments in compressional tectonic settings. The release of fluids at mud volcanoes during repeated explosive episodes has been documented at numerous sites and the outflows resemble the eruption of basaltic magma. As magma, the material erupted from a mud volcano becomes more fluid and degasses while rising and decompressing. The release of those gases from mud volcanism is estimated to be a significant contributor both to fluid flux from the lithosphere to the hydrosphere, and to the atmospheric budget of some greenhouse gases, particularly methane. For these reasons, we simulated the fluid dynamics of mud volcanoes using a newly-developed compressible multiphase and multidimensional transient solver in the OpenFOAM framework, taking into account the multicomponent nature (CH4, CO2, H2O) of the fluid mixture, the gas exsolution during the ascent and the associated changes in the constitutive properties of the phases. The numerical model has been tested with conditions representative of the LUSI, a mud volcano that has been erupting since May 2006 in the densely populated Sidoarjo regency (East Java, Indonesia), forcing the evacuation of 40,000 people and destroying industry, farmland, and over 10,000 homes. The activity of LUSI mud volcano has been well documented (Vanderkluysen et al., 2014) and here we present a comparison of observed gas fluxes and mud extrusion rates with the outcomes of numerical simulations. Vanderkluysen, L.; Burton, M. R.; Clarke, A. B.; Hartnett, H. E. & Smekens, J.-F. Composition and flux of explosive gas release at LUSI mud volcano (East Java, Indonesia) Geochem. Geophys. Geosyst., Wiley-Blackwell, 2014, 15, 2932-2946

  19. Alaska volcanoes guidebook for teachers

    Science.gov (United States)

    Adleman, Jennifer N.

    2011-01-01

    Alaska’s volcanoes, like its abundant glaciers, charismatic wildlife, and wild expanses inspire and ignite scientific curiosity and generate an ever-growing source of questions for students in Alaska and throughout the world. Alaska is home to more than 140 volcanoes, which have been active over the last 2 million years. About 90 of these volcanoes have been active within the last 10,000 years and more than 50 of these have been active since about 1700. The volcanoes in Alaska make up well over three-quarters of volcanoes in the United States that have erupted in the last 200 years. In fact, Alaska’s volcanoes erupt so frequently that it is almost guaranteed that an Alaskan will experience a volcanic eruption in his or her lifetime, and it is likely they will experience more than one. It is hard to imagine a better place for students to explore active volcanism and to understand volcanic hazards, phenomena, and global impacts. Previously developed teachers’ guidebooks with an emphasis on the volcanoes in Hawaii Volcanoes National Park (Mattox, 1994) and Mount Rainier National Park in the Cascade Range (Driedger and others, 2005) provide place-based resources and activities for use in other volcanic regions in the United States. Along the lines of this tradition, this guidebook serves to provide locally relevant and useful resources and activities for the exploration of numerous and truly unique volcanic landscapes in Alaska. This guidebook provides supplemental teaching materials to be used by Alaskan students who will be inspired to become educated and prepared for inevitable future volcanic activity in Alaska. The lessons and activities in this guidebook are meant to supplement and enhance existing science content already being taught in grade levels 6–12. Correlations with Alaska State Science Standards and Grade Level Expectations adopted by the Alaska State Department of Education and Early Development (2006) for grades six through eleven are listed at

  20. The deep structure of Axial Volcano

    Science.gov (United States)

    West, Michael Edwin

    The subsurface structure of Axial Volcano, near the intersection of the Juan de Fuca Ridge and the Cobb-Eickelberg seamount chain in the northeast Pacific, is imaged from an active source seismic experiment. At a depth of 2.25 to 3.5 km beneath Axial lies an 8 km x 12 km region of very low seismic velocities that can only be explained by the presence of magma. In the center of this magma storage chamber at 2--3.5 km below sea floor, the crust is at least 10--20% melt. At depths of 4--5 km there is evidence of additional low concentrations of magma (a few percent) over a larger area. In total, 5--11 km3 of magma are stored in the mid-crust beneath Axial. This is more melt than has been positively identified under any basaltic volcano on Earth. It is also far more than the 0.1--0.2 km3 emplaced during the 1998 eruption. The implied residence time in the magma reservoir of a few hundred to a few thousand years agrees with geochemical trends which suggest prolonged storage and mixing of magmas. The large volume of melt bolsters previous observations that Axial provides much of the material to create crust along its 50 km rift zones. A high velocity ring-shaped feature sits above the magma chamber just outside the caldera walls. This feature is believed to be the result of repeated dike injections from the magma body to the surface during the construction of the volcanic edifice. A rapid change in crustal thickness from 8 to 11 km within 15 km of the caldera implies focused delivery of melt from the mantle. The high flux of magma suggests that melting occurs deeper in the mantle than along the nearby ridge. Melt supply to the volcano is not connected to any plumbing system associated with the adjacent segments of the Juan de Fuca Ridge. This suggests that, despite Axial's proximity to the ridge, the Cobb hot spot currently drives the supply of melt to the volcano.

  1. Geology of El Chichon volcano, Chiapas, Mexico

    Science.gov (United States)

    Duffield, Wendell A.; Tilling, Robert I.; Canul, Rene

    1984-03-01

    The (pre-1982) 850-m-high andesitic stratovolcano El Chichón, active during Pleistocene and Holocene time, is located in rugged, densely forested terrain in northcentral Chiapas, México. The nearest neighboring Holocene volcanoes are 275 km and 200 km to the southeast and northwest, respectively. El Chichón is built on Tertiary siltstone and sandstone, underlain by Cretaceous dolomitic limestone; a 4-km-deep bore hole near the east base of the volcano penetrated this limestone and continued 770 m into a sequence of Jurassic or Cretaceous evaporitic anhydrite and halite. The basement rocks are folded into generally northwest-trending anticlines and synclines. El Chichón is built over a small dome-like structure superposed on a syncline, and this structure may reflect cumulative deformation related to growth of a crustal magma reservoir beneath the volcano. The cone of El Chichón consists almost entirely of pyroclastic rocks. The pre-1982 cone is marked by a 1200-m-diameter (explosion?) crater on the southwest flank and a 1600-m-diameter crater apparently of similar origin at the summit, a lava dome partly fills each crater. The timing of cone and dome growth is poorly known. Field evidence indicates that the flank dome is older than the summit dome, and K-Ar ages from samples high on the cone suggest that the flank dome is older than about 276,000 years. At least three pyroclastic eruptions have occurred during the past 1250 radiocarbon years. Nearly all of the pyroclastic and dome rocks are moderately to highly porphyritic andesite, with plagioclase, hornblende and clinopyroxene the most common phenocrysts. Geologists who mapped El Chichón in 1980 and 1981 warned that the volcano posed a substantial hazard to the surrounding region. This warning was proven to be prophetic by violent eruptions that occurred in March and April of 1982. These eruptions blasted away nearly all of the summit dome, blanketed the surrounding region with tephra, and sent pyroclastic

  2. Volcano-ice interactions on Mars

    International Nuclear Information System (INIS)

    Allen, C.C.

    1979-01-01

    Central volcanic eruptions beneath terrestrial glaciers have built steep-sided, flat-topped mountains composed of pillow lava, glassy tuff, capping flows, and cones of basalt. Subglacial fissure eruptions produced ridges of similar compostion. In some places the products from a number of subglacial vents have combined to form widespread deposits. The morphologies of these subglacial volcanoes are distinctive enough to allow their recognition at the resolutions characteristic of Viking orbiter imagery. Analogs to terrestrial subglacial volcanoes have been identified on the northern plains and near the south polar cap of Mars. The polar feature provides probable evidence of volcanic eruptions beneath polar ice. A mixed unit of rock and ice is postulated to have overlain portions of the northern plains, with eruptions into this ground ice having produced mountains and ridges analogous to those in Iceland. Subsequent breakdown of this unit due to ice melting revealed the volcanic features. Estimated heights of these landforms indicate that the ice-rich unit once ranged from approximately 100 to 1200 m thick

  3. Laboratory volcano geodesy

    Science.gov (United States)

    Færøvik Johannessen, Rikke; Galland, Olivier; Mair, Karen

    2014-05-01

    intrusion can be excavated and photographed from several angles to compute its 3D shape with the same photogrammetry method. Then, the surface deformation pattern can be directly compared with the shape of underlying intrusion. This quantitative dataset is essential to quantitatively test and validate classical volcano geodetic models.

  4. Eco-friendly porous concrete using bottom ash aggregate for marine ranch application.

    Science.gov (United States)

    Lee, Byung Jae; Prabhu, G Ganesh; Lee, Bong Chun; Kim, Yun Yong

    2016-03-01

    This article presents the test results of an investigation carried out on the reuse of coal bottom ash aggregate as a substitute material for coarse aggregate in porous concrete production for marine ranch applications. The experimental parameters were the rate of bottom ash aggregate substitution (30%, 50% and 100%) and the target void ratio (15%, 20% and 25%). The cement-coated granular fertiliser was substituted into a bottom ash aggregate concrete mixture to improve marine ranch applications. The results of leaching tests revealed that the bottom ash aggregate has only a negligible amount of the ten deleterious substances specified in the Ministry of Environment - Enforcement Regulation of the Waste Management Act of Republic Korea. The large amount of bubbles/air gaps in the bottom ash aggregate increased the voids of the concrete mixtures in all target void ratios, and decreased the compressive strength of the porous concrete mixture; however, the mixture substituted with 30% and 10% of bottom ash aggregate and granular fertiliser, respectively, showed an equal strength to the control mixture. The sea water resistibility of the bottom ash aggregate substituted mixture was relatively equal to that of the control mixture, and also showed a great deal of improvement in the degree of marine organism adhesion compared with the control mixture. No fatality of fish was observed in the fish toxicity test, which suggested that bottom ash aggregate was a harmless material and that the combination of bottom ash aggregate and granular fertiliser with substitution rates of 30% and 10%, respectively, can be effectively used in porous concrete production for marine ranch application. © The Author(s) 2015.

  5. Green electricity in abundance. A photovoltaic roof lends a ranch in the style of the 50s a contemporary note; Gruenstrom im Ueberfluss. Ein Photovoltaikdach verleiht einer Ranch im Stil der 50er-Jahre einen zeitgenoessischen Akzent

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, Matthew; Krause, Matthias B.

    2013-03-15

    Landlady Kate Kennedy wanted to build her property in a conservation area three hours' drive south of San Francisco in a ranch-style house. Architect Jonathan Feldman added energy-efficient elements and a roof-integrated photovoltaic system to the project. Kennedy now produces more electricity than it can consume. [German] Hausherrin Kate Kennedy wollte ihr Anwesen in einem Naturschutzgebiet drei Autostunden suedlich von San Francisco unbedingt im Stil eines Ranch-Hauses bauen. Architekt Jonathan Feldman fuegte dem Projekt energieeffiziente Elemente und eine dachintegrierte Photovoltaikanlage hinzu. Nun produziert Kennedy mehr Solarstrom, als sie verbrauchen kann.

  6. Wake deficit measurements on the Jess and Souza Ranches, Altamont Pass

    Energy Technology Data Exchange (ETDEWEB)

    Nierenburg, R. (Altamont Energy Corp., San Rafael, CA (USA))

    1990-04-01

    This report is ninth in a series of documents presenting the findings of field test under DOE's Cooperative Field Test Program (CFTP) with the wind industry. This report provides results of a project conducted by Altamont Energy Corp. (AEC) to measure wake deficits on the Jess and Sousa Ranches in Altamont Pass, CA. This research enhances and complements other DOE-funded projects to refine estimates of wind turbine array effects. This project will help explain turbine performance variability caused by wake effects. 4 refs., 28 figs., 106 tabs.

  7. Natural mortality amoung four common ungulate species on Letaba Ranch, Limpopo Province, South Africa

    Directory of Open Access Journals (Sweden)

    H.P. Cronje

    2002-01-01

    Full Text Available Five years of mortality data of impala Aepyceros melampus, blue wildebeest Connochaetes taurinus, buffalo Syncerus caffer and kudu Tragelaphus strepsiceros have been used to describe the minimum mortality profiles of the respective species in an open savanna system with the full compliment of predators. Predation is the principle cause of natural mortalities on the study site, Letaba Ranch, which is adjacent to the Kruger National Park. The principle cause of impala mortality are leopards Panthera pardus and wild dogs Lycaon pictus. Lion Panthera leo were major contributors to the mortality of wildebeest and buffalo. Anthrax Bacillus anthracis was the main cause of kudu mortality.

  8. What Happened to Our Volcano?

    Science.gov (United States)

    Mangiante, Elaine Silva

    2006-01-01

    In this article, the author presents an investigative approach to "understanding Earth changes." The author states that students were familiar with earthquakes and volcanoes in other regions of the world but never considered how the land beneath their feet had experienced changes over time. Here, their geology unit helped them understand…

  9. Morphometry of terrestrial shield volcanoes

    Science.gov (United States)

    Grosse, Pablo; Kervyn, Matthieu

    2018-03-01

    Shield volcanoes are described as low-angle edifices built primarily by the accumulation of successive lava flows. This generic view of shield volcano morphology is based on a limited number of monogenetic shields from Iceland and Mexico, and a small set of large oceanic islands (Hawaii, Galápagos). Here, the morphometry of 158 monogenetic and polygenetic shield volcanoes is analyzed quantitatively from 90-meter resolution SRTM DEMs using the MORVOLC algorithm. An additional set of 24 lava-dominated 'shield-like' volcanoes, considered so far as stratovolcanoes, are documented for comparison. Results show that there is a large variation in shield size (volumes from 0.1 to > 1000 km3), profile shape (height/basal width (H/WB) ratios mostly from 0.01 to 0.1), flank slope gradients (average slopes mostly from 1° to 15°), elongation and summit truncation. Although there is no clear-cut morphometric difference between shield volcanoes and stratovolcanoes, an approximate threshold can be drawn at 12° average slope and 0.10 H/WB ratio. Principal component analysis of the obtained database enables to identify four key morphometric descriptors: size, steepness, plan shape and truncation. Hierarchical cluster analysis of these descriptors results in 12 end-member shield types, with intermediate cases defining a continuum of morphologies. The shield types can be linked in terms of growth stages and shape evolution, related to (1) magma composition and rheology, effusion rate and lava/pyroclast ratio, which will condition edifice steepness; (2) spatial distribution of vents, in turn related to the magmatic feeding system and the tectonic framework, which will control edifice plan shape; and (3) caldera formation, which will condition edifice truncation.

  10. Iridium emissions from Hawaiian volcanoes

    International Nuclear Information System (INIS)

    Finnegan, D.L.; Zoller, W.H.; Miller, T.M.

    1988-01-01

    Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were collected using a filterpack system consisting of a Teflon particle filter followed by a series of 4 base-treated Whatman filters. The samples were analyzed by INAA for over 40 elements. As previously reported in the literature, Ir was first detected on particle filters at the Mauna Loa Observatory and later from non-erupting high temperature vents at Kilauea. Since that time Ir was found in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Enrichment factors for Ir in the volcanic fumes range from 10,000 to 100,000 relative to BHVO. Charcoal impregnated filters following a particle filter were collected to see if a significant amount of the Ir was in the gas phase during sample collection. Iridium was found on charcoal filters collected close to the vent, no Ir was found on the charcoal filters. This indicates that all of the Ir is in particulate form very soon after its release. Ratios of Ir to F and Cl were calculated for the samples from Mauna Loa and Kilauea collected during fountaining activity. The implications for the KT Ir anomaly are still unclear though as Ir was not found at volcanoes other than those at Hawaii. Further investigations are needed at other volcanoes to ascertain if basaltic volcanoes other than hot spots have Ir enrichments in their fumes

  11. Iridium emissions from Hawaiian volcanoes

    Science.gov (United States)

    Finnegan, D. L.; Zoller, W. H.; Miller, T. M.

    1988-01-01

    Particle and gas samples were collected at Mauna Loa volcano during and after its eruption in March and April, 1984 and at Kilauea volcano in 1983, 1984, and 1985 during various phases of its ongoing activity. In the last two Kilauea sampling missions, samples were collected during eruptive activity. The samples were collected using a filterpack system consisting of a Teflon particle filter followed by a series of 4 base-treated Whatman filters. The samples were analyzed by INAA for over 40 elements. As previously reported in the literature, Ir was first detected on particle filters at the Mauna Loa Observatory and later from non-erupting high temperature vents at Kilauea. Since that time Ir was found in samples collected at Kilauea and Mauna Loa during fountaining activity as well as after eruptive activity. Enrichment factors for Ir in the volcanic fumes range from 10,000 to 100,000 relative to BHVO. Charcoal impregnated filters following a particle filter were collected to see if a significant amount of the Ir was in the gas phase during sample collection. Iridium was found on charcoal filters collected close to the vent, no Ir was found on the charcoal filters. This indicates that all of the Ir is in particulate form very soon after its release. Ratios of Ir to F and Cl were calculated for the samples from Mauna Loa and Kilauea collected during fountaining activity. The implications for the KT Ir anomaly are still unclear though as Ir was not found at volcanoes other than those at Hawaii. Further investigations are needed at other volcanoes to ascertain if basaltic volcanoes other than hot spots have Ir enrichments in their fumes.

  12. Archaeological survey of the McGee Ranch vicinity, Hanford Site, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Gard, H.A.; Poet, R.M.

    1992-09-01

    In response to a request for a cultural resources review from Westinghouse Hanford Company for the Action Plan for Characterization of McGee Ranch Soil, Pacific Northwest Laboratory's Hanford Cultural Resources Laboratory (HCRL) conducted an archaeological survey of the McGee Ranch vicinity, located in the northwest portion of the Hanford Site. Staff members covered 8.4 km{sup 2} and recorded 42 cultural resources; 22 sites, and 20 isolated artifacts. Only 2 sites and 3 isolates were attributed to a prehistoric Native American occupation. The historic sites date from the turn of the century to the 1940s and are representative of the settlement patterns that occurred throughout the Columbia Basin. In addition to an archaeological pedestrian survey of the project area, we conducted literature and records searches and examined available aerial photographs. Records kept at HCRL were reviewed to determine if any archaeological survey had been conducted previously within the project area. Although no survey had been conducted, portions of the area adjacent to project boundaries were surveyed in 1988 and 1990. During those surveys, historic and prehistoric cultural resources were observed, increasing the possibility that similar land usage had taken place within the current project boundaries. Literature searches established a general historical sequence for this area. Aerial photographs alerted researchers to homesteads and linear features, such as roads and irrigation ditches, that might not be apparent from ground level.

  13. Archaeological survey of the McGee Ranch vicinity, Hanford Site, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Gard, H.A.; Poet, R.M.

    1992-09-01

    In response to a request for a cultural resources review from Westinghouse Hanford Company for the Action Plan for Characterization of McGee Ranch Soil, Pacific Northwest Laboratory`s Hanford Cultural Resources Laboratory (HCRL) conducted an archaeological survey of the McGee Ranch vicinity, located in the northwest portion of the Hanford Site. Staff members covered 8.4 km{sup 2} and recorded 42 cultural resources; 22 sites, and 20 isolated artifacts. Only 2 sites and 3 isolates were attributed to a prehistoric Native American occupation. The historic sites date from the turn of the century to the 1940s and are representative of the settlement patterns that occurred throughout the Columbia Basin. In addition to an archaeological pedestrian survey of the project area, we conducted literature and records searches and examined available aerial photographs. Records kept at HCRL were reviewed to determine if any archaeological survey had been conducted previously within the project area. Although no survey had been conducted, portions of the area adjacent to project boundaries were surveyed in 1988 and 1990. During those surveys, historic and prehistoric cultural resources were observed, increasing the possibility that similar land usage had taken place within the current project boundaries. Literature searches established a general historical sequence for this area. Aerial photographs alerted researchers to homesteads and linear features, such as roads and irrigation ditches, that might not be apparent from ground level.

  14. Cattle ranching intensification in Brazil can reduce global greenhouse gas emissions by sparing land from deforestation.

    Science.gov (United States)

    Cohn, Avery S; Mosnier, Aline; Havlík, Petr; Valin, Hugo; Herrero, Mario; Schmid, Erwin; O'Hare, Michael; Obersteiner, Michael

    2014-05-20

    This study examines whether policies to encourage cattle ranching intensification in Brazil can abate global greenhouse gas (GHG) emissions by sparing land from deforestation. We use an economic model of global land use to investigate, from 2010 to 2030, the global agricultural outcomes, land use changes, and GHG abatement resulting from two potential Brazilian policies: a tax on cattle from conventional pasture and a subsidy for cattle from semi-intensive pasture. We find that under either policy, Brazil could achieve considerable sparing of forests and abatement of GHGs, in line with its national policy targets. The land spared, particularly under the tax, is far less than proportional to the productivity increased. However, the tax, despite prompting less adoption of semi-intensive ranching, delivers slightly more forest sparing and GHG abatement than the subsidy. This difference is explained by increased deforestation associated with increased beef consumption under the subsidy and reduced deforestation associated with reduced beef consumption under the tax. Complementary policies to directly limit deforestation could help limit these effects. GHG abatement from either the tax or subsidy appears inexpensive but, over time, the tax would become cheaper than the subsidy. A revenue-neutral combination of the policies could be an element of a sustainable development strategy for Brazil and other emerging economies seeking to balance agricultural development and forest protection.

  15. Amphibians and reptiles of C. E. Miller Ranch and the Sierra Vieja, Chihuahuan Desert, Texas, USA

    Directory of Open Access Journals (Sweden)

    Drew R. Davis

    2018-02-01

    Full Text Available We report the occurrence of 50 species of amphibians and reptiles recently collected on C. E. Miller Ranch and the Sierra Vieja in the Chihuahuan Desert of Texas, USA and describe their perceived distribution and abundance across various habitat associations of the region. Our recent surveys follow intense, historic sampling of amphibians and reptiles from this region in 1948. Of the 50 species detected in recent surveys, six were not collected in 1948 and an additional three species documented in 1948 have yet to be detected in a 14-year period of recent surveys. Combining data from both historic and recent surveys, a total of 53 species of amphibians and reptiles are known from the ranch (11 amphibians, 42 reptiles. Land stewardship and conservation practices have likely contributed to the persistence of the majority of these species through time. Additionally, we discuss the status of amphibians and reptiles not collected during recent surveys and comment on potential species that have not yet been detected.

  16. Amphibians and reptiles of C. E. Miller Ranch and the Sierra Vieja, Chihuahuan Desert, Texas, USA.

    Science.gov (United States)

    Davis, Drew R; LaDuc, Travis J

    2018-01-01

    We report the occurrence of 50 species of amphibians and reptiles recently collected on C. E. Miller Ranch and the Sierra Vieja in the Chihuahuan Desert of Texas, USA and describe their perceived distribution and abundance across various habitat associations of the region. Our recent surveys follow intense, historic sampling of amphibians and reptiles from this region in 1948. Of the 50 species detected in recent surveys, six were not collected in 1948 and an additional three species documented in 1948 have yet to be detected in a 14-year period of recent surveys. Combining data from both historic and recent surveys, a total of 53 species of amphibians and reptiles are known from the ranch (11 amphibians, 42 reptiles). Land stewardship and conservation practices have likely contributed to the persistence of the majority of these species through time. Additionally, we discuss the status of amphibians and reptiles not collected during recent surveys and comment on potential species that have not yet been detected.

  17. Remote Sensing Analysis of the Sierra Blanca (Faskin Ranch) Low-Level Radioactive Waste Disposal Site, Hudspeth County, Texas

    International Nuclear Information System (INIS)

    LeMone, D. V.; Dodge, R.; Xie, H.; Langford, R. P.; Keller, G. R.

    2002-01-01

    Remote sensing images provide useful physical information, revealing such features as geological structure, vegetation, drainage patterns, and variations in consolidated and unconsolidated lithologies. That technology has been applied to the failed Sierra Blanca (Faskin Ranch) shallow burial low-level radioactive waste disposal site selected by the Texas Low-Level Radioactive Waste Disposal Authority. It has been re-examined using data from LANDSAT satellite series. The comparison of the earlier LANDSAT V (5/20/86) (30-m resolution) with the later new, higher resolution ETM imagery (10/23/99) LANDSAT VII data (15-m resolution) clearly shows the superiority of the LANDSAT VII data. The search for surficial indications of evidence of fatal flaws at the Sierra Blanca site utilizing was not successful, as it had been in the case of the earlier remote sensing analysis of the failed Fort Hancock site utilizing LANDSAT V data. The authors conclude that the tectonic activity at the Sierra Blanca site is much less recent and active than in the previously studied Fort Hancock site. The Sierra Blanca site failed primarily on the further needed documentation concerning a subsurface fault underneath the site and environmental justice issues. The presence of this fault was not revealed using the newer LANDSAT VII data. Despite this fact, it must be remembered that remote sensing provides baseline documentation for determining future physical and financial remediation responsibilities. On the basis of the two sites examined by LANDSAT remote sensing imaging, it is concluded that it is an essential, cost-effective tool that should be utilized not only in site examination but also in all nuclear-related facilities

  18. Aleutian Islands Coastal Resources Inventory and Environmental Sensitivity Maps: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains point locations of active volcanoes as compiled by Motyka et al., 1993. Eighty-nine volcanoes with eruptive phases in the Quaternary are...

  19. 77 FR 48138 - Topaz Solar Farms LLC; High Plains Ranch II, LLC; Bethel Wind Energy LLC; Rippey Wind Energy LLC...

    Science.gov (United States)

    2012-08-13

    ... Ranch II, LLC; Bethel Wind Energy LLC; Rippey Wind Energy LLC; Pacific Wind, LLC; Colorado Highlands Wind, LLC; Shooting Star Wind Project, LLC; Notice of Effectiveness of Exempt Wholesale Generator or... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. EG12-63-000; EG12-64-000...

  20. Developing ecological site and state-and-transition models for grazed riparian pastures at Tejon Ranch, California

    Science.gov (United States)

    Felix P. Ratcliff; James Bartolome; Michele Hammond; Sheri Spiegal; Michael White

    2015-01-01

    Ecological site descriptions and associated state-and-transition models are useful tools for understanding the variable effects of management and environment on range resources. Models for woody riparian sites have yet to be fully developed. At Tejon Ranch, in the southern San Joaquin Valley of California, we are using ecological site theory to investigate the role of...

  1. 93 Years of stand density and land-use legacy research at the Coulter Ranch Study Site

    Science.gov (United States)

    Andrew J. Sanchez Meador; Margaret M. Moore

    2008-01-01

    In 1913, the Fort Valley Experimental Forest initiated an unprecedented case-study experiment to determine the effects of harvesting methods on tree regeneration and growth on a ponderosa pine-Gambel oak forest at Coulter Ranch in northern Arizona. The harvesting methods examined were seed-tree, group selection, and light selection. In addition, the effects of...

  2. 93 years of stand density and land-use legacy research at the Coulter Ranch Study Site (P-53)

    Science.gov (United States)

    Andrew J. Sanchez Meador; Margaret M. Moore

    2008-01-01

    In 1913, the Fort Valley Experimental Forest initiated an unprecedented case-study experiment to determine the effects of harvesting methods on tree regeneration and growth on a ponderosa pine-Gambel oak forest at Coulter Ranch in northern Arizona. The harvesting methods examined were seed-tree, group selection, and light selection. In addition, the effects of...

  3. Flank tectonics of Martian volcanoes

    International Nuclear Information System (INIS)

    Thomas, P.J.; Squyres, S.W.; Carr, M.H.

    1990-01-01

    On the flanks of Olympus Mons is a series of terraces, concentrically distributed around the caldera. Their morphology and location suggest that they could be thrust faults caused by compressional failure of the cone. In an attempt to understand the mechanism of faulting and the possible influences of the interior structure of Olympus Mons, the authors have constructed a numerical model for elastic stresses within a Martian volcano. In the absence of internal pressurization, the middle slopes of the cone are subjected to compressional stress, appropriate to the formation of thrust faults. These stresses for Olympus Mons are ∼250 MPa. If a vacant magma chamber is contained within the cone, the region of maximum compressional stress is extended toward the base of the cone. If the magma chamber is pressurized, extensional stresses occur at the summit and on the upper slopes of the cone. For a filled but unpressurized magma chamber, the observed positions of the faults agree well with the calculated region of high compressional stress. Three other volcanoes on Mars, Ascraeus Mons, Arsia Mons, and Pavonis Mons, possess similar terraces. Extending the analysis to other Martian volcanoes, they find that only these three and Olympus Mons have flank stresses that exceed the compressional failure strength of basalt, lending support to the view that the terraces on all four are thrust faults

  4. 3D electrical conductivity tomography of volcanoes

    Science.gov (United States)

    Soueid Ahmed, A.; Revil, A.; Byrdina, S.; Coperey, A.; Gailler, L.; Grobbe, N.; Viveiros, F.; Silva, C.; Jougnot, D.; Ghorbani, A.; Hogg, C.; Kiyan, D.; Rath, V.; Heap, M. J.; Grandis, H.; Humaida, H.

    2018-05-01

    Electrical conductivity tomography is a well-established galvanometric method for imaging the subsurface electrical conductivity distribution. We characterize the conductivity distribution of a set of volcanic structures that are different in terms of activity and morphology. For that purpose, we developed a large-scale inversion code named ECT-3D aimed at handling complex topographical effects like those encountered in volcanic areas. In addition, ECT-3D offers the possibility of using as input data the two components of the electrical field recorded at independent stations. Without prior information, a Gauss-Newton method with roughness constraints is used to solve the inverse problem. The roughening operator used to impose constraints is computed on unstructured tetrahedral elements to map complex geometries. We first benchmark ECT-3D on two synthetic tests. A first test using the topography of Mt. St Helens volcano (Washington, USA) demonstrates that we can successfully reconstruct the electrical conductivity field of an edifice marked by a strong topography and strong variations in the resistivity distribution. A second case study is used to demonstrate the versatility of the code in using the two components of the electrical field recorded on independent stations along the ground surface. Then, we apply our code to real data sets recorded at (i) a thermally active area of Yellowstone caldera (Wyoming, USA), (ii) a monogenetic dome on Furnas volcano (the Azores, Portugal), and (iii) the upper portion of the caldera of Kīlauea (Hawai'i, USA). The tomographies reveal some of the major structures of these volcanoes as well as identifying alteration associated with high surface conductivities. We also review the petrophysics underlying the interpretation of the electrical conductivity of fresh and altered volcanic rocks and molten rocks to show that electrical conductivity tomography cannot be used as a stand-alone technique due to the non-uniqueness in

  5. Late Holocene volcanism at Medicine Lake Volcano, northern California Cascades

    Science.gov (United States)

    Donnelly-Nolan, Julie M.; Champion, Duane E.; Grove, Timothy L.

    2016-05-23

    Late Holocene volcanism at Medicine Lake volcano in the southern Cascades arc exhibited widespread and compositionally diverse magmatism ranging from basalt to rhyolite. Nine well-characterized eruptions have taken place at this very large rear-arc volcano since 5,200 years ago, an eruptive frequency greater than nearly all other Cascade volcanoes. The lavas are widely distributed, scattered over an area of ~300 km2 across the >2,000-km2 volcano. The eruptions are radiocarbon dated and the ages are also constrained by paleomagnetic data that provide strong evidence that the volcanic activity occurred in three distinct episodes at ~1 ka, ~3 ka, and ~5 ka. The ~1-ka final episode produced a variety of compositions including west- and north-flank mafic flows interspersed in time with fissure rhyolites erupted tangential to the volcano’s central caldera, including the youngest and most spectacular lava flow at the volcano, the ~950-yr-old compositionally zoned Glass Mountain flow. At ~3 ka, a north-flank basalt eruption was followed by an andesite eruption 27 km farther south that contains quenched basalt inclusions. The ~5-ka episode produced two caldera-focused dacitic eruptions. Quenched magmatic inclusions record evidence of intrusions that did not independently reach the surface. The inclusions are present in five andesitic, dacitic, and rhyolitic host lavas, and were erupted in each of the three episodes. Compositional and mineralogic evidence from mafic lavas and inclusions indicate that both tholeiitic (dry) and calcalkaline (wet) parental magmas were present. Petrologic evidence records the operation of complex, multi-stage processes including fractional crystallization, crustal assimilation, and magma mixing. Experimental evidence suggests that magmas were stored at 3 to 6 km depth prior to eruption, and that both wet and dry parental magmas were involved in generating the more silicic magmas. The broad distribution of eruptive events and the relative

  6. Element fluxes from Copahue Volcano, Argentina

    Science.gov (United States)

    Varekamp, J. C.

    2003-12-01

    Copahue volcano in Argentina has an active volcano-magmatic hydrothermal system that emits fluids with pH=0.3 that feed a river system. River flux measurements and analytical data provide element flux data from 1997 to 2003, which includes the eruptive period of July to December 2000. The fluids have up to 6.5 percent sulfate, 1 percent Cl and ppm levels of B, As, Cu, Zn and Pb. The hydrothermal system acts as a perfect scrubber for magmatic gases during the periods of passive degassing, although the dissolved magmatic gases are modified through water rock interaction and mineral precipitation. The magmatic SO2 disproportionates into sulfate and liquid elemental sulfur at about 300 C; the sulfate is discharged with the fluids, whereas the liquid sulfur is temporarily retained in the reservoir but ejected during phreatic and hydrothermal eruptions. The intrusion and chemical attack of new magma in the hydrothermal reservoir in early 2000 was indicated by strongly increased Mg concentrations and Mg fluxes, and higher Mg/Cl and Mg/K values. The hydrothermal discharge has acidified a large glacial lake (0.5 km3) to pH=2 and the lake effluents acidify the exiting river. Even more than 100 km downstream, the effects of acid pulses from the lake are evident from red coated boulders and fish die-offs. The river-bound sulfate fluxes from the system range from 70 to 200 kilotonnes/year. The equivalent SO2 output of the whole volcanic system ranges from 150 to 500 tonnes/day, which includes the fraction of native sulfur that formed inside the mountain but does not include the release of SO2 into the atmosphere during the eruptions. Trace element fluxes of the river will be scaled up and compared with global element fluxes from meteoric river waters (subterranean volcanic weathering versus watershed weathering).

  7. Long-term surveillance plan for the Collins Ranch disposal site, Lakeview, Oregon

    International Nuclear Information System (INIS)

    1994-08-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Collins Ranch disposal site, Lakeview, Oregon, describes the surveillance activities for the disposal cell. The U.S. Department of Energy (DOE) will carry out these activities to ensure that the disposal cell continues to function as designed. This final LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials. This LTSP documents whether the land and interests are owned by the United States and details how long-term care of the disposal site will be carried out. It is based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992a)

  8. Research on Environmental Adjustment of Cloud Ranch Based on BP Neural Network PID Control

    Science.gov (United States)

    Ren, Jinzhi; Xiang, Wei; Zhao, Lin; Wu, Jianbo; Huang, Lianzhen; Tu, Qinggang; Zhao, Heming

    2018-01-01

    In order to make the intelligent ranch management mode replace the traditional artificial one gradually, this paper proposes a pasture environment control system based on cloud server, and puts forward the PID control algorithm based on BP neural network to control temperature and humidity better in the pasture environment. First, to model the temperature and humidity (controlled object) of the pasture, we can get the transfer function. Then the traditional PID control algorithm and the PID one based on BP neural network are applied to the transfer function. The obtained step tracking curves can be seen that the PID controller based on BP neural network has obvious superiority in adjusting time and error, etc. This algorithm, calculating reasonable control parameters of the temperature and humidity to control environment, can be better used in the cloud service platform.

  9. Draft Environmental Impact Report/Environmental Impact Statement. Cullinan Ranch Specific Plan. Appendices.

    Science.gov (United States)

    1983-05-01

    0XandA±liA Poison hemlock Cgn~i lfAQUIAtW Hottentot-fig 14espmbrvunthe~mmgjj jaumea 1LU31A carnos * Sea lavender Lim~nium califgrnicum miner’s lettuce ...MeagubryAnthomuw odu~lef Jaumea. JAI.mA ZAXn2M Sea lavender Liumnim £&JJ.±oLnicim Miner’s lettuce Montia perflnaa Li nanthus LTfAnDnhILE granAilau...PROPUCT IN P 100 W 4tM POLLINATION Il 12.10 190 1320 TOTAL 1901 93,00 II I ECONOMIC FEASIBILITY OF THE ". CULLINAN RANCH FOR AGR I CULTURAL PRODUCT I ON 1

  10. Volcanoes and human history

    Science.gov (United States)

    Cashman, K. V.; Giordano, G.

    2008-10-01

    The study of volcanic hazards leads inevitably to questions of how past cultures have lived in volcanically active regions of the world. Here we summarize linkages between volcanological, archaeological and anthropological studies of historic and prehistoric volcanic eruptions, with the goal of evaluating the impact of past eruptions on human populations to better prepare for future events. We use examples from papers collected in this volume to illustrate ways in which volcanological studies aid archaeological investigations by providing basic stratigraphic markers and information about the nature and timing of specific volcanic events. We then turn to archaeological perspectives, which provide physical evidence of the direct impacts of volcanic eruptions, such as site abandonment and human migration, as well as indirect impacts on local cultures as reflected in human artifacts. Finally we review anthropological studies of societal responses to past and recent volcanic eruptions. We pay particular attention to both the psychological impact of catastrophic events and records of these impacts encoded within oral traditions. Taken together these studies record drastic short-term eruption impacts but adaptation to volcanic activity over the longer term, largely through strategies of adaptive land use.

  11. K-Ar ages of the Hiruzen volcano group and the Daisen volcano

    International Nuclear Information System (INIS)

    Tsukui, Masashi; Nishido, Hirotsugu; Nagao, Keisuke.

    1985-01-01

    Seventeen volcanic rocks of the Hiruzen volcano group and the Daisen volcano, in southwest Japan, were dated by the K-Ar method to clarify the age of volcanic activity in this region and the evolution of these composite volcanoes. The eruption ages of the Hiruzen volcano group were revealed to be about 0.9 Ma to 0.5 Ma, those of the Daisen volcano to be about 1 Ma to very recent. These results are consistent with geological and paleomagnetic data of previous workers. Effusion of lavas in the area was especially vigorous at 0.5+-0.1 Ma. It was generally considered that the Hiruzen volcano group had erupted during latest Pliocene to early Quaternary and it is older than the Daisen volcano, mainly from their topographic features. However, their overlapping eruption ages and petrographical similarities of the lavas of the Hiruzen volcano group and the Daisen volcano suggest that they may be included in the Daisen volcano in a broad sense. The aphyric andesite, whose eruption age had been correlated to Wakurayama andesite (6.34+-0.19 Ma) in Matsue city and thought to be the basement of the Daisen volcano, was dated to be 0.46+-0.04 Ma. It indicates that petrographically similar aphyric andesite erupted sporadically at different time and space in the San'in district. (author)

  12. Cosmic rays from 1017eV to beyond 1020eV: evidence from the fly's eye experiment and ground arrays.

    Science.gov (United States)

    Sokolsky, P.

    The study of cosmic rays with energies well above the knee (1015eV) of the spectrum has a long history. Beginning with the pioneering work of Linsley and the Volcano Ranch array, followed by the SUGAR, Haverah Park, Yakutsk, Akeno and AGASA array and the Fly's Eye detector, evidence has been steadily accumulating that the spectrum exhibits a change in slope near 10×1018eV. This flattening may indicate that the spectrum in this region is largely extragalactic in origin. If the sources of this spectrum are sufficiently distant, a cut-off due to the interaction of near 1020eV protons with black body photons should be observed. Recent data from the AGASA and Fly's Eye detectors have brought to bear information of spectral shape, composition and anisotropy to this study. In addition to clarifying the nature of the spectral structure, these new results lead to the surprising conclusion that nearby cosmic ray sources must exist that produce particles with energies well in excess of 1020eV. New experiments are being designed which will have the enormous apertures necessary for detecting these very rare events.

  13. Patterns in thermal emissions from the volcanoes of the Aleutian Islands

    Science.gov (United States)

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

    2012-12-01

    Using AVHRR data 1993-2011 and the Alaska Volcano Observatory's Okmok II Algorithm, the thermal emissions from all volcanoes in the Aleutian Islands were converted from temperature to power emission and examined for periodicity. The emissions were also summed to quantify the total energy released throughout the period. It was found that in the period April 1997 - January 2004 (37% of the period) the power emission from the volcanoes of the island arc declined sharply to constitute just 5.7% of the total power output for the period (138,311 MW), and this was attributable to just three volcanoes: Veniaminof (1.0%), Cleveland (1.5%) and Shishaldin (3.2%). This period of apparent reduced activity contrasts with the periods both before and after and is unrelated to the number of sensors in orbit at the time. What is also evident from the data set is that in terms of overall power emission over this period, the majority of emitted energy is largely attributable to those volcanoes which erupt with regularity (again, Veniaminof [29.7%], Cleveland [17%] and Shishaldin [11.4%]), as opposed to from the relatively few, large scale events (i.e. Reboubt [5.4%], Okmok [8.3%], Augustine [9.7%]; Pavlov [13.9%] being an exception). Sum power emission from volcanoes in the Aleutian Islands (1993-2011)

  14. Geoflicks Reviewed--Films about Hawaiian Volcanoes.

    Science.gov (United States)

    Bykerk-Kauffman, Ann

    1994-01-01

    Reviews 11 films on volcanic eruptions in the United States. Films are given a one- to five-star rating and the film's year, length, source and price are listed. Top films include "Inside Hawaiian Volcanoes" and "Kilauea: Close up of an Active Volcano." (AIM)

  15. Orographic Flow over an Active Volcano

    Science.gov (United States)

    Poulidis, Alexandros-Panagiotis; Renfrew, Ian; Matthews, Adrian

    2014-05-01

    Orographic flows over and around an isolated volcano are studied through a series of numerical model experiments. The volcano top has a heated surface, so can be thought of as "active" but not erupting. A series of simulations with different atmospheric conditions and using both idealised and realistic configurations of the Weather Research and Forecast (WRF) model have been carried out. The study is based on the Soufriere Hills volcano, located on the island of Montserrat in the Caribbean. This is a dome-building volcano, leading to a sharp increase in the surface skin temperature at the top of the volcano - up to tens of degrees higher than ambient values. The majority of the simulations use an idealised topography, in order for the results to have general applicability to similar-sized volcanoes located in the tropics. The model is initialised with idealised atmospheric soundings, representative of qualitatively different atmospheric conditions from the rainy season in the tropics. The simulations reveal significant changes to the orographic flow response, depending upon the size of the temperature anomaly and the atmospheric conditions. The flow regime and characteristic features such as gravity waves, orographic clouds and orographic rainfall patterns can all be qualitatively changed by the surface heating anomaly. Orographic rainfall over the volcano can be significantly enhanced with increased temperature anomaly. The implications for the eruptive behaviour of the volcano and resulting secondary volcanic hazards will also be discussed.

  16. Volcano-ice interaction as a microbial habitat on Earth and Mars.

    Science.gov (United States)

    Cousins, Claire R; Crawford, Ian A

    2011-09-01

    Volcano-ice interaction has been a widespread geological process on Earth that continues to occur to the present day. The interaction between volcanic activity and ice can generate substantial quantities of liquid water, together with steep thermal and geochemical gradients typical of hydrothermal systems. Environments available for microbial colonization within glaciovolcanic systems are wide-ranging and include the basaltic lava edifice, subglacial caldera meltwater lakes, glacier caves, and subsurface hydrothermal systems. There is widespread evidence of putative volcano-ice interaction on Mars throughout its history and at a range of latitudes. Therefore, it is possible that life on Mars may have exploited these habitats, much in the same way as has been observed on Earth. The sedimentary and mineralogical deposits resulting from volcano-ice interaction have the potential to preserve evidence of any indigenous microbial populations. These include jökulhlaup (subglacial outflow) sedimentary deposits, hydrothermal mineral deposits, basaltic lava flows, and subglacial lacustrine deposits. Here, we briefly review the evidence for volcano-ice interactions on Mars and discuss the geomicrobiology of volcano-ice habitats on Earth. In addition, we explore the potential for the detection of these environments on Mars and any biosignatures these deposits may contain.

  17. SmallWorld Behavior of the Worldwide Active Volcanoes Network: Preliminary Results

    Science.gov (United States)

    Spata, A.; Bonforte, A.; Nunnari, G.; Puglisi, G.

    2009-12-01

    We propose a preliminary complex networks based approach in order to model and characterize volcanoes activity correlation observed on a planetary scale over the last two thousand years. Worldwide volcanic activity is in fact related to the general plate tectonics that locally drives the faults activity, that in turn controls the magma upraise beneath the volcanoes. To find correlations among different volcanoes could indicate a common underlying mechanism driving their activity and could help us interpreting the deeper common dynamics controlling their unrest. All the first evidences found testing the procedure, suggest the suitability of this analysis to investigate global volcanism related to plate tectonics. The first correlations found, in fact, indicate that an underlying common large-scale dynamics seems to drive volcanic activity at least around the Pacific plate, where it collides and subduces beneath American, Eurasian and Australian plates. From this still preliminary analysis, also more complex relationships among volcanoes lying on different tectonic margins have been found, suggesting some more complex interrelationships between different plates. The understanding of eventually detected correlations could be also used to further implement warning systems, relating the unrest probabilities of a specific volcano also to the ongoing activity to the correlated ones. Our preliminary results suggest that, as for other many physical and biological systems, an underlying organizing principle of planetary volcanoes activity might exist and it could be a small-world principle. In fact we found that, from a topological perspective, volcanoes correlations are characterized by the typical features of small-world network: a high clustering coefficient and a low characteristic path length. These features confirm that global volcanoes activity is characterized by both short and long-range correlations. We stress here the fact that numerical simulation carried out in

  18. The 2014 eruptions of Pavlof Volcano, Alaska

    Science.gov (United States)

    Waythomas, Christopher F.; Haney, Matthew M.; Wallace, Kristi; Cameron, Cheryl E.; Schneider, David J.

    2017-12-22

    Pavlof Volcano is one of the most frequently active volcanoes in the Aleutian Island arc, having erupted more than 40 times since observations were first recorded in the early 1800s . The volcano is located on the Alaska Peninsula (lat 55.4173° N, long 161.8937° W), near Izembek National Wildlife Refuge. The towns and villages closest to the volcano are Cold Bay, Nelson Lagoon, Sand Point, and King Cove, which are all within 90 kilometers (km) of the volcano (fig. 1). Pavlof is a symmetrically shaped stratocone that is 2,518 meters (m) high, and has about 2,300 m of relief. The volcano supports a cover of glacial ice and perennial snow roughly 2 to 4 cubic kilometers (km3) in volume, which is mantled by variable amounts of tephra fall, rockfall debris, and pyroclastic-flow deposits produced during historical eruptions. Typical Pavlof eruptions are characterized by moderate amounts of ash emission, lava fountaining, spatter-fed lava flows, explosions, and the accumulation of unstable mounds of spatter on the upper flanks of the volcano. The accumulation and subsequent collapse of spatter piles on the upper flanks of the volcano creates hot granular avalanches, which erode and melt snow and ice, and thereby generate watery debris-flow and hyperconcentrated-flow lahars. Seismic instruments were first installed on Pavlof Volcano in the early 1970s, and since then eruptive episodes have been better characterized and specific processes have been documented with greater certainty. The application of remote sensing techniques, including the use of infrasound data, has also aided the study of more recent eruptions. Although Pavlof Volcano is located in a remote part of Alaska, it is visible from Cold Bay, Sand Point, and Nelson Lagoon, making distal observations of eruptive activity possible, weather permitting. A busy air-travel corridor that is utilized by a numerous transcontinental and regional air carriers passes near Pavlof Volcano. The frequency of air travel

  19. Exploring Geology on the World-Wide Web--Volcanoes and Volcanism.

    Science.gov (United States)

    Schimmrich, Steven Henry; Gore, Pamela J. W.

    1996-01-01

    Focuses on sites on the World Wide Web that offer information about volcanoes. Web sites are classified into areas of Global Volcano Information, Volcanoes in Hawaii, Volcanoes in Alaska, Volcanoes in the Cascades, European and Icelandic Volcanoes, Extraterrestrial Volcanism, Volcanic Ash and Weather, and Volcano Resource Directories. Suggestions…

  20. Geophysical Exploration on the Structure of Volcanoes: Two Case Histories

    Energy Technology Data Exchange (ETDEWEB)

    Furumoto, A. S.

    1974-01-01

    Geophysical methods of exploration were used to determine the internal structure of Koolau Volcano in Hawaii and of Rabaul Volcano in New Guinea. By use of gravity and seismic data the central vent or plug of Koolau Volcano was outlined. Magnetic data seem to indicate that the central plug is still above the Curie Point. If so, the amount of heat energy available is tremendous. As for Rabaul Volcano, it is located in a region characterized by numerous block faulting. The volcano is only a part of a large block that has subsided. Possible geothermal areas exist near the volcano but better potential areas may exist away from the volcano.

  1. Instrumentation Recommendations for Volcano Monitoring at U.S. Volcanoes Under the National Volcano Early Warning System

    Science.gov (United States)

    Moran, Seth C.; Freymueller, Jeff T.; LaHusen, Richard G.; McGee, Kenneth A.; Poland, Michael P.; Power, John A.; Schmidt, David A.; Schneider, David J.; Stephens, George; Werner, Cynthia A.; White, Randall A.

    2008-01-01

    As magma moves toward the surface, it interacts with anything in its path: hydrothermal systems, cooling magma bodies from previous eruptions, and (or) the surrounding 'country rock'. Magma also undergoes significant changes in its physical properties as pressure and temperature conditions change along its path. These interactions and changes lead to a range of geophysical and geochemical phenomena. The goal of volcano monitoring is to detect and correctly interpret such phenomena in order to provide early and accurate warnings of impending eruptions. Given the well-documented hazards posed by volcanoes to both ground-based populations (for example, Blong, 1984; Scott, 1989) and aviation (for example, Neal and others, 1997; Miller and Casadevall, 2000), volcano monitoring is critical for public safety and hazard mitigation. Only with adequate monitoring systems in place can volcano observatories provide accurate and timely forecasts and alerts of possible eruptive activity. At most U.S. volcanoes, observatories traditionally have employed a two-component approach to volcano monitoring: (1) install instrumentation sufficient to detect unrest at volcanic systems likely to erupt in the not-too-distant future; and (2) once unrest is detected, install any instrumentation needed for eruption prediction and monitoring. This reactive approach is problematic, however, for two reasons. 1. At many volcanoes, rapid installation of new ground-1. based instruments is difficult or impossible. Factors that complicate rapid response include (a) eruptions that are preceded by short (hours to days) precursory sequences of geophysical and (or) geochemical activity, as occurred at Mount Redoubt (Alaska) in 1989 (24 hours), Anatahan (Mariana Islands) in 2003 (6 hours), and Mount St. Helens (Washington) in 1980 and 2004 (7 and 8 days, respectively); (b) inclement weather conditions, which may prohibit installation of new equipment for days, weeks, or even months, particularly at

  2. A comparison of some methods used to estimate the grazing capacity of a game ranch in Northern Province, South Africa

    Directory of Open Access Journals (Sweden)

    A.G. Schmidt

    1995-08-01

    Full Text Available The grazing capacity of a game ranch in Northern Province was estimated in a number of different ways using rainfall and herbaceous composition and phytomass data. The results indicate that the grazing capacity under the present environmental conditions should be approximately 50 of the recommended agricultural grazer stocking rate. This is in agreement with recent literature, indicating that the methods used should be suitable for determining a first approximation of grazing capacity in the mixed bushveld of Northern Province.

  3. Geologic Mapping, Volcanic Stages and Magmatic Processes in Hawaiian Volcanoes

    Science.gov (United States)

    Sinton, J. M.

    2005-12-01

    The concept of volcanic stages arose from geologic mapping of Hawaiian volcanoes. Subaerial Hawaiian lava successions can be divided generally into three constructional phases: an early (shield) stage dominated by thin-bedded basaltic lava flows commonly associated with a caldera; a later (postshield) stage with much thicker bedded, generally lighter colored lava flows commonly containing clinopyroxene; calderas are absent in this later stage. Following periods of quiescence of a half million years or more, some Hawaiian volcanoes have experienced renewed (rejuvenated) volcanism. Geological and petrographic relations irrespective of chemical composition led to the identification of mappable units on Niihau, Kauai, Oahu, Molokai, Maui and Hawaii, which form the basis for this 3-fold division of volcanic activity. Chemical data have complicated the picture. There is a growing tendency to assign volcanic stage based on lava chemistry, principally alkalicity, into tholeiitic shield, alkalic postshield, and silica undersaturated rejuvenation, despite the evidence for interbedded tholeiitic and alkalic basalts in many shield formations, and the presence of mildly tholeiitic lavas in some postshield and rejuvenation formations. A consistent characteristic of lava compositions from most postshield formations is evidence for post-melting evolution at moderately high pressures (3-7 kb). Thus, the mapped shield to postshield transitions primarily reflect the disappearance of shallow magma chambers (and associated calderas) in Hawaiian volcanoes, not the earlier (~100 ka earlier in Waianae Volcano) decline in partial melting that leads to the formation of alkalic parental magmas. Petrological signatures of high-pressure evolution are high-temperature crystallization of clinopyroxene and delayed crystallization of plagioclase, commonly to <3 % MgO. Petrologic modeling using pMELTS and MELTS algorithms allows for quantification of the melting and fractionation conditions giving

  4. Unzipping of the volcano arc, Japan

    Science.gov (United States)

    Stern, R.J.; Smoot, N.C.; Rubin, M.

    1984-01-01

    A working hypothesis for the recent evolution of the southern Volcano Arc, Japan, is presented which calls upon a northward-progressing sundering of the arc in response to a northward-propagating back-arc basin extensional regime. This model appears to explain several localized and recent changes in the tectonic and magrnatic evolution of the Volcano Arc. Most important among these changes is the unusual composition of Iwo Jima volcanic rocks. This contrasts with normal arc tholeiites typical of the rest of the Izu-Volcano-Mariana and other primitive arcs in having alkaline tendencies, high concentrations of light REE and other incompatible elements, and relatively high silica contents. In spite of such fractionated characteristics, these lavas appear to be very early manifestations of a new volcanic and tectonic cycle in the southern Volcano Arc. These alkaline characteristics and indications of strong regional uplift are consistent with the recent development of an early stage of inter-arc basin rifting in the southern Volcano Arc. New bathymetric data are presented in support of this model which indicate: 1. (1) structural elements of the Mariana Trough extend north to the southern Volcano Arc. 2. (2) both the Mariana Trough and frontal arc shoal rapidly northwards as the Volcano Arc is approached. 3. (3) rugged bathymetry associated with the rifted Mariana Trough is replaced just south of Iwo Jima by the development of a huge dome (50-75 km diameter) centered around Iwo Jima. Such uplifted domes are the immediate precursors of rifts in other environments, and it appears that a similar situation may now exist in the southern Volcano Arc. The present distribution of unrifted Volcano Arc to the north and rifted Mariana Arc to the south is interpreted not as a stable tectonic configuration but as representing a tectonic "snapshot" of an arc in the process of being rifted to form a back-arc basin. ?? 1984.

  5. Volcanoes

    Science.gov (United States)

    ... Extreme Heat Older Adults (Aged 65+) Infants and Children Chronic Medical Conditions Low Income Athletes Outdoor Workers Pets Hot Weather Tips Warning Signs and Symptoms FAQs Social Media How to Stay Cool Missouri Cooling Centers Extreme ...

  6. Common processes at unique volcanoes – a volcanological conundrum

    OpenAIRE

    Katharine eCashman; Juliet eBiggs

    2014-01-01

    An emerging challenge in modern volcanology is the apparent contradiction between the perception that every volcano is unique, and classification systems based on commonalities among volcano morphology and eruptive style. On the one hand, detailed studies of individual volcanoes show that a single volcano often exhibits similar patterns of behavior over multiple eruptive episodes; this observation has led to the idea that each volcano has its own distinctive pattern of behavior (or “personali...

  7. Linking space observations to volcano observatories in Latin America: Results from the CEOS DRM Volcano Pilot

    Science.gov (United States)

    Delgado, F.; Pritchard, M. E.; Biggs, J.; Arnold, D. W. D.; Poland, M. P.; Ebmeier, S. K.; Wauthier, C.; Wnuk, K.; Parker, A. L.; Amelug, F.; Sansosti, E.; Mothes, P. A.; Macedo, O.; Lara, L.; Zoffoli, S.; Aguilar, V.

    2015-12-01

    Within Latin American, about 315 volcanoes that have been active in the Holocene, but according to the United Nations Global Assessment of Risk 2015 report (GAR15) 202 of these volcanoes have no seismic, deformation or gas monitoring. Following the 2012 Santorini Report on satellite Earth Observation and Geohazards, the Committee on Earth Observation Satellites (CEOS) has developed a 3-year pilot project to demonstrate how satellite observations can be used to monitor large numbers of volcanoes cost-effectively, particularly in areas with scarce instrumentation and/or difficult access. The pilot aims to improve disaster risk management (DRM) by working directly with the volcano observatories that are governmentally responsible for volcano monitoring, and the project is possible thanks to data provided at no cost by international space agencies (ESA, CSA, ASI, DLR, JAXA, NASA, CNES). Here we highlight several examples of how satellite observations have been used by volcano observatories during the last 18 months to monitor volcanoes and respond to crises -- for example the 2013-2014 unrest episode at Cerro Negro/Chiles (Ecuador-Colombia border); the 2015 eruptions of Villarrica and Calbuco volcanoes, Chile; the 2013-present unrest and eruptions at Sabancaya and Ubinas volcanoes, Peru; the 2015 unrest at Guallatiri volcano, Chile; and the 2012-present rapid uplift at Cordon Caulle, Chile. Our primary tool is measurements of ground deformation made by Interferometric Synthetic Aperture Radar (InSAR) but thermal and outgassing data have been used in a few cases. InSAR data have helped to determine the alert level at these volcanoes, served as an independent check on ground sensors, guided the deployment of ground instruments, and aided situational awareness. We will describe several lessons learned about the type of data products and information that are most needed by the volcano observatories in different countries.

  8. Patterns of deformation and volcanic flows associated with lithospheric loading by large volcanoes on Venus

    Science.gov (United States)

    Mcgovern, Patrick J.; Solomon, Sean C.

    1993-01-01

    Magellan radar imaging and topography data are now available for a number of volcanoes on Venus greater than 100 km in radius. These data can be examined to reveal evidence of the flexural response of the lithosphere to the volcanic load. On Venus, erosion and sediment deposition are negligible, so tectonic evidence of deformation around large volcanoes should be evident except where buried by very young flows. Radar images reveal that most tectonic features and flow units on the flanks of these volcanoes have predominantly radial orientations. However, both Tepev Mons in Bell Regio and Sapas Mons in Atla Regio exhibit circumferential graben on their flanks. In addition, images reveal several flow units with an annular character around the north and west flanks of Tepev Mons. This pattern most likely results from ponding of flows in an annular flexural moat. Maat Mons in Atla Regio and Sif Mons in Eistla Regio are examples of volcanoes that lack circumferential graben and annular flows; discernible flow units and fractures on these constructs appear to be predominantly radial. Altimetry data can also provide evidence of flexural response. Tepev Mons is partially encircled by depressions that may be sections of a flexural moat that has not been completely filled. The locations of these depressions generally coincide with the annular flows described above. There is weaker evidence for such depressions around Maat Mons as well. The lack of circumferential tectonic features around most volcanoes on Venus might be explained by gradual moat filling and coverage by radial flows. The depressions around Tepev (and possible Maat) may indicate that this process is currently continuing. We use analytic models of plate flexure in an axisymmetric geometry to constrain the elastic plate thickness supporting Tepev Mons. If we consider the outer radius of the ponded flows to be the edge of a moat, we find that models with elastic plate thickness of 10-20 km fit best. Finite element

  9. Hydrothermal systems and volcano geochemistry

    Science.gov (United States)

    Fournier, R.O.

    2007-01-01

    The upward intrusion of magma from deeper to shallower levels beneath volcanoes obviously plays an important role in their surface deformation. This chapter will examine less obvious roles that hydrothermal processes might play in volcanic deformation. Emphasis will be placed on the effect that the transition from brittle to plastic behavior of rocks is likely to have on magma degassing and hydrothermal processes, and on the likely chemical variations in brine and gas compositions that occur as a result of movement of aqueous-rich fluids from plastic into brittle rock at different depths. To a great extent, the model of hydrothermal processes in sub-volcanic systems that is presented here is inferential, based in part on information obtained from deep drilling for geothermal resources, and in part on the study of ore deposits that are thought to have formed in volcanic and shallow plutonic environments.

  10. Volcanoes of the World: Reconfiguring a scientific database to meet new goals and expectations

    Science.gov (United States)

    Venzke, Edward; Andrews, Ben; Cottrell, Elizabeth

    2015-04-01

    that feature. One especially significant audit involved re-evaluating the categories of evidence used to include a volcano in the Holocene list, and reviewing in detail the entries in low-certainty categories. Concurrently, we developed a new data entry system that may in the future allow trusted users outside of Smithsonian to input data into VOTW. A redesigned website now provides new search tools and data download options. We are collaborating with organizations that manage volcano and eruption databases, physical sample databases, and geochemical databases to allow real-time connections and complex queries. VOTW serves the volcanological community by providing a clear and consistent core database of distinctly identified volcanoes and eruptions to advance goals in research, civil defense, and public outreach.

  11. Drill baby drill: An analysis of how energy development displaced ranching's dominance over the BLM's subgovernment policymaking environment

    Science.gov (United States)

    Forbis, Robert Earl, Jr.

    Academic literature analyzing the Bureau of Land Management (BLM) land-use subgovernment stops at the Taylor Grazing Act and concludes that the historical development of administering grazing on public lands led to the capture of the BLM by ranching interests. Using a two-pronged methodological approach of process tracing and elite interviews this dissertation seeks to advance our collective knowledge of subgovernment theory by (a) clarifying the impact executive decision-making has on subgovernments and (b) identifying the conditions under which strategically competitive behavior between two competing subgovernment actors occurs. The dissertation seeks to update the literature by explaining what has caused the BLM to shift from a rancher-dominated agency to an energy dominated agency by identifying conditions under which subgovernment actors strategically respond to a political conflict. The research poses two questions: (1) how have executive actions disrupted an existing balance of power in a so-called "strong corner" of an entrenched subgovernment system and (2) what happens when conflict and competition break out between allied members of the system? Analysis indicates that as the BLM responded to Executive actions emphasizing domestic energy production, a conflict emerged between traditional allies: ranching and energy. Triggered by the unintended consequence of awakening long-dormant legislation, split-estate energy development---where property rights are severed between private surface and federal mineral estates---expanded across the West. In turn, this expansion helped establish the conditions for conflict and in doing so disrupted the balance of power between large public resource use interests in the relatively stable land-use subgovernment of the BLM. Indicative of energy's emerging dominance of the BLM's subgovernment, split-estate energy development led ranching interests to seek the protection of their Western state legislatures. This shift in

  12. Development and Engineering Design in Support of "Rover Ranch": A K-12 Outreach Software Project

    Science.gov (United States)

    Pascali, Raresh

    2003-01-01

    A continuation of the initial development started in the summer of 1999, the body of work performed in support of 'ROVer Ranch' Project during the present fellowship dealt with the concrete concept implementation and resolution of the related issues. The original work performed last summer focused on the initial examination and articulation of the concept treatment strategy, audience and market analysis for the learning technologies software. The presented work focused on finalizing the set of parts to be made available for building an AERCam Sprint type robot and on defining, testing and implementing process necessary to convert the design engineering files to VRML files. Through reverse engineering, an initial set of mission critical systems was designed for beta testing in schools. The files were created in ProEngineer, exported to VRML 1.0 and converted to VRML 97 (VRML 2.0) for final integration in the software. Attributes for each part were assigned using an in-house developed JAVA based program. The final set of attributes for each system, their mutual interaction and the identification of the relevant ones to be tracked, still remain to be decided.

  13. Thermal environment characterization for the bovine cattle ranching in the Valle del Cauca, Colombia

    Directory of Open Access Journals (Sweden)

    Raúl Andres Molina Benavides

    2016-10-01

    Full Text Available The influence of climate on animal behavior has been demonstrated for many years. Climatic variables such as temperature (T, ° C, relative humidity (RH, %, solar radiation (SR, W / m2 and wind speed (WS, m / s, outside their normal range, can displace ruminants of their comfort zone, which can results in negative impact on their productivity and reproduction behavior. In order to characterize the thermal environment of bovine cattle ranching in the Valle del Cauca department, two biometeorological indexes (heat load index for dairy cows and meat cattle were performed to develop an animal - environment relationship. The indexes were applied to the most representative Valle del Cauca department climatic ranges (T = 20-35; RH = 60-100; WS = 0-10, finding that for dairy cows under the mentioned conditions of T> 23, RH> 80 and 0 WS, starting to show signals of heat stress, while for beef cattle starts with T> 25, RH> 60 and WS <1.5. In conclusion, these indexes are useful tools to determine the degree of heat stress that may occur on farms during certain times of day for certain months of the year, helping to plan actions to control its effect in cattle and subsequently, mitigate the impacts on their productive and reproductive performance.

  14. Sustainable Cattle Ranching in Practice: Moving from Theory to Planning in Colombia's Livestock Sector

    Science.gov (United States)

    Lerner, Amy M.; Zuluaga, Andrés Felipe; Chará, Julián; Etter, Andrés; Searchinger, Timothy

    2017-08-01

    A growing population with increasing consumption of milk and dairy require more agricultural output in the coming years, which potentially competes with forests and other natural habitats. This issue is particularly salient in the tropics, where deforestation has traditionally generated cattle pastures and other commodity crops such as corn and soy. The purpose of this article is to review the concepts and discussion associated with reconciling food production and conservation, and in particular with regards to cattle production, including the concepts of land-sparing and land-sharing. We then present these concepts in the specific context of Colombia, where there are efforts to increase both cattle production and protect tropical forests, in order to discuss the potential for landscape planning for sustainable cattle production. We outline a national planning approach, which includes disaggregating the diverse cattle sector and production types, identifying biophysical, and economic opportunities and barriers for sustainable intensification in cattle ranching, and analyzing areas suitable for habitat restoration and conservation, in order to plan for both land-sparing and land-sharing strategies. This approach can be used in other contexts across the world where there is a need to incorporate cattle production into national goals for carbon sequestration and habitat restoration and conservation.

  15. Sustainable Cattle Ranching in Practice: Moving from Theory to Planning in Colombia's Livestock Sector.

    Science.gov (United States)

    Lerner, Amy M; Zuluaga, Andrés Felipe; Chará, Julián; Etter, Andrés; Searchinger, Timothy

    2017-08-01

    A growing population with increasing consumption of milk and dairy require more agricultural output in the coming years, which potentially competes with forests and other natural habitats. This issue is particularly salient in the tropics, where deforestation has traditionally generated cattle pastures and other commodity crops such as corn and soy. The purpose of this article is to review the concepts and discussion associated with reconciling food production and conservation, and in particular with regards to cattle production, including the concepts of land-sparing and land-sharing. We then present these concepts in the specific context of Colombia, where there are efforts to increase both cattle production and protect tropical forests, in order to discuss the potential for landscape planning for sustainable cattle production. We outline a national planning approach, which includes disaggregating the diverse cattle sector and production types, identifying biophysical, and economic opportunities and barriers for sustainable intensification in cattle ranching, and analyzing areas suitable for habitat restoration and conservation, in order to plan for both land-sparing and land-sharing strategies. This approach can be used in other contexts across the world where there is a need to incorporate cattle production into national goals for carbon sequestration and habitat restoration and conservation.

  16. Multi-parametric investigation of the volcano-hydrothermal system at Tatun Volcano Group, Northern Taiwan

    Science.gov (United States)

    Rontogianni, S.; Konstantinou, K. I.; Lin, C.-H.

    2012-07-01

    The Tatun Volcano Group (TVG) is located in northern Taiwan near the capital Taipei. In this study we selected and analyzed almost four years (2004-2007) of its seismic activity. The seismic network established around TVG initially consisted of eight three-component seismic stations with this number increasing to twelve by 2007. Local seismicity mainly involved high frequency (HF) earthquakes occurring as isolated events or as part of spasmodic bursts. Mixed and low frequency (LF) events were observed during the same period but more rarely. During the analysis we estimated duration magnitudes for the HF earthquakes and used a probabilistic non-linear method to accurately locate all these events. The complex frequencies of LF events were also analyzed with the Sompi method indicating fluid compositions consistent with a misty or dusty gas. We juxtaposed these results with geochemical/temperature anomalies extracted from fumarole gas and rainfall levels covering a similar period. This comparison is interpreted in the context of a model proposed earlier for the volcano-hydrothermal system of TVG where fluids and magmatic gases ascend from a magma body that lies at around 7-8 km depth. Most HF earthquakes occur as a response to stresses induced by fluid circulation within a dense network of cracks pervading the upper crust at TVG. The largest (ML ~ 3.1) HF event that occurred on 24 April 2006 at a depth of 5-6 km had source characteristics compatible with that of a tensile crack. It was followed by an enrichment in magmatic components of the fumarole gases as well as a fumarole temperature increase, and provides evidence for ascending fluids from a magma body into the shallow hydrothermal system. This detailed analysis and previous physical volcanology observations at TVG suggest that the region is volcanically active and that measures to mitigate potential hazards have to be considered by the local authorities.

  17. Multi-parametric investigation of the volcano-hydrothermal system at Tatun Volcano Group, Northern Taiwan

    Directory of Open Access Journals (Sweden)

    S. Rontogianni

    2012-07-01

    Full Text Available The Tatun Volcano Group (TVG is located in northern Taiwan near the capital Taipei. In this study we selected and analyzed almost four years (2004–2007 of its seismic activity. The seismic network established around TVG initially consisted of eight three-component seismic stations with this number increasing to twelve by 2007. Local seismicity mainly involved high frequency (HF earthquakes occurring as isolated events or as part of spasmodic bursts. Mixed and low frequency (LF events were observed during the same period but more rarely. During the analysis we estimated duration magnitudes for the HF earthquakes and used a probabilistic non-linear method to accurately locate all these events. The complex frequencies of LF events were also analyzed with the Sompi method indicating fluid compositions consistent with a misty or dusty gas. We juxtaposed these results with geochemical/temperature anomalies extracted from fumarole gas and rainfall levels covering a similar period. This comparison is interpreted in the context of a model proposed earlier for the volcano-hydrothermal system of TVG where fluids and magmatic gases ascend from a magma body that lies at around 7–8 km depth. Most HF earthquakes occur as a response to stresses induced by fluid circulation within a dense network of cracks pervading the upper crust at TVG. The largest (ML ~ 3.1 HF event that occurred on 24 April 2006 at a depth of 5–6 km had source characteristics compatible with that of a tensile crack. It was followed by an enrichment in magmatic components of the fumarole gases as well as a fumarole temperature increase, and provides evidence for ascending fluids from a magma body into the shallow hydrothermal system. This detailed analysis and previous physical volcanology observations at TVG suggest that the region is volcanically active and that measures to mitigate potential hazards have to be considered by the local authorities.

  18. Felsic maar-diatreme volcanoes: a review

    Science.gov (United States)

    Ross, Pierre-Simon; Carrasco Núñez, Gerardo; Hayman, Patrick

    2017-02-01

    breccias (Kelian, Mt. Rawdon). Pyroclastic rocks in the diatreme are typically poorly sorted, and ash-rich. They contain a heterolithic mix of juvenile clasts and lithic clasts from various stratigraphic levels. Megablocks derived from the ejecta ring or the country rocks are often found in the diatremes. Evidence for multiple explosions is in the form of steep crosscutting pyroclastic bodies within some diatremes and fragments of pyroclastic rocks within other pyroclastic facies. Pyroclastic rocks are cut by coherent felsic dikes and plugs which may have been feeders to lava domes at the surface. Allowing for the difference in magma composition, felsic maar-diatreme volcanoes have many similarities with their ultramafic to mafic equivalents. Differences include a common association with felsic domes, inside the crater or just outside (Wau), although the domes within the crater may be destroyed during the eruption (Hoya de Estrada, Tepexitl); the dikes and plugs feeding and invading felsic diatremes seem larger; the processes of phreatomagmatic explosions involving felsic magmas may be different.

  19. Digital Data for Volcano Hazards in the Mount Jefferson Region, Oregon

    Science.gov (United States)

    Schilling, S.P.; Doelger, S.; Walder, J.S.; Gardner, C.A.; Conrey, R.M.; Fisher, B.J.

    2008-01-01

    Mount Jefferson has erupted repeatedly for hundreds of thousands of years, with its last eruptive episode during the last major glaciation which culminated about 15,000 years ago. Geologic evidence shows that Mount Jefferson is capable of large explosive eruptions. The largest such eruption occurred between 35,000 and 100,000 years ago. If Mount Jefferson erupts again, areas close to the eruptive vent will be severely affected, and even areas tens of kilometers (tens of miles) downstream along river valleys or hundreds of kilometers (hundreds of miles) downwind may be at risk. Numerous small volcanoes occupy the area between Mount Jefferson and Mount Hood to the north, and between Mount Jefferson and the Three Sisters region to the south. These small volcanoes tend not to pose the far-reaching hazards associated with Mount Jefferson, but are nonetheless locally important. A concern at Mount Jefferson, but not at the smaller volcanoes, is the possibility that small-to-moderate sized landslides could occur even during periods of no volcanic activity. Such landslides may transform as they move into lahars (watery flows of rock, mud, and debris) that can inundate areas far downstream. The geographic information system (GIS) volcano hazard data layer used to produce the Mount Jefferson volcano hazard map in USGS Open-File Report 99-24 (Walder and others, 1999) is included in this data set. Both proximal and distal hazard zones were delineated by scientists at the Cascades Volcano Observatory and depict various volcano hazard areas around the mountain.

  20. Lahar hazards at Mombacho Volcano, Nicaragua

    Science.gov (United States)

    Vallance, J.W.; Schilling, S.P.; Devoli, G.

    2001-01-01

    Mombacho volcano, at 1,350 meters, is situated on the shores of Lake Nicaragua and about 12 kilometers south of Granada, a city of about 90,000 inhabitants. Many more people live a few kilometers southeast of Granada in 'las Isletas de Granada and the nearby 'Peninsula de Aseses. These areas are formed of deposits of a large debris avalanche (a fast moving avalanche of rock and debris) from Mombacho. Several smaller towns with population, in the range of 5,000 to 12,000 inhabitants are to the northwest and the southwest of Mombacho volcano. Though the volcano has apparently not been active in historical time, or about the last 500 years, it has the potential to produce landslides and debris flows (watery flows of mud, rock, and debris -- also known as lahars when they occur on a volcano) that could inundate these nearby populated areas. -- Vallance, et.al., 2001

  1. Analysis of volcano rocks by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sitek, J.; Dekan, J.

    2012-01-01

    In this work we have analysed the basalt rock from Mount Ba tur volcano situated on the Island of Bali in Indonesia.We compared our results with composition of basalt rocks from some other places on the Earth. (authors)

  2. Moessbauer Spectroscopy study of Quimsachata Volcano materials

    International Nuclear Information System (INIS)

    Dominguez, A.G.B.

    1988-01-01

    It has been studied volcanic lava from Quimsachata Volcano in Pem. Moessbauer Spectroscopy, X-ray diffraction, electronic and optical microscopy allowed the identification of different mineralogical phases. (A.C.AS.) [pt

  3. Lahar hazards at Agua volcano, Guatemala

    Science.gov (United States)

    Schilling, S.P.; Vallance, J.W.; Matías, O.; Howell, M.M.

    2001-01-01

    At 3760 m, Agua volcano towers more than 3500 m above the Pacific coastal plain to the south and 2000 m above the Guatemalan highlands to the north. The volcano is within 5 to 10 kilometers (km) of Antigua, Guatemala and several other large towns situated on its northern apron. These towns have a combined population of nearly 100,000. It is within about 20 km of Escuintla (population, ca. 100,000) to the south. Though the volcano has not been active in historical time, or about the last 500 years, it has the potential to produce debris flows (watery flows of mud, rock, and debris—also known as lahars when they occur on a volcano) that could inundate these nearby populated areas.

  4. Persistent growth of a young andesite lava cone: Bagana volcano, Papua New Guinea

    Science.gov (United States)

    Wadge, G.; McCormick Kilbride, B. T.; Edmonds, M.; Johnson, R. W.

    2018-05-01

    Bagana, an andesite lava cone on Bougainville Island, Papua New Guinea, is thought to be a very young central volcano. We have tested this idea by estimating the volumes of lava extruded over different time intervals (1-, 2-, 3-, 9-, 15-, 70-years) using digital elevation models (DEMs), mainly created from satellite data. Our results show that the long-term extrusion rate at Bagana, measured over years to decades, has remained at about 1.0 m3 s-1. We present models of the total edifice volume, and show that, if our measured extrusion rates are representative, the volcano could have been built in only 300 years. It could also possibly have been built at a slower rate during a longer, earlier period of growth. Six kilometres NNW of Bagana, an andesite-dacite volcano, Billy Mitchell, had a large, caldera-forming plinian eruption 437 years ago. We consider the possibility that, as a result of this eruption, the magma supply was diverted from Billy Mitchell to Bagana. It seems that Bagana is a rare example of a very youthful, polygenetic, andesite volcano. The characteristics of such a volcano, based on the example of Bagana, are: a preponderance of lava products over pyroclastic products, a high rate of lava extrusion maintained for decades, a very high rate of SO2 emission, evidence of magma batch fractionation and location in a trans-tensional setting at the end of an arc segment above a very steeply dipping and rapidly converging subduction zone.

  5. Combining Volcano Monitoring Timeseries Analyses with Bayesian Belief Networks to Update Hazard Forecast Estimates

    Science.gov (United States)

    Odbert, Henry; Hincks, Thea; Aspinall, Willy

    2015-04-01

    Volcanic hazard assessments must combine information about the physical processes of hazardous phenomena with observations that indicate the current state of a volcano. Incorporating both these lines of evidence can inform our belief about the likelihood (probability) and consequences (impact) of possible hazardous scenarios, forming a basis for formal quantitative hazard assessment. However, such evidence is often uncertain, indirect or incomplete. Approaches to volcano monitoring have advanced substantially in recent decades, increasing the variety and resolution of multi-parameter timeseries data recorded at volcanoes. Interpreting these multiple strands of parallel, partial evidence thus becomes increasingly complex. In practice, interpreting many timeseries requires an individual to be familiar with the idiosyncrasies of the volcano, monitoring techniques, configuration of recording instruments, observations from other datasets, and so on. In making such interpretations, an individual must consider how different volcanic processes may manifest as measureable observations, and then infer from the available data what can or cannot be deduced about those processes. We examine how parts of this process may be synthesised algorithmically using Bayesian inference. Bayesian Belief Networks (BBNs) use probability theory to treat and evaluate uncertainties in a rational and auditable scientific manner, but only to the extent warranted by the strength of the available evidence. The concept is a suitable framework for marshalling multiple strands of evidence (e.g. observations, model results and interpretations) and their associated uncertainties in a methodical manner. BBNs are usually implemented in graphical form and could be developed as a tool for near real-time, ongoing use in a volcano observatory, for example. We explore the application of BBNs in analysing volcanic data from the long-lived eruption at Soufriere Hills Volcano, Montserrat. We show how our method

  6. Effects of Volcanoes on the Natural Environment

    Science.gov (United States)

    Mouginis-Mark, Peter J.

    2005-01-01

    The primary focus of this project has been on the development of techniques to study the thermal and gas output of volcanoes, and to explore our options for the collection of vegetation and soil data to enable us to assess the impact of this volcanic activity on the environment. We originally selected several volcanoes that have persistent gas emissions and/or magma production. The investigation took an integrated look at the environmental effects of a volcano. Through their persistent activity, basaltic volcanoes such as Kilauea (Hawaii) and Masaya (Nicaragua) contribute significant amounts of sulfur dioxide and other gases to the lower atmosphere. Although primarily local rather than regional in its impact, the continuous nature of these eruptions means that they can have a major impact on the troposphere for years to decades. Since mid-1986, Kilauea has emitted about 2,000 tonnes of sulfur dioxide per day, while between 1995 and 2000 Masaya has emotted about 1,000 to 1,500 tonnes per day (Duffel1 et al., 2001; Delmelle et al., 2002; Sutton and Elias, 2002). These emissions have a significant effect on the local environment. The volcanic smog ("vog" ) that is produced affects the health of local residents, impacts the local ecology via acid rain deposition and the generation of acidic soils, and is a concern to local air traffic due to reduced visibility. Much of the work that was conducted under this NASA project was focused on the development of field validation techniques of volcano degassing and thermal output that could then be correlated with satellite observations. In this way, we strove to develop methods by which not only our study volcanoes, but also volcanoes in general worldwide (Wright and Flynn, 2004; Wright et al., 2004). Thus volcanoes could be routinely monitored for their effects on the environment. The selected volcanoes were: Kilauea (Hawaii; 19.425 N, 155.292 W); Masaya (Nicaragua; 11.984 N, 86.161 W); and Pods (Costa Rica; 10.2OoN, 84.233 W).

  7. Final Environmental Impact Report/Environmental Impact Statement, Cullinan Ranch Specific Plan, City of Vallejo, Solano County, California.

    Science.gov (United States)

    1984-05-01

    Report Oil Adobe/Frates Ranch Project, City of Petaluma, April 1981. Sedway Cooke and Angus McDonald Associates, Petaluma Wastewater Irrigation Study...Vallejo contribute to City revenues via a franchise tax, the total of iich for the 1981-1982 Budget is expected to be $410,472 a year, or $13.69 per...493,200 -- Transient Occupancy Tax 156,600 .,Real Property Conveyance Tax 285,800 Business License Tax 66,400 Franchise Fees 61,600 Vehicle in-Lieu Fee

  8. Volcanoes in the Classroom--an Explosive Learning Experience.

    Science.gov (United States)

    Thompson, Susan A.; Thompson, Keith S.

    1996-01-01

    Presents a unit on volcanoes for third- and fourth-grade students. Includes demonstrations; video presentations; building a volcano model; and inviting a scientist, preferably a vulcanologist, to share his or her expertise with students. (JRH)

  9. Volcanostratigraphic Approach for Evaluation of Geothermal Potential in Galunggung Volcano

    Science.gov (United States)

    Ramadhan, Q. S.; Sianipar, J. Y.; Pratopo, A. K.

    2016-09-01

    he geothermal systems in Indonesia are primarily associated with volcanoes. There are over 100 volcanoes located on Sumatra, Java, and in the eastern part of Indonesia. Volcanostratigraphy is one of the methods that is used in the early stage for the exploration of volcanic geothermal system to identify the characteristics of the volcano. The stratigraphy of Galunggung Volcano is identified based on 1:100.000 scale topographic map of Tasikmalaya sheet, 1:50.000 scale topographic map and also geological map. The schematic flowchart for evaluation of geothermal exploration is used to interpret and evaluate geothermal potential in volcanic regions. Volcanostratigraphy study has been done on Galunggung Volcano and Talaga Bodas Volcano, West Java, Indonesia. Based on the interpretation of topographic map and analysis of the dimension, rock composition, age and stress regime, we conclude that both Galunggung Volcano and Talaga Bodas Volcano have a geothermal resource potential that deserve further investigation.

  10. Some Recent USF Studies at Volcanoes in Central America

    Science.gov (United States)

    McNutt, S. R.

    2014-12-01

    Scientists at the University of South Florida (USF) have been working in Central America for several decades. Efforts have focused on Physical Volcanology in Nicaragua, GPS in Costa Rica, and assessment of Geothermal projects in El Salvador, amongst others. Two years ago a Seismology Lab was established at USF. Personnel now include three Professors, a Post-Doc, and 4 graduate students. Seismic and GPS networks were installed at Telica Volcano, Nicaragua, in 2010 by Roman, LaFemina and colleagues. Data are recorded on site and recovered several times per year at this persistently restless volcano, which has rates of 5 to 1400 low frequency seismic events per day (Rodgers et al., submitted). Proposals have been submitted to install instruments on other Nicaraguan volcanoes, including seismometers, GPS, infrasound, and lightning sensors. This suite of instruments has proven to be very effective to study a range of volcanic processes. The proposals have not been successful to date (some are pending), and alternative funding sources are being explored. One interesting scientific issue is the presence of strong seasonal effects, specifically a pronounced rainy season and dry season and possible interaction between shallow volcanic processes and surface waters. We are also pursuing a variety of studies that are complementary to the instrumental efforts. One such study is examining volcanic earthquake swarms, with the focus to date on identifying diagnostics. One clear pattern is that peak rates often occur early in swarms, whereas the largest M event occurs late. Additional evidence suggests that the seismic source size grows systematically, especially for events with similar waveforms (families). Recognition of such patterns, linked to processes, may help to improve monitoring and better take advantage of instrumental data to reduce vulnerability from eruptions.

  11. Volcano Trial Case on GEP: Systematically processing EO data

    OpenAIRE

    Baumann, Andreas Bruno Graziano

    2017-01-01

    Volcanoes can be found all over the world; on land and below water surface. Even nowadays not all volcanoes are known. About 600 erupted in geologically recent times and about 50-70 volcanoes are currently active. Volcanoes can cause earthquakes; throw out blasts and tephras; release (toxic) gases; lava can flow relatively slow down the slopes; mass movements like debris avalanches, and landslides can cause tsunamis; and fast and hot pyroclastic surge, flows, and lahars can travel fast down ...

  12. Volcano Geodesy: Recent developments and future challenges

    Science.gov (United States)

    Fernandez, Jose F.; Pepe, Antonio; Poland, Michael; Sigmundsson, Freysteinn

    2017-01-01

    Ascent of magma through Earth's crust is normally associated with, among other effects, ground deformation and gravity changes. Geodesy is thus a valuable tool for monitoring and hazards assessment during volcanic unrest, and it provides valuable data for exploring the geometry and volume of magma plumbing systems. Recent decades have seen an explosion in the quality and quantity of volcano geodetic data. New datasets (some made possible by regional and global scientific initiatives), as well as new analysis methods and modeling practices, have resulted in important changes to our understanding of the geodetic characteristics of active volcanism and magmatic processes, from the scale of individual eruptive vents to global compilations of volcano deformation. Here, we describe some of the recent developments in volcano geodesy, both in terms of data and interpretive tools, and discuss the role of international initiatives in meeting future challenges for the field.

  13. Soil radon response around an active volcano

    International Nuclear Information System (INIS)

    Segovia, N.; Valdes, C.; Pena, P.; Mena, M.; Tamez, E.

    2001-01-01

    Soil radon behavior related to the volcanic eruptive period 1997-1999 of Popocatepetl volcano has been studied as a function of the volcanic activity. Since the volcano is located 60 km from Mexico City, the risk associated with an explosive eruptive phase is high and an intense surveillance program has been implemented. Previous studies in this particular volcano showed soil radon pulses preceding the initial phase of the eruption. The radon survey was performed with LR-115 track detectors at a shallow depth and the effect of the soil moisture during the rainy season has been observed on the detectors response. In the present state of the volcanic activity the soil radon behavior has shown more stability than in previous eruptive stages

  14. Predicting the Timing and Location of the next Hawaiian Volcano

    Science.gov (United States)

    Russo, Joseph; Mattox, Stephen; Kildau, Nicole

    2010-01-01

    The wealth of geologic data on Hawaiian volcanoes makes them ideal for study by middle school students. In this paper the authors use existing data on the age and location of Hawaiian volcanoes to predict the location of the next Hawaiian volcano and when it will begin to grow on the floor of the Pacific Ocean. An inquiry-based lesson is also…

  15. Interdisciplinary studies of eruption at Chaiten Volcano, Chile

    Science.gov (United States)

    John S. Pallister; Jon J. Major; Thomas C. Pierson; Richard P. Hoblitt; Jacob B. Lowenstern; John C. Eichelberger; Lara. Luis; Hugo Moreno; Jorge Munoz; Jonathan M. Castro; Andres Iroume; Andrea Andreoli; Julia Jones; Fred Swanson; Charlie Crisafulli

    2010-01-01

    There was keen interest within the volcanology community when the first large eruption of high-silica rhyolite since that of Alaska's Novarupta volcano in 1912 began on 1 May 2008 at Chaiten volcano, southern Chile, a 3-kilometer-diameter caldera volcano with a prehistoric record of rhyolite eruptions. Vigorous explosions occurred through 8 May 2008, after which...

  16. How Do Volcanoes Affect Human Life? Integrated Unit.

    Science.gov (United States)

    Dayton, Rebecca; Edwards, Carrie; Sisler, Michelle

    This packet contains a unit on teaching about volcanoes. The following question is addressed: How do volcanoes affect human life? The unit covers approximately three weeks of instruction and strives to present volcanoes in an holistic form. The five subject areas of art, language arts, mathematics, science, and social studies are integrated into…

  17. Living with Volcanoes: Year Eleven Teaching Resource Unit.

    Science.gov (United States)

    Le Heron, Kiri; Andrews, Jill; Hooks, Stacey; Larnder, Michele; Le Heron, Richard

    2000-01-01

    Presents a unit on volcanoes and experiences with volcanoes that helps students develop geography skills. Focuses on four volcanoes: (1) Rangitoto Island; (2) Lake Pupuke; (3) Mount Smart; and (4) One Tree Hill. Includes an answer sheet and resources to use with the unit. (CMK)

  18. Volcanoes muon imaging using Cherenkov telescopes

    International Nuclear Information System (INIS)

    Catalano, O.; Del Santo, M.; Mineo, T.; Cusumano, G.; Maccarone, M.C.; Pareschi, G.

    2016-01-01

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  19. Volcanoes muon imaging using Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Catalano, O. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Del Santo, M., E-mail: melania@ifc.inaf.it [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Mineo, T.; Cusumano, G.; Maccarone, M.C. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Pareschi, G. [INAF Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807, Merate (Italy)

    2016-01-21

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  20. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Benjamin

    2017-01-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  1. The origin of the Hawaiian Volcano Observatory

    International Nuclear Information System (INIS)

    Dvorak, John

    2011-01-01

    I first stepped through the doorway of the Hawaiian Volcano Observatory in 1976, and I was impressed by what I saw: A dozen people working out of a stone-and-metal building perched at the edge of a high cliff with a spectacular view of a vast volcanic plain. Their primary purpose was to monitor the island's two active volcanoes, Kilauea and Mauna Loa. I joined them, working for six weeks as a volunteer and then, years later, as a staff scientist. That gave me several chances to ask how the observatory had started.

  2. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael P.; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Ben

    2017-08-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  3. Volcanology and volcano sedimentology of Sahand region

    International Nuclear Information System (INIS)

    Moine Vaziri, H.; Amine Sobhani, E.

    1977-01-01

    There was no volcano in Precambrian and Mesozoic eras in Iran, but in most place of Iran during the next eras volcanic rocks with green series and Dacites were seen. By the recent survey in Sahand mountain in NW of Iran volcanography, determination of rocks and the age of layers were estimated. The deposits of Precambrian as sediment rocks are also seen in the same area. All of volcanic periods in this place were studied; their extrusive rocks, their petrography and the result of their analytical chemistry were discussed. Finally volcano sedimentology of Sahand mountain were described

  4. The origin of the Hawaiian Volcano Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Dvorak, John [University of Hawaii' s Institute for Astronomy (United States)

    2011-05-15

    I first stepped through the doorway of the Hawaiian Volcano Observatory in 1976, and I was impressed by what I saw: A dozen people working out of a stone-and-metal building perched at the edge of a high cliff with a spectacular view of a vast volcanic plain. Their primary purpose was to monitor the island's two active volcanoes, Kilauea and Mauna Loa. I joined them, working for six weeks as a volunteer and then, years later, as a staff scientist. That gave me several chances to ask how the observatory had started.

  5. Nature's refineries — Metals and metalloids in arc volcanoes

    Science.gov (United States)

    Henley, R.W.; Berger, Byron R.

    2013-01-01

    Chemical data for fumaroles and for atmospheric gas and ash plumes from active arc volcanoes provide glimpses of the rates of release of metal and metalloids, such as Tl and Cd, from shallow and mid-crust magmas. Data from copper deposits formed in ancient volcanoes at depths of up to about 1500 m in the fractures below paleo-fumaroles, and at around 2000–4000 m in association with sub-volcanic intrusions (porphyry copper deposits) provide evidence of sub-surface deposition of Cu–Au–Ag–Mo and a range of other minor elements including Te, Se, As and Sb. These deposits, or ‘sinks’, of metals consistently record sustained histories of magmatic gas streaming through volcanic systems interspersed by continuing intrusive and eruptive activity. Here we integrate data from ancient and modern volcanic systems and show that the fluxes of metals and metalloids are controlled by a) the maintenance of fracture permeability in the stressed crust below volcanoes and b) the chemical processes that are triggered as magmatic gas, initially undersaturated with metals and metalloids, expands from lithostatic to very low pressure conditions through fracture arrays. The recognition of gas streaming may also account for the phenomenon of ‘excess degassing’, and defines an integral, but generally understated, component of active volcanic systems – a volcanic gas core – that is likely to be integral to the progression of eruptions to Plinean state.Destabilization of solvated molecular metal and metalloid species in magmatic gas mixtures and changes in their redox state are triggered, as it expands to the surface by abrupt pressure drops, or throttles' in the fracture array that guides expansion to the surface. The electronically harder, low electronegativity metals, such as copper and iron, deposit rapidly in response to expansion followed more slowly by arsenic with antimony as sulfosalts. Heavy, large radius, softer elements such as bismuth, lead, and thallium

  6. Increased Melting of Glaciers during Cotopaxi volcano awakening in 2015

    Science.gov (United States)

    Ramon, Patricio; Vallejo, Silvia; Almeida, Marco; Gomez, Juan Pablo; Caceres, Bolivar

    2016-04-01

    Cotopaxi (5897 m), located about 50 km south of Quito (Ecuador), is one of the most active volcanoes in the Andes and its historical eruptions have caused a great impact on the population by the generation of lahars along its three main drainages (N, S, E). Starting on April 2015 the seismic monitoring networks and the SO2 gas detection network in May 2015 showed a significant increase from their background values, in June a geodetic instrument located in the NE flank started to record inflation; all this indicated the beginning of a new period of unrest. On August 14, five small phreatic explosions occurred, accompanied by large gas and ash emissions, ash falls were reported to the W of the volcano and to the S of Quito capital city. Three new episodes of ash and gas emissions occurred afterwards and towards the end of November 2015, the different monitoring parameters indicated a progressive reduction in the activity of the volcano. Since August 18 almost weekly overflights were made in order to conduct thermal (FLIR camera), visual and SO2 gas monitoring. Towards the end of August thermal measurements showed for the first time the presence of new thermal anomalies (13.5 to 16.3 °C) located in the crevices of the N glaciers, at the same time fumarolic gases were observed coming out from those fractures. On a flight made on September 3, the presence of water coming out from the basal fronts of the northern glaciers was clearly observed and the formation of narrow streams of water running downslope, while it was evident the appearance of countless new crevices in the majority of glacier ends, but also new cracks and rockslides on the upper flanks. All this led to the conclusion that an abnormal process was producing the melting of the glaciers around the volcano. Starting on September it was possible to observe the presence of small secondary lahars descending several streams and we estimated that many of them are due to increased glacier melting. Later

  7. The Ash of Ohlson Ranch: A well-dated Stratigraphic Marker for Constraining Deformation Across the Northern San Andreas Fault

    Science.gov (United States)

    McLaughlin, R. J.; Vazquez, J. A.; Fleck, R. J.; DeLong, S.; Sarna-Wojcicki, A.; Wan, E.; Powell, C., II; Prentice, C. S.

    2012-12-01

    The marine to non-marine transgressional - regressional Ohlson Ranch Formation of northern California was deposited mainly east of the San Andreas Fault and the Gualala structural block during Pliocene sea level high stands. The formation transitions eastward from marine to fluvial deposits and the marine strata are deposited on a mildly warped, pholad-bored erosional surface cut near Pliocene sea level (probably above storm wave-base), on rocks of the Coastal and Central belts of the Franciscan Complex. West of the San Andreas fault near Point Arena, a right-laterally displaced remnant of the wave-cut surface occurs at ca. 100m above modern sea level. East of the fault this surface varies in elevation from ca. 200-350m and a 12-15 cm thick light gray silicic tephra, the ash of Ohlson Ranch (AOR) locally occurs ~10m above the base of the marine section. The AOR consists of very fine-grained glass shards with conspicuous brown biotite in the upper 2 cm and rare co-magmatic clinopyroxene, hornblende and euhedral, weakly zoned zircons. The zircons are relatively uniform in size and little abraded, suggesting they are primary and not re-worked. The fine-grained nature of the AOR deposit suggests it is water lain and chemical analysis of the volcanic glass indicates that the eruptive source was in the southern Cascade Range. We analyzed both polished section mounts of zircon crystals and unpolished rims by ion microprobe (SHRIMP-RG) and LA-ICPMS in order to establish a precise U-Pb age for the AOR. Ages were adjusted for initial 230Th deficiency in the U-Pb chain using Th/U measured in zircon and host glass shards. Thirty-two zircon grains measured by LA-ICPMS at the University of Arizona LaserChron Center yield a mean U-Pb age of 4.58 ± 0.30 Ma (2σ , MSWD=0.53, n=23). SHRIMP analyses of zircon interiors exposed in polished epoxy-mounts yield a mean U-Pb age of 4.36 ± 0.11 Ma (2σ, MSWD 0.72, n=19). To further refine the likely eruption age of the AOR, the SHRIMP was

  8. Understanding the monotonous life of open vent mafic volcanoes

    Science.gov (United States)

    Costa Rodriguez, F.; Ruth, D. C. S.; Bornas, M.; Rivera, D. J. V. I.

    2016-12-01

    Mafic open vent volcanoes display prominent degassing plumes during quiescence but also erupt frequently, every few months or years. Their small and mildly explosive eruptions (volatile contents indicate that the magma reservoir system extends at least to 5 km depth. Mg/Fe pyroxene zoning and diffusion modeling suggests that mafic magma intrusion in a shallow, crystal-rich and more evolved reservoir has occurred repeatedly. The time scale for this process is the same for all 9 events, starting about 2 years prior and continuing up to eruption. We estimate the relative proportions of injecting to resident magma that vary from about 0.2 to 0.7, probably reflecting the local crystal-melt interaction during intrusion. The near constant magma composition is probably the result of buffering of new incoming magma by a crystal-rich upper reservoir, and erupted magmas are physical mixtures. However, we do not find evidence of large-scale crystal recycling from one eruption to another, implying the resetting of the system after each event. The recurrent eruptions and intrusions could be driven by the near continuous degassing of the volcano that induces a mass imbalance which leads to magma movement from depth to the shallow system [e.g., 1]. [1] Girona et al. (2016). Science Reports doi:10.1038/srep18212

  9. Mud Volcanoes - Analogs to Martian Cones and Domes (by the Thousands!)

    Science.gov (United States)

    Allen, Carlton C.; Oehler, Dorothy

    2010-01-01

    laboratory analyses of surface samples collected from mud volcanoes in Azerbaijan, Taiwan and Japan. X-ray diffraction, visible / near infrared reflectance spectroscopy and Raman spectroscopy show that the samples are dominated by mixed-layer smectite clays, along with quartz, calcite and pyrite. Thin section analysis by optical and scanning electron microscopy confirms the mineral identifications. These samples also contain chemical and morphological biosignatures, including common microfossils, with evidence of partial replacement by pyrite. The bulk samples contain approximately 1 wt% total organic carbon and 0.4 mg / gm volatile hydrocarbons. The thousands of features in Acidalia Planitia cited as analogous to terrestrial mud volcanoes clearly represent an important element in the sedimentary record of Mars. Their location, in the distal depocenter for massive Hesperian-age floods, suggests that they contain fine-grained sediments from a large catchment area in the martian highlands. We have proposed these features as a new class of exploration target that can provide access to minimally-altered material from significant depth. By analogy to terrestrial mud volcanoes, these features may also be excellent sites for the sampling martian organics and subsurface microbial life, if such exist or ever existed.

  10. Recent Inflation of Kilauea Volcano

    Science.gov (United States)

    Miklius, A.; Poland, M.; Desmarais, E.; Sutton, A.; Orr, T.; Okubo, P.

    2006-12-01

    Over the last three years, geodetic monitoring networks and satellite radar interferometry have recorded substantial inflation of Kilauea's magma system, while the Pu`u `O`o eruption on the east rift zone has continued unabated. Combined with the approximate doubling of carbon dioxide emission rates at the summit during this period, these observations indicate that the magma supply rate to the volcano has increased. Since late 2003, the summit area has risen over 20 cm, and a 2.5 km-long GPS baseline across the summit area has extended almost half a meter. The center of inflation has been variable, with maximum uplift shifting from an area near the center of the caldera to the southeastern part of the caldera in 2004-2005. In 2006, the locus of inflation shifted again, to the location of the long-term magma reservoir in the southern part of the caldera - the same area that had subsided more than 1.5 meters during the last 23 years of the ongoing eruption. In addition, the southwest rift zone reversed its long-term trend of subsidence and began uplifting in early 2006. The east rift zone has shown slightly accelerated rates of extension, but with a year-long hiatus following the January 2005 south flank aseismic slip event. Inflation rates have varied greatly. Accelerated rates of extension and uplift in early 2005 and 2006 were also associated with increased seismicity. Seismicity occurred not only at inflation centers, but was also triggered on the normal faulting area northwest of the caldera and the strike-slip faulting area in the upper east rift zone. In early 2006, at about the time that we started recording uplift on the southwest rift zone, the rate of earthquakes extending from the summit into the southwest rift zone at least quadrupled. The most recent previous episode of inflation at Kilauea, in 2002, may have resulted from reduced lava- transport capacity, as it was associated with decreased outflow at the eruption site. In contrast, eruption volumes

  11. Air-cooled volcanoes ? New insights on convective airflow process within Miyakejima and Piton de la Fournaise volcanoes

    Science.gov (United States)

    Antoine, R.; Geshi, N.; Kurita, K.; Aoki, Y.; Ichihara, M.; Staudacher, T.; Bachelery, P.

    2012-04-01

    winter 2008 and summer 2010. Moreover, the velocities and temperature contrast between the fracture and the atmosphere were close to the ones recorded at Miyakejima. Finally, the temperature profiles realized across the fractures and confirmed by the infrared thermography data allowed us to define the convective patterns. This study represents the first detection and characterization of air convection at a seasonal scale within fractures on volcanoes. It constitutes a preliminary step to further investigations dedicated to the understanding of the perturbation of such systems before eruptions. [1] Antoine R., Baratoux D., Rabinowicz M., Fontaine F.J., Bachèlery P., Staudacher T., Saracco G., Finizola A., Thermal infrared images analysis of a quiescent cone on Piton de La Fournaise volcano: Evidence for convective air flow within an unconsolidated soil, Journal of Volcanology and Geothermal Research, Volume 183, Issues 3-4, 2009, Pages 228-244.

  12. Growth and degradation of Hawaiian volcanoes: Chapter 3 in Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Clague, David A.; Sherrod, David R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    The 19 known shield volcanoes of the main Hawaiian Islands—15 now emergent, 3 submerged, and 1 newly born and still submarine—lie at the southeast end of a long-lived hot spot chain. As the Pacific Plate of the Earth’s lithosphere moves slowly northwestward over the Hawaiian hot spot, volcanoes are successively born above it, evolve as they drift away from it, and eventually die and subside beneath the ocean surface.

  13. Carbonate assimilation at Merapi volcano, Java Indonesia

    DEFF Research Database (Denmark)

    Chadwick, J.P; Troll, V.R; Ginibre,, C.

    2007-01-01

    Recent basaltic andesite lavas from Merapi volcano contain abundant, complexly zoned, plagioclase phenocrysts, analysed here for their petrographic textures, major element composition and Sr isotope composition. Anorthite (An) content in individual crystals can vary by as much as 55 mol% (An40^95...

  14. Probing magma reservoirs to improve volcano forecasts

    Science.gov (United States)

    Lowenstern, Jacob B.; Sisson, Thomas W.; Hurwitz, Shaul

    2017-01-01

    When it comes to forecasting eruptions, volcano observatories rely mostly on real-time signals from earthquakes, ground deformation, and gas discharge, combined with probabilistic assessments based on past behavior [Sparks and Cashman, 2017]. There is comparatively less reliance on geophysical and petrological understanding of subsurface magma reservoirs.

  15. Biological Studies on a Live Volcano.

    Science.gov (United States)

    Zipko, Stephen J.

    1992-01-01

    Describes scientific research on an Earthwatch expedition to study Arenal, one of the world's most active volcanoes, in north central Costa Rica. The purpose of the two-week project was to monitor and understand the past and ongoing development of a small, geologically young, highly active stratovolcano in a tropical, high-rainfall environment.…

  16. Of volcanoes, saints, trash, and frogs

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    , at the same time as political elections and economic hardship. During one year of ethnographic fieldwork volcanoes, saints, trash and frogs were among the nonhuman entities referred to in conversations and engaged with when responding to the changes that trouble the world and everyday life of Arequipans...

  17. Geophysical monitoring of the Purace volcano, Colombia

    Directory of Open Access Journals (Sweden)

    M. Arcila

    1996-06-01

    Full Text Available Located in the extreme northwestern part of the Los Coconucos volcanic chain in the Central Cordillera, the Purace is one of Colombia's most active volcanoes. Recent geological studies indicate an eruptive history of mainly explosive behavior which was marked most recently by a minor ash eruption in 1977. Techniques used to forecast the renewal of activity of volcanoes after a long period of quiescence include the monitoring of seismicity and ground deformation near the volcano. As a first approach toward the monitoring of the Purace volcano, Southwest Seismological Observatory (OSSO, located in the city of Cali, set up one seismic station in 1986. Beginning in June 1991, the seismic signals have also been transmitted to the Colombian Geological Survey (INGEOMINAS at the Volcanological and Seismological Observatory (OVS-UOP, located in the city of Popayan. Two more seismic stations were installed early in 1994 forming a minimum seismic network and a geodetic monitoring program for ground deformation studies was established and conducted by INGEOMINAS.

  18. Muons reveal the interior of volcanoes

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    The MU-RAY project has the very challenging aim of providing a “muon X-ray” of the Vesuvius volcano (Italy) using a detector that records the muons hitting it after traversing the rock structures of the volcano. This technique was used for the first time in 1971 by the Nobel Prize-winner Louis Alvarez, who was searching for unknown burial chambers in the Chephren pyramid.   The location of the muon detector on the slopes of the Vesuvius volcano. Like X-ray scans of the human body, muon radiography allows researchers to obtain an image of the internal structures of the upper levels of volcanoes. Although such an image cannot help to predict ‘when’ an eruption might occur, it can, if combined with other observations, help to foresee ‘how’ it could develop and serves as a powerful tool for the study of geological structures. Muons come from the interaction of cosmic rays with the Earth's atmosphere. They are able to traverse layers of ro...

  19. False Color Image of Volcano Sapas Mons

    Science.gov (United States)

    1991-01-01

    This false-color image shows the volcano Sapas Mons, which is located in the broad equatorial rise called Atla Regio (8 degrees north latitude and 188 degrees east longitude). The area shown is approximately 650 kilometers (404 miles) on a side. Sapas Mons measures about 400 kilometers (248 miles) across and 1.5 kilometers (0.9 mile) high. Its flanks show numerous overlapping lava flows. The dark flows on the lower right are thought to be smoother than the brighter ones near the central part of the volcano. Many of the flows appear to have been erupted along the flanks of the volcano rather than from the summit. This type of flank eruption is common on large volcanoes on Earth, such as the Hawaiian volcanoes. The summit area has two flat-topped mesas, whose smooth tops give a relatively dark appearance in the radar image. Also seen near the summit are groups of pits, some as large as one kilometer (0.6 mile) across. These are thought to have formed when underground chambers of magma were drained through other subsurface tubes and lead to a collapse at the surface. A 20 kilometer-diameter (12-mile diameter) impact crater northeast of the volcano is partially buried by the lava flows. Little was known about Atla Regio prior to Magellan. The new data, acquired in February 1991, show the region to be composed of at least five large volcanoes such as Sapas Mons, which are commonly linked by complex systems of fractures or rift zones. If comparable to similar features on Earth, Atla Regio probably formed when large volumes of molten rock upwelled from areas within the interior of Venus known as'hot spots.' Magellan is a NASA spacecraft mission to map the surface of Venus with imaging radar. The basic scientific instrument is a synthetic aperture radar, or SAR, which can look through the thick clouds perpetually shielding the surface of Venus. Magellan is in orbit around Venus which completes one turn around its axis in 243 Earth days. That period of time, one Venus day

  20. Hazard maps of Colima volcano, Mexico

    Science.gov (United States)

    Suarez-Plascencia, C.; Nunez-Cornu, F. J.; Escudero Ayala, C. R.

    2011-12-01

    Colima volcano, also known as Volcan de Fuego (19° 30.696 N, 103° 37.026 W), is located on the border between the states of Jalisco and Colima and is the most active volcano in Mexico. Began its current eruptive process in February 1991, in February 10, 1999 the biggest explosion since 1913 occurred at the summit dome. The activity during the 2001-2005 period was the most intense, but did not exceed VEI 3. The activity resulted in the formation of domes and their destruction after explosive events. The explosions originated eruptive columns, reaching attitudes between 4,500 and 9,000 m.a.s.l., further pyroclastic flows reaching distances up to 3.5 km from the crater. During the explosive events ash emissions were generated in all directions reaching distances up to 100 km, slightly affected nearby villages as Tuxpan, Tonila, Zapotlán, Cuauhtemoc, Comala, Zapotitlan de Vadillo and Toliman. During the 2005 this volcano has had an intense effusive-explosive activity, similar to the one that took place during the period of 1890 through 1900. Intense pre-plinian eruption in January 20, 1913, generated little economic losses in the lower parts of the volcano due to low population density and low socio-economic activities at the time. Shows the updating of the volcanic hazard maps published in 2001, where we identify whit SPOT satellite imagery and Google Earth, change in the land use on the slope of volcano, the expansion of the agricultural frontier on the east and southeast sides of the Colima volcano, the population inhabiting the area is approximately 517,000 people, and growing at an annual rate of 4.77%, also the region that has shown an increased in the vulnerability for the development of economic activities, supported by the construction of highways, natural gas pipelines and electrical infrastructure that connect to the Port of Manzanillo to Guadalajara city. The update the hazard maps are: a) Exclusion areas and moderate hazard for explosive events

  1. ARSENIC REMOVAL FROM DRINKING WATER BY POINT OF USE REVERSE OSMOSIS. EPA DEMONSTRATION PROJECT AT SUNSET RANCH DEVELOPMENT IN HOMEDALE, ID. SIX-MONTH EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the first six months of the point of use arsenic removal treatment technology demonstration project at the Sunset Ranch Development in Homedale, ID. The objectives of the project are to evaluate t...

  2. Give Water a Hand. Farm and Ranch Site Action Guide. Organizing Water Conservation and Pollution Prevention Service Projects in Your Community.

    Science.gov (United States)

    Wisconsin Univ., Madison. Coll. of Agricultural and Life Sciences.

    Students grades 4-8 can use this guide to explore the topics of water, and water conservation on a farm or ranch, while conducting an environmental community service project. Youth groups, led by a group leader, work with local experts from business, government, or environmental organizations to complete the project. Nine activity sections involve…

  3. Mauna Kea volcano's ongoing 18-year swarm

    Science.gov (United States)

    Wech, A.; Thelen, W. A.

    2017-12-01

    Mauna Kea is a large postshield-stage volcano that forms the highest peak on Hawaii Island. The 4,205-meter high volcano erupted most recently between 6,000 and 4,500 years ago and exhibits relatively low rates of seismicity, which are mostly tectonic in origin resulting from lithospheric flexure under the weight of the volcano. Here we identify deep repeating earthquakes occurring beneath the summit of Mauna Kea. These earthquakes, which are not part of the Hawaiian Volcano Observatory's regional network catalog, were initially detected through a systematic search for coherent seismicity using envelope cross-correlation, and subsequent analysis revealed the presence of a long-term, ongoing swarm. The events have energy concentrated at 2-7 Hz, and can be seen in filtered waveforms dating back to the earliest continuous data from a single station archived at IRIS from November 1999. We use a single-station (3 component) match-filter analysis to create a catalog of the repeating earthquakes for the past 18 years. Using two templates created through phase-weighted stacking of thousands of sta/lta-triggers, we find hundreds of thousands of M1.3-1.6 earthquakes repeating every 7-12 minutes throughout this entire time period, with many smaller events occurring in between. The earthquakes occur at 28-31 km depth directly beneath the summit within a conspicuous gap in seismicity surrounding the flanks of the volcano. Magnitudes and periodicity are remarkably stable long-term, but do exhibit slight variability and occasionally display higher variability on shorter time scales. Network geometry precludes obtaining a reliable focal mechanism, but we interpret the frequency content and hypocenters to infer a volcanic source distinct from the regional tectonic seismicity responding to the load of the island. In this model, the earthquakes may result from the slow, persistent degassing of a relic magma chamber at depth.

  4. Geochemical studies on island arc volcanoes

    International Nuclear Information System (INIS)

    Notsu, Kenji

    1998-01-01

    This paper summarizes advances in three topics of geochemical studies on island arc volcanoes, which I and my colleagues have been investigating. First one is strontium isotope studies of arc volcanic rocks mainly from Japanese island arcs. We have shown that the precise spatial distribution of the 87 Sr/ 86 Sr ratio reflects natures of the subduction structure and slab-mantle interaction. Based on the 87 Sr/ 86 Sr ratio of volcanic rocks in the northern Kanto district, where two plates subduct concurrently with different directions, the existence of an aseismic portion of the Philippine Sea plate ahead of the seismic one was suggested. Second one is geochemical monitoring of active arc volcanoes. 3 He/ 4 He ratio of volcanic volatiles was shown to be a good indicator to monitor the behavior of magma: ascent and drain-back of magma result in increase and decrease in the ratio, respectively. In the case of 1986 eruptions of Izu-Oshima volcano, the ratio began to increase two months after big eruptions, reaching the maximum and decreased. Such delayed response is explained in terms of travelling time of magmatic helium from the vent area to the observation site along the underground steam flow. Third one is remote observation of volcanic gas chemistry of arc volcanoes, using an infrared absorption spectroscopy. During Unzen eruptions starting in 1990, absorption features of SO 2 and HCl of volcanic gas were detected from the observation station at 1.3 km distance. This was the first ground-based remote detection of HCl in volcanic gas. In the recent work at Aso volcano, we could identify 5 species (CO, COS, CO 2 , SO 2 and HCl) simultaneously in the volcanic plume spectra. (author)

  5. The missing link between submarine volcano and promising geothermal potential in Jinshan, Northern Taiwan

    Science.gov (United States)

    Wang, S. C.; Hutchings, L.; Chang, C. C.; Lee, C. S.

    2017-12-01

    The Tatun volcanic group (TVG) and the Keelung submarine volcano (KSV) are active volcanoes and surrounding three nuclear plant sites in north Taiwan. The famous Jinshan-Wanli hot springs locates between TVG and KSV, moreover, the geochemical anomalies of acidic boiling springs on the seacoast infer that the origin is from magmatic fluids, sea water and meteoric water mixture, strongly implying that mantle fluids ascends into the shallow crust. The evidence for a magma chamber, submarine volcano, and boiling springs have a close spatial relationship. Based on UNECE specifications to Geothermal Energy Resources (2016), the Jinshan-Wanli geothermal area could be classified as Known Geothermal Energy Source for geothermal direct use and Potential Geothermal Energy Source for conventional geothermal system. High resolution reservoir exploration and modeling in Jinshan-Wanli geothermal area is developing for drilling risk mitigation. The geothermal team of National Taiwan Ocean University and local experts are cooperating for further exploration drilling and geothermal source evaluation. Keywords: geothermal resource evaluation, Jinshan-Wanli geothermal area, submarine volcano

  6. The anatomy of an andesite volcano: A time-stratigraphic study of andesite petrogenesis and crustal evolution at Ruapehu volcano, New Zealand

    DEFF Research Database (Denmark)

    Price, R.C.; Gamble, J.A.; Smith, I.E.M.

    2012-01-01

    Ruapehu, New Zealand’s largest active andesite volcano is located at the southern tip of the Taupo Volcanic Zone (TVZ), the main locus of subduction-related volcanism in the North Island. Geophysical data indicate that crustal thickness transitions from ... Ruapehu. The volcano is built on a basement of Mesozoic metagreywacke and geophysical evidence together with xenoliths contained in lavas indicates that this is underlain by oceanic, meta-igneous lower crust. The present-day Ruapehu edifice has been constructed by a series of eruptive events that produced...... and andesite. Dacite also occurs but only one basalt flow has been identified. There have been progressive changes in the minor and trace element chemistry and isotopic composition of Ruapehu eruptives over time. In comparison with rocks from younger formations, Te Herenga eruptives have lower K2O abundances...

  7. HEMATOLOGICAL BLOOD PARAMETERS OF YOUNG-OF-THE-YEAR CARPS (CYPRINIDAE REARED USING FISH RANCHING TECHNOLOGY IN THE SOUTHERN UKRAINE

    Directory of Open Access Journals (Sweden)

    Yu. Volichenko

    2015-12-01

    Full Text Available Purpose. To investigate the hematological characteristics of blood young-of-the-year carps reared using fish ranching technology in the southern Ukraine and to establish certain correlations between the main fish technical features of the studied groups of the young-of-the-year fish. Methodology. The studies were based on field and experimental methods adopted for fisheries, biochemical and statistical studies. Findings. The paper contains the data on mean fish weight, hematological and biochemical parameters of serum of young-of-the-year carps reared using fish ranching technology. Based on a comparative analysis of the obtained data, we detected significant peculiarities and qualitative difference in the absence of foam cells and basophils, which distinguish carp from the group of herbivorous fish, established significant correlations between mean fish weight and hematologic indices of blood. Marked by fish-breeding relationships with signs like weight and some parameters of blood components in all studied fish: hemoglobin in the range from 0.7858 to 0.9943, number of erythrocytes from 0.7843 to 0.9942, lymphocytes from 0.7848 to 0.9949, сholеsterol from 0.7640 to 0.9616 and triglycerides of 0.7499 in silver carp (Hypophthalmichthys molitrix and 0.9616 in common carp (Cyprinus carpio carpio. To show these relationships graphically, we used regression analysis and the obtained regression equations can give an accurate assessment of the quality of fish seeds through hematological blood parameters and mean weight. Originality. The analysis of hematological parameters of blood of young-of-the-year carps: common carp (Cyprinus carpio carpio, silver carp (Hypophthalmichthys molitrix, bighead carp (Hypophthalmichthys nobilis, grass carp (Ctenopharyngodon idella reared using fish ranching technology in the south of Ukraine was performed for the first time. Practical value. The obtained data allow scientifically recommending them as a component of

  8. Space Radar Image of Colombian Volcano

    Science.gov (United States)

    1999-01-01

    This is a radar image of a little known volcano in northern Colombia. The image was acquired on orbit 80 of space shuttle Endeavour on April 14, 1994, by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The volcano near the center of the image is located at 5.6 degrees north latitude, 75.0 degrees west longitude, about 100 kilometers (65 miles) southeast of Medellin, Colombia. The conspicuous dark spot is a lake at the bottom of an approximately 3-kilometer-wide (1.9-mile) volcanic collapse depression or caldera. A cone-shaped peak on the bottom left (northeast rim) of the caldera appears to have been the source for a flow of material into the caldera. This is the northern-most known volcano in South America and because of its youthful appearance, should be considered dormant rather than extinct. The volcano's existence confirms a fracture zone proposed in 1985 as the northern boundary of volcanism in the Andes. The SIR-C/X-SAR image reveals another, older caldera further south in Colombia, along another proposed fracture zone. Although relatively conspicuous, these volcanoes have escaped widespread recognition because of frequent cloud cover that hinders remote sensing imaging in visible wavelengths. Four separate volcanoes in the Northern Andes nations ofColombia and Ecuador have been active during the last 10 years, killing more than 25,000 people, including scientists who were monitoring the volcanic activity. Detection and monitoring of volcanoes from space provides a safe way to investigate volcanism. The recognition of previously unknown volcanoes is important for hazard evaluations because a number of major eruptions this century have occurred at mountains that were not previously recognized as volcanoes. Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of

  9. Common processes at unique volcanoes – a volcanological conundrum

    Directory of Open Access Journals (Sweden)

    Katharine eCashman

    2014-11-01

    Full Text Available An emerging challenge in modern volcanology is the apparent contradiction between the perception that every volcano is unique, and classification systems based on commonalities among volcano morphology and eruptive style. On the one hand, detailed studies of individual volcanoes show that a single volcano often exhibits similar patterns of behaviour over multiple eruptive episodes; this observation has led to the idea that each volcano has its own distinctive pattern of behaviour (or personality. In contrast, volcano classification schemes define eruption styles referenced to type volcanoes (e.g. Plinian, Strombolian, Vulcanian; this approach implicitly assumes that common processes underpin volcanic activity and can be used to predict the nature, extent and ensuing hazards of individual volcanoes. Actual volcanic eruptions, however, often include multiple styles, and type volcanoes may experience atypical eruptions (e.g., violent explosive eruptions of Kilauea, Hawaii1. The volcanological community is thus left with a fundamental conundrum that pits the uniqueness of individual volcanic systems against generalization of common processes. Addressing this challenge represents a major challenge to volcano research.

  10. Magma-carbonate interaction processes and associated CO2 release at Merapi volcano, Indonesia: insights from experimental petrology

    NARCIS (Netherlands)

    Deegan, F.M.; Troll, V.R.; Freda, C.; Misti, V.; Chadwick, J.P.

    2010-01-01

    There is considerable evidence for continuing, late-stage interaction between the magmatic system at Merapi volcano, Indonesia, and local crustal carbonate (limestone). Calc-silicate xenoliths within Merapi basaltic-andesite eruptive rocks display textures indicative of intense interaction between

  11. Vascular plants diversity of El Aribabi Conservation Ranch: A private natural protected area in northern Sonora, Mexico

    Science.gov (United States)

    J. Jesus Sanchez-Escalante; Denise Z. Avila-Jimenez; David A. Delgado-Zamora; Liliana Armenta-Cota; Thomas R. Van Devender; Ana Lilia. Reina-Guerrero

    2013-01-01

    In northeastern Sonora, isolated Sky Island mountain ranges with desertscrub, desert grassland, oak woodland, and pine-oak forest have high biodiversity. El Aribabi Conservation Ranch in the Sierra Azul (from 30°51’13”N, 110°41’9”W to 30°46’38”N, 110°32’3”W) was designated a Private Protected Natural Area by the Comisión Nacional de Áreas Naturales Protegidas in March...

  12. The dynamical interactions of Amazon deforestation, intensification of cattle ranching and technology adoption: insights from a socio-ecological model

    Science.gov (United States)

    Müller-Hansen, Finn; Heitzig, Jobst; Donges, Jonathan F.; Cardoso, Manoel F.; Kurths, Jürgen; Thonicke, Kirsten

    2017-04-01

    Deforestation in the tropics - with vast consequences for the ecosystem and climate - is mainly driven by subsequent land use, which is not only determined by environmental and economic constraints but also influenced by the use of different production technologies. Inefficient production technologies can lead to excessive use of land, especially in areas where land is easily available and accessible. Here, the adoption of new technologies could help to use already converted land more intensively and ease pressures on ecologically valuable areas. In this study, we take the Brazilian Amazon as a prominent example region to explore the interplay of land-use decisions with environmental and economic dynamics in the process of land-use intensification and frontier expansion. Expansion of pasture land for cattle ranching to satisfy increasing domestic and international demands is one of the important drivers for deforestation in the Brazilian Amazon. Pasture run-down and following land abandonment further drive the expansion of deforestation frontiers into pristine forests. Therefore, intensification of livestock production, especially better pasture management, could potentially reduce deforestation. However, a number of reasons including the large spatial extent of the region make the process of comparing the effectiveness of different management techniques, technologies and policies in the region difficult. Therefore, the effectiveness and possible outcomes of policies to foster intensification are highly debated in the literature. Some authors deny that intensification policies are a viable option to spare forests as long as they are not a scarce resource [1] while others insist that intensification has an effect if only supported by the right policies [2]. In this presentation, we introduce a concise agent-based model to study conditions under which intensification can reduce deforestation and explore the trade-offs between intensified and extensive land uses

  13. Naturally occurring Influenza A virus subtype H1N2 infection in a Midwest United States mink (Mustela vison) ranch.

    Science.gov (United States)

    Yoon, Kyoung-Jin; Schwartz, Kent; Sun, Dong; Zhang, Jianqiang; Hildebrandt, Hugh

    2012-03-01

    Influenza A virus (FLUAV) causes acute respiratory disease in humans and a variety of animal species. The virus tends to remain within the species of origin; nonetheless, naturally occurring cross-species transmission of FLUAV has been periodically documented. Multiple cross-species transmissions of FLUAV have been reported from companion animals and captive wild animals, neither of which is historically considered as natural hosts of FLUAV. In the fall of 2010, mink (Mustela vison) inhabiting a 15,000-head mink farm in the Midwest United States experienced persistent severe respiratory distress and nose and/or mouth bleeding. Mink losses averaged approximately 10 animals per day. Six dead mink at 6 months of age were submitted to the Iowa State University Veterinary Diagnostic Laboratory for diagnostic investigation. Gross and microscopic examinations revealed that all 6 mink had hemorrhagic bronchointerstitial pneumonia. Hemolytic Escherichia coli was isolated from lungs, probably accounting for hemorrhagic pneumonia. All animals tested negative for Canine distemper virus and Aleutian mink disease virus. Interestingly, FLUAV of H1N2 subtype, which contained the matrix gene of swine lineage, was detected in the lungs. Serological follow-up on mink that remained in the ranch until pelting also confirmed that the ranch had been exposed to FLUAV of H1 subtype (δ clade). The case study suggests that FLUAV should be included in the differential diagnosis when mink experience epidemics of respiratory disease. Since the source of FLUAV appeared to be uncooked turkey meat, feeding animals fully cooked ration should be considered as a preventive measure.

  14. Potemkin Ranch : blending industrial buildings into their surrounding environments is a good idea that may yet catch on

    International Nuclear Information System (INIS)

    Stastny, P.

    2006-01-01

    The oil and gas industry is attempting to blend into their surroundings in order to improve relations with landowners. This article presented details of a 7.5 million-cubic-feet-per-day gas facility disguised as a cattleman's ranch through the use of convincing facades. The compressor unit is disguised as a ranch house, while the dehydration unit looks like a carriage house. Electrical controls are housed in a separate bunkhouse. In 2001, a skid-mounted refrigeration unit was added and enclosed in a barn facade. The total cost over and above a typical metal-clad gas facility was approximately $100,000, almost 4 per cent of the total facility cost of $2.5 million. While some companies have been using colour to camouflage facilities for many years, other companies have placed more importance on noise suppression, which can add 10 to 20 per cent to the cost of each building. In order to improve noise control, some facilities are now being constructed in topographical low spots with insulated enclosures and hospital-grade mufflers. Pioneer Canada has recently camouflaged a gas facility to mimic a farm which was subsequently fitted with standard noise attenuation. The company's new standard of noise reduction has resulted in additional costs of up to $200,000 per site. Landowners have commented favourably on Pioneer Canada's camouflage efforts. It was concluded that as land access becomes an even bigger issue in some plays, operators may increasingly use architectural features to make their facilities less obtrusive. 5 figs

  15. Potemkin Ranch : blending industrial buildings into their surrounding environments is a good idea that may yet catch on

    Energy Technology Data Exchange (ETDEWEB)

    Stastny, P.

    2006-09-15

    The oil and gas industry is attempting to blend into their surroundings in order to improve relations with landowners. This article presented details of a 7.5 million-cubic-feet-per-day gas facility disguised as a cattleman's ranch through the use of convincing facades. The compressor unit is disguised as a ranch house, while the dehydration unit looks like a carriage house. Electrical controls are housed in a separate bunkhouse. In 2001, a skid-mounted refrigeration unit was added and enclosed in a barn facade. The total cost over and above a typical metal-clad gas facility was approximately $100,000, almost 4 per cent of the total facility cost of $2.5 million. While some companies have been using colour to camouflage facilities for many years, other companies have placed more importance on noise suppression, which can add 10 to 20 per cent to the cost of each building. In order to improve noise control, some facilities are now being constructed in topographical low spots with insulated enclosures and hospital-grade mufflers. Pioneer Canada has recently camouflaged a gas facility to mimic a farm which was subsequently fitted with standard noise attenuation. The company's new standard of noise reduction has resulted in additional costs of up to $200,000 per site. Landowners have commented favourably on Pioneer Canada's camouflage efforts. It was concluded that as land access becomes an even bigger issue in some plays, operators may increasingly use architectural features to make their facilities less obtrusive. 5 figs.

  16. Darwin's triggering mechanism of volcano eruptions

    Science.gov (United States)

    Galiev, Shamil

    2010-05-01

    Charles Darwin wrote that ‘… the elevation of many hundred square miles of territory near Concepcion is part of the same phenomenon, with that splashing up, if I may so call it, of volcanic matter through the orifices in the Cordillera at the moment of the shock;…' and ‘…a power, I may remark, which acts in paroxysmal upheavals like that of Concepcion, and in great volcanic eruptions,…'. Darwin reports that ‘…several of the great chimneys in the Cordillera of central Chile commenced a fresh period of activity ….' In particular, Darwin reported on four-simultaneous large eruptions from the following volcanoes: Robinson Crusoe, Minchinmavida, Cerro Yanteles and Peteroa (we cite the Darwin's sentences following his The Voyage of the Beagle and researchspace. auckland. ac. nz/handle/2292/4474). Let us consider these eruptions taking into account the volcano shape and the conduit. Three of the volcanoes (Minchinmavida (2404 m), Cerro Yanteles (2050 m), and Peteroa (3603 m)) are stratovolcanos and are formed of symmetrical cones with steep sides. Robinson Crusoe (922 m) is a shield volcano and is formed of a cone with gently sloping sides. They are not very active. We may surmise, that their vents had a sealing plug (vent fill) in 1835. All these volcanoes are conical. These common features are important for Darwin's triggering model, which is discussed below. The vent fill material, usually, has high level of porosity and a very low tensile strength and can easily be fragmented by tension waves. The action of a severe earthquake on the volcano base may be compared with a nuclear blast explosion of the base. It is known, that after a underground nuclear explosion the vertical motion and the surface fractures in a tope of mountains were observed. The same is related to the propagation of waves in conical elements. After the explosive load of the base. the tip may break and fly off at high velocity. Analogous phenomenon may be generated as a result of a

  17. The isotopic composition of postshield lavas from Mauna Kea volcano, Hawaii

    International Nuclear Information System (INIS)

    Kennedy, A.K.; Fray, F.A.; Kwon, S.T.; West, H.B.

    1991-01-01

    The postshield eruptive stage of Mauna Kea volcano, Hawaii, can be divided into an early basaltic substage, the Hamakua Volcanics, containing picrites, ankaramites, alkalic and tholeiitic basalt, and a hawaiite substage, the Laupahoehoe Volcanics, containing only hawaiites and rare mugearites. Cumulate gabbroic xenoliths in Laupahoehoe Volcanics have isotopic ratios similar to the Hamakua Volcanics, and these gabbros provide constaints on the crustal evolution of Mauna Kea lavas. Because of the small variation in 87 Sr/ 86 Sr (0.70335-0.70362), 143 Nd/ 144 Nd (0.51297-0.51308) and 206 Pb/ 204 Pb (18.306-18.440), lavas from both substages must contain relatively fixed proportions of depleted, enriched and primitive mantle components. In addition, there is Sr, Nd and Pb isotopic overlap between tholeiitic and alkalic Hamakua basalts. However, the steep 207 Pb/ 204 Pb vs. 206 Pb/ 204 Pb arrays of postshield lavas from Mauna Kea, West Maui and Haleakala volcanoes and the existence of rare samples with high 207 Pb/ 204 Pb, up to 15.548, requires an unusual component in some Hawaiian lavas. This component is unlikely to be derived from sediments or MORB lithosphere, and it may be a minor plume component. Lavas erupted during the postshield stage of Mauna Kea volcano do not define a systematic temporal trend of varying 87 Sr/ 86 Sr and 143 Nd/ 144 Nd. This result contrasts with the temporal trend defined by lavas from Haleakala Volcano and provides evidence for important differences between the origin and evolution of different Hawaiian volcanoes. However, the Laupahoehoe Volcanics trend to lower 206 Pb/ 204 Pb ratios than the Hamakua Volcanics. (orig./WL)

  18. Silicic magma generation at Askja volcano, Iceland

    Science.gov (United States)

    Sigmarsson, O.

    2009-04-01

    Rate of magma differentiation is an important parameter for hazard assessment at active volcanoes. However, estimates of these rates depend on proper understanding of the underlying magmatic processes and magma generation. Differences in isotope ratios of O, Th and B between silicic and in contemporaneous basaltic magmas have been used to emphasize their origin by partial melting of hydrothermally altered metabasaltic crust in the rift-zones favoured by a strong geothermal gradient. An alternative model for the origin of silicic magmas in the Iceland has been proposed based on U-series results. Young mantle-derived mafic protolith is thought to be metasomatized and partially melted to form the silicic end-member. However, this model underestimates the compositional variations of the hydrothermally-altered basaltic crust. New data on U-Th disequilibria and O-isotopes in basalts and dacites from Askja volcano reveal a strong correlation between (230Th/232Th) and delta 18O. The 1875 AD dacite has the lowest Th- and O isotope ratios (0.94 and -0.24 per mille, respectively) whereas tephra of evolved basaltic composition, erupted 2 months earlier, has significantly higher values (1.03 and 2.8 per mille, respectively). Highest values are observed in the most recent basalts (erupted in 1920 and 1961) inside the Askja caldera complex and out on the associated fissure swarm (Sveinagja basalt). This correlation also holds for older magma such as an early Holocene dacites, which eruption may have been provoked by rapid glacier thinning. Silicic magmas at Askja volcano thus bear geochemical signatures that are best explained by partial melting of extensively hydrothermally altered crust and that the silicic magma source has remained constant during the Holocene at least. Once these silicic magmas are formed they appear to erupt rapidly rather than mixing and mingling with the incoming basalt heat-source that explains lack of icelandites and the bi-modal volcanism at Askja

  19. Geothermal Exploration of Newberry Volcano, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Waibel, Albert F. [Columbia Geoscience, Pasco, WA (United States); Frone, Zachary S. [Southern Methodist Univ., Dallas, TX (United States); Blackwell, David D. [Southern Methodist Univ., Dallas, TX (United States)

    2014-12-01

    Davenport Newberry (Davenport) has completed 8 years of exploration for geothermal energy on Newberry Volcano in central Oregon. Two deep exploration test wells were drilled by Davenport on the west flank of the volcano, one intersected a hydrothermal system; the other intersected isolated fractures with no hydrothermal interconnection. Both holes have bottom-hole temperatures near or above 315°C (600°F). Subsequent to deep test drilling an expanded exploration and evaluation program was initiated. These efforts have included reprocessing existing data, executing multiple geological, geophysical, geochemical programs, deep exploration test well drilling and shallow well drilling. The efforts over the last three years have been made possible through a DOE Innovative Exploration Technology (IET) Grant 109, designed to facilitate innovative geothermal exploration techniques. The combined results of the last 8 years have led to a better understanding of the history and complexity of Newberry Volcano and improved the design and interpretation of geophysical exploration techniques with regard to blind geothermal resources in volcanic terrain.

  20. Electrical structure of Newberry Volcano, Oregon

    Science.gov (United States)

    Fitterman, D.V.; Stanley, W.D.; Bisdorf, R.J.

    1988-01-01

    From the interpretation of magnetotelluric, transient electromagnetic, and Schlumberger resistivity soundings, the electrical structure of Newberry Volcano in central Oregon is found to consist of four units. From the surface downward, the geoelectrical units are 1) very resistive, young, unaltered volcanic rock, (2) a conductive layer of older volcanic material composed of altered tuffs, 3) a thick resistive layer thought to be in part intrusive rocks, and 4) a lower-crustal conductor. This model is similar to the regional geoelectrical structure found throughout the Cascade Range. Inside the caldera, the conductive second layer corresponds to the steep temperature gradient and alteration minerals observed in the USGS Newberry 2 test-hole. Drill hole information on the south and north flanks of the volcano (test holes GEO N-1 and GEO N-3, respectively) indicates that outside the caldera the conductor is due to alteration minerals (primarily smectite) and not high-temperature pore fluids. On the flanks of Newberry the conductor is generally deeper than inside the caldera, and it deepens with distance from the summit. A notable exception to this pattern is seen just west of the caldera rim, where the conductive zone is shallower than at other flank locations. The volcano sits atop a rise in the resistive layer, interpreted to be due to intrusive rocks. -from Authors

  1. Monitoring active volcanoes: The geochemical approach

    Directory of Open Access Journals (Sweden)

    Takeshi Ohba

    2011-06-01

    Full Text Available

    The geochemical surveillance of an active volcano aims to recognize possible signals that are related to changes in volcanic activity. Indeed, as a consequence of the magma rising inside the volcanic "plumbing system" and/or the refilling with new batches of magma, the dissolved volatiles in the magma are progressively released as a function of their relative solubilities. When approaching the surface, these fluids that are discharged during magma degassing can interact with shallow aquifers and/or can be released along the main volcano-tectonic structures. Under these conditions, the following main degassing processes represent strategic sites to be monitored.

    The main purpose of this special volume is to collect papers that cover a wide range of topics in volcanic fluid geochemistry, which include geochemical characterization and geochemical monitoring of active volcanoes using different techniques and at different sites. Moreover, part of this volume has been dedicated to the new geochemistry tools.

  2. Nanoscale volcanoes: accretion of matter at ion-sculpted nanopores.

    Science.gov (United States)

    Mitsui, Toshiyuki; Stein, Derek; Kim, Young-Rok; Hoogerheide, David; Golovchenko, J A

    2006-01-27

    We demonstrate the formation of nanoscale volcano-like structures induced by ion-beam irradiation of nanoscale pores in freestanding silicon nitride membranes. Accreted matter is delivered to the volcanoes from micrometer distances along the surface. Volcano formation accompanies nanopore shrinking and depends on geometrical factors and the presence of a conducting layer on the membrane's back surface. We argue that surface electric fields play an important role in accounting for the experimental observations.

  3. Efficient inversion of volcano deformation based on finite element models : An application to Kilauea volcano, Hawaii

    Science.gov (United States)

    Charco, María; González, Pablo J.; Galán del Sastre, Pedro

    2017-04-01

    The Kilauea volcano (Hawaii, USA) is one of the most active volcanoes world-wide and therefore one of the better monitored volcanoes around the world. Its complex system provides a unique opportunity to investigate the dynamics of magma transport and supply. Geodetic techniques, as Interferometric Synthetic Aperture Radar (InSAR) are being extensively used to monitor ground deformation at volcanic areas. The quantitative interpretation of such surface ground deformation measurements using geodetic data requires both, physical modelling to simulate the observed signals and inversion approaches to estimate the magmatic source parameters. Here, we use synthetic aperture radar data from Sentinel-1 radar interferometry satellite mission to image volcano deformation sources during the inflation along Kilauea's Southwest Rift Zone in April-May 2015. We propose a Finite Element Model (FEM) for the calculation of Green functions in a mechanically heterogeneous domain. The key aspect of the methodology lies in applying the reciprocity relationship of the Green functions between the station and the source for efficient numerical inversions. The search for the best-fitting magmatic (point) source(s) is generally conducted for an array of 3-D locations extending below a predefined volume region. However, our approach allows to reduce the total number of Green functions to the number of the observation points by using the, above mentioned, reciprocity relationship. This new methodology is able to accurately represent magmatic processes using physical models capable of simulating volcano deformation in non-uniform material properties distribution domains, which eventually will lead to better description of the status of the volcano.

  4. Geologic map of Medicine Lake volcano, northern California

    Science.gov (United States)

    Donnelly-Nolan, Julie M.

    2011-01-01

    Medicine Lake volcano forms a broad, seemingly nondescript highland, as viewed from any angle on the ground. Seen from an airplane, however, treeless lava flows are scattered across the surface of this potentially active volcanic edifice. Lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, cover more than 2,000 km2 east of the main axis of the Cascade Range in northern California. Across the Cascade Range axis to the west-southwest is Mount Shasta, its towering volcanic neighbor, whose stratocone shape contrasts with the broad shield shape of Medicine Lake volcano. Hidden in the center of Medicine Lake volcano is a 7 km by 12 km summit caldera in which nestles its namesake, Medicine Lake. The flanks of Medicine Lake volcano, which are dotted with cinder cones, slope gently upward to the caldera rim, which reaches an elevation of nearly 8,000 ft (2,440 m). The maximum extent of lavas from this half-million-year-old volcano is about 80 km north-south by 45 km east-west. In postglacial time, 17 eruptions have added approximately 7.5 km3 to its total estimated volume of 600 km3, and it is considered to be the largest by volume among volcanoes of the Cascades arc. The volcano has erupted nine times in the past 5,200 years, a rate more frequent than has been documented at all other Cascades arc volcanoes except Mount St. Helens.

  5. The critical role of volcano monitoring in risk reduction

    Directory of Open Access Journals (Sweden)

    R. I. Tilling

    2008-01-01

    Full Text Available Data from volcano-monitoring studies constitute the only scientifically valid basis for short-term forecasts of a future eruption, or of possible changes during an ongoing eruption. Thus, in any effective hazards-mitigation program, a basic strategy in reducing volcano risk is the initiation or augmentation of volcano monitoring at historically active volcanoes and also at geologically young, but presently dormant, volcanoes with potential for reactivation. Beginning with the 1980s, substantial progress in volcano-monitoring techniques and networks – ground-based as well space-based – has been achieved. Although some geochemical monitoring techniques (e.g., remote measurement of volcanic gas emissions are being increasingly applied and show considerable promise, seismic and geodetic methods to date remain the techniques of choice and are the most widely used. Availability of comprehensive volcano-monitoring data was a decisive factor in the successful scientific and governmental responses to the reawakening of Mount St. elens (Washington, USA in 1980 and, more recently, to the powerful explosive eruptions at Mount Pinatubo (Luzon, Philippines in 1991. However, even with the ever-improving state-of-the-art in volcano monitoring and predictive capability, the Mount St. Helens and Pinatubo case histories unfortunately still represent the exceptions, rather than the rule, in successfully forecasting the most likely outcome of volcano unrest.

  6. Volcano-Monitoring Instrumentation in the United States, 2008

    Science.gov (United States)

    Guffanti, Marianne; Diefenbach, Angela K.; Ewert, John W.; Ramsey, David W.; Cervelli, Peter F.; Schilling, Steven P.

    2010-01-01

    The United States is one of the most volcanically active countries in the world. According to the global volcanism database of the Smithsonian Institution, the United States (including its Commonwealth of the Northern Mariana Islands) is home to about 170 volcanoes that are in an eruptive phase, have erupted in historical time, or have not erupted recently but are young enough (eruptions within the past 10,000 years) to be capable of reawakening. From 1980 through 2008, 30 of these volcanoes erupted, several repeatedly. Volcano monitoring in the United States is carried out by the U.S. Geological Survey (USGS) Volcano Hazards Program, which operates a system of five volcano observatories-Alaska Volcano Observatory (AVO), Cascades Volcano Observatory (CVO), Hawaiian Volcano Observatory (HVO), Long Valley Observatory (LVO), and Yellowstone Volcano Observatory (YVO). The observatories issue public alerts about conditions and hazards at U.S. volcanoes in support of the USGS mandate under P.L. 93-288 (Stafford Act) to provide timely warnings of potential volcanic disasters to the affected populace and civil authorities. To make efficient use of the Nation's scientific resources, the volcano observatories operate in partnership with universities and other governmental agencies through various formal agreements. The Consortium of U.S. Volcano Observatories (CUSVO) was established in 2001 to promote scientific cooperation among the Federal, academic, and State agencies involved in observatory operations. Other groups also contribute to volcano monitoring by sponsoring long-term installation of geophysical instruments at some volcanoes for specific research projects. This report describes a database of information about permanently installed ground-based instruments used by the U.S. volcano observatories to monitor volcanic activity (unrest and eruptions). The purposes of this Volcano-Monitoring Instrumentation Database (VMID) are to (1) document the Nation's existing

  7. Emission of SO2, CO2, and H2S from Augustine Volcano, 2002-2008: Chapter 26 in The 2006 eruption of Augustine Volcano, Alaska

    Science.gov (United States)

    McGee, Kenneth A.; Doukas, Michael P.; McGimsey, Robert G.; Neal, Christina A.; Wessels, Rick L.; Power, John A.; Coombs, Michelle L.; Freymueller, Jeffrey T.

    2010-01-01

    Airborne surveillance of gas emissions from Augustine Volcano and other Cook Inlet volcanoes began in 1990 to identify baseline emission levels during noneruptive conditions. Gas measurements at Augustine for SO2, CO2, and H2S showed essentially no evidence of anomalous degassing through spring 2005. Neither did a measurement on May 10, 2005, right after the onset of low level seismicity and inflation. The following measurement, on December 20, 2005, showed Augustine to be degassing about 600 metric tons per day (t/d) of SO2, and by January 4, 2006, only 7 days before the first explosive event, SO2 emissions had climbed to ten times that amount. Maximum emission rates measured during the subsequent eruption were: 8,930 t/d SO2 (February 24, 2006), 1,800 t/d CO2 (March 9, 2006), and 4.3 t/d H2S (January 19, 2006). In total, 45 measurements for SO2 were made from December 2005 through the end of 2008, with 19 each for CO2 and H2S during the same period. Molar CO2/SO2 ratios averaged about 1.6. In general, SO2 emissions appeared to increase during inflation of the volcanic edifice, whereas CO2 emissions were at their highest during the period of deflation associated with the vigorous effusive phase of the eruption in March. High SO2 was probably associated with degassing of shallow magma, whereas high CO2 likely reflected deep (>4 km) magma recharge of the sub-volcanic plumbing system, For the 2005–6 period, the volcano released a total of about 1.5×106 tons of CO2 to the atmosphere, a level similar to the annual output of a medium-sized natural-gas-fired powerplant. Augustine also emitted about 8×105 tons of SO2, similar to that produced by the 1976 and 1986 eruptions of the volcano.

  8. Data assimilation strategies for volcano geodesy

    Science.gov (United States)

    Zhan, Yan; Gregg, Patricia M.

    2017-09-01

    Ground deformation observed using near-real time geodetic methods, such as InSAR and GPS, can provide critical information about the evolution of a magma chamber prior to volcanic eruption. Rapid advancement in numerical modeling capabilities has resulted in a number of finite element models targeted at better understanding the connection between surface uplift associated with magma chamber pressurization and the potential for volcanic eruption. Robust model-data fusion techniques are necessary to take full advantage of the numerical models and the volcano monitoring observations currently available. In this study, we develop a 3D data assimilation framework using the Ensemble Kalman Filter (EnKF) approach in order to combine geodetic observations of surface deformation with geodynamic models to investigate volcanic unrest. The EnKF sequential assimilation method utilizes disparate data sets as they become available to update geodynamic models of magma reservoir evolution. While the EnKF has been widely applied in hydrologic and climate modeling, the adaptation for volcano monitoring is in its initial stages. As such, our investigation focuses on conducting a series of sensitivity tests to optimize the EnKF for volcano applications and on developing specific strategies for assimilation of geodetic data. Our numerical experiments illustrate that the EnKF is able to adapt well to the spatial limitations posed by GPS data and the temporal limitations of InSAR, and that specific strategies can be adopted to enhance EnKF performance to improve model forecasts. Specifically, our numerical experiments indicate that: (1) incorporating additional iterations of the EnKF analysis step is more efficient than increasing the number of ensemble members; (2) the accuracy of the EnKF results are not affected by initial parameter assumptions; (3) GPS observations near the center of uplift improve the quality of model forecasts; (4) occasionally shifting continuous GPS stations to

  9. Spatio-temporal evolution of volcano seismicity: A laboratory study

    Science.gov (United States)

    Benson, Philip M.; Vinciguerra, Sergio; Meredith, Philip G.; Young, R. Paul

    2010-08-01

    We report a laboratory and microstructural study of a suite of deformation experiments in which basalt from Mount Etna volcano is deformed and fractured at an effective confining pressure representative of conditions under a volcanic edifice (40 MPa). Particular attention was paid to the formation of a fracture and damage zone with which to stimulate coupled hydro-mechanical interactions that create the various types of seismicity recorded on volcanic edifices, and which usually precede eruption. Location of AE events through time shows the formation of a fault plane during which waveforms exhibit the typical high frequency characteristics of volcano-tectonic (VT) earthquakes. We found that these VT earthquakes were particularly pronounced when generated using dry samples, compared to samples saturated with a pore fluid (water). VT events generated during deformation of water saturated sample are characterised by a distinctive high frequency onset and a longer, low frequency coda exhibiting properties often seen in the field as hybrid events. We present evidence that hybrid events are, in fact, the common type of volcanic seismic event with either VT or low frequency (LF) events representing end members, and whose proportion depend on pore fluid being present in the rock type being deformed, as well as how close the rock is to failure. We find a notable trend of reducing instances of hybrid events leading up to the failure stage in our experiments, suggesting that during this stage, the pore fluid present in the rock moves sufficiently quickly to provide a resonance, seen as a LF coda. Our data supports recent modeling and field studies that postulate that hybrid events generated in volcanic areas are likely to be generated through the interaction of hydrothermal fluids moving through a combination of pre-existing microcrack networks and larger faults, such as those we observe in forensic (post-test) examination.

  10. The 2003 phreatomagmatic eruptions of Anatahan volcano - Textural and petrologic features of deposits at an emergent island volcano

    Science.gov (United States)

    Pallister, J.S.; Trusdell, F.A.; Brownfield, I.K.; Siems, D.F.; Budahn, J.R.; Sutley, S.F.

    2005-01-01

    Stratigraphic and field data are used in conjunction with textural and chemical evidence (including data from scanning electron microscope, electron microprobe, X-ray fluorescence, X-ray diffraction, and instrumental neutron activation analysis) to establish that the 2003 eruption of Anatahan volcano was mainly phreatomagmatic, dominated by explosive interaction of homogeneous composition low-viscosity crystal-poor andesite magma with water. The hydromagmatic mode of eruption contributed to the significant height of initial eruptive columns and to the excavation and eruption of altered rock debris from the sub-volcanic hydrothermal system. Volatile contents of glass inclusions in equilibrium phenocrysts less abundances of these constituents in matrix glass times the estimated mass of juvenile magma indicate minimum emissions of 19 kt SO2 and 13 kt Cl. This petrologic estimate of SO2 emission is an order-of-magnitude less than an estimate from TOMS. Similarly, inferred magma volumes from the petrologic data are an order of magnitude greater than those modeled from deformation data. Both discrepancies indicate additional sources of volatiles, likely derived from a separate fluid phase in the magma. The paucity of near-source volcanic-tectonic earthquakes preceding the eruption, and the dominance of sustained long-period tremor are attributed to the ease of ascent of the hot low-viscosity andesite, followed by a shallow phreatomagmatic mode of eruption. Phreatomagmatic eruptions are probably more common at emergent tropical island volcanoes, where shallow fresh-water lenses occur at near-sea-level vents. These relations suggest that phreatomagmatic explosions contributed to the formation of many of the near-sea-level craters and possibly even to the small calderas at the other Mariana islands.

  11. The glaciovolcanic evolution of an andesitic edifice, South Crater, Tongariro volcano, New Zealand

    Science.gov (United States)

    Cole, R. P.; White, J. D. L.; Conway, C. E.; Leonard, G. S.; Townsend, D. B.; Pure, L. R.

    2018-02-01

    Unusual deposits, mapped and logged in detail, around the summit area of Tongariro volcano, Tongariro Volcanic Centre, New Zealand indicate that the construction and evolution of a substantial portion of this andesitic stratovolcano was beneath a significant ice cap or summit glacier. As the edifice was built under and through the overlying ice, the style of volcanism evolved in a complex history of growth. Initially, a ≥ 100 m thick, widespread hyaloclastite deposit was emplaced within a subglacial, eruption-formed meltwater lake. This was followed by several phases of effusive and explosive eruptions, producing lava flows and primary volcaniclastic deposits emplaced along channels carved into the ice by heated meltwater. The clastic deposits contain quenched bombs and structural features that indicate waterlain transport and emplacement, and soft sediment deformation. Such accumulation of water on a steep-sided edifice without evidence for a subaerial crater lake, along with lava flow features indicating confinement, suggest that a substantial summit glacier was responsible for the production and retention of water, and the architecture of these deposits. Recent studies at nearby Ruapehu volcano have provided good evidence for glaciovolcanic interactions during the last glacial period. However, until now, little was known of the physical lava-ice interactions in the Centre during the last interglacial period and the earlier part of the last glacial period (110-64 ka). These new data support a reinterpretation for the volcanic evolution of the older Tongariro edifice and the emplacement mechanisms of primary volcaniclastic deposits. They also help to constrain local ice thicknesses and extents at the times of eruption. In addition, this study contributes to a sparse global catalogue of glaciovolcanic deposits of andesitic composition, particularly of primary volcaniclastics preserved at mid-latitude stratovolcanoes. The variety of deposit types indicates a

  12. Air Force Health Study (Project RANCH HAND II). An Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides. Baseline Morbidity Study Results

    Science.gov (United States)

    1984-02-24

    the cranial nerves, peripheral nerves or central nervous system function of the Ranch Handers. As expected, there was a profound influence of diabetes ...Vagina fused, had operation 1 753 1 Defective kidney 1 Malformation of right kidney 1 Infantile polycystic kidney disease 754 Talipes 2 Club foot 2...e.g., matched originals only and the entire comparison group). Further, for specific analyses, participants with diabetes and pedal edema have been

  13. Watershed Restoration on Black Drake Ranch: Humility vs. hubris in applying incomplete scientific information to real world applications

    Science.gov (United States)

    Bulkley, G. B.; Mattenberger, S.

    2009-12-01

    Black Drake Ranch comprises ~1000 acres of Klamath Basin high desert in S. Central OR, containing 2.5m reaches each of the North Fork Sprague River (NFSR) and its major tributary, Five Mile Creek, a meandering meadow spring creek anchoring 26m of upstream habitat for several species of concern, including native redband trout. Decades of unenlightened management had resulted in substantial watershed degradation: channelization and diking by the U.S. Army Corps of Engineers (hubris), massive stream bank head cuts and erosion by cattle hooves, complete blockade of fish passage by two irrigation diversion dams, loss of eggs and fry in irrigation runoff, upland juniper overgrowth from fire suppression, and extensive infestation of noxious weeds. After in depth analysis by the Working Landscapes Alliance, Klamath Watershed Partnership, Oregon Dept. of Fish and Wildlife, and adjacent landowners, the landowner, a retired cellular biologist, collaborated with an United States Fish & Wildlife Service hydrologist to formulate a comprehensive Long Term Strategic Plan (LTSP) to restore a functioning ecosystem compatible with an economically viable cattle/hay ranching operation. The LTSP is based upon current best practices (CPBs) recommended by experts in relevant, but relatively young scientific fields, with the recognition that these CPBs are constantly evolving as new information becomes available, particularly relevant to this particular site. Consequently, the LTSP remains flexible, and is repeatedly revised as new information is culled from the literature, but mostly from on-site experience and errors. This LTSP entails: 1. Rotational cattle grazing and riparian fencing to allow the re-establishment of bank-stabilizing native plant populations; 2. At diversion dams, installation of fish screens and 3. re-establishment of fish passage using paleochannels revealed by aerial contour mapping; 4. Selective stream bank head cut repair to retain and thereby reduce irrigation

  14. Preliminary Volcano-Hazard Assessment for Gareloi Volcano, Gareloi Island, Alaska

    Science.gov (United States)

    Coombs, Michelle L.; McGimsey, Robert G.; Browne, Brandon L.

    2008-01-01

    Gareloi Volcano (178.794 degrees W and 51.790 degrees N) is located on Gareloi Island in the Delarof Islands group of the Aleutian Islands, about 2,000 kilometers west-southwest of Anchorage and about 150 kilometers west of Adak, the westernmost community in Alaska. This small (about 8x10 kilometer) volcano has been one of the most active in the Aleutians since its discovery by the Bering expedition in the 1740s, though because of its remote location, observations have been scant and many smaller eruptions may have gone unrecorded. Eruptions of Gareloi commonly produce ash clouds and lava flows. Scars on the flanks of the volcano and debris-avalanche deposits on the adjacent seafloor indicate that the volcano has produced large landslides in the past, possibly causing tsunamis. Such events are infrequent, occurring at most every few thousand years. The primary hazard from Gareloi is airborne clouds of ash that could affect aircraft. In this report, we summarize and describe the major volcanic hazards associated with Gareloi.

  15. Volcano art at Hawai`i Volcanoes National Park—A science perspective

    Science.gov (United States)

    Gaddis, Ben; Kauahikaua, James P.

    2018-03-26

    Long before landscape photography became common, artists sketched and painted scenes of faraway places for the masses. Throughout the 19th century, scientific expeditions to Hawaiʻi routinely employed artists to depict images for the people back home who had funded the exploration and for those with an interest in the newly discovered lands. In Hawaiʻi, artists portrayed the broad variety of people, plant and animal life, and landscapes, but a feature of singular interest was the volcanoes. Painters of early Hawaiian volcano landscapes created art that formed a cohesive body of work known as the “Volcano School” (Forbes, 1992). Jules Tavernier, Charles Furneaux, and D. Howard Hitchcock were probably the best known artists of this school, and their paintings can be found in galleries around the world. Their dramatic paintings were recognized as fine art but were also strong advertisements for tourists to visit Hawaiʻi. Many of these masterpieces are preserved in the Museum and Archive Collection of Hawaiʻi Volcanoes National Park, and in this report we have taken the opportunity to match the artwork with the approximate date and volcanological context of the scene.

  16. Evolution of deep crustal magma structures beneath Mount Baekdu volcano (MBV) intraplate volcano in northeast Asia

    Science.gov (United States)

    Rhie, J.; Kim, S.; Tkalcic, H.; Baag, S. Y.

    2017-12-01

    Heterogeneous features of magmatic structures beneath intraplate volcanoes are attributed to interactions between the ascending magma and lithospheric structures. Here, we investigate the evolution of crustal magmatic stuructures beneath Mount Baekdu volcano (MBV), which is one of the largest continental intraplate volcanoes in northeast Asia. The result of our seismic imaging shows that the deeper Moho depth ( 40 km) and relatively higher shear wave velocities (>3.8 km/s) at middle-to-lower crustal depths beneath the volcano. In addition, the pattern at the bottom of our model shows that the lithosphere beneath the MBV is shallower (interpret the observations as a compositional double layering of mafic underplating and a overlying cooled felsic structure due to fractional crystallization of asthenosphere origin magma. To achieve enhanced vertical and horizontal model coverage, we apply two approaches in this work, including (1) a grid-search based phase velocity measurement using real-coherency of ambient noise data and (2) a transdimensional Bayesian joint inversion using multiple ambient noise dispersion data.

  17. Understanding cyclic seismicity and ground deformation patterns at volcanoes: Intriguing lessons from Tungurahua volcano, Ecuador

    Science.gov (United States)

    Neuberg, Jürgen W.; Collinson, Amy S. D.; Mothes, Patricia A.; Ruiz, Mario C.; Aguaiza, Santiago

    2018-01-01

    Cyclic seismicity and ground deformation patterns are observed on many volcanoes worldwide where seismic swarms and the tilt of the volcanic flanks provide sensitive tools to assess the state of volcanic activity. Ground deformation at active volcanoes is often interpreted as pressure changes in a magmatic reservoir, and tilt is simply translated accordingly into inflation and deflation of such a reservoir. Tilt data recorded by an instrument in the summit area of Tungurahua volcano in Ecuador, however, show an intriguing and unexpected behaviour on several occasions: prior to a Vulcanian explosion when a pressurisation of the system would be expected, the tilt signal declines significantly, hence indicating depressurisation. At the same time, seismicity increases drastically. Envisaging that such a pattern could carry the potential to forecast Vulcanian explosions on Tungurahua, we use numerical modelling and reproduce the observed tilt patterns in both space and time. We demonstrate that the tilt signal can be more easily explained as caused by shear stress due to viscous flow resistance, rather than by pressurisation of the magmatic plumbing system. In general, our numerical models prove that if magma shear viscosity and ascent rate are high enough, the resulting shear stress is sufficient to generate a tilt signal as observed on Tungurahua. Furthermore, we address the interdependence of tilt and seismicity through shear stress partitioning and suggest that a joint interpretation of tilt and seismicity can shed new light on the eruption potential of silicic volcanoes.

  18. Volcano monitoring with an infrared camera: first insights from Villarrica Volcano

    Science.gov (United States)

    Rosas Sotomayor, Florencia; Amigo Ramos, Alvaro; Velasquez Vargas, Gabriela; Medina, Roxana; Thomas, Helen; Prata, Fred; Geoffroy, Carolina

    2015-04-01

    This contribution focuses on the first trials of the, almost 24/7 monitoring of Villarrica volcano with an infrared camera. Results must be compared with other SO2 remote sensing instruments such as DOAS and UV-camera, for the ''day'' measurements. Infrared remote sensing of volcanic emissions is a fast and safe method to obtain gas abundances in volcanic plumes, in particular when the access to the vent is difficult, during volcanic crisis and at night time. In recent years, a ground-based infrared camera (Nicair) has been developed by Nicarnica Aviation, which quantifies SO2 and ash on volcanic plumes, based on the infrared radiance at specific wavelengths through the application of filters. Three Nicair1 (first model) have been acquired by the Geological Survey of Chile in order to study degassing of active volcanoes. Several trials with the instruments have been performed in northern Chilean volcanoes, and have proven that the intervals of retrieved SO2 concentration and fluxes are as expected. Measurements were also performed at Villarrica volcano, and a location to install a ''fixed'' camera, at 8km from the crater, was discovered here. It is a coffee house with electrical power, wifi network, polite and committed owners and a full view of the volcano summit. The first measurements are being made and processed in order to have full day and week of SO2 emissions, analyze data transfer and storage, improve the remote control of the instrument and notebook in case of breakdown, web-cam/GoPro support, and the goal of the project: which is to implement a fixed station to monitor and study the Villarrica volcano with a Nicair1 integrating and comparing these results with other remote sensing instruments. This works also looks upon the strengthen of bonds with the community by developing teaching material and giving talks to communicate volcanic hazards and other geoscience topics to the people who live "just around the corner" from one of the most active volcanoes

  19. Imaging magma plumbing beneath Askja volcano, Iceland

    Science.gov (United States)

    Greenfield, Tim; White, Robert S.

    2015-04-01

    Volcanoes during repose periods are not commonly monitored by dense instrumentation networks and so activity during periods of unrest is difficult to put in context. We have operated a dense seismic network of 3-component, broadband instruments around Askja, a large central volcano in the Northern Volcanic Zone, Iceland, since 2006. Askja last erupted in 1961, with a relatively small basaltic lava flow. Since 1975 the central caldera has been subsiding and there has been no indication of volcanic activity. Despite this, Askja has been one of the more seismically active volcanoes in Iceland. The majority of these events are due to an extensive geothermal area within the caldera and tectonically induced earthquakes to the northeast which are not related to the magma plumbing system. More intriguing are the less numerous deeper earthquakes at 12-24km depth, situated in three distinct areas within the volcanic system. These earthquakes often show a frequency content which is lower than the shallower activity, but they still show strong P and S wave arrivals indicative of brittle failure, despite their location being well below the brittle-ductile boundary, which, in Askja is ~7km bsl. These earthquakes indicate the presence of melt moving or degassing at depth while the volcano is not inflating, as only high strain rates or increased pore fluid pressures would cause brittle fracture in what is normally an aseismic region in the ductile zone. The lower frequency content must be the result of a slower source time function as earthquakes which are both high frequency and low frequency come from the same cluster, thereby discounting a highly attenuating lower crust. To image the plumbing system beneath Askja, local and regional earthquakes have been used as sources to solve for the velocity structure beneath the volcano. Travel-time tables were created using a finite difference technique and the residuals were used to solve simultaneously for both the earthquake locations

  20. Mineralogical and geochemical study of mud volcanoes in north ...

    African Journals Online (AJOL)

    The gulf of Cadiz is one of the most interesting areas to study mud volcanoes and structures related to cold fluid seeps since their discovery in 1999. In this study, we present results from gravity cores collected from Ginsburg and Meknes mud volcanoes and from circular structure located in the gulf of Cadiz (North Atlantic ...

  1. 36 CFR 7.25 - Hawaii Volcanoes National Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Hawaii Volcanoes National Park. 7.25 Section 7.25 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.25 Hawaii Volcanoes National Park. (a...

  2. Using Google Earth to Study the Basic Characteristics of Volcanoes

    Science.gov (United States)

    Schipper, Stacia; Mattox, Stephen

    2010-01-01

    Landforms, natural hazards, and the change in the Earth over time are common material in state and national standards. Volcanoes exemplify these standards and readily capture the interest and imagination of students. With a minimum of training, students can recognize erupted materials and types of volcanoes; in turn, students can relate these…

  3. Volcano ecology: Disturbance characteristics and assembly of biological communities

    Science.gov (United States)

    Volcanic eruptions are powerful expressions of Earth’s geophysical forces which have shaped and influenced ecological systems since the earliest days of life. The study of the interactions of volcanoes and ecosystems, termed volcano ecology, focuses on the ecological responses of organisms and biolo...

  4. Isotopic evolution of Mauna Loa volcano

    International Nuclear Information System (INIS)

    Kurz, M.D.; Kammer, D.P.

    1991-01-01

    In an effort to understand the temporal helium isotopic variations in Mauna Loa volcano, we have measured helium, strontium and lead isotopes in a suite of Mauna Loa lavas that span most of the subaerial eruptive history of the volcano. The lavas range in age from historical flows to Ninole basalt which are thought to be several hundred thousand years old. Most of the samples younger than 30 ka in age (Kau Basalt) are radiocarbon-dated flows, while the samples older than 30 ka are stratigraphically controlled (Kahuku and Ninole Basalt). The data reveal a striking change in the geochemistry of the lavas approximately 10 ka before present. The lavas older than 10 ka are characterized by high 3 He/ 4 He (≅ 16-20 times atmospheric), higher 206 Pb/ 204 Pb (≅ 18.2), and lower 87 Sr/ 86 Sr(≅ 0.70365) ratios than the younger Kau samples (having He, Pb and Sr ratios of approximately 8.5 x atmospheric, 18.1 and 0.70390, respectively). The historical lavas are distinct in having intermediate Sr and Pb isotopic compositions with 3 He/ 4 He ratios similar to the other young Kau basalt (≅ 8.5 x atmospheric). The isotopic variations are on a shorter time scale (100 to 10,000 years) than has previously been observed for Hawaiian volcanoes, and demonstrate the importance of geochronology and stratigraphy to geochemical studies. The data show consistency between all three isotope systems, which suggests that the variations are not related to magma chamber degassing processes, and that helium is not decoupled from the other isotopes. However, the complex temporal evolution suggests that three distinct mantle sources are required to explain the isotopic data. Most of the Mauna Loa isotopic variations could be explained by mixing between a plume type source, similar to Loihi, and an asthenospheric source with helium isotopic composition close to MORB and elevated Sr isotopic values. (orig./WL)

  5. Monte Carlo Volcano Seismic Moment Tensors

    Science.gov (United States)

    Waite, G. P.; Brill, K. A.; Lanza, F.

    2015-12-01

    Inverse modeling of volcano seismic sources can provide insight into the geometry and dynamics of volcanic conduits. But given the logistical challenges of working on an active volcano, seismic networks are typically deficient in spatial and temporal coverage; this potentially leads to large errors in source models. In addition, uncertainties in the centroid location and moment-tensor components, including volumetric components, are difficult to constrain from the linear inversion results, which leads to a poor understanding of the model space. In this study, we employ a nonlinear inversion using a Monte Carlo scheme with the objective of defining robustly resolved elements of model space. The model space is randomized by centroid location and moment tensor eigenvectors. Point sources densely sample the summit area and moment tensors are constrained to a randomly chosen geometry within the inversion; Green's functions for the random moment tensors are all calculated from modeled single forces, making the nonlinear inversion computationally reasonable. We apply this method to very-long-period (VLP) seismic events that accompany minor eruptions at Fuego volcano, Guatemala. The library of single force Green's functions is computed with a 3D finite-difference modeling algorithm through a homogeneous velocity-density model that includes topography, for a 3D grid of nodes, spaced 40 m apart, within the summit region. The homogenous velocity and density model is justified by long wavelength of VLP data. The nonlinear inversion reveals well resolved model features and informs the interpretation through a better understanding of the possible models. This approach can also be used to evaluate possible station geometries in order to optimize networks prior to deployment.

  6. Volcano morphometry and volume scaling on Venus

    Science.gov (United States)

    Garvin, J. B.; Williams, R. S., Jr.

    1994-01-01

    A broad variety of volcanic edifices have been observed on Venus. They ranged in size from the limits of resolution of the Magellan SAR (i.e., hundreds of meters) to landforms over 500 km in basal diameter. One of the key questions pertaining to volcanism on Venus concerns the volume eruption rate or VER, which is linked to crustal productivity over time. While less than 3 percent of the surface area of Venus is manifested as discrete edifices larger than 50 km in diameter, a substantial component of the total crustal volume of the planet over the past 0.5 Ga is related to isolated volcanoes, which are certainly more easily studied than the relatively diffusely defined plains volcanic flow units. Thus, we have focused our efforts on constraining the volume productivity of major volcanic edifices larger than 100 km in basal diameter. Our approach takes advantage of the topographic data returned by Magellan, as well as our database of morphometric statistics for the 20 best known lava shields of Iceland, plus Mauna Loa of Hawaii. As part of this investigation, we have quantified the detailed morphometry of nearly 50 intermediate to large scale edifices, with particular attention to their shape systematics. We found that a set of venusian edifices which include Maat, Sapas, Tepev, Sif, Gula, a feature at 46 deg S, 215 deg E, as well as the shield-like structure at 10 deg N, 275 deg E are broadly representative of the approx. 400 volcanic landforms larger than 50 km. The cross-sectional shapes of these 7 representative edifices range from flattened cones (i.e., Sif) similar to classic terrestrial lava shields such as Mauna Loa and Skjaldbreidur, to rather dome-like structures which include Maat and Sapas. The majority of these larger volcanoes surveyed as part of our study displayed cross-sectional topographies with paraboloidal shaped, in sharp contrast with the cone-like appearance of most simple terrestrial lava shields. In order to more fully explore the

  7. Cataloging tremor at Kilauea Volcano, Hawaii

    Science.gov (United States)

    Thelen, W. A.; Wech, A.

    2013-12-01

    Tremor is a ubiquitous seismic feature on Kilauea volcano, which emanates from at least three distinct sources. At depth, intermittent tremor and earthquakes thought to be associated with the underlying plumbing system of Kilauea (Aki and Koyanagi, 1981) occurs approximately 40 km below and 40 km SW of the summit. At the summit of the volcano, nearly continuous tremor is recorded close to a persistently degassing lava lake, which has been present since 2008. Much of this tremor is correlated with spattering at the lake surface, but tremor also occurs in the absence of spattering, and was observed at the summit of the volcano prior to the appearance of the lava lake, predominately in association with inflation/deflation events. The third known source of tremor is in the area of Pu`u `O`o, a vent that has been active since 1983. The exact source location and depth is poorly constrained for each of these sources. Consistently tracking the occurrence and location of tremor in these areas through time will improve our understanding of the plumbing geometry beneath Kilauea volcano and help identify precursory patterns in tremor leading to changes in eruptive activity. The continuous and emergent nature of tremor precludes the use of traditional earthquake techniques for automatic detection and location of seismicity. We implement the method of Wech and Creager (2008) to both detect and localize tremor seismicity in the three regions described above. The technique uses an envelope cross-correlation method in 5-minute windows that maximizes tremor signal coherency among seismic stations. The catalog is currently being built in near-realtime, with plans to extend the analysis to the past as time and continuous data availability permits. This automated detection and localization method has relatively poor depth constraints due to the construction of the envelope function. Nevertheless, the epicenters distinguish activity among the different source regions and serve as

  8. Degassing Processes at Persistently Active Explosive Volcanoes

    Science.gov (United States)

    Smekens, Jean-Francois

    Among volcanic gases, sulfur dioxide (SO2) is by far the most commonly measured. More than a monitoring proxy for volcanic degassing, SO 2 has the potential to alter climate patterns. Persistently active explosive volcanoes are characterized by short explosive bursts, which often occur at periodic intervals numerous times per day, spanning years to decades. SO 2 emissions at those volcanoes are poorly constrained, in large part because the current satellite monitoring techniques are unable to detect or quantify plumes of low concentration in the troposphere. Eruption plumes also often show high concentrations of ash and/or aerosols, which further inhibit the detection methods. In this work I focus on quantifying volcanic gas emissions at persistently active explosive volcanoes and their variations over short timescales (minutes to hours), in order to document their contribution to natural SO2 flux as well as investigate the physical processes that control their behavior. In order to make these measurements, I first develop and assemble a UV ground-based instrument, and validate it against an independently measured source of SO2 at a coal-burning power plant in Arizona. I establish a measurement protocol and demonstrate that the instrument measures SO 2 fluxes with Indonesia), a volcano that has been producing cycles of repeated explosions with periods of minutes to hours for the past several decades. Semeru produces an average of 21-71 tons of SO2 per day, amounting to a yearly output of 8-26 Mt. Using the Semeru data, along with a 1-D transient numerical model of magma ascent, I test the validity of a model in which a viscous plug at the top of the conduit produces cycles of eruption and gas release. I find that it can be a valid hypothesis to explain the observed patterns of degassing at Semeru. Periodic behavior in such a system occurs for a very narrow range of conditions, for which the mass balance between magma flux and open-system gas escape repeatedly

  9. Mud Volcanoes as Exploration Targets on Mars

    Science.gov (United States)

    Allen, Carlton C.; Oehler, Dorothy Z.

    2010-01-01

    Tens of thousands of high-albedo mounds occur across the southern part of the Acidalia impact basin on Mars. These structures have geologic, physical, mineralogic, and morphologic characteristics consistent with an origin from a sedimentary process similar to terrestrial mud volcanism. The potential for mud volcanism in the Northern Plains of Mars has been recognized for some time, with candidate mud volcanoes reported from Utopia, Isidis, northern Borealis, Scandia, and the Chryse-Acidalia region. We have proposed that the profusion of mounds in Acidalia is a consequence of this basin's unique geologic setting as the depocenter for the tune fraction of sediments delivered by the outflow channels from the highlands.

  10. Galactic Super-volcano in Action

    Science.gov (United States)

    2010-08-01

    A galactic "super-volcano" in the massive galaxy M87 is erupting and blasting gas outwards, as witnessed by NASA's Chandra X-ray Observatory and NSF's Very Large Array. The cosmic volcano is being driven by a giant black hole in the galaxy's center and preventing hundreds of millions of new stars from forming. Astronomers studying this black hole and its effects have been struck by the remarkable similarities between it and a volcano in Iceland that made headlines earlier this year. At a distance of about 50 million light years, M87 is relatively close to Earth and lies at the center of the Virgo cluster, which contains thousands of galaxies. M87's location, coupled with long observations over Chandra's lifetime, has made it an excellent subject for investigations of how a massive black hole impacts its environment. "Our results show in great detail that supermassive black holes have a surprisingly good control over the evolution of the galaxies in which they live," said Norbert Werner of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University and the SLAC National Accelerator Laboratory, who led one of two papers describing the study. "And it doesn't stop there. The black hole's reach extends ever farther into the entire cluster, similar to how one small volcano can affect practically an entire hemisphere on Earth." The cluster surrounding M87 is filled with hot gas glowing in X-ray light, which is detected by Chandra. As this gas cools, it can fall toward the galaxy's center where it should continue to cool even faster and form new stars. However, radio observations with the Very Large Array suggest that in M87 jets of very energetic particles produced by the black hole interrupt this process. These jets lift up the relatively cool gas near the center of the galaxy and produce shock waves in the galaxy's atmosphere because of their supersonic speed. The scientists involved in this research have found the interaction of this cosmic

  11. Mud Volcanoes of Trinidad as Astrobiological Analogs for Martian Environments

    Directory of Open Access Journals (Sweden)

    Riad Hosein

    2014-10-01

    Full Text Available Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i Digity; (ii Piparo and (iii Devil’s Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region.

  12. Measurements of radon and chemical elements: Popocatepetl volcano

    International Nuclear Information System (INIS)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V.; Armienta, M.A.; Valdes, C.; Mena, M.; Seidel, J.L.; Monnin, M.

    2002-01-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  13. Mud Volcanoes of Trinidad as Astrobiological Analogs for Martian Environments

    Science.gov (United States)

    Hosein, Riad; Haque, Shirin; Beckles, Denise M.

    2014-01-01

    Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC) was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i) Digity; (ii) Piparo and (iii) Devil’s Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region. PMID:25370529

  14. Tsunamis generated by eruptions from mount st. Augustine volcano, alaska.

    Science.gov (United States)

    Kienle, J; Kowalik, Z; Murty, T S

    1987-06-12

    During an eruption of the Alaskan volcano Mount St. Augustine in the spring of 1986, there was concern about the possibility that a tsunami might be generated by the collapse of a portion of the volcano into the shallow water of Cook Inlet. A similar edifice collapse of the volcano and ensuing sea wave occurred during an eruption in 1883. Other sea waves resulting in great loss of life and property have been generated by the eruption of coastal volcanos around the world. Although Mount St. Augustine remained intact during this eruptive cycle, a possible recurrence of the 1883 events spurred a numerical simulation of the 1883 sea wave. This simulation, which yielded a forecast of potential wave heights and travel times, was based on a method that could be applied generally to other coastal volcanos.

  15. Mud volcanoes of trinidad as astrobiological analogs for martian environments.

    Science.gov (United States)

    Hosein, Riad; Haque, Shirin; Beckles, Denise M

    2014-10-13

    Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC) was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i) Digity; (ii) Piparo and (iii) Devil's Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region.

  16. Establishment, test and evaluation of a prototype volcano surveillance system

    Science.gov (United States)

    Ward, P. L.; Eaton, J. P.; Endo, E.; Harlow, D.; Marquez, D.; Allen, R.

    1973-01-01

    A volcano-surveillance system utilizing 23 multilevel earthquake counters and 6 biaxial borehole tiltmeters is being installed and tested on 15 volcanoes in 4 States and 4 foreign countries. The purpose of this system is to give early warning when apparently dormant volcanoes are becoming active. The data are relayed through the ERTS-Data Collection System to Menlo Park for analysis. Installation was completed in 1972 on the volcanoes St. Augustine and Iliamna in Alaska, Kilauea in Hawaii, Baker, Rainier and St. Helens in Washington, Lassen in California, and at a site near Reykjavik, Iceland. Installation continues and should be completed in April 1973 on the volcanoes Santiaguito, Fuego, Agua and Pacaya in Guatemala, Izalco in El Salvador and San Cristobal, Telica and Cerro Negro in Nicaragua.

  17. Stability analysis of Western flank of Cumbre Vieja volcano (La Palma) using numerical modelling

    Science.gov (United States)

    Bru, Guadalupe; Gonzalez, Pablo J.; Fernandez-Merodo, Jose A.; Fernandez, Jose

    2016-04-01

    La Palma volcanic island is one of the youngest of the Canary archipelago, being a composite volcano formed by three overlapping volcanic centers. There are clear onshore and offshore evidences of past giant landslides that have occurred during its evolution. Currently, the active Cumbre Vieja volcano is in an early development state (Carracedo et al., 2001). The study of flank instability processes aim to assess, among other hazards, catastrophic collapse and potential tsunami generation. Early studies of the potential instability of Cumbre Vieja volcano western flank have focused on the use of sparse geodetic networks (Moss et al. 1999), surface geological mapping techniques (Day et al. 1999) and offshore bathymetry (Urgeles et al. 1999). Recently, a dense GNSS network and satellite radar interferometry results indicate ground motion consistent with deep-seated creeping processes (Prieto et al. 2009, Gonzalez et al. 2010). In this work, we present a geomechanical advanced numerical model that captures the ongoing deformation processes at Cumbre Vieja. We choose the Finite Elements Method (FEM) which is based in continuum mechanics and is the most used for geotechnical applications. FEM has the ability of using arbitrary geometry, heterogeneities, irregular boundaries and different constitutive models representative of the geotechnical units involved. Our main contribution is the introduction of an inverse approach to constrain the geomechanical parameters using satellite radar interferometry displacements. This is the first application of such approach on a large volcano flank study. We suggest that the use of surface displacements and inverse methods to rigorously constrain the geomechanical model parameter space is a powerful tool to understand volcano flank instability. A particular important result of the studied case is the estimation of displaced rock volume, which is a parameter of critical importance for simulations of Cumbre Vieja tsunamigenic hazard

  18. Crust-Mantle Interactions at Pico de Orizaba (Citlaltepetl) Volcano, Mexico.

    Science.gov (United States)

    Schaaf, P.; Carrasco, G.

    2006-12-01

    Pico de Orizaba (Citlaltepetl) volcano constitutes the easternmost and highest stratovolcano of the subduction- related Plio-Quaternary Trans-Mexican Volcanic Belt (TMVB). The volcano can be divided into three main constructional stages. Its activity started during the mid-Pleistocene. The present cone was built on the remnants of the ancestral buildings by eruption of amphibole-two pyroxene dacitic lava flows, the most recent of which was erupted in the seventeenth century. The volcano is surrounded to the SW by monogenetic Quaternary cindercones and maars. All representative units were sampled in this work for geochemical and isotopic purposes, including a small quartzitic xenolith found in the basaltic monogenetic suite. Volcanic products of the stratocone are quite heterogeneous and range from calc-alkaline basaltic andesites to dome rhyolites, also displayed by a wide range of SiO2 and MgO (72.6-53.2 and 7.0-0.3 wt. %, respectively). In comparison to other TMVB stratovolcanoes (e.g., Colima, Nevado de Toluca), Pico de Orizaba shows similar 87Sr/86Sr ratios (0.7037-0.7048) but considerably more evolved Nd-Pb isotopic ratios (eNd: -1.8 to + 1.4; 206Pb/204Pb: 18.61-18.78). Elevated LILE concentrations and depleted HFSE witness the importance of slab- derived aqueous fluids and metasomatic reactions between the subducting lithosphere and overlying mantle wedge. On the other hand, Pico de Orizaba volcano shows additionally high crustal contributions of a source with depleted Sr and enriched Nd and Pb isotopic signatures, best explained by considerable assimilation of the local Grenvillian basement in magma generation processes. In contrast to Popocatépetl volcano with a high-level magma reservoir emplacement (7-8 km) and obvious interaction with the carbonate-dominated shallow basement rocks (e.g. elevated 87Sr/86Sr ratios and CO2 in gas plumes), this effect cannot be observed at Pico de Orizaba volcano, although a regional Cretaceous limestone basement is also

  19. Translating Volcano Hazards Research in the Cascades Into Community Preparedness

    Science.gov (United States)

    Ewert, J. W.; Driedger, C. L.

    2015-12-01

    Research by the science community into volcanic histories and physical processes at Cascade volcanoes in the states of Washington, Oregon, and California has been ongoing for over a century. Eruptions in the 20th century at Lassen Peak and Mount St. Helen demonstrated the active nature of Cascade volcanoes; the 1980 eruption of Mount St. Helens was a defining moment in modern volcanology. The first modern volcano hazards assessments were produced by the USGS for some Cascade volcanoes in the 1960s. A rich scientific literature exists, much of which addresses hazards at these active volcanoes. That said community awareness, planning, and preparation for eruptions generally do not occur as a result of a hazard analyses published in scientific papers, but by direct communication with scientists. Relative to other natural hazards, volcanic eruptions (or large earthquakes, or tsunami) are outside common experience, and the public and many public officials are often surprised to learn of the impacts volcanic eruptions could have on their communities. In the 1980s, the USGS recognized that effective hazard communication and preparedness is a multi-faceted, long-term undertaking and began working with federal, state, and local stakeholders to build awareness and foster community action about volcano hazards. Activities included forming volcano-specific workgroups to develop coordination plans for volcano emergencies; a concerted public outreach campaign; curriculum development and teacher training; technical training for emergency managers and first responders; and development of hazard information that is accessible to non-specialists. Outcomes include broader ownership of volcano hazards as evidenced by bi-national exchanges of emergency managers, community planners, and first responders; development by stakeholders of websites focused on volcano hazards mitigation; and execution of table-top and functional exercises, including evacuation drills by local communities.

  20. Detection of Babesia spp. in free-ranging Pukus, Kobus vardonii, on a game ranch in Zambia.

    Science.gov (United States)

    Munang'andu, Hetron Mweemba; Munyeme, Musso; Nambota, Andrew Mubila; Nalubamba, King Shimumbo; Siamudaala, Victor M

    2011-12-01

    Babesia spp. were detected from 4 asymptomatic pukus captured on a game ranch in central Zambia in October 2008. Blood smears were examined in 4 species of aymptomatic free-ranging antelopes, namely the puku (Kobus vordanii), reedbuck (Redunca arundinum), bushbuck (Tragelaphus sylvaticus), and kudu (Tragelaphus strepsiceros), and showed the presence of Babesia parasites only in the puku. In the puku, the prevalence of babesiosis was estimated at 33.3% (n = 12), while the overall prevalence in all examined animals was 8.5% (n = 47). The parasites showed morphological characteristics of paired ring-like stages with the length varying between 1.61 µm and 3.02 µm (mean = 2.12 µm, n = 27; SD = 0.76 µm). Both the infected and non-infected pukus showed good body condition scores (BCS), while the dominant tick species detected from all animals were Rhipicephalus appendiculatus, Rhipicephalus spp., and Boophilus spp. To our knowledge this is the first report of Babesia spp. infection in pukus in Zambia. These findings suggest that wildlife could play an important role in the epidemiology of babesiosis in Zambia.

  1. Monitoring changes in seismic velocity related to an ongoing rapid inflation event at Okmok volcano, Alaska

    Science.gov (United States)

    Bennington, Ninfa; Haney, Matt; De Angelis, Silvio; Thurber, Clifford; Freymueller, Jeff

    2015-01-01

    Okmok is one of the most active volcanoes in the Aleutian Arc. In an effort to improve our ability to detect precursory activity leading to eruption at Okmok, we monitor a recent, and possibly ongoing, GPS-inferred rapid inflation event at the volcano using ambient noise interferometry (ANI). Applying this method, we identify changes in seismic velocity outside of Okmok’s caldera, which are related to the hydrologic cycle. Within the caldera, we observe decreases in seismic velocity that are associated with the GPS-inferred rapid inflation event. We also determine temporal changes in waveform decorrelation and show a continual increase in decorrelation rate over the time associated with the rapid inflation event. Themagnitude of relative velocity decreases and decorrelation rate increases are comparable to previous studies at Piton de la Fournaise that associate such changes with increased production of volatiles and/ormagmatic intrusion within the magma reservoir and associated opening of fractures and/or fissures. Notably, the largest decrease in relative velocity occurs along the intrastation path passing nearest to the center of the caldera. This observation, along with equal amplitude relative velocity decreases revealed via analysis of intracaldera autocorrelations, suggests that the inflation sourcemay be located approximately within the center of the caldera and represent recharge of shallow magma storage in this location. Importantly, there is a relative absence of seismicity associated with this and previous rapid inflation events at Okmok. Thus, these ANI results are the first seismic evidence of such rapid inflation at the volcano.

  2. Forecasting Effusive Dynamics and Decompression Rates by Magmastatic Model at Open-vent Volcanoes.

    Science.gov (United States)

    Ripepe, Maurizio; Pistolesi, Marco; Coppola, Diego; Delle Donne, Dario; Genco, Riccardo; Lacanna, Giorgio; Laiolo, Marco; Marchetti, Emanuele; Ulivieri, Giacomo; Valade, Sébastien

    2017-06-20

    Effusive eruptions at open-conduit volcanoes are interpreted as reactions to a disequilibrium induced by the increase in magma supply. By comparing four of the most recent effusive eruptions at Stromboli volcano (Italy), we show how the volumes of lava discharged during each eruption are linearly correlated to the topographic positions of the effusive vents. This correlation cannot be explained by an excess of pressure within a deep magma chamber and raises questions about the actual contributions of deep magma dynamics. We derive a general model based on the discharge of a shallow reservoir and the magmastatic crustal load above the vent, to explain the linear link. In addition, we show how the drastic transition from effusive to violent explosions can be related to different decompression rates. We suggest that a gravity-driven model can shed light on similar cases of lateral effusive eruptions in other volcanic systems and can provide evidence of the roles of slow decompression rates in triggering violent paroxysmal explosive eruptions, which occasionally punctuate the effusive phases at basaltic volcanoes.

  3. Three-dimensional stochastic adjustment of volcano geodetic network in Arenal volcano, Costa Rica

    Science.gov (United States)

    Muller, C.; van der Laat, R.; Cattin, P.-H.; Del Potro, R.

    2009-04-01

    Volcano geodetic networks are a key instrument to understanding magmatic processes and, thus, forecasting potentially hazardous activity. These networks are extensively used on volcanoes worldwide and generally comprise a number of different traditional and modern geodetic surveying techniques such as levelling, distances, triangulation and GNSS. However, in most cases, data from the different methodologies are surveyed, adjusted and analysed independently. Experience shows that the problem with this procedure is the mismatch between the excellent correlation of position values within a single technique and the low cross-correlation of such values within different techniques or when the same network is surveyed shortly after using the same technique. Moreover one different independent network for each geodetic surveying technique strongly increase logistics and thus the cost of each measurement campaign. It is therefore important to develop geodetic networks which combine the different geodetic surveying technique, and to adjust geodetic data together in order to better quantify the uncertainties associated to the measured displacements. In order to overcome the lack of inter-methodology data integration, the Geomatic Institute of the University of Applied Sciences of Western Switzerland (HEIG-VD) has developed a methodology which uses a 3D stochastic adjustment software of redundant geodetic networks, TRINET+. The methodology consists of using each geodetic measurement technique for its strengths relative to other methodologies. Also, the combination of the measurements in a single network allows more cost-effective surveying. The geodetic data are thereafter adjusted and analysed in the same referential frame. The adjustment methodology is based on the least mean square method and links the data with the geometry. Trinet+ also allows to run a priori simulations of the network, hence testing the quality and resolution to be expected for a determined network even

  4. Pleistocene cohesive debris flows at Nevado de Toluca Volcano, central Mexico

    Science.gov (United States)

    Capra, L.; Macías, J. L.

    2000-10-01

    During the Pleistocene, intense hydrothermal alteration promoted a flank failure of the southern portion of Nevado de Toluca volcano. This event produced a debris avalanche that transformed into a cohesive debris flow (Pilcaya deposit) owing to water saturation and weakness of the altered pre-avalanche rocks. The Pilcaya debris flow traveled along a narrow tectonic depression up to a distance of 40 km and then spread over a flat plain reaching up to 55 km from the volcano summit. This transition zone corresponds with a sudden break in slope from 5 to 0.5° that caused a rapid reduction in velocity and thickening of the flow that consequently reduced its competence to transport large particles. The resulting deposit thickens from 15 to 40 m, and contains boulders up to 15 m in diameter that form hummocky morphology close to the transitional zone. Sometime after the emplacement of the Pilcaya debris flow, heavy rains and superficial drainage contributed to remobilize the upper portions of the deposit causing two secondary lahars. These debris flows called El Mogote, traveled up to 75 km from the volcano. The edifice collapse generated lahars with a total volume of 2.8 km3 that devastated an approximate area of 250 km2. The area versus volume plot for both deposits shows that the magnitude of the event is comparable to other cohesive debris flows such as the Teteltzingo lahar (Pico de Orizaba, Mexico) and the Osceola mudflow (Mount Rainier, Wa). The Pilcaya debris flow represents additional evidence of debris flow transformed from a flank failure, a potentially devastating phenomenon that could threaten distant areas from the volcano previously considered without risk.

  5. Volcano hazards in the San Salvador region, El Salvador

    Science.gov (United States)

    Major, J.J.; Schilling, S.P.; Sofield, D.J.; Escobar, C.D.; Pullinger, C.R.

    2001-01-01

    San Salvador volcano is one of many volcanoes along the volcanic arc in El Salvador (figure 1). This volcano, having a volume of about 110 cubic kilometers, towers above San Salvador, the country’s capital and largest city. The city has a population of approximately 2 million, and a population density of about 2100 people per square kilometer. The city of San Salvador and other communities have gradually encroached onto the lower flanks of the volcano, increasing the risk that even small events may have serious societal consequences. San Salvador volcano has not erupted for more than 80 years, but it has a long history of repeated, and sometimes violent, eruptions. The volcano is composed of remnants of multiple eruptive centers, and these remnants are commonly referred to by several names. The central part of the volcano, which contains a large circular crater, is known as El Boquerón, and it rises to an altitude of about 1890 meters. El Picacho, the prominent peak of highest elevation (1960 meters altitude) to the northeast of the crater, and El Jabali, the peak to the northwest of the crater, represent remnants of an older, larger edifice. The volcano has erupted several times during the past 70,000 years from vents central to the volcano as well as from smaller vents and fissures on its flanks [1] (numerals in brackets refer to end notes in the report). In addition, several small cinder cones and explosion craters are located within 10 kilometers of the volcano. Since about 1200 A.D., eruptions have occurred almost exclusively along, or a few kilometers beyond, the northwest flank of the volcano, and have consisted primarily of small explosions and emplacement of lava flows. However, San Salvador volcano has erupted violently and explosively in the past, even as recently as 800 years ago. When such eruptions occur again, substantial population and infrastructure will be at risk. Volcanic eruptions are not the only events that present a risk to local

  6. Chemical compositions of lavas from Myoko volcano group

    International Nuclear Information System (INIS)

    Hasenaka, Toshiaki; Yoshida, Takeyoshi; Hayatsu, Kenji.

    1995-01-01

    In the volcanic rocks produced in island arc and continental margin arc, the phenomena of magma mixing is observed considerably generally. The research on these phenomena has been carried out also in Japan, and the periodically refilled magma chamber model has been proposed. In this report, the results of the photon activation analysis for the volcanic rock samples of Myoko volcano, for which the magma chamber model that the supply of basalt magma is periodically received was proposed, and of which the age of eruption and the stratigraphy are clearly known, are shown, and the above model is examined together with the published data of fluorescent X-ray analysis and others. The history of activities and the rate of magma extrusion of Myoko volcano group are described. The modal compositions of the volcanic rock samples of Myoko and Kurohime volcanos, for which photon activation analysis was carried out, are shown and discussed. The results of the analysis of the chemical composition of 39 volcanic rock samples from Myoko, Kurohime and Iizuna volcanos are shown. The primary magma in Myoko volcano group, the crystallization differentiation depth and moisture content of magma in Myoko and Kurohime volcanos, the presumption of Felsic and Mafic end-members in R type andesite in Myoko volcano group, and the change of magma composition with lapse of time are described. (K.I.)

  7. Chemical compositions of lavas from Myoko volcano group

    Energy Technology Data Exchange (ETDEWEB)

    Hasenaka, Toshiaki; Yoshida, Takeyoshi [Tohoku Univ., Sendai (Japan). Faculty of Science; Hayatsu, Kenji

    1995-08-01

    In the volcanic rocks produced in island arc and continental margin arc, the phenomena of magma mixing is observed considerably generally. The research on these phenomena has been carried out also in Japan, and the periodically refilled magma chamber model has been proposed. In this report, the results of the photon activation analysis for the volcanic rock samples of Myoko volcano, for which the magma chamber model that the supply of basalt magma is periodically received was proposed, and of which the age of eruption and the stratigraphy are clearly known, are shown, and the above model is examined together with the published data of fluorescent X-ray analysis and others. The history of activities and the rate of magma extrusion of Myoko volcano group are described. The modal compositions of the volcanic rock samples of Myoko and Kurohime volcanos, for which photon activation analysis was carried out, are shown and discussed. The results of the analysis of the chemical composition of 39 volcanic rock samples from Myoko, Kurohime and Iizuna volcanos are shown. The primary magma in Myoko volcano group, the crystallization differentiation depth and moisture content of magma in Myoko and Kurohime volcanos, the presumption of Felsic and Mafic end-members in R type andesite in Myoko volcano group, and the change of magma composition with lapse of time are described. (K.I.)

  8. SAR interferometry applications on active volcanoes. State of the art and perspectives for volcano monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Puglisi, G.; Coltelli, M. [Istituto Nazionale di Geofisica e Vulcanologia, Catania (Italy)

    2001-02-01

    In this paper the application of the Synthetic Aperture Radar Interferometry (INSAR) on volcanology is analysed. Since it is not a real novelty among the different applications of INSAR in Earth Observation activities, at the beginning of this paper it is analysed the state of the art of the researches in this field. During the discussion, the point of view of volcanologists is favoured because it is considered that the first applications were often badly aimed. Consequently, the initial INSAR performances in volcanology were overrated with respect to the real capabilities of this technique. This fact lead to discover some unexpected limitations in INSAR usage in volcano monitoring, but, at the same time, spurred on scientists to overcome these drawbacks. The results achieved recently allow to better apply SAR to volcanology; in the paper a possible operative work-plan aimed at introducing INSAR in the volcano monitoring system is presented.

  9. Geologic Map of the Summit Region of Kilauea Volcano, Hawaii

    Science.gov (United States)

    Neal, Christina A.; Lockwood, John P.

    2003-01-01

    This report consists of a large map sheet and a pamphlet. The map shows the geology, some photographs, description of map units, and correlation of map units. The pamphlet gives the full text about the geologic map. The area covered by this map includes parts of four U.S. Geological Survey 7.5' topographic quadrangles (Kilauea Crater, Volcano, Ka`u Desert, and Makaopuhi). It encompasses the summit, upper rift zones, and Koa`e Fault System of Kilauea Volcano and a part of the adjacent, southeast flank of Mauna Loa Volcano. The map is dominated by products of eruptions from Kilauea Volcano, the southernmost of the five volcanoes on the Island of Hawai`i and one of the world's most active volcanoes. At its summit (1,243 m) is Kilauea Crater, a 3 km-by-5 km collapse caldera that formed, possibly over several centuries, between about 200 and 500 years ago. Radiating away from the summit caldera are two linear zones of intrusion and eruption, the east and the southwest rift zones. Repeated subaerial eruptions from the summit and rift zones have built a gently sloping, elongate shield volcano covering approximately 1,500 km2. Much of the volcano lies under water; the east rift zone extends 110 km from the summit to a depth of more than 5,000 m below sea level; whereas the southwest rift zone has a more limited submarine continuation. South of the summit caldera, mostly north-facing normal faults and open fractures of the Koa`e Fault System extend between the two rift zones. The Koa`e Fault System is interpreted as a tear-away structure that accommodates southward movement of Kilauea's flank in response to distension of the volcano perpendicular to the rift zones.

  10. Mount Meager Volcano, Canada: a Case Study for Landslides on Glaciated Volcanoes

    Science.gov (United States)

    Roberti, G. L.; Ward, B. C.; van Wyk de Vries, B.; Falorni, G.; Perotti, L.; Clague, J. J.

    2015-12-01

    Mount Meager is a strato-volcano massif in the Northern Cascade Volcanic Arc (Canada) that erupted in 2350 BP, the most recent in Canada. To study the stability of the Massif an international research project between France ( Blaise Pascal University), Italy (University of Turin) and Canada (Simon Fraser University) and private companies (TRE - sensing the planet) has been created. A complex history of glacial loading and unloading, combined with weak, hydrothermally altered rocks has resulted in a long record of catastrophic landslides. The most recent, in 2010 is the third largest (50 x 106 m3) historical landslide in Canada. Mount Meager is a perfect natural laboratory for gravity and topographic processes such as landslide activity, permafrost and glacial dynamics, erosion, alteration and uplift on volcanoes. Research is aided by a rich archive of aerial photos of the Massif (1940s up to 2006): complete coverage approximately every 10 years. This data set has been processed and multi-temporal, high resolution Orthophoto and DSMs (Digital Surface Models) have been produced. On these digital products, with the support on field work, glacial retreat and landslide activity have been tracked and mapped. This has allowed for the inventory of unstable areas, the identification of lava flows and domes, and the general improvement on the geologic knowledge of the massif. InSAR data have been used to monitor the deformation of the pre-2010 failure slope. It will also be used to monitor other unstable slopes that potentially can evolve to catastrophic collapses of up to 1 km3 in volume, endangering local communities downstream the volcano. Mount Meager is definitively an exceptional site for studying the dynamics of a glaciated, uplifted volcano. The methodologies proposed can be applied to other volcanic areas with high erosion rates such as Alaska, Cascades, and the Andes.

  11. Muon imaging of volcanoes with Cherenkov telescopes

    Science.gov (United States)

    Carbone, Daniele; Catalano, Osvaldo; Cusumano, Giancarlo; Del Santo, Melania; La Parola, Valentina; La Rosa, Giovanni; Maccarone, Maria Concetta; Mineo, Teresa; Pareschi, Giovanni; Sottile, Giuseppe; Zuccarello, Luciano

    2017-04-01

    The quantitative understanding of the inner structure of a volcano is a key feature to model the processes leading to paroxysmal activity and, hence, to mitigate volcanic hazards. To pursue this aim, different geophysical techniques are utilized, that are sensitive to different properties of the rocks (elastic, electrical, density). In most cases, these techniques do not allow to achieve the spatial resolution needed to characterize the shallowest part of the plumbing system and may require dense measurements in active zones, implying a high level of risk. Volcano imaging through cosmic-ray muons is a promising technique that allows to overcome the above shortcomings. Muons constantly bombard the Earth's surface and can travel through large thicknesses of rock, with an energy loss depending on the amount of crossed matter. By measuring the absorption of muons through a solid body, one can deduce the density distribution inside the target. To date, muon imaging of volcanic structures has been mainly achieved with scintillation detectors. They are sensitive to noise sourced from (i) the accidental coincidence of vertical EM shower particles, (ii) the fake tracks initiated from horizontal high-energy electrons and low-energy muons (not crossing the target) and (iii) the flux of upward going muons. A possible alternative to scintillation detectors is given by Cherenkov telescopes. They exploit the Cherenkov light emitted when charged particles (like muons) travel through a dielectric medium, with velocity higher than the speed of light. Cherenkov detectors are not significantly affected by the above noise sources. Furthermore, contrarily to scintillator-based detectors, Cherenkov telescopes permit a measurement of the energy spectrum of the incident muon flux at the installation site, an issue that is indeed relevant for deducing the density distribution inside the target. In 2014, a prototype Cherenkov telescope was installed at the Astrophysical Observatory of Serra

  12. Large-N in Volcano Settings: Volcanosri

    Science.gov (United States)

    Lees, J. M.; Song, W.; Xing, G.; Vick, S.; Phillips, D.

    2014-12-01

    We seek a paradigm shift in the approach we take on volcano monitoring where the compromise from high fidelity to large numbers of sensors is used to increase coverage and resolution. Accessibility, danger and the risk of equipment loss requires that we develop systems that are independent and inexpensive. Furthermore, rather than simply record data on hard disk for later analysis we desire a system that will work autonomously, capitalizing on wireless technology and in field network analysis. To this end we are currently producing a low cost seismic array which will incorporate, at the very basic level, seismological tools for first cut analysis of a volcano in crises mode. At the advanced end we expect to perform tomographic inversions in the network in near real time. Geophone (4 Hz) sensors connected to a low cost recording system will be installed on an active volcano where triggering earthquake location and velocity analysis will take place independent of human interaction. Stations are designed to be inexpensive and possibly disposable. In one of the first implementations the seismic nodes consist of an Arduino Due processor board with an attached Seismic Shield. The Arduino Due processor board contains an Atmel SAM3X8E ARM Cortex-M3 CPU. This 32 bit 84 MHz processor can filter and perform coarse seismic event detection on a 1600 sample signal in fewer than 200 milliseconds. The Seismic Shield contains a GPS module, 900 MHz high power mesh network radio, SD card, seismic amplifier, and 24 bit ADC. External sensors can be attached to either this 24-bit ADC or to the internal multichannel 12 bit ADC contained on the Arduino Due processor board. This allows the node to support attachment of multiple sensors. By utilizing a high-speed 32 bit processor complex signal processing tasks can be performed simultaneously on multiple sensors. Using a 10 W solar panel, second system being developed can run autonomously and collect data on 3 channels at 100Hz for 6 months

  13. Dynamic triggering of volcano drumbeat-like seismicity at the Tatun volcano group in Taiwan

    Science.gov (United States)

    Lin, Cheng-Horng

    2017-07-01

    Periodical seismicity during eruptions has been observed at several volcanoes, such as Mount St. Helens and Soufrière Hills. Movement of magma is often considered one of the most important factors in its generation. Without any magma movement, drumbeat-like (or heartbeat-like) periodical seismicity was detected twice beneath one of the strongest fumarole sites (Dayoukeng) among the Tatun volcano group in northern Taiwan in 2015. Both incidences of drumbeat-like seismicity were respectively started after felt earthquakes in Taiwan, and then persisted for 1-2 d afterward with repetition intervals of ∼18 min between any two adjacent events. The phenomena suggest both drumbeat-like (heartbeat-like) seismicity sequences were likely triggered by dynamic waves generated by the two felt earthquakes. Thus, rather than any involvement of magma, a simplified pumping system within a degassing conduit is proposed to explain the generation of drumbeat-like seismicity. The collapsed rocks within the conduit act as a piston, which was repeatedly lifted up by ascending gas from a deeper reservoir and dropped down when the ascending gas was escaping later. These phenomena show that the degassing process is still very strong in the Tatun volcano group in Taiwan, even though it has been dormant for about several thousand years.

  14. Developing geophysical monitoring at Mayon volcano, a collaborative project EOS-PHIVOLCS

    Science.gov (United States)

    Hidayat, D.; Laguerta, E.; Baloloy, A.; Valerio, R.; Marcial, S. S.

    2011-12-01

    Mayon is an openly-degassed volcano, producing mostly small, frequent eruptions, most recently in Aug-Sept 2006 and Dec 2009. Mayon volcano status is level 1 with low seismicity dominated mostly local and regional tectonic earthquakes with continuous emission of SO2 from its crater. A research collaboration between Earth Observatory of Singapore-NTU and Philippine Institute of Volcanology and Seismology (PHIVOLCS) have been initiated in 2010 with effort to develop a multi-disciplinary monitoring system around Mayon includes geophysical monitoring, gas geochemical monitoring, and petrologic studies. Currently there are 4 broadband seismographs, 3 short period instruments, and 4 tiltmeters. These instruments will be telemetered to the Lignon Hill Volcano Observatory through radio and 3G broadband internet. We also make use of our self-made low-cost datalogger which has been operating since Jan 2011, performing continuous data acquisition with sampling rate of 20 minute/sample and transmitted through gsm network. First target of this monitoring system is to obtain continuous multi parameter data transmitted in real time to the observatory from different instruments. Tectonically, Mayon is located in the Oas Graben, a northwest-trending structural depression. Previous study using InSAR data, showing evidence of a left-lateral oblique slip movement of the fault North of Mayon. Understanding on what structures active deformation is occurring and how deformation signal is currently partitioned between tectonic and volcanic origin is a key for characterizing magma movement in the time of unrest. Preliminary analysis of the tangential components of tiltmeters (particularly the stations 5 and 7.5 NE from the volcano) shows gradual inflation movement over a few months period. The tangential components for tiltmeters are roughly perpendicular to the fault north of Mayon. This may suggest downward tilting of the graben in the northern side of Mayon. Another possibility is that

  15. Deep magma transport at Kilauea volcano, Hawaii

    Science.gov (United States)

    Wright, T.L.; Klein, F.W.

    2006-01-01

    The shallow part of Kilauea's magma system is conceptually well-understood. Long-period and short-period (brittle-failure) earthquake swarms outline a near-vertical magma transport path beneath Kilauea's summit to 20 km depth. A gravity high centered above the magma transport path demonstrates that Kilauea's shallow magma system, established early in the volcano's history, has remained fixed in place. Low seismicity at 4-7 km outlines a storage region from which magma is supplied for eruptions and intrusions. Brittle-failure earthquake swarms shallower than 5 km beneath the rift zones accompany dike emplacement. Sparse earthquakes extend to a decollement at 10-12 km along which the south flank of Kilauea is sliding seaward. This zone below 5 km can sustain aseismic magma transport, consistent with recent tomographic studies. Long-period earthquake clusters deeper than 40 km occur parallel to and offshore of Kilauea's south coast, defining the deepest seismic response to magma transport from the Hawaiian hot spot. A path connecting the shallow and deep long-period earthquakes is defined by mainshock-aftershock locations of brittle-failure earthquakes unique to Kilauea whose hypocenters are deeper than 25 km with magnitudes from 4.4 to 5.2. Separation of deep and shallow long-period clusters occurs as the shallow plumbing moves with the volcanic edifice, while the deep plumbing is centered over the hotspot. Recent GPS data agrees with the volcano-propagation vector from Kauai to Maui, suggesting that Pacific plate motion, azimuth 293.5?? and rate of 7.4 cm/yr, has been constant over Kilauea's lifetime. However, volcano propagation on the island of Hawaii, azimuth 325??, rate 13 cm/yr, requires southwesterly migration of the locus of melting within the broad hotspot. Deep, long-period earthquakes lie west of the extrapolated position of Kilauea backward in time along a plate-motion vector, requiring southwesterly migration of Kilauea's magma source. Assumed ages of 0

  16. Space Radar Image of Kilauea Volcano, Hawaii

    Science.gov (United States)

    1994-01-01

    This is a deformation map of the south flank of Kilauea volcano on the big island of Hawaii, centered at 19.5 degrees north latitude and 155.25 degrees west longitude. The map was created by combining interferometric radar data -- that is data acquired on different passes of the space shuttle which are then overlayed to obtain elevation information -- acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar during its first flight in April 1994 and its second flight in October 1994. The area shown is approximately 40 kilometers by 80 kilometers (25 miles by 50 miles). North is toward the upper left of the image. The colors indicate the displacement of the surface in the direction that the radar instrument was pointed (toward the right of the image) in the six months between images. The analysis of ground movement is preliminary, but appears consistent with the motions detected by the Global Positioning System ground receivers that have been used over the past five years. The south flank of the Kilauea volcano is among the most rapidly deforming terrains on Earth. Several regions show motions over the six-month time period. Most obvious is at the base of Hilina Pali, where 10 centimeters (4 inches) or more of crustal deformation can be seen in a concentrated area near the coastline. On a more localized scale, the currently active Pu'u O'o summit also shows about 10 centimeters (4 inches) of change near the vent area. Finally, there are indications of additional movement along the upper southwest rift zone, just below the Kilauea caldera in the image. Deformation of the south flank is believed to be the result of movements along faults deep beneath the surface of the volcano, as well as injections of magma, or molten rock, into the volcano's 'plumbing' system. Detection of ground motions from space has proven to be a unique capability of imaging radar technology. Scientists hope to use deformation data acquired by SIR-C/X-SAR and future imaging

  17. Tecuamburro Volcano, Guatemala: exploration geothermal gradient drilling and results

    Science.gov (United States)

    Goff, S.J.; Goff, F.; Janik, C.J.

    1992-01-01

    Results of geological, volcanological, hydrogeochemical, and geophysical field studies conducted in 1988 and 1989 at the Tecuamburro geothermal site, Guatemala, indicate that there is a substantial shallow heat source beneath the area of youngest volcanism. Gases from acid-sulfate springs near Laguna Ixpaco consistently yield maximum estimated subsurface temperatures of 300??C. To obtain information on subsurface temperatures and temperature gradients, stratigraphy, fracturing, hydrothermal alteration, and hydrothermal fluids, a geothermal gradient core hole (TCB-1) was drilled to 808 m low on the northern flank of the Tecuamburro Volcano complex. The hole is located 300 m south of a 300m-diameter phreatic crater. Laguna Ixpaco, dated at 2910 years. TCB-1 temperature logs do not indicate isothermal conditions at depth and the calculated thermal gradient from 500-800 m is 230??C/km. Bottom hole temperature is close to 240??C. Calculated heat flow values are around 350-400 mW/m2. Fluid-inclusion and secondary-alteration studies indicate that veins and secondary minerals were formed at temperatures equal to or slightly less than present temperatures; thus, the Tecuamburro geothermal system may still be heating up. The integration of results from the TCB-1 gradient core hole with results from field studies provides strong evidence that the Tecuamburro area holds great promise for geothermal resource development. ?? 1992.

  18. Geomechanical rock properties of a basaltic volcano

    Directory of Open Access Journals (Sweden)

    Lauren N Schaefer

    2015-06-01

    Full Text Available In volcanic regions, reliable estimates of mechanical properties for specific volcanic events such as cyclic inflation-deflation cycles by magmatic intrusions, thermal stressing, and high temperatures are crucial for building accurate models of volcanic phenomena. This study focuses on the challenge of characterizing volcanic materials for the numerical analyses of such events. To do this, we evaluated the physical (porosity, permeability and mechanical (strength properties of basaltic rocks at Pacaya Volcano (Guatemala through a variety of laboratory experiments, including: room temperature, high temperature (935 °C, and cyclically-loaded uniaxial compressive strength tests on as-collected and thermally-treated rock samples. Knowledge of the material response to such varied stressing conditions is necessary to analyze potential hazards at Pacaya, whose persistent activity has led to 13 evacuations of towns near the volcano since 1987. The rocks show a non-linear relationship between permeability and porosity, which relates to the importance of the crack network connecting the vesicles in these rocks. Here we show that strength not only decreases with porosity and permeability, but also with prolonged stressing (i.e., at lower strain rates and upon cooling. Complimentary tests in which cyclic episodes of thermal or load stressing showed no systematic weakening of the material on the scale of our experiments. Most importantly, we show the extremely heterogeneous nature of volcanic edifices that arise from differences in porosity and permeability of the local lithologies, the limited lateral extent of lava flows, and the scars of previous collapse events. Input of these process-specific rock behaviors into slope stability and deformation models can change the resultant hazard analysis. We anticipate that an increased parameterization of rock properties will improve mitigation power.

  19. Ash and Steam, Soufriere Hills Volcano, Monserrat

    Science.gov (United States)

    2002-01-01

    International Space Station crew members are regularly alerted to dynamic events on the Earth's surface. On request from scientists on the ground, the ISS crew observed and recorded activity from the summit of Soufriere Hills on March 20, 2002. These two images provide a context view of the island (bottom) and a detailed view of the summit plume (top). When the images were taken, the eastern side of the summit region experienced continued lava growth, and reports posted on the Smithsonian Institution's Weekly Volcanic Activity Report indicate that 'large (50-70 m high), fast-growing, spines developed on the dome's summit. These spines periodically collapsed, producing pyroclastic flows down the volcano's east flank that sometimes reached the Tar River fan. Small ash clouds produced from these events reached roughly 1 km above the volcano and drifted westward over Plymouth and Richmond Hill. Ash predominately fell into the sea. Sulfur dioxide emission rates remained high. Theodolite measurements of the dome taken on March 20 yielded a dome height of 1,039 m.' Other photographs by astronauts of Montserrat have been posted on the Earth Observatory: digital photograph number ISS002-E-9309, taken on July 9, 2001; and a recolored and reprojected version of the same image. Digital photograph numbers ISS004-E-8972 and 8973 were taken 20 March, 2002 from Space Station Alpha and were provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  20. Antarctic volcanoes: A remote but significant hazard

    Science.gov (United States)

    Geyer, Adelina; Martí, Alex; Folch, Arnau; Giralt, Santiago

    2017-04-01

    Ash emitted during explosive volcanic eruptions can be dispersed over massive areas of the globe, posing a threat to both human health and infrastructures, such as the air traffic. Some of the last eruptions occurred during this decade (e.g. 14/04/2010 - Eyjafjallajökull, Iceland; 24/05/2011-Grímsvötn, Iceland; 05/06/2011-Puyehue-Cordón Caulle, Chile) have strongly affected the air traffic in different areas of the world, leading to economic losses of billions of euros. From the tens of volcanoes located in Antarctica, at least nine are known to be active and five of them have reported volcanic activity in historical times. However, until now, no attention has been paid to the possible social, economical and environmental consequences of an eruption that would occur on high southern latitudes, perhaps because it is considered that its impacts would be minor or local, and mainly restricted to the practically inhabited Antarctic continent. We show here, as a case study and using climate models, how volcanic ash emitted during a regular eruption of one of the most active volcanoes in Antarctica, Deception Island (South Shetland Islands), could reach the African continent as well as Australia and South America. The volcanic cloud could strongly affect the air traffic not only in the region and at high southern latitudes, but also the flights connecting Africa, South America and Oceania. Results obtained are crucial to understand the patterns of volcanic ash distribution at high southern latitudes with obvious implications for tephrostratigraphical and chronological studies that provide valuable isochrones with which to synchronize palaeoclimate records. This research was partially funded by the MINECO grants VOLCLIMA (CGL2015-72629-EXP)and POSVOLDEC(CTM2016-79617-P)(AEI/FEDER, UE), the Ramón y Cajal research program (RYC-2012-11024) and the NEMOH European project (REA grant 34 agreement n° 289976).

  1. Geophysical image of the hydrothermal system of Merapi volcano

    Science.gov (United States)

    Byrdina, S.; Friedel, S.; Vandemeulebrouck, J.; Budi-Santoso, A.; Suhari; Suryanto, W.; Rizal, M. H.; Winata, E.; Kusdaryanto

    2017-01-01

    We present an image of the hydrothermal system of Merapi volcano based on results from electrical resistivity tomography (ERT), self-potential, and CO2 flux mappings. The ERT models identify two distinct low-resistivity bodies interpreted as two parts of a probably interconnected hydrothermal system: at the base of the south flank and in the summit area. In the summit area, a sharp resistivity contrast at ancient crater rim Pasar-Bubar separates a conductive hydrothermal system (20-50 Ω m) from the resistive andesite lava flows and pyroclastic deposits (2000-50,000 Ω m). The existence of preferential fluid circulation along this ancient crater rim is also evidenced by self-potential data. The significative diffuse CO2 degassing (with a median value of 400 g m-2 d-1) is observed in a narrow vicinity of the active crater rim and close to the ancient rim of Pasar-Bubar. The total CO2 degassing across the accessible summital area with a surface of 1.4 ṡ 105 m2 is around 20 t d-1. Before the 2010 eruption, Toutain et al. (2009) estimated a higher value of the total diffuse degassing from the summit area (about 200-230 t d-1). This drop in the diffuse degassing from the summit area can be related to the decrease in the magmatic activity, to the change of the summit morphology, to the approximations used by Toutain et al. (2009), or, more likely, to a combination of these factors. On the south flank of Merapi, the resistivity model shows spectacular stratification. While surficial recent andesite lava flows are characterized by resistivity exceeding 100,000 Ω m, resistivity as low as 10 Ω m has been encountered at a depth of 200 m at the base of the south flank and was interpreted as a presence of the hydrothermal system. No evidence of the hydrothermal system is found on the basis of the north flank at the same depth. This asymmetry might be caused by the asymmetry of the heat supply source of Merapi whose activity is moving south or/and to the asymmetry in

  2. Spatial variability in degassing at Erebus volcano, Antarctica

    Science.gov (United States)

    Ilanko, Tehnuka; Oppenheimer, Clive; Kyle, Philip; Burgisser, Alain

    2015-04-01

    Erebus volcano on Ross Island, Antarctica, hosts an active phonolitic lava lake, along with a number of persistently degassing vents in its summit crater. Flank degassing also occurs through ice caves and towers. The longevity of the lake, and its stable convection, have been the subject of numerous studies, including Fourier transform infrared (FTIR) spectroscopy of the lava lake. Two distinct gas compositions were previously identified in the main lava lake plume (Oppenheimer et al., 2009; 2011): a persistent 'conduit' gas with a more oxidised signature, ascribed to degassing through a permeable magma conduit; and a H2O- and SO2- enriched 'lake' composition that increases and decreases cyclically due to shallow degassing of incoming magma batches. During the past decade of annual field seasons on Erebus, gas compositions have been measured through FTIR spectroscopy at multiple sites around Erebus volcano, including flank degassing through an ice cave (Warren Cave). We present measurements from four such vents, and compare their compositions to those emitted from the main lava lake. Summit degassing involves variable proportions of H2O, CO2, CO, SO2, HF, HCl, OCS. Cyclicity is evident in some summit vents, but with signatures indicative of shallower magmatic degassing than that of the lava lake. By contrast, flank degassing at Warren Cave is dominated by H2O, CO2, and CH4. The spatial variability in gas compositions within the summit crater suggests an alternative origin for 'conduit' and 'lake' degassing to previous models that assume permeability in the main conduit. Rather, the two compositions observed in main lake degassing may be a result of decoupled 'conduit' gas and pulses of magma rising through discrete fractures before combining in the lake floor or the main plume. Smaller vents around the crater thus emit isolated 'lake' or 'conduit' compositions while their combined signature is observed in the lava lake. We suggest that this separation between gas

  3. Magma supply, storage, and transport at shield-stage Hawaiian volcanoes: Chapter 5 in Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Poland, Michael P.; Miklius, Asta; Montgomery-Brown, Emily K.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    The characteristics of magma supply, storage, and transport are among the most critical parameters governing volcanic activity, yet they remain largely unconstrained because all three processes are hidden beneath the surface. Hawaiian volcanoes, particularly Kīlauea and Mauna Loa, offer excellent prospects for studying subsurface magmatic processes, owing to their accessibility and frequent eruptive and intrusive activity. In addition, the Hawaiian Volcano Observatory, founded in 1912, maintains long records of geological, geophysical, and geochemical data. As a result, Hawaiian volcanoes have served as both a model for basaltic volcanism in general and a starting point for many studies of volcanic processes.

  4. Determinants of persistence and tolerance of carnivores on Namibian ranches: implications for conservation on Southern African private lands.

    Directory of Open Access Journals (Sweden)

    Peter Andrew Lindsey

    Full Text Available Changing land use patterns in southern Africa have potential to dramatically alter the prospects for carnivore conservation. Understanding these influences is essential for conservation planning. We interviewed 250 ranchers in Namibia to assess human tolerance towards and the distribution of large carnivores. Cheetahs (Acinonyx jubatus, leopards (Panthera pardus and brown hyaenas (Hyaena brunnea were widely distributed on Namibian farmlands, spotted hyaenas (Crocuta crocuta had a narrower distribution, and wild dogs (Lycaon pictus and lions (Panthera leo are largely limited to areas near source populations. Farmers were most tolerant of leopards and least tolerant of lions, wild dogs and spotted hyaenas. Several factors relating to land use correlated consistently with carnivore-presence and landowner tolerance. Carnivores were more commonly present and/or tolerated where; wildlife diversity and biomass were higher; income from wildlife was higher; income from livestock was lower; livestock biomass was lower; in conservancies; game fencing was absent; and financial losses from livestock depredation were lower. Efforts to create conditions whereby the costs associated with carnivores are lowest, and which confer financial value to them are likely to be the most effective means of promoting carnivore conservation. Such conditions are achieved where land owners pool land to create conservancies where livestock are replaced with wildlife (or where livestock husbandry is improved and where wildlife generates a significant proportion of ranch income. Additional measures, such as promoting improved livestock husbandry and educational outreach efforts may also help achieve coexistence with carnivores. Our findings provide insights into conditions more conducive to the persistence of and tolerance towards large carnivores might be increased on private (and even communal lands in Namibia, elsewhere in southern and East Africa and other parts of the world

  5. One hundred years of volcano monitoring in Hawaii

    Science.gov (United States)

    Kauahikaua, Jim; Poland, Mike

    2012-01-01

    In 2012 the Hawaiian Volcano Observatory (HVO), the oldest of five volcano observatories in the United States, is commemorating the 100th anniversary of its founding. HVO's location, on the rim of Kilauea volcano (Figure 1)—one of the most active volcanoes on Earth—has provided an unprecedented opportunity over the past century to study processes associated with active volcanism and develop methods for hazards assessment and mitigation. The scientifically and societally important results that have come from 100 years of HVO's existence are the realization of one man's vision of the best way to protect humanity from natural disasters. That vision was a response to an unusually destructive decade that began the twentieth century, a decade that saw almost 200,000 people killed by the effects of earthquakes and volcanic eruptions.

  6. The Active Lava Flows of Kilauea Volcano, Hawaii

    Indian Academy of Sciences (India)

    'lahar' is from Indonesia, a country with some of the most active and destructive volcanoes .... tourist-dependent businesses such as airlines, rental car compa- nies, and hotels. ... excellent viewing conditions and photo opportunities. The heat.

  7. Vegetation damage and recovery after Chiginagak Volcano Crater drainage event

    Data.gov (United States)

    Department of the Interior — From August 20 — 23, 2006, I revisited Chiginigak volcano to document vegetation recovery after the crater drainage event that severely damaged vegetation in May of...

  8. Optimising methods for community-based sea cucumber ranching: Experimental releases of cultured juvenile Holothuria scabra into seagrass meadows in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Cathy Hair

    2016-05-01

    Full Text Available Hatchery-cultured juveniles of the commercial holothurian, sandfish (Holothuria scabra, were used for release experiments in a variety of marine habitats under traditional marine tenure near Kavieng, Papua New Guinea (PNG. Juveniles of approximately 4 g mean weight were released inside 100 m2 sea pens installed within seagrass meadows nearby partner communities, under the care of local ‘wardens’. Within each sea pen, varying levels of protection (free release, 1-day cage and 7-day cage were provided at release in order to determine if short-term predator exclusion improved survival. Ossicles of juvenile sandfish were tagged with different fluorochromes for each treatment and sandfish survival and growth was recorded after release. A range of biophysical parameters were recorded at the four sites. Contrary to expectations, short-term cage protection did not lead to higher survival at three sites, while a fourth site, despite meeting all considered criteria for suitable release habitat, experienced total loss of juveniles. There were significant differences in mean weight of juveniles between sites after four months. Multivariate analysis of biophysical factors clearly separated the sea pen habitats, strongly differentiating the best-performing site from the others. However, further research is needed to elucidate which biophysical or human factors are most useful in predicting the quality of potential sea ranch sites. Methods developed or refined through these trials could be used to establish pilot test plots at potential ranching sites to assess site suitability and provide guidance on the level of animal husbandry required before commencing community sea ranching operations in New Ireland Province, PNG. Keywords: Holothuria scabra, Mariculture, Sea pens, Predator exclusion, Principal components analysis, Biophysical variables

  9. Penguin Bank: A Loa-Trend Hawaiian Volcano

    Science.gov (United States)

    Xu, G.; Blichert-Toft, J.; Clague, D. A.; Cousens, B.; Frey, F. A.; Moore, J. G.

    2007-12-01

    Hawaiian volcanoes along the Hawaiian Ridge from Molokai Island in the northwest to the Big Island in the southeast, define two parallel trends of volcanoes known as the Loa and Kea spatial trends. In general, lavas erupted along these two trends have distinctive geochemical characteristics that have been used to define the spatial distribution of geochemical heterogeneities in the Hawaiian plume (e.g., Abouchami et al., 2005). These geochemical differences are well established for the volcanoes forming the Big Island. The longevity of the Loa- Kea geochemical differences can be assessed by studying East and West Molokai volcanoes and Penguin Bank which form a volcanic ridge perpendicular to the Loa and Kea spatial trends. Previously we showed that East Molokai volcano (~1.5 Ma) is exclusively Kea-like and that West Molokai volcano (~1.8 Ma) includes lavas that are both Loa- and Kea-like (Xu et al., 2005 and 2007).The submarine Penguin Bank (~2.2 Ma), probably an independent volcano constructed west of West Molokai volcano, should be dominantly Loa-like if the systematic Loa and Kea geochemical differences were present at ~2.2 Ma. We have studied 20 samples from Penguin Bank including both submarine and subaerially-erupted lavas recovered by dive and dredging. All lavas are tholeiitic basalt representing shield-stage lavas. Trace element ratios, such as Sr/Nb and Zr/Nb, and isotopic ratios of Sr and Nd clearly are Loa-like. On an ɛNd-ɛHf plot, Penguin Bank lavas fall within the field defined by Mauna Loa lavas. Pb isotopic data lie near the Loa-Kea boundary line defined by Abouchami et al. (2005). In conclusion, we find that from NE to SW, i.e., perpendicular to the Loa and Kea spatial trend, there is a shift from Kea-like East Molokai lavas to Loa-like Penguin Bank lavas with the intermediate West Molokai volcano having lavas with both Loa- and Kea-like geochemical features. Therefore, the Loa and Kea geochemical dichotomy exhibited by Big Island volcanoes

  10. Volcanic stratigraphy and evidence of magma mixing in the Quaternary Payún Matrú volcano, andean backarc in western Argentina Estratigrafía volcánica y evidencia de mezcla de magmas en el volcán Payún Matrú del Cuaternario, en el retroarco andino de Argentina occidental

    Directory of Open Access Journals (Sweden)

    Irene R Hernando

    2012-01-01

    Full Text Available The Payún Matrú Volcanic Field is located in the Payenia Basaltic Province of the recent back-arc of western Argentina (35°S-38°S. This province is younger than 5 Ma, and most of its volcanic activity took place since 2 Ma. The Payún Matrú Volcanic Field contains two composite volcanoes, Payún Matrú and Payún Liso, and two basaltic fields in an E-W oriented zone, located east and west of the Payún Matrú volcano. Payún Matrú is the largest volcano of this volcanic field, and consists of a shield-shaped edifice with a circular summit caldera of 8 km in diameter. The composition of both composite volcanoes is alkaline and predominantly trachytic, having also minor intermediate lavas. The basaltic fields consist of basalts and trachybasalts, with clinopyroxene and abundant olivine as phenocrysts and also in the groundmass. Textures indicating mixing and mingling processes, such as dusty plagioclases along with clear ones, biotite replaced by anhydrous minerals and two groundmasses with a fluid-fluid relationship, are common in the early pre-caldera stage of Payún Matrú and some post-caldera lavas. The latest post-caldera lavas are trachytic, with clean sanidine phenocrysts without disequilibrium textures. A remarkable characteristic of the Payún Matrú Volcanic Field is the fact that the Payún Matrú caldera is surrounded by basaltic fields at its base, while no basalts were erupted in the caldera region. We propose that the absence of basaltic lavas in the Payún Matrú volcano is due to the presence of a magmatic chamber below it, and that the mafic magmas rising from deeper levels were unable to erupt without interaction with more evolved melts. Intermediate hybrid magmas produced as a consequence of magma mixing and mingling between basaltic and trachytic magmas, are present in the early and mid-history of Payún Matrú volcano. We present here new information about the Quaternary Payún Matrú Volcanic Field derived from field

  11. Volcano-hydrothermal energy research at white Island, New Zealand

    International Nuclear Information System (INIS)

    Allis, R.G.

    1994-01-01

    This paper presents the White Island (New Zealand) volcano-hydrothermal research project by the N.Z. DSIR and the Geological Survey of Japan, which is investigating the coupling between magmatic and geothermal systems. The first phase of this investigation is a geophysical survey of the crater floor of the andesite volcano, White Island during 1991/1992, to be followed by drilling from the crater floor into the hydrothermal system. (TEC). 4 figs., 8 refs

  12. Geochemical signatures of tephras from Quaternary Antarctic Peninsula volcanoes

    OpenAIRE

    Kraus,Stefan; Kurbatov,Andrei; Yates,Martin

    2013-01-01

    In the northern Antarctic Peninsula area, at least 12 Late Plelstocene-Holocene volcanic centers could be potential sources of tephra layers in the region. We present unique geochemical fingerprints for ten of these volcanoes using major, trace, rare earth element, and isotope data from 95 samples of tephra and other eruption products. The volcanoes have predominantly basaltic and basaltic andesitic compositions. The Nb/Y ratio proves useful to distinguish between volcanic centers located on ...

  13. Numerical tsunami hazard assessment of the submarine volcano Kick 'em Jenny in high resolution are

    Science.gov (United States)

    Dondin, Frédéric; Dorville, Jean-Francois Marc; Robertson, Richard E. A.

    2016-04-01

    Landslide-generated tsunami are infrequent phenomena that can be potentially highly hazardous for population located in the near-field domain of the source. The Lesser Antilles volcanic arc is a curved 800 km chain of volcanic islands. At least 53 flank collapse episodes have been recognized along the arc. Several of these collapses have been associated with underwater voluminous deposits (volume > 1 km3). Due to their momentum these events were likely capable of generating regional tsunami. However no clear field evidence of tsunami associated with these voluminous events have been reported but the occurrence of such an episode nowadays would certainly have catastrophic consequences. Kick 'em Jenny (KeJ) is the only active submarine volcano of the Lesser Antilles Arc (LAA), with a current edifice volume estimated to 1.5 km3. It is the southernmost edifice of the LAA with recognized associated volcanic landslide deposits. The volcano appears to have undergone three episodes of flank failure. Numerical simulations of one of these episodes associated with a collapse volume of ca. 4.4 km3 and considering a single pulse collapse revealed that this episode would have produced a regional tsunami with amplitude of 30 m. In the present study we applied a detailed hazard assessment on KeJ submarine volcano (KeJ) form its collapse to its waves impact on high resolution coastal area of selected island of the LAA in order to highlight needs to improve alert system and risk mitigation. We present the assessment process of tsunami hazard related to shoreline surface elevation (i.e. run-up) and flood dynamic (i.e. duration, height, speed...) at the coast of LAA island in the case of a potential flank collapse scenario at KeJ. After quantification of potential initial volumes of collapse material using relative slope instability analysis (RSIA, VolcanoFit 2.0 & SSAP 4.5) based on seven geomechanical models, the tsunami source have been simulate by St-Venant equations-based code

  14. Modeling elk and bison carrying capacity for Great Sand Dunes National Park, Baca National Wildlife Refuge, and The Nature Conservancy's Medano Ranch, Colorado

    Science.gov (United States)

    Wockner, Gary; Boone, Randall; Schoenecker, Kathryn A.; Zeigenfuss, Linda C.

    2015-01-01

    Great Sand Dunes National Park and Preserve and the neighboring Baca National Wildlife Refuge constitute an extraordinary setting that offers a variety of opportunities for outdoor recreation and natural resource preservation in the San Luis Valley of Colorado. Adjacent to these federal lands, the Nature Conservancy (TNC) manages the historic Medano Ranch. The total land area of these three conservation properties is roughly 121,500 hectares (ha). It is a remote and rugged area in which resource managers must balance the protection of natural resources with recreation and neighboring land uses. The management of wild ungulates in this setting presents challenges, as wild ungulates move freely across public and private landscapes.

  15. Recent Seismicity in the Ceboruco Volcano, Western Mexico

    Science.gov (United States)

    Nunez, D.; Chávez-Méndez, M. I.; Nuñez-Cornu, F. J.; Sandoval, J. M.; Rodriguez-Ayala, N. A.; Trejo-Gomez, E.

    2017-12-01

    The Ceboruco volcano is the largest (2280 m.a.s.l) of several volcanoes along the Tepic-Zacoalco rift zone in Nayarit state (Mexico). During the last 1000 years, this volcano had effusive-explosive episodes with eight eruptions providing an average of one eruption each 125 years. Since the last eruption occurred in 1870, 147 years ago, a new eruption likelihood is really high and dangerous due to nearby population centers, important roads and lifelines that traverse the volcano's slopes. This hazards indicates the importance of monitoring the seismicity associated with the Ceboruco volcano whose ongoing activity is evidenced by fumaroles and earthquakes. During 2003 and 2008, this region was registered by just one Lennartz Marslite seismograph featuring a Lennartz Le3D sensor (1 Hz) [Rodríguez Uribe et al. (2013)] where they observed that seismicity rates and stresses appear to be increasing indicating higher levels of activity within the volcano. Until July 2017, a semi-permanent network with three Taurus (Nanometrics) and one Q330 Quanterra (Kinemetrics) digitizers with Lennartz 3Dlite sensors of 1 Hz natural frequency was registering in the area. In this study, we present the most recent seismicity obtained by the semi-permanent network and a temporary network of 21 Obsidians 4X and 8X (Kinemetrics) covering an area of 16 km x 16 km with one station every 2.5-3 km recording from November 2016 to July 2017.

  16. Petrologic insights into basaltic volcanism at historically active Hawaiian volcanoes: Chapter 6 in Characteristics of Hawaiian volcanoes

    Science.gov (United States)

    Helz, Rosalind L.; Clague, David A.; Sisson, Thomas W.; Thornber, Carl R.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.

    2014-01-01

    Study of the petrology of Hawaiian volcanoes, in particular the historically active volcanoes on the Island of Hawai‘i, has long been of worldwide scientific interest. When Dr. Thomas A. Jaggar, Jr., established the Hawaiian Volcano Observatory (HVO) in 1912, detailed observations on basaltic activity at Kīlauea and Mauna Loa volcanoes increased dramatically. The period from 1912 to 1958 saw a gradual increase in the collection and analysis of samples from the historical eruptions of Kīlauea and Mauna Loa and development of the concepts needed to evaluate them. In a classic 1955 paper, Howard Powers introduced the concepts of magnesia variation diagrams, to display basaltic compositions, and olivine-control lines, to distinguish between possibly comagmatic and clearly distinct basaltic lineages. In particular, he and others recognized that Kīlauea and Mauna Loa basalts must have different sources.

  17. The diversity of mud volcanoes in the landscape of Azerbaijan

    Science.gov (United States)

    Rashidov, Tofig

    2014-05-01

    As the natural phenomenon the mud volcanism (mud volcanoes) of Azerbaijan are known from the ancient times. The historical records describing them are since V century. More detail study of this natural phenomenon had started in the second half of XIX century. The term "mud volcano" (or "mud hill") had been given by academician H.W. Abich (1863), more exactly defining this natural phenomenon. All the previous definitions did not give such clear and capacious explanation of it. In comparison with magmatic volcanoes, globally the mud ones are restricted in distribution; they mainly locate within the Alpine-Himalayan, Pacific and Central Asian mobile belts, in more than 30 countries (Columbia, Trinidad Island, Italy, Romania, Ukraine, Georgia, Azerbaijan, Turkmenistan, Iran, Pakistan, Indonesia, Burma, Malaysia, etc.). Besides it, the zones of mud volcanoes development are corresponded to zones of marine accretionary prisms' development. For example, the South-Caspian depression, Barbados Island, Cascadia (N.America), Costa-Rica, Panama, Japan trench. Onshore it is Indonesia, Japan, and Trinidad, Taiwan. The mud volcanism with non-accretionary conditions includes the areas of Black Sea, Alboran Sea, the Gulf of Mexico (Louisiana coast), Salton Sea. But new investigations reveal more new mud volcanoes and in places which were not considered earlier as the traditional places of mud volcanoes development (e.g. West Nile Rive delta). Azerbaijan is the classic region of mud volcanoes development. From over 800 world mud volcanoes there are about 400 onshore and within the South-Caspian basin, which includes the territory of East Azerbaijan (the regions of Shemakha-Gobustan and Low-Kura River, Absheron peninsula), adjacent water area of South Caspian (Baku and Absheron archipelagoes) and SW Turkmenistan and represents an area of great downwarping with thick (over 25 km) sedimentary series. Generally, in the modern relief the mud volcanoes represent more or less large uplifts

  18. Geologic field-trip guide to Medicine Lake Volcano, northern California, including Lava Beds National Monument

    Science.gov (United States)

    Donnelly-Nolan, Julie M.; Grove, Timothy L.

    2017-08-17

    Medicine Lake volcano is among the very best places in the United States to see and walk on a variety of well-exposed young lava flows that range in composition from basalt to rhyolite. This field-trip guide to the volcano and to Lava Beds National Monument, which occupies part of the north flank, directs visitors to a wide range of lava flow compositions and volcanic phenomena, many of them well exposed and Holocene in age. The writing of the guide was prompted by a field trip to the California Cascades Arc organized in conjunction with the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) quadrennial meeting in Portland, Oregon, in August of 2017. This report is one of a group of three guides describing the three major volcanic centers of the southern Cascades Volcanic Arc. The guides describing the Mount Shasta and Lassen Volcanic Center parts of the trip share an introduction, written as an overview to the IAVCEI field trip. However, this guide to Medicine Lake volcano has descriptions of many more stops than are included in the 2017 field trip. The 23 stops described here feature a range of compositions and volcanic phenomena. Many other stops are possible and some have been previously described, but these 23 have been selected to highlight the variety of volcanic phenomena at this rear-arc center, the range of compositions, and for the practical reason that they are readily accessible. Open ground cracks, various vent features, tuffs, lava-tube caves, evidence for glaciation, and lava flows that contain inclusions and show visible evidence of compositional zonation are described and visited along the route.

  19. Volcanic Processes and Geology of Augustine Volcano, Alaska

    Science.gov (United States)

    Waitt, Richard B.; Beget, James E.

    2009-01-01

    Augustine Island (volcano) in lower Cook Inlet, Alaska, has erupted repeatedly in late-Holocene and historical times. Eruptions typically beget high-energy volcanic processes. Most notable are bouldery debris avalanches containing immense angular clasts shed from summit domes. Coarse deposits of these avalanches form much of Augustine's lower flanks. A new geologic map at 1:25,000 scale depicts these deposits, these processes. We correlate deposits by tephra layers calibrated by many radiocarbon dates. Augustine Volcano began erupting on the flank of a small island of Jurassic clastic-sedimentary rock before the late Wisconsin glaciation (late Pleistocene). The oldest known effusions ranged from olivine basalt explosively propelled by steam, to highly explosive magmatic eruptions of dacite or rhyodacite shed as pumice flows. Late Wisconsin piedmont glaciers issuing from the mountainous western mainland surrounded the island while dacitic eruptive debris swept down the south volcano flank. Evidence is scant for eruptions between the late Wisconsin and about 2,200 yr B.P. On a few south-flank inliers, thick stratigraphically low pumiceous pyroclastic-flow and fall deposits probably represent this period from which we have no radiocarbon dates on Augustine Island. Eruptions between about 5,350 and 2,200 yr B.P. we know with certainty by distal tephras. On Shuyak Island 100 km southeast of Augustine, two distal fall ashes of Augustinian chemical provenance (microprobe analysis of glass) date respectively between about 5,330 and 5,020 yr B.P. and between about 3,620 and 3,360 yr B.P. An Augustine ash along Kamishak Creek 70 km southwest of Augustine dates between about 3,850 and 3,660 yr B.P. A probably Augustinian ash lying within peat near Homer dates to about 2,275 yr B.P. From before 2,200 yr B.P. to the present, Augustine eruptive products abundantly mantle the island. During this period, numerous coarse debris avalanches swept beyond Augustine's coast, most

  20. The Powell Volcano Remote Sensing Working Group Overview

    Science.gov (United States)

    Reath, K.; Pritchard, M. E.; Poland, M. P.; Wessels, R. L.; Biggs, J.; Carn, S. A.; Griswold, J. P.; Ogburn, S. E.; Wright, R.; Lundgren, P.; Andrews, B. J.; Wauthier, C.; Lopez, T.; Vaughan, R. G.; Rumpf, M. E.; Webley, P. W.; Loughlin, S.; Meyer, F. J.; Pavolonis, M. J.

    2017-12-01

    Hazards from volcanic eruptions pose risks to the lives and livelihood of local populations, with potential global impacts to businesses, agriculture, and air travel. The 2015 Global Assessment of Risk report notes that 800 million people are estimated to live within 100 km of 1400 subaerial volcanoes identified as having eruption potential. However, only 55% of these volcanoes have any type of ground-based monitoring. The only methods currently available to monitor these unmonitored volcanoes are space-based systems that provide a global view. However, with the explosion of data techniques and sensors currently available, taking full advantage of these resources can be challenging. The USGS Powell Center Volcano Remote Sensing Working Group is working with many partners to optimize satellite resources for global detection of volcanic unrest and assessment of potential eruption hazards. In this presentation we will describe our efforts to: 1) work with space agencies to target acquisitions from the international constellation of satellites to collect the right types of data at volcanoes with forecasting potential; 2) collaborate with the scientific community to develop databases of remotely acquired observations of volcanic thermal, degassing, and deformation signals to facilitate change detection and assess how these changes are (or are not) related to eruption; and 3) improve usage of satellite observations by end users at volcano observatories that report to their respective governments. Currently, the group has developed time series plots for 48 Latin American volcanoes that incorporate variations in thermal, degassing, and deformation readings over time. These are compared against eruption timing and ground-based data provided by the Smithsonian Institute Global Volcanism Program. Distinct patterns in unrest and eruption are observed at different volcanoes, illustrating the difficulty in developing generalizations, but highlighting the power of remote sensing

  1. Communication Between Volcanoes: a Possible Path

    Science.gov (United States)

    Linde, A. T.; Sacks, I. S.

    2002-12-01

    The Japan Meteorological Agency installed and operates a network of Sacks-Evertson type borehole strainmeters in south-east Honshu. One of these instruments is on Izu-Oshima, a volcanic island at the northern end of the Izu-Bonin arc. That strainmeter recorded large strain changes associated with the 1986 eruption of Miharayama on the island and, over the period from 1980 to the 1986 eruption, the amplitude of the solid earth tides changed by almost a factor of two. Miyake-jima, about 75 km south of Izu-Oshima, erupted in October 1983. No deformation monitoring was available on Miyake but several changes occurred in the strain record at Izu-Oshima. There was a clear decrease in amplitude of the long-term strain rate. Short period (~hour) events recorded by the strainmeter became much more frequent about 6 months before the Miyake eruption and ceased following the eruption. At the time of the Miyake eruption, the rate of increase of the tidal amplitude also decreased. While all of these changes were observed on a single instrument, they are very different types of change. From a number of independent checks, we can be sure that the strainmeter did not experience any change in performance at that time. Thus it recorded a change in deformation behavior in three very different frequency bands: over very long term, at tidal periods (~day) and at very short periods (~hour). It appears that the distant eruption in 1983 had an effect on the magmatic system under Izu-Oshima. It is likely that these changes were enhanced to the observed level because Izu-Oshima was itself close to eruption failure. More recent tomographic and seismic attenuation work in the Tohoku (northern Honshu) area has shown the existence of a low velocity, high attenuation horizontally elongated structure under the volcanic front. This zone, likely to contain partial melt, is horizontally continuous along the front. If such a structure exists in the similar tectonic setting for these volcanoes, it

  2. Volatile Element Fluxes at Copahue Volcano, Argentina

    Science.gov (United States)

    Varekamp, J. C.

    2002-05-01

    Copahue volcano has a crater lake and acid hot springs that discharge into the Rio Agrio river system. These fluids are very concentrated (up to 6 % sulfate), rich in rock-forming elements (up to 2000 ppm Mg) and small spheres of native sulfur float in the crater lake. The stable isotope composition of the waters (delta 18O =-2.1 to + 3.6 per mille; delta D = -49 to -26 per mille) indicates that the hot spring waters are at their most concentrated about 70% volcanic brine and 30 % glacial meltwater. The crater lake waters have similar mixing proportions but added isotope effects from intense evaporation. Further dilution of the waters in the Rio Agrio gives values closer to local meteoric waters (delta 18O = -11 per mille; delta D = -77 per mille), whereas evaporation in closed ponds led to very heavy water (up to delta 18O = +12 per mille). The delta 34S value of dissolved sulfate is +14.2 per mille, whereas the native sulfur has values of -8.2 to -10.5 per mille. The heavy sulfate probably formed when SO2 disproportionated into bisulfate and native sulfur at about 300 C. We measured the sulfate fluxes in the Rio Agrio, which ranged from 20-40 kilotons S/year. The whole system was releasing sulfur at an equivalent rate of about 250-650 tons SO2/day. From the river flux sulfur values and the stochiometry of the disproportionation reaction we calculated the rate of liquid sulfur storage inside the volcano (6000 m3/year). During the eruptions of 1995/2000, large amounts of that stored liquid sulfur were ejected as pyroclastic sulfur. The calculated rate of rock dissolution (from rock- forming element fluxes in the Rio Agrio) suggests that the void space generated by rock dissolution is largely filled by native sulfur and silica. The S/Cl ratio in the hydrothermal fluids is about 2, whereas glass inclusions have S/Cl = 0.2, indicating the strong preferential degassing of sulfur.

  3. Magma Dynamics in Dome-Building Volcanoes

    Science.gov (United States)

    Kendrick, J. E.; Lavallée, Y.; Hornby, A. J.; Schaefer, L. N.; Oommen, T.; Di Toro, G.; Hirose, T.

    2014-12-01

    The frequent and, as yet, unpredictable transition from effusive to explosive volcanic behaviour is common to active composite volcanoes, yet our understanding of the processes which control this evolution is poor. The rheology of magma, dictated by its composition, porosity and crystal content, is integral to eruption behaviour and during ascent magma behaves in an increasingly rock-like manner. This behaviour, on short timescales in the upper conduit, provides exceptionally dynamic conditions that favour strain localisation and failure. Seismicity released by this process can be mimicked by damage accumulation that releases acoustic signals on the laboratory scale, showing that the failure of magma is intrinsically strain-rate dependent. This character aids the development of shear zones in the conduit, which commonly fracture seismogenically, producing fault surfaces that control the last hundreds of meters of ascent by frictional slip. High-velocity rotary shear (HVR) experiments demonstrate that at ambient temperatures, gouge behaves according to Byerlee's rule at low slip velocities. At rock-rock interfaces, mechanical work induces comminution of asperities and heating which, if sufficient, may induce melting and formation of pseudotachylyte. 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 bulk composition, mineralogy and glass content of the magma all influence frictional behaviour, which supersedes buoyancy as the controlling factor in magma ascent. In the conduit of dome-building volcanoes, the fracture and slip processes are further complicated: slip-rate along the conduit margin fluctuates. The shear-thinning frictional melt yields a tendency for extremely unstable slip thanks to its pivotal position with regard to the glass transition. This thermo-kinetic transition bestows the viscoelastic melt with the ability to either flow or

  4. Volcano surveillance by ACR silver fox

    Science.gov (United States)

    Patterson, M.C.L.; Mulligair, A.; Douglas, J.; Robinson, J.; Pallister, J.S.

    2005-01-01

    Recent growth in the business of unmanned air vehicles (UAVs) both in the US and abroad has improved their overall capability, resulting in a reduction in cost, greater reliability and adoption into areas where they had previously not been considered. Uses in coastal and border patrol, forestry and agriculture have recently been evaluated in an effort to expand the observed area and reduce surveillance and reconnaissance costs for information gathering. The scientific community has both contributed and benefited greatly in this development. A larger suite of light-weight miniaturized sensors now exists for a range of applications which in turn has led to an increase in the gathering of information from these autonomous vehicles. In October 2004 the first eruption of Mount St Helens since 1986 caused tremendous interest amoUg people worldwide. Volcanologists at the U.S. Geological Survey rapidly ramped up the level of monitoring using a variety of ground-based sensors deployed in the crater and on the flanks of the volcano using manned helicopters. In order to develop additional unmanned sensing methods that can be used in potentially hazardous and low visibility conditions, a UAV experiment was conducted during the ongoing eruption early in November. The Silver Fox UAV was flown over and inside the crater to perform routine observation and data gathering, thereby demonstrating a technology that could reduce physical risk to scientists and other field operatives. It was demonstrated that UAVs can be flown autonomously at an active volcano and can deliver real time data to a remote location. Although still relatively limited in extent, these initial flights provided information on volcanic activity and thermal conditions within the crater and at the new (2004) lava dome. The flights demonstrated that readily available visual and infrared video sensors mounted in a small and relatively low-cost aerial platform can provide useful data on volcanic phenomena. This was

  5. Three-dimensional P-wave velocity structure derived from local earthquakes at the Katmai group of volcanoes, Alaska

    Science.gov (United States)

    Jolly, A.D.; Moran, S.C.; McNutt, S.R.; Stone, D.B.

    2007-01-01

    < 2.2), Trident (0.5 < b < 1.5) and Katmai Caldera (0.8 < b < 1.8) had stable b-values indicating the robustness of the observations. The strong high b-value region at Mageik volcano is mainly associated with an earthquake swarm in October, 1996 that possibly indicates a shallow intrusion or influx of gas. The new velocity and spatial b-value results, in conjunction with prior gravity (Bouguer anomalies up to - 40??mgal) and interferometry (several cm uplift) data, provide strong evidence in favor of partially molten rock at shallow depths beneath the Mageik-Katmai-Novarupta region. Moderately low velocities beneath Martin and Katmai suggest that old, mostly solidified intrusions exist beneath these volcanoes. Higher relative velocities beneath the Griggs and Snowy vents suggest that no magma is resident in the shallow crust beneath these volcanoes. ?? 2006 Elsevier B.V.

  6. Parasites gastro-intestinaux d'antilopes et de buffles (Syncerus caffer brachyceros du ranch de gibier de Nazinga au Burkina Faso

    Directory of Open Access Journals (Sweden)

    Belem AMG.

    2009-01-01

    Full Text Available Gastro-intestinal parasites of antelopes and buffalos (Syncerus caffer brachyceros from the Nazinga game ranch in Burkina Faso. Parasitological survey done on the digestive tracts of antelopes [roans (Hippotragus equinus koba, hartebeests (Alcelaphus buselaphus major, defassa waterbucks (Kobus ellipsiprymnus defassa, oribis (Ourebia ourebi quadriscopa] and buffalos (Syncerus caffer brachyceros from the Nazinga game ranch in Burkina Faso allowed the identification of gastrointestinal parasites and the estimation of their prevalence and load. Nine different nematode species and three cestode species were found. Females and larvae of Cooperia were not identified up to the species level and were recognized as Cooperia spp. The nematode species found were: Haemonchus contortus, Trichostrongylus axei, Cooperia curticei, Cooperia spatulata, Skrjabinema sp., Trichostrongylus colubriformis, Trichuris ovis, Bunostomum phlebotomum, and Oesophagostomum sp. Cestodes’ species were: Moniezia expansa, Avitellina centripunctata, and Stilesia globipunctata. It was also noted without a thorough investigation the presence of Setaria labiato-papillosa in the abdominal cavity and paramphistomes in the rumen. In spite of the presence of parasites on the antelopes and buffalos, their killing out percentages (47.5 to 54.7% indicated a good physical status.

  7. Impact of early salmon louse, Lepeophtheirus salmonis, infestation and differences in survival and marine growth of sea-ranched Atlantic salmon, Salmo salar L., smolts 1997–2009

    Science.gov (United States)

    Skilbrei, O T; Finstad, B; Urdal, K; Bakke, G; Kroglund, F; Strand, R

    2013-01-01

    The impact of salmon lice on the survival of migrating Atlantic salmon smolts was studied by comparing the adult returns of sea-ranched smolts treated for sea lice using emamectin benzoate or substance EX with untreated control groups in the River Dale in western Norway. A total of 143 500 smolts were released in 35 release groups in freshwater from 1997 to 2009 and in the fjord system from 2007 to 2009. The adult recaptures declined gradually with release year and reached minimum levels in 2007. This development corresponded with poor marine growth and increased age at maturity of ranched salmon and in three monitored salmon populations and indicated unfavourable conditions in the Norwegian Sea. The recapture rate of treated smolts was significantly higher than the controls in three of the releases performed: the only release in 1997, one of three in 2002 and the only group released in sea water in 2007. The effect of treating the smolts against salmon lice was smaller than the variability in return rates between release groups, and much smaller that variability between release years, but its overall contribution was still significant (P < 0.05) and equivalent to an odds ratio of the probability of being recaptured of 1.17 in favour of the treated smolts. Control fish also tended to be smaller as grilse (P = 0.057), possibly due to a sublethal effect of salmon lice. PMID:23311746

  8. The Utilization of Historical Data and Geospatial Technology Advances at the Jornada Experimental Range to Support Western America Ranching Culture

    Directory of Open Access Journals (Sweden)

    Kris Havstad

    2011-09-01

    that afford the opportunity to obtain high (5 cm resolution data now required for rangeland monitoring. The Jornada team is now a leader in civil UAV applications in the USA. The scientific advances at the Jornada in fields such as remote sensing can be traced to the original Western America ranching culture that established the Jornada in 1912 and which persists as an important influence in shaping research directions today.

  9. Advances in volcano monitoring and risk reduction in Latin America

    Science.gov (United States)

    McCausland, W. A.; White, R. A.; Lockhart, A. B.; Marso, J. N.; Assitance Program, V. D.; Volcano Observatories, L. A.

    2014-12-01

    We describe results of cooperative work that advanced volcanic monitoring and risk reduction. The USGS-USAID Volcano Disaster Assistance Program (VDAP) was initiated in 1986 after disastrous lahars during the 1985 eruption of Nevado del Ruiz dramatizedthe need to advance international capabilities in volcanic monitoring, eruption forecasting and hazard communication. For the past 28 years, VDAP has worked with our partners to improve observatories, strengthen monitoring networks, and train observatory personnel. We highlight a few of the many accomplishments by Latin American volcano observatories. Advances in monitoring, assessment and communication, and lessons learned from the lahars of the 1985 Nevado del Ruiz eruption and the 1994 Paez earthquake enabled the Servicio Geológico Colombiano to issue timely, life-saving warnings for 3 large syn-eruptive lahars at Nevado del Huila in 2007 and 2008. In Chile, the 2008 eruption of Chaitén prompted SERNAGEOMIN to complete a national volcanic vulnerability assessment that led to a major increase in volcano monitoring. Throughout Latin America improved seismic networks now telemeter data to observatories where the decades-long background rates and types of seismicity have been characterized at over 50 volcanoes. Standardization of the Earthworm data acquisition system has enabled data sharing across international boundaries, of paramount importance during both regional tectonic earthquakes and during volcanic crises when vulnerabilities cross international borders. Sharing of seismic forecasting methods led to the formation of the international organization of Latin American Volcano Seismologists (LAVAS). LAVAS courses and other VDAP training sessions have led to international sharing of methods to forecast eruptions through recognition of precursors and to reduce vulnerabilities from all volcano hazards (flows, falls, surges, gas) through hazard assessment, mapping and modeling. Satellite remote sensing data

  10. SUBMARINE VOLCANO CHARACTERISTICS IN SABANG WATERS

    Directory of Open Access Journals (Sweden)

    Hananto Kurnio

    2017-07-01

    Full Text Available The aim of the study is to understand the characteristics of a volcano occurred in marine environment, as Weh Island where Sabang City located is still demonstrated its volcanic cone morphology either through satellite imagery or bathymetric map. Methods used were marine geology, marine geophysics and oceanography. Results show that surface volcanism (sea depth less than 50 m take place as fumaroles, solfataras, hot ground, hot spring, hot mud pool and alteration in the vicinities of seafloor and coastal area vents. Seismic records also showed acoustic turbidity in the sea water column due to gas bubblings produced by seafloor fumaroles. Geochemical analyses show that seafloor samples in the vicinities of active and non-active fumarole vent are abundances with rare earth elements (REE. These were interpreted that the fumarole bring along REE through its gases and deposited on the surrounding seafloor surface. Co-existence between active fault of Sumatra and current volcanism produce hydrothermal mineralization in fault zone as observed in Serui and Pria Laot-middle of Weh Island which both are controlled by normal faults and graben.

  11. Energy budget of the volcano Stromboli, Italy

    Science.gov (United States)

    Mcgetchin, T. R.; Chouet, B. A.

    1979-01-01

    The results of the analyses of movies of eruptions at Stromboli, Italy, and other available data are used to discuss the question of its energy partitioning among various energy transport mechanisms. Energy is transported to the surface from active volcanoes in at least eight modes, viz. conduction (and convection) of the heat through the surface, radiative heat transfer from the vent, acoustical radiation in blast and jet noise, seismic radiation, thermal energy of ejected particles, kinetic energy of ejected particles, thermal energy of ejected gas, and kinetic energy of ejected gas. Estimated values of energy flux from Stromboli by these eight mechanisms are tabulated. The energy budget of Stromboli in its normal mode of activity appears to be dominated by heat conduction (and convection) through the ground surface. Heat carried by eruption gases is the most important of the other energy transfer modes. Radiated heat from the open vent and heat carried by ejected lava particles also contribute to the total flux, while seismic energy accounts for about 0.5% of the total. All other modes are trivial by comparison.

  12. Geomorphological classification of post-caldera volcanoes in the Buyan-Bratan caldera, North Bali, Indonesia

    Science.gov (United States)

    Okuno, Mitsuru; Harijoko, Agung; Wayan Warmada, I.; Watanabe, Koichiro; Nakamura, Toshio; Taguchi, Sachihiro; Kobayashi, Tetsuo

    2017-12-01

    A landform of the post-caldera volcanoes (Lesung, Tapak, Sengayang, Pohen, and Adeng) in the Buyan-Bratan caldera on the island of Bali, Indonesia can be classified by topographic interpretation. The Tapak volcano has three craters, aligned from north to south. Lava effused from the central crater has flowed downward to the northwest, separating the Tamblingan and Buyan Lakes. This lava also covers the tip of the lava flow from the Lesung volcano. Therefore, it is a product of the latest post-caldera volcano eruption. The Lesung volcano also has two craters, with a gully developing on the pyroclastic cone from the northern slope to the western slope. Lava from the south crater has flowed down the western flank, beyond the caldera rim. Lava distributed on the eastern side from the south also surrounds the Sengayang volcano. The Adeng volcano is surrounded by debris avalanche deposits from the Pohen volcano. Based on these topographic relationships, Sengayang volcano appears to be the oldest of the post-caldera volcanoes, followed by the Adeng, Pohen, Lesung, and Tapak volcanoes. Coarse-grained scoria falls around this area are intercalated with two foreign tephras: the Samalas tephra (1257 A.D.) from Lombok Island and the Penelokan tephra (ca. 5.5 kBP) from the Batur caldera. The source of these scoria falls is estimated to be either the Tapak or Lesung volcano, implying that at least two volcanoes have erupted during the Holocene period.

  13. Volcano related atmospheric toxicants in Hilo and Hawaii Volcanoes National Park: implications for human health.

    Science.gov (United States)

    Michaud, Jon-Pierre; Krupitsky, Dmitry; Grove, John S; Anderson, Bruce S

    2005-08-01

    Volcanic fog (vog) from Kilauea volcano on the island of Hawaii includes a variety of chemical species including sulfur compounds and traces of metals such as mercury. The metal species seen tended to be in the nanograms per cubic meter range, whereas oxides of sulfur: SO2 and SO3 and sulfate aerosols, were in the range of micrograms per cubic meter and rarely even as high as a few milligrams per cubic meter of air (nominally ppb to ppm). These sulfur species are being investigated for associations with both acute and chronic changes in human health status. The sulfate aerosols tend to be less than 1 microm in diameter and tend to dominate the mass of this submicron size mode. The sulfur chemistry is dynamic, changing composition from predominantly sulfur dioxide and trioxide gasses near the volcano, to predominantly sulfate aerosols on the west side of the island. Time, concentration and composition characteristics of submicron aerosols and sulfur dioxide are described with respect to the related on-going health studies and public health management concerns. Exposures to sulfur dioxide and particulate matter equal to or less than 1 microm in size were almost always below the national ambient air quality standards (NAAQS). These standards do not however consider the acidic nature and submicron size of the aerosol, nor the possibility of the aerosol and the sulfur dioxide interacting in their toxicity. Time series plots, histograms and descriptive statistics of hourly averages give the reader a sense of some of the exposures observed.

  14. Infrared observations of eclipses of Io, its thermophysical parameters, and the thermal radiation of the Loki volcano and environs

    Science.gov (United States)

    Sinton, William M.; Kaminski, Charles

    1988-01-01

    Observations of Io during eclipses by Jupiter in 1981-1984 are reported. Data obtained at 3.45-30 microns using bolometer system No. 1 on the 3-m IRTF telescope at Mauna Kea are presented in extensive tables and graphs and analyzed by means of least-squares fitting of thermophysical models to the eclipse cooling and heating curves, thermal-radiation calculations for the Io volcanoes, and comparison with Voyager data. Best fits are obtained for a model comprising (1) a bright region with a vertically inhomogeneous surface and (2) a dark vertically homogeneous region with thermal inertia only about 0.1 times that of (1). Little evidence of volcanic-flux variability during the period is found, and the majority (but not all) of the excess thermal IR radiation in the sub-Jovian hemisphere is attributed to the Loki volcano and its lava lake.

  15. Vents Pattern Analysis at Etna volcano (Sicily, Italy).

    Science.gov (United States)

    Brancato, Alfonso; Tusa, Giuseppina; Coltelli, Mauro; Proietti, Cristina; Branca, Stefano

    2014-05-01

    Mount Etna is a composite stratovolcano located along the Ionian coast of eastern Sicily. It is characterized by basaltic eruptions, both effusive and explosive, occurred during a complex eruptive history over the last 500 ka. Flank eruptions occur at an interval of decades, mostly concentrated along the NE, S and W rift zones. A vent clustering at various scales is a common feature in many volcanic settings. In order to identify the clusters within the studied area, a spatial point pattern analysis is undertaken using vent positions, both known and reconstructed. It reveals both clustering and spatial regularity in the Etna region at different distances. The visual inspection of the vent spatial distribution suggests a clustering on the rift zones of Etna volcano. To confirm this evidence, a coarse analysis is performed by the application of Ξ2- and t-test simple statistics. Then, a refined analysis is performed by using the Ripley K-function (Ripley, 1976), whose estimator K(d), knowing the area of the study region and the number of vents, allow us to calculate the distance among two different location of events. The above estimator can be easier transformed by using the Besag L-function (Besag, 1977); the peaks of positive L(d)=[K(d)/π]1/2 -d values indicate clustering while troughs of negative values stand for regularity for their corresponding distances d (L(d)=0 indicates complete spatial randomness). Spatial pattern of flank vents is investigated in order to model the spatial distribution of likely eruptive vents for the next event, basically in terms of relative probabilities. For this, a Gaussian kernel technique is used, and the L(d) function is adopted to generate an optimal smoothing bandwidth based on the clustering behaviour of the Etna volcano. A total of 154 vents (among which 36 are reconstructed), related to Etna flank activity of the last 4.0 ka, is used to model future vent opening. The investigated region covers an area of 850 km2, divided

  16. Tephra compositions from Late Quaternary volcanoes around the Antarctic Peninsula

    Science.gov (United States)

    Kraus, S.

    2009-12-01

    Crustal extension and rifting processes opened the Bransfield Strait between the South Shetland Islands and the Antarctic Peninsula during the last 4 Ma. Similar processes on the Peninsula's eastern side are responsible for volcanism along Larsen Rift. There are at least 11 volcanic centers with known or suspected Late Pleistocene / Holocene explosive activity (Fig. 1). Fieldwork was carried out on the islands Deception, Penguin, Bridgeman and Paulet, moreover at Melville Peak (King George Is.) and Rezen Peak (Livingston Is.). Of special importance is the second ever reported visit and sampling at Sail Rock, and the work on never before visited outcrops on the northern slopes and at the summit of Cape Purvis volcano (Fig. 1). The new bulk tephra ICP-MS geochemical data provide a reliable framework to distinguish the individual volcanic centers from each other. According to their Mg-number, Melville Peak and Penguin Island represent the most primitive magma source. Nb/Y ratios higher than 0.67 in combination with elevated Th/Yb and Ta/Yb ratios and strongly enriched LREE seem to be diagnostic to distinguish the volcanoes located along the Larsen Rift from those associated with Bransfield Rift. Sr/Y ratios discriminate between the individual Larsen Rift volcanoes, Paulet Island showing considerably higher values than Cape Purvis volcano. Along Bransfield Rift, Bridgeman Island and Melville Peak have notably lower Nb/Y and much higher Th/Nb than Deception Island, Penguin Island and Sail Rock. The latter displays almost double the Th/Yb ratio as compared to Deception Island, and also much higher LREE enrichment but extraordinarily low Ba/Th, discriminating it from Penguin Island. Such extremely low Ba/Th ratios are also typical for Melville Peak, but for none of the other volcanoes. Penguin Island has almost double the Ba/Th and Sr/Y ratios higher than any other investigated volcano. Whereas the volcanoes located in the northern part of Bransfield Strait have Zr

  17. Nabro and Mallahle Volcanoes, Eritrea and Ethiopia, SRTM Colored Height and Shaded Relief

    Science.gov (United States)

    2004-01-01

    The area known as the Afar Triangle is located at the northern end of the East Africa Rift, where it approaches the southeastern end of the Red Sea and the southwestern end of the Gulf of Aden. The East African Rift, the Red Sea, and the Gulf of Aden are all zones where Earth's crust is pulling apart in a process known as crustal spreading. Their three-way meeting is known as a triple junction, and their spreading creates a triangular topographic depression for which the area was named.Not surprisingly, the topographic effects of crustal spreading are more dramatic in the Afar Triangle than anywhere else upon Earth's landmasses. The spreading is primarily evident as patterns of numerous tension cracks. But some of these cracks provide conduits for magma to rise to the surface to form volcanoes.Shown here are a few of the volcanoes of the Afar Triangle. The larger two are Nabro Volcano (upper right, in Eritrea) and Mallahle Volcano (lower left, in Ethiopia). Nabro Volcano shows clear evidence of multiple episodes of activity that resulted in a crater in a crater in a crater. Many volcanoes in this area are active, including one nearby that last erupted in 1990.This image was created directly from an SRTM elevation model. A shade image was derived by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark. The shade image was then combined with a color coding of topographic height, with green at the lower elevations, rising through yellow, orange, and red, up to purple at the highest elevations.Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth

  18. 14C ages of Omuroyama volcano, Izu Peninsula

    International Nuclear Information System (INIS)

    Saito, Toshihito; Takahashi, Shuichi; Wada, Hideki

    2003-01-01

    A partly carbonized wood trunk was discovered below the Omuroyama tephra covered by a lava, and it was dated to be 3,700±100 y. B.P., by the benzene liquid scintillation method for radiocarbon age determination. We have investigated the circumstance of the discovery of the wood sample based on an interview of the person who collected the sample during his operation of building construction. According to him, the wood specimen was found at 1.5-2 m depth beneath the ground level when the operator removed the massive blackish lava block. This specimen was laid down covered by black sandy pebbles. The size of the wood trunk was 105 cm long and 45 cm and 35 cm along wide and short diameter, respectively. We also revealed the burial environment of the wood to be related with the Omuroyama tephras and lava flow, based on our volcanostratigraphic observation of the surrounding area. The tephras covering the trunk were identified as the Omuroyama tephra B, C, and D, which were defined by Koyano et al. (1996) around this area, and these tephras were covered by the Omuroyama lava flow II (Koyano et al., 1996). The wood trunk was mostly fresh and only its branch was burned. It can be estimated that the trunk has been preserved surrounded by ground water, since several tons of ground water gushed out when the aquifer was opened for construction. On this context, this trunk was buried at the early stage of the volcanism of Omuroyama volcano covered by the tephras, and later also covered by the Omuroyama lava II. We can not conclude that the burned branch is ascribed to direct burning by the Omuroyama lava flow II but this 14 C dating resultant is also concordant all archaeological evidences reported. (author)

  19. Deep long-period earthquakes beneath Washington and Oregon volcanoes

    Science.gov (United States)

    Nichols, M.L.; Malone, S.D.; Moran, S.C.; Thelen, W.A.; Vidale, J.E.

    2011-01-01

    Deep long-period (DLP) earthquakes are an enigmatic type of seismicity occurring near or beneath volcanoes. They are commonly associated with the presence of magma, and found in some cases to correlate with eruptive activity. To more thoroughly understand and characterize DLP occurrence near volcanoes in Washington and Oregon, we systematically searched the Pacific Northwest Seismic Network (PNSN) triggered earthquake catalog for DLPs occurring between 1980 (when PNSN began collecting digital data) and October 2009. Through our analysis we identified 60 DLPs beneath six Cascade volcanic centers. No DLPs were associated with volcanic activity, including the 1980-1986 and 2004-2008 eruptions at Mount St. Helens. More than half of the events occurred near Mount Baker, where the background flux of magmatic gases is greatest among Washington and Oregon volcanoes. The six volcanoes with DLPs (counts in parentheses) are Mount Baker (31), Glacier Peak (9), Mount Rainier (9), Mount St. Helens (9), Three Sisters (1), and Crater Lake (1). No DLPs were identified beneath Mount Adams, Mount Hood, Mount Jefferson, or Newberry Volcano, although (except at Hood) that may be due in part to poorer network coverage. In cases where the DLPs do not occur directly beneath the volcanic edifice, the locations coincide with large structural faults that extend into the deep crust. Our observations suggest the occurrence of DLPs in these areas could represent fluid and/or magma transport along pre-existing tectonic structures in the middle crust. ?? 2010 Elsevier B.V.

  20. Geochemistry and volatile content of magmas feeding explosive eruptions at Telica volcano (Nicaragua)

    Science.gov (United States)

    Robidoux, P.; Rotolo, S. G.; Aiuppa, A.; Lanzo, G.; Hauri, E. H.

    2017-07-01

    Telica volcano, in north-west Nicaragua, is a young stratovolcano of intermediate magma composition producing frequent Vulcanian to phreatic explosive eruptions. The Telica stratigraphic record also includes examples of (pre)historic sub-Plinian activity. To refine our knowledge of this very active volcano, we analyzed major element composition and volatile content of melt inclusions from some stratigraphically significant Telica tephra deposits. These include: (1) the Scoria Telica Superior (STS) deposit (2000 to 200 years Before Present; Volcanic Explosive Index, VEI, of 2-3) and (2) pyroclasts from the post-1970s eruptive cycle (1982; 2011). Based on measurements with nanoscale secondary ion mass spectrometry, olivine-hosted (forsterite [Fo] > 80) glass inclusions fall into 2 distinct clusters: a group of H2O-rich (1.8-5.2 wt%) inclusions, similar to those of nearby Cerro Negro volcano, and a second group of CO2-rich (360-1700 μg/g CO2) inclusions (Nejapa, Granada). Model calculations show that CO2 dominates the equilibrium magmatic vapor phase in the majority of the primitive inclusions (XCO2 > 0.62-0.95). CO2, sulfur (generally 400 MPa) and early crystallization of magmas. Chlorine exhibits a wide concentration range (400-2300 μg/g) in primitive olivine-entrapped melts (likely suggesting variable source heterogeneity) and is typically enriched in the most differentiated melts (1000-3000 μg/g). Primitive, volatile-rich olivine-hosted melt inclusions (entrapment pressures, 5-15 km depth) are exclusively found in the largest-scale Telica eruptions (exemplified by STS in our study). These eruptions are thus tentatively explained as due to injection of deep CO2-rich mafic magma into the shallow crustal plumbing system. More recent (post-1970), milder (VEI 1-2) eruptions, instead, do only exhibit evidence for low-pressure (P viscosity of resident magma in shallow plumbing system (< 2.4 km), due to crystallization and degassing.

  1. Rangitoto Volcano Drilling Project: Life of a Small 'Monogenetic' Basaltic Shield in the Auckland Volcanic Field

    Science.gov (United States)

    Shane, P. A. R.; Linnell, T.; Lindsay, J. M.; Smith, I. E.; Augustinus, P. M.; Cronin, S. J.

    2014-12-01

    Rangitoto is a small basaltic shield volcano representing the most recent and most voluminous episode of volcanism in the Auckland Volcanic Field, New Zealand. Auckland City is built on the field, and hence, Rangitoto's importance in hazard-risk modelling. The symmetrical edifice, ~6 km wide and 260 m high, has volume of 1.78 km3. It comprises summit scoria cones and a lava field. However, the lack of deep erosion dissection has prevented the development of an eruptive stratigraphy. Previous studies suggested construction in a relatively short interval at 550-500 yrs BP. However, microscopic tephra have been interpreted as evidence of intermittent activity from 1498 +/- 140 to 504 +/- 6 yrs BP, a longevity of 1000 years. A 150-m-deep hole was drilled through the edifice in February 2014 to obtain a continuous core record. The result is an unparalleled stratigraphy of the evolution of a small shield volcano. The upper 128 m of core comprises at least 27 lava flows with thicknesses in the range 0.3-15 m, representing the main shield-building phase. Underlying marine sediments are interbedded with 8 m of pyroclastic lapilli, and a thin lava flow, representing the explosive phreatomagmatic birth of the volcano. Preliminary geochemical analyses reveal suite of relatively uniform transitional basalts (MgO = 8.1 to 9.7 wt %). However, 4 compositional groups are distinguished that were erupted in sequential order. High-MgO magmas were erupted first, followed by a two more heterogeneous groups displaying differentiation trends with time. Finally, distinct low-MgO basalts were erupted. Each magma type appears to represent a new magma batch. The core places the magma types in a time series, which can be correlated to the surface lava field. Hence, allowing a geometrical reconstruction of the shield growth. Additional petrologic investigations are providing insight to magmatic ascent processes, while radiocarbon and paleomagnetic secular variation studies will reveal the

  2. Late Pleistocene flank collapse of Zempoala volcano (Central Mexico) and the role of fault reactivation

    Science.gov (United States)

    Arce, José Luis; Macías, Rodolfo; García Palomo, Armando; Capra, Lucia; Macías, José Luis; Layer, Paul; Rueda, Hernando

    2008-11-01

    Zempoala is an extinct Pleistocene (˜ 0.7-0.8 Ma) stratovolcano that together with La Corona volcano (˜ 0.9 Ma) forms the southern end of the Sierra de las Cruces volcanic range, Central Mexico. The volcano consists of andesitic and dacitic lava flows and domes, as well as pyroclastic and epiclastic sequences, and has had a complex history with several flank collapses. One of these collapses occurred during the late Pleistocene on the S-SE flank of the volcano and produced the Zempoala debris avalanche deposit. This collapse could have been triggered by the reactivation of two normal fault systems (E-W and NE-SW), although magmatic activity cannot be absolutely excluded. The debris avalanche traveled 60 km to the south, covers an area of 600 km 2 and has a total volume of 6 km 3, with a calculated Heim coefficient (H/L) of 0.03. Based on the textural characteristics of the deposit we recognized three zones: proximal, axial, and lateral distal zone. The proximal zone consists of debris avalanche blocks that develop a hummocky topography; the axial zone corresponds with the main debris avalanche deposit made of large clasts set in a sandy matrix, which transformed to a debris flow in the lateral distal portion. The deposit is heterolithologic in composition, with dacitic and andesitic fragments from the old edifice that decrease in volume as bulking of exotic clasts from the substratum increase. Several cities (Cuernavaca, Jojutla de Juárez, Alpuyeca) with associated industrial, agricultural, and tourism activities have been built on the deposit, which pose in evidence the possible impact in case of a new event with such characteristics, since the area is still tectonically active.

  3. ARSENIC REMOVAL FROM DRINKING WATER BY POINT-OF-USE (POU) REVERSE OSMOSIS. U.S. EPA DEMONSTRATION PROJECT AT SUNSET RANCH DEVELOPMENT IN HOMEDALE, ID. FINAL PERFORMANCE EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the arsenic removal technology demonstration project at the Sunset Ranch Development in Homedale, ID. The objectives of the project are to evaluate: 1) the effectiveness of a point of use (POU) re...

  4. Economic, social, and cultural aspects of livestock ranching on the Española and Canjilon Ranger Districts of the Santa Fe and Carson National Forests: a pilot study

    Science.gov (United States)

    Carol Raish; Alice M. McSweeney

    2003-01-01

    The ranches of northern New Mexico, composed of land and livestock, are integral components of family and community life. This pilot study examines current economic, social, and cultural aspects of livestock operations owned by ranchers with Federal grazing permits (permittees) on the Canjilon and Española Ranger Districts of the Santa Fe and Carson National...

  5. Tremor Source Location at Okmok Volcano

    Science.gov (United States)

    Reyes, C. G.; McNutt, S. R.

    2007-12-01

    Initial results using an amplitude-based tremor location program have located several active tremor episodes under Cone A, a vent within Okmok volcano's 10 km caldera. Okmok is an andesite volcano occupying the north-eastern half of Umnak Island, in the Aleutian islands. Okmok is defined by a ~2000 y.b.p. caldera that contains multiple cinder cones. Cone A, the youngest of these, extruded lava in 1997 covering the caldera floor. Since April 2003, continuous seismic data have been recorded from eight vertical short-period stations (L4-C's) installed at distances from Cone A ranging from 2 km to 31 km. In 2004 four additional 3- component broadband stations were added, co-located with continuous GPS stations. InSAR and GPS measurements of post-eruption deformation show that Okmok experienced several periods of rapid inflation (Mann and Freymueller, 2002), from the center of the 10 km diameter caldera. While there are few locatable VT earthquakes, there has been nearly continuous low-level tremor with stronger amplitude bursts occurring at variable rates and durations. The character of occurrence remained relatively constant over the course of days to weeks until the signal ceased in mid 2005. Within any day, tremor behavior remains fairly consistent, with bursts closely resembling each other, suggesting a single main process or source location. The tremor is composed of irregular waves with a broad range of frequencies, though most energy resides between ~2 Hz and 6 Hz. Attempts to locate the tremor using traditional arrival time methods fail because the signal is emergent, with envelopes too ragged to correlate on time scales that hold much hope for a location. Instead, focus was shifted to the amplitude ratios at various stations. Candidates for the tremor source include the center of inflation and Cone A, 3 km to the south-west. For all dates on record, data were band pass filtered between 1 and 5 Hz, then evaluated in 20.48 second windows (N=2048, sampling rate

  6. Basaltic cannibalism at Thrihnukagigur volcano, Iceland

    Science.gov (United States)

    Hudak, M. R.; Feineman, M. D.; La Femina, P. C.; Geirsson, H.

    2014-12-01

    Magmatic assimilation of felsic continental crust is a well-documented, relatively common phenomenon. The extent to which basaltic crust is assimilated by magmas, on the other hand, is not well known. Basaltic cannibalism, or the wholesale incorporation of basaltic crustal material into a basaltic magma, is thought to be uncommon because basalt requires more energy than higher silica rocks to melt. Basaltic materials that are unconsolidated, poorly crystalline, or palagonitized may be more easily ingested than fully crystallized massive basalt, thus allowing basaltic cannibalism to occur. Thrihnukagigur volcano, SW Iceland, offers a unique exposure of a buried cinder cone within its evacuated conduit, 100 m below the main vent. The unconsolidated tephra is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to a vent that produced lava and tephra during the ~4 Ka fissure eruption. Preliminary petrographic and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) analyses indicate that there are two populations of plagioclase present in the system - Population One is stubby (aspect ratio 2.1), subhedral to euhedral, and has much higher Ba/Sr ratios. Population One crystals are observed in the cinder cone, dike, and surface lavas, whereas Population Two crystals are observed only in the dike and surface lavas. This suggests that a magma crystallizing a single elongate population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the stubbier population of phenocrysts. This conceptual model for basaltic cannibalism is supported by field observations of large-scale erosion upward into the tephra, which is coated by magma flow-back indicating that magma was involved in the thermal etching. While the unique exposure at Thrihnukagigur makes it an exceptional place to investigate basaltic cannibalism, we suggest that it is not limited to this volcanic system. Rather it is a process that likely

  7. Design of smart sensing components for volcano monitoring

    Science.gov (United States)

    Xu, M.; Song, W.-Z.; Huang, R.; Peng, Y.; Shirazi, B.; LaHusen, R.; Kiely, A.; Peterson, N.; Ma, A.; Anusuya-Rangappa, L.; Miceli, M.; McBride, D.

    2009-01-01

    In a volcano monitoring application, various geophysical and geochemical sensors generate continuous high-fidelity data, and there is a compelling need for real-time raw data for volcano eruption prediction research. It requires the network to support network synchronized sampling, online configurable sensing and situation awareness, which pose significant challenges on sensing component design. Ideally, the resource usages shall be driven by the environment and node situations, and the data quality is optimized under resource constraints. In this paper, we present our smart sensing component design, including hybrid time synchronization, configurable sensing, and situation awareness. Both design details and evaluation results are presented to show their efficiency. Although the presented design is for a volcano monitoring application, its design philosophy and framework can also apply to other similar applications and platforms. ?? 2009 Elsevier B.V.

  8. Postshield stage transitional volcanism on Mahukona Volcano, Hawaii

    Science.gov (United States)

    Clague, D.A.; Calvert, A.T.

    2009-01-01

    Age spectra from 40Ar/39Ar incremental heating experiments yield ages of 298??25 ka and 310??31 ka for transitional composition lavas from two cones on submarine Mahukona Volcano, Hawaii. These ages are younger than the inferred end of the tholeiitic shield stage and indicate that the volcano had entered the postshield alkalic stage before going extinct. Previously reported elevated helium isotopic ratios of lavas from one of these cones were incorrectly interpreted to indicate eruption during a preshield alkalic stage. Consequently, high helium isotopic ratios are a poor indicator of eruptive stage, as they occur in preshield, shield, and postshield stage lavas. Loihi Seamount and Kilauea are the only known Hawaiian volcanoes where the volume of preshield alkalic stage lavas can be estimated. ?? Springer-Verlag 2008.

  9. Sutter Buttes-the lone volcano in California's Great Valley

    Science.gov (United States)

    Hausback, Brain P.; Muffler, L.J. Patrick; Clynne, Michael A.

    2011-01-01

    The volcanic spires of the Sutter Buttes tower 2,000 feet above the farms and fields of California's Great Valley, just 50 miles north-northwest of Sacramento and 11 miles northwest of Yuba City. The only volcano within the valley, the Buttes consist of a central core of volcanic domes surrounded by a large apron of fragmental volcanic debris. Eruptions at the Sutter Buttes occurred in early Pleistocene time, 1.6 to 1.4 million years ago. The Sutter Buttes are not part of the Cascade Range of volcanoes to the north, but instead are related to the volcanoes in the Coast Ranges to the west in the vicinity of Clear Lake, Napa Valley, and Sonoma Valley.

  10. Digital Geologic Map Database of Medicine Lake Volcano, Northern California

    Science.gov (United States)

    Ramsey, D. W.; Donnelly-Nolan, J. M.; Felger, T. J.

    2010-12-01

    Medicine Lake volcano, located in the southern Cascades ~55 km east-northeast of Mount Shasta, is a large rear-arc, shield-shaped volcano with an eruptive history spanning nearly 500 k.y. Geologic mapping of Medicine Lake volcano has been digitally compiled as a spatial database in ArcGIS. Within the database, coverage feature classes have been created representing geologic lines (contacts, faults, lava tubes, etc.), geologic unit polygons, and volcanic vent location points. The database can be queried to determine the spatial distributions of different rock types, geologic units, and other geologic and geomorphic features. These data, in turn, can be used to better understand the evolution, growth, and potential hazards of this large, rear-arc Cascades volcano. Queries of the database reveal that the total area covered by lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, is about 2,200 km2, encompassing all or parts of 27 U.S. Geological Survey 1:24,000-scale topographic quadrangles. The maximum extent of these lavas is about 80 km north-south by 45 km east-west. Occupying the center of Medicine Lake volcano is a 7 km by 12 km summit caldera in which nestles its namesake, Medicine Lake. The flanks of the volcano, which are dotted with cinder cones, slope gently upward to the caldera rim, which reaches an elevation of nearly 2,440 m. Approximately 250 geologic units have been mapped, only half a dozen of which are thin surficial units such as alluvium. These volcanic units mostly represent eruptive events, each commonly including a vent (dome, cinder cone, spatter cone, etc.) and its associated lava flow. Some cinder cones have not been matched to lava flows, as the corresponding flows are probably buried, and some flows cannot be correlated with vents. The largest individual units on the map are all basaltic in composition, including the late Pleistocene basalt of Yellowjacket Butte (296 km2 exposed), the largest unit on the

  11. Earth Girl Volcano: An Interactive Game for Disaster Preparedness

    Science.gov (United States)

    Kerlow, Isaac

    2017-04-01

    Earth Girl Volcano is an interactive casual strategy game for disaster preparedness. The project is designed for mainstream audiences, particularly for children, as an engaging and fun way to learn about volcano hazards. Earth Girl is a friendly character that kids can easily connect with and she helps players understand how to best minimize volcanic risk. Our previous award-winning game, Earth Girl Tsunami, has seen success on social media, and is available as a free app for both Android and iOS tables and large phones in seven languages: Indonesian, Thai, Tamil, Japanese, Chinese, Spanish, French and English. This is the first public viewing of the Earth Girl Volcano new game prototype.

  12. Multiple Active Volcanoes in the Northeast Lau Basin

    Science.gov (United States)

    Baker, E. T.; Resing, J. A.; Lupton, J. E.; Walker, S. L.; Embley, R. W.; Rubin, K. H.; Buck, N.; de Ronde, C. E.; Arculus, R. J.

    2010-12-01

    The northeast Lau Basin occupies a complex geological area between the Tafua arc front, the E-W trending Tonga Trench, and the Northeast Lau Spreading Center. These boundaries create multiple zones of extension and thus provide abundant opportunities for magma to invade the crust. The 25-km-long chain of “Mata” volcanoes lies near the center of this area, separated from both the arc front and the spreading ridge. In 2008 we discovered hydrothermal venting on the largest and most southerly of these volcanoes, W and E Mata. In 2010 we visited the 7 smaller volcanoes that form a 15-km-long arcuate sweep to the north from W and E Mata (the “North Matas”). We also revisited W and E Mata. Over each volcano we conducted CTD tows to map plumes and collect water samples. Based on the CTD results, camera tows searched for seafloor sources on three volcanoes. The N Mata volcanoes, extending from Mata Taha (1) in the south to Mata Fitu (7) in the north, lie within a prominent gap in the shallow bathymetry along the southern border of the Tonga trench. Northward from E Mata the Mata volcanoes degrade from large symmetrical cones to smaller and blocky volcanic edifices. Summit depths range from 1165 m (W Mata) to 2670 m (Mata Nima (5)). The most active volcano in the chain is the erupting W Mata, with an intense plume that extended 250 m above the summit. Hydrothermal temperature anomalies (Δθ, corrected for hydrographic masking effects) reached ˜1.7°C, with light-scattering values as high as 2-5 ΔNTU. The 2010 surveys now show that 6 of the 7 N Mata volcanoes are also hydrothermally active. Along the N Matas, Δθ and ΔNTU signals ranged from robust to weak, but distinct oxidation-reduction potential (aka Eh) anomalies confirmed active venting in each case. The most concentrated plumes were found near Mata Ua (2) and Mata Fitu (7), with Δθ and ΔNTU maxima of 0.1-0.17°C and 0.3, respectively. Despite the variability in plume strength, however, ΔNTU/Δθ ratios

  13. Determining the stress field in active volcanoes using focal mechanisms

    Directory of Open Access Journals (Sweden)

    Bruno Massa

    2016-11-01

    Full Text Available Stress inversion of seismological datasets became an essential tool to retrieve the stress field of active tectonics and volcanic areas. In particular, in volcanic areas, it is able to put constrains on volcano-tectonics and in general in a better understanding of the volcano dynamics. During the last decades, a wide range of stress inversion techniques has been proposed, some of them specifically conceived to manage seismological datasets. A modern technique of stress inversion, the BRTM, has been applied to seismological datasets available at three different regions of active volcanism: Mt. Somma-Vesuvius (197 Fault Plane Solutions, FPSs, Campi Flegrei (217 FPSs and Long Valley Caldera (38,000 FPSs. The key role of stress inversion techniques in the analysis of the volcano dynamics has been critically discussed. A particular emphasis was devoted to performances of the BRTM applied to volcanic areas.

  14. Inside the volcano: The how and why of Thrihnukagigur volcano, Iceland

    Science.gov (United States)

    LaFemina, Peter; Hudak, Michael; Feineman, Maureen; Geirsson, Halldor; Normandeau, Jim; Furman, Tanya

    2015-04-01

    The Thrihnukagigur volcano, located in the Brennisteinsfjöll fissure swarm on the Reykjanes Peninsula, Iceland, offers a unique exposure of the upper magmatic plumbing system of a monogenetic volcano. The volcano formed during a dike-fed strombolian eruption ~3500 BP with flow-back leaving an evacuated conduit, elongated parallel to the regional maximum horizontal stress. At least two vents were formed above the dike, as well as several small hornitos south-southwest of the main vent. In addition to the evacuated conduit, a cave exists 120 m below the vent. The cave exposes stacked lava flows and a buried cinder cone. The unconsolidated tephra of the cone is cross-cut by a NNE-trending dike, which runs across the ceiling of this cave to the vent that produced lava and tephra during the ~3500 BP fissure eruption. We present geochemical, petrologic and geologic observations, including a high-resolution three-dimensional scan of the system that indicate the dike intersected, eroded and assimilated unconsolidated tephra from the buried cinder cone, thus excavating a region along the dike, allowing for future slumping and cave formation. Two petrographically distinct populations of plagioclase phenocrysts are present in the system: a population of smaller (maximum length 1 mm) acicular phenocrysts and a population of larger (maximum length 10 mm) tabular phenocrysts that is commonly broken and displays disequilibrium sieve textures. The acicular plagioclase crystals are present in the dike and lavas while the tabular crystals are in these units and the buried tephra. An intrusion that appears not to have interacted with the tephra has only acicular plagioclase. This suggests that a magma crystallizing a single acicular population of plagioclase intruded the cinder cone and rapidly assimilated the tephra, incorporating the tabular population of phenocrysts from the cone. Petrographic thin-sections of lavas sampled near the vent show undigested fragments of tephra from

  15. 2004 Deformation of Okmok Volcano,Alaska, USA

    Science.gov (United States)

    Fournier, T. J.; Freymueller, J. T.

    2004-12-01

    Okmok Volcano is a basaltic shield volcano with a 10km diameter caldera located on Umnak Island in the Aleutian Arc, Alaska. Okmok has had frequent effusive eruptions, the latest in 1997. In 2002 the Alaska Volcano Observatory installed a seismic network and three continuous GPS stations. Two stations are located in the caldera and one is located at the base of the volcano at Fort Glenn. Because of instrumentation problems the GPS network was not fully operational until August 2003. A fourth GPS site, located on the south flank of the volcano, came online in September 2004. The three continuous GPS instruments captured a rapid inflation event at Okmok Volcano spanning 6 months from March to August 2004. The instruments give a wonderful time-series of the episode but poor spatial coverage. Modeling the deformation is accomplished by supplementing the continuous data with campaign surveys conducted in the summers of 2002, 2003 and 2004. Displacements between the 2002 and 2003 campaigns show a large inflation event between those time periods. The continuous and campaign data suggest that deformation at Okmok is characterized by short-lived rapid inflation interspersed with periods of moderate inflation. Velocities during the 2004 event reached a maximum of 31cm/yr in the vertical direction and 15cm/yr eastward at the station OKCD, compared with the pre-inflation velocities of 4cm/yr in the vertical and 2.5cm/yr southeastward. Using a Mogi point source model both prior to and during the inflation gives a source location in the center of the caldera and a depth of about 3km. The source strength rate is three times larger during the inflation event than the period preceding it. Based on the full time series of campaign and continuous GPS data, it appears that the variation in inflation rate results from changes in the magma supply rate and not from changes in the depth of the source.

  16. Measuring Gases Using Drones at Turrialba Volcano, Costa Rica

    Science.gov (United States)

    Stix, J.; Alan, A., Jr.; Corrales, E.; D'Arcy, F.; de Moor, M. J.; Diaz, J. A.

    2016-12-01

    We are currently developing a series of drones and associated instrumentation to study Turrialba volcano in Costa Rica. This volcano has shown increasing activity during the last 20 years, and the volcano is currently in a state of heightened unrest as exemplified by recent explosive activity in May-August 2016. The eruptive activity has made the summit area inaccessible to normal gas monitoring activities, prompting development of new techniques to measure gas compositions. We have been using two drones, a DJI Spreading Wings S1000 octocopter and a Turbo Ace Matrix-i quadcopter, to airlift a series of instruments to measure volcanic gases in the plume of the volcano. These instruments comprise optical and electrochemical sensors to measure CO2, SO2, and H2S concentrations which are considered the most significant species to help forecast explosive eruptions and determine the relative proportions of magmatic and hydrothermal components in the volcanic gas. Additionally, cameras and sensors to measure air temperature, relative humidity, atmospheric pressure, and GPS location are included in the package to provide meteorological and geo-referenced information to complement the concentration data and provide a better picture of the volcano from a remote location. The integrated payloads weigh 1-2 kg, which can typically be flown by the drones in 10-20 minutes at altitudes of 2000-4000 meters. Preliminary tests at Turrialba in May 2016 have been very encouraging, and we are in the process of refining both the drones and the instrumentation packages for future flights. Our broader goals are to map gases in detail with the drones in order to make flux measurements of each species, and to apply this approach at other volcanoes.

  17. Investigation of the Dashigil mud volcano (Azerbaijan) using beryllium-10

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.J., E-mail: kjkim@kigam.re.kr [Korea Geological Research Division, Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Baskaran, M.; Jweda, J. [Department of Geology, Wayne State University, Detroit, MI 48202 (United States); Feyzullayev, A.A.; Aliyev, C. [Geology Institute of the Azerbaijan National Academy of Sciences (ANAS), Baku, AZ 1143 (Azerbaijan); Matsuzaki, H. [MALT, University of Tokyo, Tokyo (Japan); Jull, A.J.T. [NSF Arizona AMS Lab, University of Arizona, AZ 85721 (United States)

    2013-01-15

    We collected and analyzed five sediments from three mud volcano (MV) vents and six suspended and bottom sediment samples from the adjoining river near the Dashgil mud volcano in Azerbaijan for {sup 10}Be. These three MV are found among the 190 onshore and >150 offshore MV in this region which correspond to the western flank of the South Caspian depression. These MVs overlie the faulted and petroleum-bearing anticlines. The {sup 10}Be concentrations and {sup 10}Be/{sup 9}Be ratios are comparable to the values reported for mud volcanoes in Trinidad Island. It appears that the stable Be concentrations in Azerbaijan rivers are not perturbed by anthropogenic effects and are comparable to the much older sediments (mud volcano samples). The {sup 10}Be and {sup 9}Be concentrations in our river sediments are compared to the global data set and show that the {sup 10}Be values found for Kura River are among the lowest of any river for which data exist. We attribute this low {sup 10}Be concentration to the nature of surface minerals which are affected by the residual hydrocarbon compounds that occur commonly in the study area in particular and Azerbaijan at large. The concentrations of {sup 40}K and U-Th-series radionuclides ({sup 234}Th, {sup 210}Pb, {sup 226}Ra, and {sup 228}Ra) indicate overall homogeneity of the mud volcano samples from the three different sites. Based on the {sup 10}Be concentrations of the mud volcano samples, the age of the mud sediments could be at least as old as 4 myr.

  18. A generic model for the shallow velocity structure of volcanoes

    Science.gov (United States)

    Lesage, Philippe; Heap, Michael J.; Kushnir, Alexandra

    2018-05-01

    The knowledge of the structure of volcanoes and of the physical properties of volcanic rocks is of paramount importance to the understanding of volcanic processes and the interpretation of monitoring observations. However, the determination of these structures by geophysical methods suffers limitations including a lack of resolution and poor precision. Laboratory experiments provide complementary information on the physical properties of volcanic materials and their behavior as a function of several parameters including pressure and temperature. Nevertheless combined studies and comparisons of field-based geophysical and laboratory-based physical approaches remain scant in the literature. Here, we present a meta-analysis which compares 44 seismic velocity models of the shallow structure of eleven volcanoes, laboratory velocity measurements on about one hundred rock samples from five volcanoes, and seismic well-logs from deep boreholes at two volcanoes. The comparison of these measurements confirms the strong variability of P- and S-wave velocities, which reflects the diversity of volcanic materials. The values obtained from laboratory experiments are systematically larger than those provided by seismic models. This discrepancy mainly results from scaling problems due to the difference between the sampled volumes. The averages of the seismic models are characterized by very low velocities at the surface and a strong velocity increase at shallow depth. By adjusting analytical functions to these averages, we define a generic model that can describe the variations in P- and S-wave velocities in the first 500 m of andesitic and basaltic volcanoes. This model can be used for volcanoes where no structural information is available. The model can also account for site time correction in hypocenter determination as well as for site and path effects that are commonly observed in volcanic structures.

  19. The 2000 AD eruption of Copahue Volcano, Southern Andes

    OpenAIRE

    Naranjo, José Antonio; Polanco, Edmundo

    2004-01-01

    Although all historic eruptions of the Copahue volcano (37°45'S-71°10.2'W, 3,001 m a.s.l.) have been of low magnitude, the largest (VEI=2) and longest eruptive cycle occurred from July to October 2000. Phreatic phases characterized the main events as a former acid crater lake was blown up. Low altitude columns were deviated by low altitude winds in variable directions, but slightly predominant to the NNE. The presence of the El Agrio caldera depression to the east of Copahue volcano may have ...

  20. The recent seismicity of Teide volcano, Tenerife (Canary Islands, Spain)

    Science.gov (United States)

    D'Auria, L.; Albert, G. W.; Calvert, M. M.; Gray, A.; Vidic, C.; Barrancos, J.; Padilla, G.; García-Hernández, R.; Perez, N. M.

    2017-12-01

    Tenerife is an active volcanic island which experienced several eruptions of moderate intensity in historical times, and few explosive eruptions in the Holocene. The increasing population density and the consistent number of tourists are constantly raising the volcanic risk of the island.On 02/10/2016 a remarkable swarm of long-period events was recorded and was interpreted as the effect of a transient massive fluid discharge episode occurring within the deep hydrothermal system of Teide volcano. Actually, since Oct. 2016, the hydrothermal system of the volcano underwent a progressive pressurization, testified by the marked variation of different geochemical parameters. The most striking observation is the increase in the diffuse CO2 emission from the summit crater of Teide volcano which started increasing from a background value of about 20 tons/day and reaching a peak of 175 tons/day in Feb. 2017.The pressurization process has been accompanied by an increase in the volcano-tectonic seismicity of. Teide volcano, recorded by the Red Sísmica Canaria, managed by Instituto Volcanológico de Canarias (INVOLCAN). The network began its full operativity in Nov. 2016 and currently consists of 15 broadband seismic stations. Since Nov. 2016 the network detected more than 100 small magnitude earthquakes, located beneath Teide volcano at depths usually ranging between 5 and 15 km. On January 6th 2017 a M=2.5 earthquake was recorded in the area, being one of the strongest ever recorded since decades. Most of the events show typical features of the microseismicity of hydrothermal systems: high spatial and temporal clustering and similar waveforms of individual events which often are overlapped.We present the spatial and temporal distribution of the seismicity of Teide volcano since Nov. 2016, comparing it also with the past seismicity of the volcano. Furthermore we analyze the statistical properties of the numerous swarms recorded until now with the aid of a template

  1. Magma paths at Piton de la Fournaise Volcano

    OpenAIRE

    Michon , Laurent; Ferrazzini , Valérie; Di Muro , Andrea

    2016-01-01

    International audience; Several patterns of magma paths have been proposed since the 1980s for Piton de la Fournaise volcano. Given the significant differences, which are presented here, we propose a reappraisal of the magma intrusion paths using a 17-years-long database of volcano-tectonic seismic events and a detailed mapping of the scoria cones. At the edifice scale, the magma propagates along two N120 trending rift zones. They are wide, linear, spotted by small to large scoria cones and r...

  2. Geophysical Observations Supporting Research of Magmatic Processes at Icelandic Volcanoes

    Science.gov (United States)

    Vogfjörd, Kristín. S.; Hjaltadóttir, Sigurlaug; Roberts, Matthew J.

    2010-05-01

    Magmatic processes at volcanoes on the boundary between the European and North American plates in Iceland are observed with in-situ multidisciplinary geophysical networks owned by different national, European or American universities and research institutions, but through collaboration mostly operated by the Icelandic Meteorological Office. The terrestrial observations are augmented by space-based interferometric synthetic aperture radar (InSAR) images of the volcanoes and their surrounding surface. Together this infrastructure can monitor magma movements in several volcanoes from the base of the crust up to the surface. The national seismic network is sensitive enough to detect small scale seismicity deep in the crust under some of the voclanoes. High resolution mapping of this seismicity and its temporal progression has been used to delineate the track of the magma as it migrates upwards in the crust, either to form an intrusion at shallow levels or to reach the surface in an eruption. Broadband recording has also enabled capturing low frequency signals emanating from magmatic movements. In two volcanoes, Eyjafjallajökull and Katla, just east of the South Iceland Seismic Zone (SISZ), seismicity just above the crust-mantle boundary has revealed magma intruding into the crust from the mantle below. As the magma moves to shallower levels, the deformation of the Earth‘s surface is captured by geodetic systems, such as continuous GPS networks, (InSAR) images of the surface and -- even more sensitive to the deformation -- strain meters placed in boreholes around 200 m below the Earth‘s surface. Analysis of these signals can reveal the size and shape of the magma as well as the temporal evolution. At near-by Hekla volcano flanking the SISZ to the north, where only 50% of events are of M>1 compared to 86% of earthquakes in Eyjafjallajökull, the sensitivity of the seismic network is insufficient to detect the smallest seismicity and so the volcano appears less

  3. Monitoring Volcanoes by Use of Air-Dropped Sensor Packages

    Science.gov (United States)

    Kedar, Sharon; Rivellini, Tommaso; Webb, Frank; Blaes, Brent; Bracho, Caroline; Lockhart, Andrew; McGee, Ken

    2003-01-01

    Sensor packages that would be dropped from airplanes have been proposed for pre-eruption monitoring of physical conditions on the flanks of awakening volcanoes. The purpose of such monitoring is to gather data that could contribute to understanding and prediction of the evolution of volcanic systems. Each sensor package, denoted a volcano monitoring system (VMS), would include a housing with a parachute attached at its upper end and a crushable foam impact absorber at its lower end (see figure). The housing would contain survivable low-power instrumentation that would include a Global Positioning System (GPS) receiver, an inclinometer, a seismometer, a barometer, a thermometer, and CO2 and SO2 analyzers. The housing would also contain battery power, control, data-logging, and telecommunication subsystems. The proposal for the development of the VMS calls for the use of commercially available sensor, power, and telecommunication equipment, so that efforts could be focused on integrating all of the equipment into a system that could survive impact and operate thereafter for 30 days, transmitting data on the pre-eruptive state of a target volcano to a monitoring center. In a typical scenario, VMSs would be dropped at strategically chosen locations on the flanks of a volcano once the volcano had been identified as posing a hazard from any of a variety of observations that could include eyewitness reports, scientific observations from positions on the ground, synthetic-aperture-radar scans from aircraft, and/or remote sensing from aboard spacecraft. Once dropped, the VMSs would be operated as a network of in situ sensors that would transmit data to a local monitoring center. This network would provide observations as part of an integrated volcano-hazard assessment strategy that would involve both remote sensing and timely observations from the in situ sensors. A similar strategy that involves the use of portable sensors (but not dropping of sensors from aircraft) is

  4. Pyroclastic sulphur eruption at Poas Volcano, Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Francis, P.W.; Thorpe, R.S.; Brown, G.C.; Glasscock, J.

    1980-01-01

    The recent Voyager missions to Jupiter have highlighted the role of sulphur in volcanic processes on io. Although fumarolic sulphur and SO/sub 2/ gas are almost universal in terrestrial active volcanoes, and rare instances of sulphur lava flows have been reported, sulphur in a pyroclastic form has only been described from Poas Volcano, Costa Rica. Here we amplify the original descriptions by Bennett and Raccichini and describe a recent eruption of pyroclastic sulphur scoria and ejected blocks that are characterised by miniature sulphur stalactites and stalagmites.

  5. Crystallization and Melt Removal at Arenal Volcano, Polytopic Vector Analysis

    Science.gov (United States)

    Hidalgo, P. J.; Vogel, T. A.; Bolge, L. L.; Ehrlich, R.; Alvarado, G. E.

    2007-12-01

    Tephra sequences ET3 and ET4 from Arenal volcano in Costa Rica have recently been interpreted to be a product of crystal fractionation by Bolge and coworkers in a series of papers (2004, 2006). The two tephra units are part of a sequence of 22 tephra units that represent a 7000 year span of the Arenal volcano activity. The tephro- stratigraphy has been described extensively by Melson (1982; 1994). The ET3 and ET4 tephras were interpreted (based on major- and trace-element, isotopic analyses of whole rocks and microchemical analyses of individual phases) as clear evidence of crystal separation by gravity settling (Bolge et al., 2004, 2006). The lower ET4 tephra sequence (andesitic and crystal poor) and the upper ET3 tephra (basaltic and crystal rich) represent an inverted snapshot of the magma chamber with contrasting geochemical properties. The ET3 sequence (deeper part of the magma chamber) has nearly constant composition with only a few elements varying stratigraphically (best represented by CaO). This is consistent with gradually decreasing amounts of melt in the upper part of ET3. The lower ET4 tephra (upper part of the magma chamber) contains large chemical gradients in both incompatible and compatible elements. In the present study we use whole-rock geochemical data from the recent tephra sequences ET3 and ET4 as inputs to Polytopic Vector Analysis (PVA) (for a review of this method see Vogel and coworkers, in press). With this method we produce a three end member solution that is consistent with crystallization of Olivine, plagioclase and pyroxene from the most mafic end member (EM1) resulting in a crystal rich mush zone. As crystallization progresses the compositions of the liquids are driven towards an intermediate end member (EM3), which has an intermediate composition liquid. At EM3 composition, rapid depletion of FeO, MgO and TiO2 by crystallization of Fe-Ti oxides, rapidly drives the liquid composition towards the silicic EM1 (incompatible element

  6. Active hydrocarbon (methane) seepage at the Alboran Sea mud volcanoes indicated by specific lipid biomarkers.

    Science.gov (United States)

    Lopez-Rodriguez, C.; Stadnitskaia, A.; De Lange, G. J.; Martínez-Ruiz, F.; Comas, M.; Sinninghe Damsté, J. S.

    2012-04-01

    Mud volcanoes (MVs) and pockmark fields are known to occur in the Alboran Basin (Westernmost Mediterranean). These MVs occur above a major sedimentary depocenter that includes up to 7 km thick early Miocene to Holocene sequences. MVs located on the top of diapiric structures that originated from undercompacted Miocene clays and olistostromes. Here we provide results from geochemical data-analyses of four gravity cores acquired in the Northern Mud Volcano Field (north of the 36°N): i.e. Perejil, Kalinin and Schneiderś Heart mud expulsion structures. Extruded materials include different types of mud breccias. Specific lipid biomarkers (n-alkanes, hopanes, irregular isoprenoid hydrocarbons and Dialkyl Glycerol Diethers (DGDs) were analysed by gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS). Determination of Glycerol Dialkyl Glycerol Tetraethers (GDGTs) by high performance liquid chromatography-spectrometry (HPLC-MS), and analysis of biomarker δ13C values were performed in selected samples. Lipid biomarker analysis from the three MVs revealed similar n-alkane distributions in all mud breccia intervals, showing significant hydrocarbon-derived signals and the presence of thermally immature organic-matter admixture. This suggests that similar strata fed these MVs. The hemipelagic drapes reveal comparable n-alkane distributions, suggesting that significant upward diffusion of fluids occurs. Distributions of GDGTs are generally accepted as usefull biomarkers to locate the anaerobic oxidation of methane (AOM) in marine sediments. However, our GDGT profiles only reflect the marine thaumarchaeotal signature. There seems to be no archaea producing specific GDGTs involved in AOM in the recovered interval. Evidence of recent activity (i.e., methane gas-bubbling and chemosynthetic fauna at the Perejil MV) and the presence of specific lipid biomarker related with methanotropic archaea (Irregular Isoprenoids and DGDs), however, suggest the existence of

  7. Geochemistry and microbiology at gas hydrate and mud volcano sites in the black sea

    Science.gov (United States)

    Drews, M.; Schmaljohann, R.; Wallmann, K.

    2003-04-01

    We present geochemical and microbiological results which were obtained from sediments at gas hydrate and mud volcano sites in the Sorokin Trough (northern Black Sea, south east of the Crimean peninsula) at water depths of about 1800 to 2100 m during the METEOR cruise 52-1. The surface near sub-bottom accumulations of gas hydrates (occuring at depths of several meters or less beneath the sea floor) in the Black Sea are associated with numerous mud volcanos. At stations we investigated gas hydrates occurred below 10 cm to 100 cm with a significant influence on the sediment biochemistry. Analyses revealed high methane concentrations, anoxic and sulfidic conditions, a steep sulfate gradient, carbonate precipitation, and high anaerobic methane oxidation rates. In proximity of the so called Odessa mud volcano one investigated sampling station showed maximum methane oxidation rates in the depth horizon of a firm 2 cm thick carbonate crust layer, adhered to by a bacterial mat. This observation is taken to indicate that the bacteria are causing or mediating the crust formation by their anaerobic methane oxidation metabolism. The station was further characterised by two layers of gas hydrate fragments and lenses below 1 m depth. A 2 to 4 cm thick carbonate crust with attached bacterial mat from a Yalta mud vulcano sample (2124 m water depth) was investigated under the scanning electron microscope. The stiff gelatinous mat showed a dense and morphologically uniform population of rod shaped bacteria with only a few nests of coccoid cells. Purified mat material exhibited anaerobic methane oxidation activity. These mats resemble the type previously found in the shallow NW methane seep area of the Black Sea, where it covers carbonate chimneys. Samples from two sites atop the summit of the active but flat-topped Dvurechenskii mud volcano were characterised by very high methane oxidation rates (up to 563 nmol/cm3/d) at the sediment surface. Strong pore water gradients of chloride

  8. Monitoring quiescent volcanoes by diffuse He degassing: case study Teide volcano

    Science.gov (United States)

    Pérez, Nemesio M.; Melián, Gladys; Asensio-Ramos, María; Padrón, Eleazar; Hernández, Pedro A.; Barrancos, José; Padilla, Germán; Rodríguez, Fátima; Calvo, David; Alonso, Mar

    2016-04-01

    Tenerife (2,034 km2), the largest of the Canary Islands, is the only island that has developed a central volcanic complex (Teide-Pico Viejo stratovolcanoes), characterized by the eruption of differentiated magmas. This central volcanic complex has been built in the intersection of the three major volcanic rift-zones of Tenerife, where most of the historical volcanic activity has taken place. The existence of a volcanic-hydrothermal system beneath Teide volcano is suggested by the occurrence of a weak fumarolic system, steamy ground and high rates of diffuse CO2 degassing all around the summit cone of Teide (Pérez et al., 2013). Diffuse emission studies of non-reactive and/or highly mobile gases such as helium have recently provided promising results to detect changes in the magmatic gas component at surface related to volcanic unrest episodes (Padrón et al., 2013). The geochemical properties of He minimize the interaction of this noble gas on its movement toward the earth's surface, and its isotopic composition is not affected by subsequent chemical reactions. It is highly mobile, chemically inert, physically stable, non-biogenic, sparingly soluble in water under ambient conditions, almost non-adsorbable, and highly diffusive with a diffusion coefficient ˜10 times that of CO2. As part of the geochemical monitoring program for the volcanic surveillance of Teide volcano, yearly surveys of diffuse He emission through the surface of the summit cone of Teide volcano have been performed since 2006. Soil He emission rate was measured yearly at ˜130 sampling sites selected in the surface environment of the summit cone of Teide volcano (Tenerife, Canary Islands), covering an area of ˜0.5 km2, assuming that He emission is governed by convection and diffusion. The distribution of the sampling sites was carefully chosen to homogeneously cover the target area, allowing the computation of the total He emission by sequential Gaussian simulation (sGs). Nine surveys have been

  9. Food Sauces to Understand Volcanoes: a Learning Sequence in Middle School

    Science.gov (United States)

    Pieraccioni, Fabio; Bonaccorsi, Elena; Gioncada, Anna

    2017-04-01

    Some volcanic processes occur at pressures and temperatures very different from daily experience. Such extreme conditions, unreproducible in the classroom, can lead children to build concepts about volcanic phenomena very different from the reality (Greca & Moreira, 2000; Dove, 1998). The didactic goals of this learning sequence concern the relationships between the viscosity of magmas and types of erupted materials and their consequences on volcano shapes, to favour pupils' comprehension of what a volcano is. Viscosity and its temperature dependence can be easily experimented in class with analogue materials at room temperature (Baker et al., 2004). Our research aims are to observe the development of the thought of pupils of middle schools on volcanic phenomena; this allowed to put in evidence the benefits of this approach and to give suggestions to avoid possible critical points. We have experimented a hands-on learning sequence about volcanoes in four third classes of Tuscan middle schools, for an amount of 95 pupils, 48 females and 47 males. Sharing the principles of constructivism, we think useful that pupils start from their own direct experience for understanding natural phenomena not directly observable. Therefore, we start from the experiences and knowledge of children to build a inquiry-based itinerary (Minner et al., 2010; Pieraccioni et al., 2016). The learning sequence begins with a practical activity in which we employ common and well-known materials to introduce the concept of viscosity in order to relate various kinds of magma to the shape of volcanoes. One of the benefits of this approach is to overcome the problems of introducing complex concepts such as acidity of magmas or silica content, far from the pupils' experience and knowledge. These concepts are often used in Italian middle school textbooks to describe and classify volcanoes. The result is a list of names to learn by heart. On the contrary, by using oil, ketchup, peanut butter or honey

  10. Confirmation and calibration of computer modeling of tsunamis produced by Augustine volcano, Alaska

    Science.gov (United States)

    Beget, James E.; Kowalik, Zygmunt

    2006-01-01

    Numerical modeling has been used to calculate the characteristics of a tsunami generated by a landslide into Cook Inlet from Augustine Volcano. The modeling predicts travel times of ca. 50-75 minutes to the nearest populated areas, and indicates that significant wave amplification occurs near Mt. Iliamna on the western side of Cook Inlet, and near the Nanwelak and the Homer-Anchor Point areas on the east side of Cook Inlet. Augustine volcano last produced a tsunami during an eruption in 1883, and field evidence of the extent and height of the 1883 tsunamis can be used to test and constrain the results of the computer modeling. Tsunami deposits on Augustine Island indicate waves near the landslide source were more than 19 m high, while 1883 tsunami deposits in distal sites record waves 6-8 m high. Paleotsunami deposits were found at sites along the coast near Mt. Iliamna, Nanwelak, and Homer, consistent with numerical modeling indicating significant tsunami wave amplification occurs in these areas. 

  11. Cyclic thermal behavior associated to the degassing process at El Hierro submarine volcano, Canary Islands.

    Science.gov (United States)

    Fraile-Nuez, E.; Santana-Casiano, J. M.; González-Dávila, M.

    2016-12-01

    One year after the ceasing of magmatic activity in the shallow submarine volcano of the island of El Hierro, significant physical-chemical anomalies produced by the degassing process as: (i) thermal anomalies increase of +0.44 °C, (ii) pH decrease of -0.034 units, (iii) total dissolved inorganic carbon, CT increase by +43.5 µmol kg-1 and (iv) total alkalinity, AT by +12.81 µmol kg-1 were still present in the area. These evidences highlight the potential role of the shallow degassing processes as a natural ecosystem-scale experiments for the study of significant effects of global change stressors on marine environments. Additionally, thermal time series obtained from a temporal yo-yo CTD study, in isopycnal components, over one of the most active points of the submarine volcano have been analyzed in order to investigate the behavior of the system. Signal processing of the thermal time series highlights a strong cyclic temperature period of 125-150 min at 99.9% confidence, due to characteristic time-scales revealed in the periodogram. These long cycles might reflect dynamics occurring within the shallow magma supply system below the island of El Hierro.

  12. Study of the spatial and temporal variability of local ecosystems and glaciers of the Antisana Volcano

    Directory of Open Access Journals (Sweden)

    Mauricio Valladares Borja

    2014-12-01

    Full Text Available (Received: 2014/10/31 - Accepted: 2014/12/15The scientific interest in climate change allowed to uncover evidence demonstrating a general warming trend caused by human activities. Facts such as rising sea levels, extreme weather events and retreat of glaciers, are indicators of the presence of alterations of normal weather patterns. In Ecuador, the Antisana is a stratovolcano of strategic importance affecting the climate of the region, in the functioning of the surrounding ecosystems. It is also a reserve of water for the population of the Metropolitan District of Quito (DMQ. The glaciers of the tropical volcano are also suffering the effects of global warming. Its decline over time is of concern and should be analyzed. The present research work performed a spatial and temporal study based on historical series of aerial photographs taken between 1956 and 2011, through geo-processing capabilities of geographic information systems (GIS. The results show a significant decrease in the glaciers of the Antisana Volcano and significant changes in the surrounding local ecological formations.

  13. Multi-year high-frequency hydrothermal monitoring of selected high-threat Cascade Range volcanoes

    Science.gov (United States)

    Crankshaw, I. M.; Archfield, S. A.; Newman, A. C.; Bergfeld, D.; Clor, L. E.; Spicer, K. R.; Kelly, P. J.; Evans, W. C.; Ingebritsen, S. E.

    2018-05-01

    From 2009 to 2015 the U.S. Geological Survey (USGS) systematically monitored hydrothermal behavior at selected Cascade Range volcanoes in order to define baseline hydrothermal and geochemical conditions. Gas and water data were collected regularly at 25 sites on 10 of the highest-risk volcanoes in the Cascade Range. These sites include near-summit fumarole groups and springs/streams that show clear evidence of magmatic influence (high 3He/4He ratios and/or large fluxes of magmatic CO2 or heat). Site records consist mainly of hourly temperature and hydrothermal-flux data. Having established baseline conditions during a multiyear quiescent period, the USGS reduced monitoring frequency from 2015 to present. The archived monitoring data are housed at (doi:10.5066/F72N5088). These data (1) are suitable for retrospective comparison with other continuous geophysical monitoring data and (2) will provide context during future episodes of volcanic unrest, such that unrest-related variations at these thoroughly characterized sites will be more clearly recognizable. Relatively high-frequency year-round data are essential to achieve these objectives, because many of the time series reveal significant diurnal, seasonal, and inter-annual variability that would tend to mask unrest signals in the absence of baseline data. Here we characterize normal variability for each site, suggest strategies to detect future volcanic unrest, and explore deviations from background associated with recent unrest.

  14. Origins of hydrocarbon gas seeping out from offshore mud volcanoes in the Nile delta

    Science.gov (United States)

    Prinzhofer, Alain; Deville, Eric

    2013-04-01

    This paper discusses the origin of gas seepages (free gas or dissolved gas in ground water or brine) sampled with the Nautile submarine during the Nautinil cruise at the seafloor of the deep water area of the Nile turbiditic system on different mud volcanoes and brine pools. Generally, the gas is wet and includes C1, C2, C3, iC4, nC4, CO2. These gas samples show no evidence of biodegradation which is not the case of the gas present in the deep hydrocarbon accumulations at depth. It indicates that the gas expelled by the mud volcanoes is not issued from direct leakages from deep gas fields. The collected gas samples mainly have a thermogenic origin and show different maturities. Some samples show very high maturities indicating that these seepages are sourced from great depths, below the Messinian salt. Moreover, the different chemical compositions of the gas samples reflect not only differences in maturity but also the fact that the gas finds its origin in different deep source rocks. Carbon dioxide has an organic signature and cannot result from carbonate decomposition or mantle fluids. The crustal-derived radiogenic isotopes show that the analyzed gas samples have suffered a fractionation processes after the production of the radiogenic isotopes, due either to oil occurrence at depth interacting with the flux of gas, and/or fractionation during the fluid migration.

  15. ACTIVITY AND Vp/Vs RATIO OF VOLCANO-TECTONIC SEISMIC SWARM ZONES AT NEVADO DEL RUIZ VOLCANO, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Londoño B. John Makario

    2010-06-01

    Full Text Available An analysis of the seismic activity for volcano-tectonic earthquake (VT swarms zones at Nevado del Ruiz Volcano (NRV was carried out for the interval 1985- 2002, which is the most seismic active period at NRV until now (2010. The swarm-like seismicity of NRV was frequently concentrated in very well defined clusters around the volcano. The seismic swarm zone located at the active crater was the most active during the entire time. The seismic swarm zone located to the west of the volcano suggested some relationship with the volcanic crises. It was active before and after the two eruptions occurred in November 1985 and September 1989. It is believed that this seismic activity may be used as a monitoring tool of volcanic activity. For each seismic swarm zone the Vp/Vs ratio was also calculated by grouping of earthquakes and stations. It was found that each seismic swarm zone had a distinct Vp/Vs ratio with respect to the others, except for the crater and west swarm zones, which had the same value. The average Vp/Vs ratios for the seismic swarm zones located at the active crater and to the west of the volcano are about 6-7% lower than that for the north swarm zone, and about 3% lower than that for the south swarm zone. We suggest that the reduction of the Vp/Vs ratio is due to degassing phenomena inside the central and western earthquake swarm zones, or due to the presence of microcracks inside the volcano. This supposition is in agreement with other studies of geophysics, geochemistry and drilling surveys carried out at NRV.

  16. Subsidence of Surtsey volcano, 1967-1991

    Science.gov (United States)

    Moore, J.G.; Jakobsson, S.; Holmjarn, J.

    1992-01-01

    The Surtsey marine volcano was built on the southern insular shelf of Iceland, along the seaward extension of the east volcanic zone, during episodic explosive and effusive activity from 1963 to 1967. A 1600-m-long, east-west line of 42 bench marks was established across the island shortly after volcanic activity stopped. From 1967 to 1991 a series of leveling surveys measured the relative elevation of the original bench marks, as well as additional bench marks installed in 1979, 1982 and 1985. Concurrent measurements were made of water levels in a pit dug on the north coast, in a drill hole, and along the coastline exposed to the open ocean. These surveys indicate that the dominant vertical movement of Surtsey is a general subsidence of about 1.1??0.3 m during the 24-year period of observations. The rate of subsidence decreased from 15-20 cm/year for 1967-1968 to 1-2 cm/year in 1991. Greatest subsidence is centered about the eastern vent area. Through 1970, subsidence was locally greatest where the lava plain is thinnest, adjacent to the flanks of the eastern tephra cone. From 1982 onward, the region closest to the hydrothermal zone, which is best developed in the vicinity of the eastern vent, began showing less subsidence relative to the rest of the surveyed bench marks. The general subsidence of the island probably results from compaction of the volcanic material comprising Surtsey, compaction of the sea-floor sediments underlying the island, and possibly downwarping of the lithosphere due to the laod of Surtsey. The more localized early downwarping near the eastern tephra cone is apparently due to greater compaction of tephra relative to lava. The later diminished local subsidence near the hydrothermal zone is probably due to a minor volume increase caused by hydrous alteration of glassy tephra. However, this volume increase is concentrated at depth beneath the bottom of the 176-m-deep cased drillhole. ?? 1992 Springer-Verlag.

  17. An aerial radiological survey of the Tonopah Test Range including Clean Slate 1,2,3, Roller Coaster, decontamination area, Cactus Springs Ranch target areas. Central Nevada

    International Nuclear Information System (INIS)

    Proctor, A.E.; Hendricks, T.J.

    1995-08-01

    An aerial radiological survey was conducted of major sections of the Tonopah Test Range (TTR) in central Nevada from August through October 1993. The survey consisted of aerial measurements of both natural and man-made gamma radiation emanating from the terrestrial surface. The initial purpose of the survey was to locate depleted uranium (detecting 238 U) from projectiles which had impacted on the TTR. The examination of areas near Cactus Springs Ranch (located near the western boundary of the TTR) and an animal burial area near the Double Track site were secondary objectives. When more widespread than expected 241 Am contamination was found around the Clean Slates sites, the survey was expanded to cover the area surrounding the Clean Slates and also the Double Track site. Results are reported as radiation isopleths superimposed on aerial photographs of the area

  18. Sarcoptes mite epidemiology and treatment in African buffalo (Syncerus caffer calves captured for translocation from the Kafue game management area to game ranches

    Directory of Open Access Journals (Sweden)

    Munyeme Musso

    2010-06-01

    Full Text Available Abstract Background In Zambia, translocation of wildlife from National Parks to private owned game ranches demands that only animals free of infectious diseases that could adversely affect the expansion of the wildlife industry should be translocated to game ranches. Sarcoptes mange (Sarcoptes scarbiei has been involved in the reduction of wildlife populations in some species. Results Sarcoptes mange (Sarcoptes scarbiei was detected and eradicated from two herds of African buffalo (Syncerus caffer calves captured in the Kafue GMA in July 2004 and August 2005. The overall prevalence was estimated at 89.5% (77/86. Sex had no influence on the occurrence and severity of the disease. Of the 86 calves used in the study, 72.1% had good body condition scores, 20.9% were fair and 7.0% were poor. Of the 77 infected calves, 53.2% were mildly infected, 28.6% were moderately and 18.2% were severely infected. Body condition score was correlated to the severity of the infection (r = 0.72, p n = 86 at capture. Eradication of Sarcoptes mites from the entire herd using ivermetcin was dependant on the severity of the infection. The overall ability of ivermectin to clear the infection after the first treatment was estimated at 81.8% (n = 77. It increased to 94.8% and 100% after the second and third treatments respectively. Conclusion This is the first report on the epidemiology and treatment of Sarcoptes mange in African buffaloes in Zambia. This study improves our understanding about Sarcoptes scabiei epidemiology and treatment which will have further applications for the safe animal translocation.

  19. UAVSAR observations of triggered slip on the Imperial, Superstition Hills, and East Elmore Ranch Faults associated with the 2010 M 7.2 El Mayor-Cucapah earthquake

    Science.gov (United States)

    Donnellan, Andrea; Parker, Jay; Hensley, Scott; Pierce, Marlon; Wang, Jun; Rundle, John

    2014-03-01

    4 April 2010 M 7.2 El Mayor-Cucapah earthquake that occurred in Baja California, Mexico and terminated near the U.S. Mexican border caused slip on the Imperial, Superstition Hills, and East Elmore Ranch Faults. The pattern of slip was observed using radar interferometry from NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) instrument collected on 20-21 October 2009 and 12-13 April 2010. Right-lateral slip of 36 ± 9 and 14 ± 2 mm occurred on the Imperial and Superstition Hills Faults, respectively. Left-lateral slip of 9 ± 2 mm occurred on the East Elmore Ranch Fault. The widths of the zones of displacement increase northward suggesting successively more buried fault motion to the north. The observations show a decreasing pattern of slip northward on a series of faults in the Salton Trough stepping between the El Mayor-Cucapah rupture and San Andreas Fault. Most of the motion occurred at the time of the M 7.2 earthquake and the UAVSAR observations are consistent with field, creepmeter, GPS, and Envisat observations. An additional 28 ± 1 mm of slip at the southern end of the Imperial Fault over a <1 km wide zone was observed over a 1 day span a week after the earthquake suggesting that the fault continued to slip at depth following the mainshock. The total moment release on the three faults is 2.3 × 1023-1.2 × 1024 dyne cm equivalent to a moment magnitude release of 4.9-5.3, assuming shallow slip depths ranging from 1 to 5 km.

  20. Three-armed rifts or masked radial pattern of eruptive fissures? The intriguing case of El Hierro volcano (Canary Islands)

    Science.gov (United States)

    Becerril, L.; Galindo, I.; Martí, J.; Gudmundsson, A.

    2015-04-01

    Using new surface structural data as well as subsurface structural data obtained from seventeen water galleries, we provide a comprehensive model of the volcano-tectonic evolution of El Hierro (Canary Islands). We have identified, measured and analysed more than 1700 volcano-structural elements including vents, eruptive fissures, dykes and faults. The new data provide important information on the main structural patterns of the island and on its stress and strain fields, all of which are crucial for reliable hazard assessments. We conducted temporal and spatial analyses of the main structural elements, focusing on their relative age and association with the three main cycles in the construction of the island: the Tiñor Edifice, the El Golfo-Las Playas Edifice, and the Rift Volcanism. A radial strike distribution, which can be related to constructive episodes, is observed in the on-land structures. A similar strike distribution is seen in the submarine eruptive fissures, which are radial with respect to the centre of the island. However, the volcano-structural elements identified onshore and reflecting the entire volcano-tectonic evolution of the island also show a predominant NE-SW strike, which coincides with the main regional trend of the Canary archipelago as a whole. Two other dominant directions of structural elements, N-S and WNW-ESE, are evident from the establishment of the El Golfo-Las Playas edifice, during the second constructive cycle. We suggest that the radial-striking structures reflect comparatively uniform stress fields during the constructive episodes, mainly conditioned by the combination of overburden pressure, gravitational spreading, and magma-induced stresses in each of the volcanic edifices. By contrast, in the shallower parts of the edifice the NE-SW, N-S and WNW-ESE-striking structures reflect local stress fields related to the formation of mega-landslides and masking the general and regional radial patterns.

  1. Decreasing Magmatic Footprints of Individual Volcanos in a Waning Basaltic Field

    Energy Technology Data Exchange (ETDEWEB)

    G.A> Valentine; F.V. Perry

    2006-06-06

    The distribution and characteristics of individual basaltic volcanoes in the waning Southwestern Nevada Volcanic Field provide insight into the changing physical nature of magmatism and the controls on volcano location. During Pliocene-Pleistocene times the volumes of individual volcanoes have decreased by more than one order of magnitude, as have fissure lengths and inferred lava effusion rates. Eruptions evolved from Hawaiian-style eruptions with extensive lavas to eruptions characterized by small pulses of lava and Strombolian to violent Strombolian mechanisms. These trends indicate progressively decreasing partial melting and length scales, or magmatic footprints, of mantle source zones for individual volcanoes. The location of each volcano is determined by the location of its magmatic footprint at depth, and only by shallow structural and topographic features that are within that footprint. The locations of future volcanoes in a waning system are less likely to be determined by large-scale topography or structures than were older, larger volume volcanoes.

  2. Deep structure and origin of active volcanoes in China

    Directory of Open Access Journals (Sweden)

    Dapeng Zhao

    2010-10-01

    Full Text Available We synthesize significant recent results on the deep structure and origin of the active volcanoes in mainland China. Magmatism in the western Pacific arc and back-arc areas is caused by dehydration of the subducting slab and by corner flow in the mantle wedge, whereas the intraplate magmatism in China has different origins. The active volcanoes in Northeast China (such as the Changbai and Wudalianchi are caused by hot upwelling in the big mantle wedge (BMW above the stagnant slab in the mantle transition zone and deep slab dehydration as well. The Tengchong volcano in Southwest China is caused by a similar process in the BMW above the subducting Burma microplate (or Indian plate. The Hainan volcano in southernmost China is a hotspot fed by a lower-mantle plume which may be associated with the Pacific and Philippine Sea slabs’ deep subduction in the east and the Indian slab’s deep subduction in the west down to the lower mantle. The stagnant slab finally collapses down to the bottom of the mantle, which can trigger the upwelling of hot mantle materials from the lower mantle to the shallow mantle beneath the subducting slabs and may cause the slab–plume interactions.

  3. The first days of the new submarine volcano near Krakatoa

    NARCIS (Netherlands)

    Umbgrove, J.H.F.

    1926-01-01

    The geological history of the Krakatoa volcano, especially the eruption of 1883, is amply described in the great work “Krakatau” by R. D. M. Verheer (1885), the Report of the Krakatoa Committee (Royal Soc. London 1888) and in the publications of B. G. Escher (Handel. 1e Nederl. Indisch Natuurwet

  4. Stem Cells: A Dormant Volcano Within Our Body?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 3. Stem Cells: A Dormant Volcano Within Our Body? Devaveena Dey Annapoorni Rangarajan. General Article Volume 12 Issue 3 March 2007 pp 27-34. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Collaborative Monitoring and Hazard Mitigation at Fuego Volcano, Guatemala

    Science.gov (United States)

    Lyons, J. J.; Bluth, G. J.; Rose, W. I.; Patrick, M.; Johnson, J. B.; Stix, J.

    2007-05-01

    A portable, digital sensor network has been installed to closely monitor changing activity at Fuego volcano, which takes advantage of an international collaborative effort among Guatemala, U.S. and Canadian universities, and the Peace Corps. The goal of this effort is to improve the understanding shallow internal processes, and consequently to more effectively mitigate volcanic hazards. Fuego volcano has had more than 60 historical eruptions and nearly-continuous activity make it an ideal laboratory to study volcanic processes. Close monitoring is needed to identify base-line activity, and rapidly identify and disseminate changes in the activity which might threaten nearby communities. The sensor network is comprised of a miniature DOAS ultraviolet spectrometer fitted with a system for automated plume scans, a digital video camera, and two seismo-acoustic stations and portable dataloggers. These sensors are on loan from scientists who visited Fuego during short field seasons and donated use of their sensors to a resident Peace Corps Masters International student from Michigan Technological University for extended data collection. The sensor network is based around the local volcano observatory maintained by Instituto National de Sismologia, Vulcanologia, Metrologia e Hidrologia (INSIVUMEH). INSIVUMEH provides local support and historical knowledge of Fuego activity as well as a secure location for storage of scientific equipment, data processing, and charging of the batteries that power the sensors. The complete sensor network came online in mid-February 2007 and here we present preliminary results from concurrent gas, seismic, and acoustic monitoring of activity from Fuego volcano.

  6. Puffers and Chuggers: Statistical Curiosities in Volcano World

    Science.gov (United States)

    Lees, J. M.

    2002-12-01

    Several on-going, low level volcanic explosions exhibit background phenomena commonly known as puffing, or in some cases chugging. Recently these events have been scrutinized because of the initiation of infrasonic monitoring, whereas earlier the events may have gone undetected. The activity associated with a puffer at a volcanic vent is generally small in magnitude and is often not observed audibly. The low frequency signals are readily observed on sensitive acoustic instrumentation and they provide a new dimension for our understanding of volcanic processes at volcanoes like Stromboli and Etna that have constant puffing signals. At other volcanoes, like Karymsky volcano in Kamchatka and Sangay Volcano in Ecuador, chugging signals associated with Strombolian style eruptions also provides new insights into the physics of the conduit systems. Here we present a statistical method of event detection, and event cluster association. When multiple vents work in unison it may be difficult to separate out chugging and puffing signals between spatially separated vents. The cluster analysis automatically differentiates between the vents based on waveform characteristics in the acoustic and seismic wavefields. Data examples from May, 2001, at Stromboli and Etna, show extensive periods of puffing (1-5 second frequency) superimposed on a background of vigorous, small-scale explosive activity. At Karymsky and Sangay non-linear, dynamic models explain the fluid flow through vents which gives rise to chugging. Furthermore, the frequency of chugging events appears to be associated with the intensity of lava flows and eruption rate.

  7. Magmagenesis at Soufriere volcano St Vincent, Lesser Antilles Arc

    Science.gov (United States)

    Heath, E.; Macdonald, R.; Belkin, H.; Hawkesworth, C.; Sigurdsson, Haraldur

    1998-01-01

    Soufriere volcano of St Vincent (3 wt %, whereas various projections onto phase diagrams are more consistent with relatively anhydrous magmas. Primary magmas at Soufriere were generated by around 15% melting of mid-ocean ridge basalt type mantle sources which had been modified by addition of fluids released from the slab containing contributions from subducted sediments and mafic crust.

  8. Topography and Volcanology of the Huangtsuishan Volcano Subgroup, Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Yu-Ming Lai

    2010-01-01

    Full Text Available Combining the shaded relief topography model and the slope map from the Digital Terrain Model (DTM images, toporaphical map, field occurrences and petrography, the volcanic sequences of the Huangtsuishan Volcano Subgroup (HVS can be constructed. Two types of volcanic centers can be identified in this area. One is the Tachienhou volcanic dome, which may be located in the center of an older caldera. The other is the Huangtsui composite volcano, which is composed of interbedding lava flows and pyroclastic deposits with a volcanic crater named the Huangtsui pond at the summit. Eight lava plateaus radiated from Mts. Huangtsui and Tachienhou to the north and the east can be distinguished based on the DTM images. The volcanic deposits are comprised of four lithofacies, the lava flows, pyroclastic breccias, tuffs and lahars on the base of field occurrences. At least thirteen layers of lava flow, named the H1 to H13 can be recognized in the HVS and can be reconstructed and categorized into four stages. An old and large volcano erupted lava flows to form the products of stages one and two, then collapsed to form a caldera with a dome for the third stage. The latest stage of lava flow was poured out from the Huangtsui volcano, which formed a crater at the summit.

  9. Comparative features of volcanoes on Solar system bodies

    Science.gov (United States)

    Vidmachenko, A. P.

    2018-05-01

    The bark of many cosmic bodies is in motion because of the displacement of tectonic plates on magma. Pouring molten magma through cracks in the cortex is called a volcanic eruption. There are two main types of volcanoes: basaltic, appearing where a new material of tectonic plates is formed, and andesitic, which located in the places of destruction of these plates.The third type of volcanoes is cryovolcanoes, or ice volcanoes. This type of volcano ejects matter in the form of ice volcanic melts or steam from water, ammonia, methane. After the eruption, the cryomagma at a low temperature condenses to a solid phase. Cryovolcanoes can be formed on such objects as Pluto, Ceres, Titan, Enceladus, Europe, Triton, etc. Potential sources of energy for melting ice in the production of cryovolcanoes are tidal friction and/or radioactive decay. Semi-transparent deposits of frozen materials that can create a subsurface greenhouse effect, with the possibility of accumulating the required heat with subsequent explosive eruption, are another way to start the cryovolcano action. This type of eruption is observed on Mars and Triton. The first and second types of eruptions (basaltic and andesitic) are characteristic of terrestrial planets (Mercury, Venus, Mars) and for some satellites of the planets of the Solar system.

  10. Stratigraphy of neoproterozoic sedimentary and volcano sedimentary successions of Uruguay

    International Nuclear Information System (INIS)

    Pecoits, E.; Aubet, N.; Oyhantcabal, P.; Sanchez Bettucci, L.

    2004-01-01

    Based on the new data the different characteristics of the Neoproterozoic (volcano) sedimentary succesions of Uruguay are described and discussed. Their stratigraphic tectonics and palaeoclimatic implications are analyzed.The results of the present investigations also allow to define the Maldonado Group which would beintegrated by the Playa Hermosa and Las Ventanas formations.

  11. An Overview of Geodetic Volcano Research in the Canary Islands

    Science.gov (United States)

    Fernández, José; González, Pablo J.; Camacho, Antonio G.; Prieto, Juan F.; Brú, Guadalupe

    2015-11-01

    The Canary Islands are mostly characterized by diffuse and scattered volcanism affecting a large area, with only one active stratovolcano, the Teide-Pico Viejo complex (Tenerife). More than 2 million people live and work in the 7,447 km2 of the archipelago, resulting in an average population density three times greater than the rest of Spain. This fact, together with the growth of exposure during the past 40 years, increases volcanic risk with respect previous eruptions, as witnessed during the recent 2011-2012 El Hierro submarine eruption. Therefore, in addition to purely scientific reasons there are economic and population-security reasons for developing and maintaining an efficient volcano monitoring system. In this scenario geodetic monitoring represents an important part of the monitoring system. We describe volcano geodetic monitoring research carried out in the Canary Islands and the results obtained. We consider for each epoch the two main existing constraints: the level of volcanic activity in the archipelago, and the limitations of the techniques available at the time. Theoretical and observational aspects are considered, as well as the implications for operational volcano surveillance. Current challenges of and future perspectives in geodetic volcano monitoring in the Canaries are also presented.

  12. Volcano ecology: flourishing on the flanks of Mount St. Helens

    Science.gov (United States)

    Rhonda Mazza; Charlie Crisafulli

    2016-01-01

    Mount St. Helens’ explosive eruption on May 18, 1980, was a pivotal moment in the field of disturbance ecology. The subsequent sustained, integrated research effort has shaped the development of volcano ecology, an emerging field of focused research. Excessive heat, burial, and impact force are some of the disturbance mechanisms following an eruption. They are also...

  13. Airborne VLF survey of Izu-Oshima volcano

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Yutaka; Yukutake, Takeshi

    1988-05-17

    Resistivity distribution in underground indicates anomaly in some cases due to volcanic activity, airborne VLF survey of Izu-Oshima volcano in whole area was carried out by measurement of the anomalous vertical magnetic field. The flight direction was determined with reference to both of the transmitter direction of the VLF waves and the running direction of the geologic formation. The flight altitude and the flight lines spacing were 100 m and 200 m respectively. Typical profiles of four lines of measurement were investigated. The resistivity anomalies were indicated corresponding to the position of known geologic fissure line, the lip of the caldera, the line of the craters and side volcanos. Several anomalous trends were detected by the contour drawing of the Fraser filter output. The detected results were as follow: new volcanos with the resistivity anomaly, the resistivity anomalies spread to the north-northwest from Goshinka jaya, the anomalies due to flowed lava, the anomalies by encroached water from the caldera wall, the effects from side volcanoes and so on. The resistivity anomalies by airborne VLF survey correspond to the known volcanic activities, and they are useful for elucidation of the underground volcanism. (6 figs, 4 refs)

  14. SSMILes: Investigating Various Volcanic Eruptions and Volcano Heights.

    Science.gov (United States)

    Wagner-Pine, Linda; Keith, Donna Graham

    1994-01-01

    Presents an integrated math/science activity that shows students the differences among the three types of volcanoes using observation, classification, graphing, sorting, problem solving, measurement, averages, pattern relationships, calculators, computers, and research skills. Includes reproducible student worksheet. Lists 13 teacher resources.…

  15. Understanding the Potential for Volcanoes at Yucca Mountain

    International Nuclear Information System (INIS)

    NA

    2002-01-01

    By studying the rocks and geologic features of an area, experts can assess whether it is vulnerable to future volcanic eruptions. Scientists have performed extensive studies at and near Yucca Mountain to determine whether future volcanoes could possibly affect the proposed repository for nuclear waste

  16. Seismic instrumentation plan for the Hawaiian Volcano Observatory

    Science.gov (United States)

    Thelen, Weston A.

    2014-01-01

    The seismic network operated by the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) is the main source of authoritative data for reporting earthquakes in the State of Hawaii, including those that occur on the State’s six active volcanoes (Kīlauea, Mauna Loa, Hualālai, Mauna Kea, Haleakalā, Lō‘ihi). Of these volcanoes, Kīlauea and Mauna Loa are considered “very high threat” in a report on the rationale for a National Volcanic Early Warning System (NVEWS) (Ewert and others, 2005). This seismic instrumentation plan assesses the current state of HVO’s seismic network with respect to the State’s active volcanoes and calculates the number of stations that are needed to upgrade the current network to provide a seismic early warning capability for forecasting volcanic activity. Further, the report provides proposed priorities for upgrading the seismic network and a cost assessment for both the installation costs and maintenance costs of the improved network that are required to fully realize the potential of the early warning system.

  17. Seismic Activity at Vailulu'u, Samoa's Youngest Volcano

    Science.gov (United States)

    Konter, J.; Staudigel, H.; Hart, S.

    2002-12-01

    Submarine volcanic systems, as a product of the Earth's mantle, play an essential role in the Earth's heat budget and in the interaction between the solid Earth and the hydrosphere and biosphere. Their eruptive and intrusive activity exerts an important control on these hydrothermal systems. In March 2000, we deployed an array of five ocean bottom hydrophones (OBH) on the summit region (625-995 m water depth) of Vailulu'u Volcano (14°12.9'S;169°03.5'W); this volcano represents the active end of the Samoan hotspot chain and is one of only a few well-studied intra-plate submarine volcanoes. We monitored seismic activity for up to 12 months at low sample rate (25 Hz), and for shorter times at a higher sample rate (125 Hz). We have begun to catalogue and locate a variety of acoustic events from this network. Ambient ocean noise was filtered out by a 4th-order Butterworth bandpass filter (2.3 - 10 Hz). We distinguish small local earthquakes from teleseismic activity, mostly identified by T- (acoustic) waves, by comparison with a nearby GSN station (AFI). Most of the detected events are T-phases from teleseismic earthquakes, characterized by their emergent coda and high frequency content (up to 30 Hz); the latter distinguishes them from low frequency emergent signals associated with the volcano (e.g. tremor). A second type of event is characterized by impulsive arrivals, with coda lasting a few seconds. The differences in arrival times between stations on the volcano are too small for these events to be T-waves; they are very likely to be local events, since the GSN station in Western Samoa (AFI) shows no arrivals close in time to these events. Preliminary locations show that these small events occur approximately once per day and are located within the volcano (the 95% confidence ellipse is similar to the size of the volcano, due to the small size of the OBH network). Several events are located relatively close to each other (within a km radius) just NW of the crater.

  18. Alaska - Russian Far East connection in volcano research and monitoring

    Science.gov (United States)

    Izbekov, P. E.; Eichelberger, J. C.; Gordeev, E.; Neal, C. A.; Chebrov, V. N.; Girina, O. A.; Demyanchuk, Y. V.; Rybin, A. V.

    2012-12-01

    The Kurile-Kamchatka-Alaska portion of the Pacific Rim of Fire spans for nearly 5400 km. It includes more than 80 active volcanoes and averages 4-6 eruptions per year. Resulting ash clouds travel for hundreds to thousands of kilometers defying political borders. To mitigate volcano hazard to aviation and local communities, the Alaska Volcano Observatory (AVO) and the Institute of Volcanology and Seismology (IVS), in partnership with the Kamchatkan Branch of the Geophysical Survey of the Russian Academy of Sciences (KBGS), have established a collaborative program with three integrated components: (1) volcano monitoring with rapid information exchange, (2) cooperation in research projects at active volcanoes, and (3) volcanological field schools for students and young scientists. Cooperation in volcano monitoring includes dissemination of daily information on the state of volcanic activity in neighboring regions, satellite and visual data exchange, as well as sharing expertise and technologies between AVO and the Kamchatkan Volcanic Eruption Response Team (KVERT) and Sakhalin Volcanic Eruption Response Team (SVERT). Collaboration in scientific research is best illustrated by involvement of AVO, IVS, and KBGS faculty and graduate students in mutual international studies. One of the most recent examples is the NSF-funded Partnerships for International Research and Education (PIRE)-Kamchatka project focusing on multi-disciplinary study of Bezymianny volcano in Kamchatka. This international project is one of many that have been initiated as a direct result of a bi-annual series of meetings known as Japan-Kamchatka-Alaska Subduction Processes (JKASP) workshops that we organize together with colleagues from Hokkaido University, Japan. The most recent JKASP meeting was held in August 2011 in Petropavlovsk-Kamchatsky and brought together more than 130 scientists and students from Russia, Japan, and the United States. The key educational component of our collaborative program

  19. Sources of Magmatic Volatiles Discharging from Subduction Zone Volcanoes

    Science.gov (United States)

    Fischer, T.

    2001-05-01

    Subduction zones are locations of extensive element transfer from the Earth's mantle to the atmosphere and hydrosphere. This element transfer is significant because it can, in some fashion, instigate melt production in the mantle wedge. Aqueous fluids are thought to be the major agent of element transfer during the subduction zone process. Volatile discharges from passively degassing subduction zone volcanoes should in principle, provide some information on the ultimate source of magmatic volatiles in terms of the mantle, the crust and the subducting slab. The overall flux of volatiles from degassing volcanoes should be balanced by the amount of volatiles released from the mantle wedge, the slab and the crust. Kudryavy Volcano, Kurile Islands, has been passively degassing at 900C fumarole temperatures for at least 40 years. Extensive gas sampling at this basaltic andesite cone and application of CO2/3He, N2/3He systematics in combination with C and N- isotopes indicates that 80% of the CO2 and approximately 60% of the N 2 are contributed from a sedimentary source. The mantle wedge contribution for both volatiles is, with 12% and 17% less significant. Direct volatile flux measurements from the volcano using the COSPEC technique in combination with direct gas sampling allows for the calculation of the 3He flux from the volcano. Since 3He is mainly released from the astenospheric mantle, the amount of mantle supplying the 3He flux can be determined if initial He concentrations of the mantle melts are known. The non-mantle flux of CO2 and N2 can be calculated in similar fashion. The amount of non-mantle CO2 and N2 discharging from Kudryavy is balanced by the amount of CO2 and N2 subducted below Kudryavy assuming a zone of melting constrained by the average spacing of the volcanoes along the Kurile arc. The volatile budget for Kudryavy is balanced because the volatile flux from the volcano is relatively small (75 t/day (416 Mmol/a) SO2, 360 Mmol/a of non-mantle CO2 and

  20. Satellite monitoring of remote volcanoes improves study efforts in Alaska

    Science.gov (United States)

    Dean, K.; Servilla, M.; Roach, A.; Foster, B.; Engle, K.

    Satellite monitoring of remote volcanoes is greatly benefitting the Alaska Volcano Observatory (AVO), and last year's eruption of the Okmok Volcano in the Aleutian Islands is a good case in point. The facility was able to issue and refine warnings of the eruption and related activity quickly, something that could not have been done using conventional seismic surveillance techniques, since seismometers have not been installed at these locations.AVO monitors about 100 active volcanoes in the North Pacific (NOPAC) region, but only a handful are observed by costly and logistically complex conventional means. The region is remote and vast, about 5000 × 2500 km, extending from Alaska west to the Kamchatka Peninsula in Russia (Figure 1). Warnings are transmitted to local communities and airlines that might be endangered by eruptions. More than 70,000 passenger and cargo flights fly over the region annually, and airborne volcanic ash is a threat to them. Many remote eruptions have been detected shortly after the initial magmatic activity using satellite data, and eruption clouds have been tracked across air traffic routes. Within minutes after eruptions are detected, information is relayed to government agencies, private companies, and the general public using telephone, fax, and e-mail. Monitoring of volcanoes using satellite image data involves direct reception, real-time monitoring, and data analysis. Two satellite data receiving stations, located at the Geophysical Institute, University of Alaska Fairbanks (UAF), are capable of receiving data from the advanced very high resolution radiometer (AVHRR) on National Oceanic and Atmospheric Administration (NOAA) polar orbiting satellites and from synthetic aperture radar (SAR) equipped satellites.

  1. Volcano geodesy: Challenges and opportunities for the 21st century

    Science.gov (United States)

    Dzurisin, D.

    2000-01-01

    Intrusions of magma beneath volcanoes deform the surrounding rock and, if the intrusion is large enough, the overlying ground surface. Numerical models generally agree that, for most eruptions, subsurface volume changes are sufficient to produce measurable deformation at the surface. Studying this deformation can help to determine the location, volume, and shape of a subsurface magma body and thus to anticipate the onset and course of an eruption. This approach has been successfully applied at many restless volcanoes, especially basaltic shields and silicic calderas, using various geodetic techniques and sensors. However, its success at many intermediate-composition strato-volcanoes has been limited by generally long repose intervals, steep terrain, and structural influences that complicate the history and shape of surface deformation. These factors have made it difficult to adequately characterize deformation in space and time at many of the world's dangerous volcanoes. Recent technological advances promise to make this task easier by enabling the acquisition of geodetic data of high spatial and temporal resolution from Earth-orbiting satellites. Synthetic aperture radar interferometry (InSAR) can image ground deformation over large areas at metre-scale resolution over time-scales of a month to a few years. Global Positioning System (GPS) stations can provide continuous information on three-dimensional ground displacements at a network of key sites -information that is especially important during volcanic crises. By using InSAR to determine the shape of the displacement field and GPS to monitor temporal changes at key sites, scientists have a much better chance to capture geodetic signals that have so far been elusive at many volcanoes. This approach has the potential to provide longer-term warnings of impending volcanic activity than is possible with other monitoring techniques.

  2. Geologic Mapping of the Olympus Mons Volcano, Mars

    Science.gov (United States)

    Bleacher, J. E.; Williams, D. A.; Shean, D.; Greeley, R.

    2012-01-01

    We are in the third year of a three-year Mars Data Analysis Program project to map the morphology of the Olympus Mons volcano, Mars, using ArcGIS by ESRI. The final product of this project is to be a 1:1,000,000-scale geologic map. The scientific questions upon which this mapping project is based include understanding the volcanic development and modification by structural, aeolian, and possibly glacial processes. The project s scientific objectives are based upon preliminary mapping by Bleacher et al. [1] along a approx.80-km-wide north-south swath of the volcano corresponding to High Resolution Stereo Camera (HRSC) image h0037. The preliminary project, which covered approx.20% of the volcano s surface, resulted in several significant findings, including: 1) channel-fed lava flow surfaces are areally more abundant than tube-fed surfaces by a ratio of 5:1, 2) channel-fed flows consistently embay tube-fed flows, 3) lava fans appear to be linked to tube-fed flows, 4) no volcanic vents were identified within the map region, and 5) a Hummocky unit surrounds the summit and is likely a combination of non-channelized flows, dust, ash, and/or frozen volatiles. These results led to the suggestion that the volcano had experienced a transition from long-lived tube-forming eruptions to more sporadic and shorter-lived, channel-forming eruptions, as seen at Hawaiian volcanoes between the tholeiitic shield building phase (Kilauea to Mauna Loa) and alkalic capping phase (Hualalai and Mauna Kea).

  3. Geophysical and geochemical methods applied to investigate fissure-related hydrothermal systems on the summit area of Mt. Etna volcano (Italy)

    Science.gov (United States)

    Maucourant, Samuel; Giammanco, Salvatore; Greco, Filippo; Dorizon, Sophie; Del Negro, Ciro

    2014-06-01

    A multidisciplinary approach integrating self-potential, soil temperature, heat flux, CO2 efflux and gravity gradiometry signals was used to investigate a relatively small fissure-related hydrothermal system near the summit of Mt. Etna volcano (Italy). Measurements were performed through two different surveys carried out at the beginning and at the end of July 2009, right after the end of the long-lived 2008-2009 flank eruption and in coincidence with an increase in diffuse flank degassing related to a reactivation of the volcano, leading to the opening of a new summit vent (NSEC). The main goal was to use a multidisciplinary approach to the detection of hidden fractures in an area of evident near-surface hydrothermal activity. Despite the different methodologies used and the different geometry of the sampling grid between the surveys, all parameters concurred in confirming that the study area is crossed by faults related with the main fracture systems of the south flank of the volcano, where a continuous hydrothermal circulation is established. Results also highlighted that hydrothermal activity in this area changed both in space and in time. These changes were a clear response to variations in the magmatic system, notably to migration of magma at various depth within the main feeder system of the volcano. The results suggest that this specific area, initially chosen as the optimal test-site for the proposed approach, can be useful in order to get information on the potential reactivation of the summit craters of Mt. Etna.

  4. A Versatile Time-Lapse Camera System Developed by the Hawaiian Volcano Observatory for Use at Kilauea Volcano, Hawaii

    Science.gov (United States)

    Orr, Tim R.; Hoblitt, Richard P.

    2008-01-01

    Volcanoes can be difficult to study up close. Because it may be days, weeks, or even years between important events, direct observation is often impractical. In addition, volcanoes are often inaccessible due to their remote location and (or) harsh environmental conditions. An eruption adds another level of complexity to what already may be a difficult and dangerous situation. For these reasons, scientists at the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory (HVO) have, for years, built camera systems to act as surrogate eyes. With the recent advances in digital-camera technology, these eyes are rapidly improving. One type of photographic monitoring involves the use of near-real-time network-enabled cameras installed at permanent sites (Hoblitt and others, in press). Time-lapse camera-systems, on the other hand, provide an inexpensive, easily transportable monitoring option that offers more versatility in site location. While time-lapse systems lack near-real-time capability, they provide higher image resolution and can be rapidly deployed in areas where the use of sophisticated telemetry required by the networked cameras systems is not practical. This report describes the latest generation (as of 2008) time-lapse camera system used by HVO for photograph acquisition in remote and hazardous sites on Kilauea Volcano.

  5. Hyperacid volcano-hydrothermal fluids from Copahue volcano, Argentina: Analogs for "subduction zone fluids"?

    Science.gov (United States)

    Varekamp, J. C.

    2007-12-01

    Hyperacid concentrated Chlorine-Sulfate brines occur in many young arc volcanoes, with pH values Copahue volcanic system (Argentina) suggest reservoir temperatures of 175-300 oC, whereas the surface fluids do not exceed local boiling temperatures. These fluids are generated at much lower P-T conditions than fluids associated with a dehydrating subducted sediment complex below arc volcanoes, but their fundamental chemical compositions may have similarities. Incompatible trace element, major element concentrations and Pb isotope compositions of the fluids were used to determine the most likely rock protoliths for these fluids. Mean rock- normalized trace element diagrams then indicate which elements are quantitatively extracted from the rocks and which are left behind or precipitated in secondary phases. Most LILE show flat rock-normalized patterns, indicating close to congruent dissolution, whereas Ta-Nb-Ti show strong depletions in the rock-normalized diagrams. These HFSE are either left behind in the altered rock protolith or were precipitated along the way up. The behavior of U and Th is almost identical, suggesting that in these low pH fluids with abundant ligands Th is just as easily transported as U, which is not the case in more dilute, neutral fluids. Most analyzed fluids have steeper LREE patterns than the rocks and have negative Eu anomalies similar to the rocks. Fluids that interacted with newly intruded magma e.g., during the 2000 eruption, have much less pronounced Eu anomalies, which was most likely caused by the preferential dissolution of plagioclase when newly intruded magma interacted with the acid fluids. The fluids show a strong positive correlation between Y and Cd (similar to MORB basalts, Yi et al., JGR, 2000), suggesting that Cd is mainly a rock-derived element that may not show chalcophilic behavior. The fluids are strongly enriched (relative to rock) in As, Zn and Pb, suggesting that these elements were carried with the volcanic gas phase

  6. Hydrothermal response to a volcano-tectonic earthquake swarm, Lassen, California

    Science.gov (United States)

    Ingebritsen, Steven E.; Shelly, David R.; Hsieh, Paul A.; Clor, Laura; P.H. Seward,; Evans, William C.

    2015-01-01

    The increasing capability of seismic, geodetic, and hydrothermal observation networks allows recognition of volcanic unrest that could previously have gone undetected, creating an imperative to diagnose and interpret unrest episodes. A November 2014 earthquake swarm near Lassen Volcanic National Park, California, which included the largest earthquake in the area in more than 60 years, was accompanied by a rarely observed outburst of hydrothermal fluids. Although the earthquake swarm likely reflects upward migration of endogenous H2O-CO2 fluids in the source region, there is no evidence that such fluids emerged at the surface. Instead, shaking from the modest sized (moment magnitude 3.85) but proximal earthquake caused near-vent permeability increases that triggered increased outflow of hydrothermal fluids already present and equilibrated in a local hydrothermal aquifer. Long-term, multiparametric monitoring at Lassen and other well-instrumented volcanoes enhances interpretation of unrest and can provide a basis for detailed physical modeling.

  7. Poás volcano in Costa Rica as a hydrothermal analog for Mars

    Science.gov (United States)

    Elmaarry, M. R.; Hynek, B. M.

    2017-12-01

    Mars has experienced intensive volcanic and impact activity early in its history, coinciding with a similarly extensive hydrologic activity on a global scale. These activities constitute the main ingredients of hydrothermal activity. Data acquired from the study of Martian meteorites, remote sensing spectral observations, and robotic rovers has shown the surface of Mars to be mineralogically diverse including mineral assemblages that resemble those of analogous hydrothermal systems on Earth. In particular, evidence for extensive acid-sulfate weathering has been observed by the MERs at Gusev and Meridiani, as well as by MSL at Gale crater. Furthermore, there is growing evidence for silicic volcanism on Mars as indicated by the detection of silica-rich mudstone at Gale containing tridymite and cristobalite coupled with spectral observations indicative of felsic rocks in geographically disparate locations on Mars. For that, the Poás volcano in Costa Rica offers a geologic setting that can be analogous to similar environments on Mars. The Poás volcano is a basaltic andesite stratovolcano in central Costa Rica. Its caldera houses a highly acidic lake inside the caldera 130 m below the crater rim. The volcano has been active in recent historical times, and is currently displaying intensive activity since Apr 2017. Unaltered andesitic basalts collected from the 1953-1955 magmatic activity are mainly composed of plagioclase and minor amounts of orthopyroxene and olivine. We collected samples during our fieldwork in March 2017 (few weeks before its eruption) from fumaroles inside the caldera. The fumaroles were emitting gases at 92°C, and the acidic lake minor abundances of hematite, anatase, and amorphous silica. Most of these minerals have been observed on Mars under potentially similar settings. We plan to continue our investigation by carrying out additional analyses and compare to samples collected from earlier campaigns to gain a better understanding of how the

  8. Volcano-hydrothermal system and activity of Sirung volcano (Pantar Island, Indonesia)

    Science.gov (United States)

    Caudron, Corentin; Bernard, Alain; Murphy, Sam; Inguaggiato, Salvatore; Gunawan, Hendra

    2018-05-01

    Sirung is a frequently active volcano located in the remote parts of Western Timor (Indonesia). Sirung has a crater with several hydrothermal features including a crater lake. We present a timeseries of satellite images of the lake and chemical and isotope data from the hyperacid hydrothermal system. The fluids sampled in the crater present the typical features of hyperacidic systems with high TDS, low pH and δ34SHSO4-δ34SS0 among the highest for such lakes. The cations concentrations are predominantly controlled by the precipitation of alunite, jarosite, silica phases, native sulfur and pyrite which dominate the shallow portions of the hydrothermal system. These minerals may control shallow sealing processes thought to trigger phreatic eruptions elsewhere. Sparse Mg/Cl and SO4/Cl ratios and lake parameters derived from satellite images suggest gradual increase in heat and gas flux, most likely SO2-rich, prior to the 2012 phreatic eruption. An acidic river was sampled 8 km far from the crater and is genetically linked with the fluids rising toward the active crater. This river would therefore be a relevant target for future remote monitoring purposes. Finally, several wells and springs largely exceeded the World Health Organization toxicity limits in total arsenic and fluoride.

  9. Matrix Approach of Seismic Wave Imaging: Application to Erebus Volcano

    Science.gov (United States)

    Blondel, T.; Chaput, J.; Derode, A.; Campillo, M.; Aubry, A.

    2017-12-01

    This work aims at extending to seismic imaging a matrix approach of wave propagation in heterogeneous media, previously developed in acoustics and optics. More specifically, we will apply this approach to the imaging of the Erebus volcano in Antarctica. Volcanoes are actually among the most challenging media to explore seismically in light of highly localized and abrupt variations in density and wave velocity, extreme topography, extensive fractures, and the presence of magma. In this strongly scattering regime, conventional imaging methods suffer from the multiple scattering of waves. Our approach experimentally relies on the measurement of a reflection matrix associated with an array of geophones located at the surface of the volcano. Although these sensors are purely passive, a set of Green's functions can be measured between all pairs of geophones from ice-quake coda cross-correlations (1-10 Hz) and forms the reflection matrix. A set of matrix operations can then be applied for imaging purposes. First, the reflection matrix is projected, at each time of flight, in the ballistic focal plane by applying adaptive focusing at emission and reception. It yields a response matrix associated with an array of virtual geophones located at the ballistic depth. This basis allows us to get rid of most of the multiple scattering contribution by applying a confocal filter to seismic data. Iterative time reversal is then applied to detect and image the strongest scatterers. Mathematically, it consists in performing a singular value decomposition of the reflection matrix. The presence of a potential target is assessed from a statistical analysis of the singular values, while the corresponding eigenvectors yield the corresponding target images. When stacked, the results obtained at each depth give a three-dimensional image of the volcano. While conventional imaging methods lead to a speckle image with no connection to the actual medium's reflectivity, our method enables to

  10. Geochemical and Geophysical Signatures of Poas Volcano, Costa Rica

    Science.gov (United States)

    Martinez, M.; van Bergen, M.; Fernandez, E.; Takano, B.; Barboza, V.; Saenz, W.

    2007-05-01

    Among many research fields in volcanology, prediction of eruptions is the most important from the hazard- mitigation point of view. Most geophysicists have sought for the best physical parameters for this objective: various kinds of wave signals and geodesic data are two of such parameters. Being able to be remotely monitored gives them advantage over many other practical methods for volcano monitoring. On the other hand, increasing volcanic activity is always accompanied by mass transfer. The most swiftly-moving materials are volcanic gases which are the target geochemists have intensively studied although monitoring gases is rather tedious and limited for active volcanoes hosting crater lakes. A Japanese group lead by Bokuichiro Takano has recently developed an indirect method for monitoring gas injection into volcanic crater lakes. Polythionates are formed when SO2 and H2S are injected into the lake from subaqueous fumaroles. Such polythionates consist of chains of 4 to 6 sulphur atoms, the terminal ones of which are bonded with three oxygen atoms. The general formula for these anions is SxO62- (x= 4 to 6). Important to note is that SO2 input into the lake also depends upon the plumbing system of the volcanoes: conduits, cracks and hydrothermal reservoirs beneath the lake that usually differ from volcano to volcano. Despite such site-specific characters some general statements can be made on the behaviour of these chemical species. For example, at low volcanic activity S6O62- predominates while S4O62- and S5O62- become predominant with increasing SO2 that increases with volcanic activity. At higher SO2 input and high temperature polythionates disappear in the lake through interaction with aqueous SO2 (sulfitolysis). Thus, the ratios of the three polythionates or their absence serve as an indicator for various stages of volcanic activity. Monitoring polythionates is an independent method that can be compared with results from geophysical methods. However, it

  11. Tweed Extinct Volcano, Australia, Stereo Pair of SRTM Shaded Relief and Colored Height

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1 Australia is the only continent without any current volcanic activity, but it hosts one of the world's largest extinct volcanoes, the Tweed Volcano. Rock dating methods indicate that eruptions here lasted about three million years, ending about 20 million years ago. Twenty million years of erosion has left this landform deeply eroded yet very recognizable, appearing as a caldera with a central peak. The central peak is not an old remnant landform but is instead the erosional stub of the volcanic neck (the central pipe that carried the magma upward). It is surrounded by ring dikes, which are circular sheets of magma that solidified and now form erosion-resistant ridges. The central peak is named Mount Warning. Topography plays a central role in envisioning the volcano at its climax and in deciphering the landscape evolution that has occurred since then. Low-relief uplands interspersed between deeply eroded canyons form a radial pattern that clearly defines the shape and extent of the original volcanic dome. Erosion is most extensive on the eastern side because the eroding streams drained directly to the ocean and therefore had the steepest gradients. This asymmetry of erosion has been extreme enough that the volcano has been hollowed out by the east-flowing drainage, forming an 'erosional caldera'. Calderas usually form as the result of collapse where magmas retreat within an active volcano. If collapse occurred here, erosion may have removed the evidence, but it produced a similar landform itself. Three visualization methods were combined to produce this image: shading, color coding, and synthetic stereoscopy. The shade image was derived by computing topographic slope in the north-south direction. Northern slopes appear bright and southern slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest

  12. It's the little things that matter most: The role of volatiles in volcanoes and their magmatic roots

    Science.gov (United States)

    Keller, T.; Suckale, J.

    2017-12-01

    Many volcanic eruptions are driven by volatiles - mostly H2O and CO2 - that degas from magmas rising up beneath the volcano. Gas expands during ascent, thus frequently creating lavas with upward of 50% vesicularity. That is a particularly compelling observation considering that volatiles are only present at concentrations of order 100 ppm in the mantle source. Yet, even at these small concentrations, volatiles significantly lower the peridotite solidus. That leads to the production of reactive volatile-rich melts at depth, which has important consequences for melt transport in the asthenosphere. Thus, volatiles have a pivotal role both at the beginning and the end of the magmatic storyline. A growing amount of observational evidence provides various perspectives on these systems. Volcanic products are characterised increasingly well by geochemical and petrological data. And, volcano monitoring now often provides continuous records of degassing flux and composition. What is missing to better interpret these data are coupled fluid mechanic and thermodynamic models that link melt production and reactive transport in the mantle and crust with degassing-driven volcanic activity at the surface. Such models need to describe the deformation and segregation of multiple material phases (liquids, solids, gases) and track the reactive transport of diverse chemical components (major elements, trace elements, volatiles). I will present progress towards a generalization of existing two-phase model for melt transport in the mantle, extending them to three-phase flows appropriate for magma circulation and degassing in volcanoes. What sets the two environments apart is the presence of a compressible vapor in volcanoes. Also, volcanic degassing may occur by convecting suspensions as well as porous segregation. The model framework we are developing for these processes is based on mixture theory. Uncovering the underlying physics that connects these diverse expressions of magma

  13. Historical tephra-stratigraphy of the Cosiguina Volcano (Western Nicaragua)

    International Nuclear Information System (INIS)

    Hradecky, Petr; Rapprich, Vladislav

    2008-01-01

    New detailed geological field studies and 14 C dating of the Cosiguina Volcano (westernmost Nicaragua) have allowed to reconstruct a geological map of the volcano and to establish a recent stratigraphy, including three historical eruptions. Five major sequences are represented. I: pyroclastic flows around 1500 AD, II: pyroclastic flows, scoria and pumice flows and surges, III: pyroclastic deposits related to a littoral crater, IV: pyroclastic flows related to 1709 AD eruption, and finally, V: pyroclastic deposits corresponding to the cataclysmic 1835 AD phreatic, phreatomagmatic and subplinian eruption, which seems to be relatively small-scale in comparison with the preceding historical eruptions. The pulsating geochemical character of the pyroclastic rocks in the last five centuries has been documented. The beginning of every eruption is marked by increasing contents of silica and Zr. Based on that, regardless of present-day volcanic repose, the entire Cosiguina Peninsula should be considered as a very hazardous volcanic area. (author)

  14. The Mediterranean Supersite Volcanoes (MED-SUV) Project: an overview

    Science.gov (United States)

    Puglisi, Giuseppe

    2014-05-01

    The EC FP7 MEDiterranean SUpersite Volcanoes (MED-SUV) EC-FP7 Project, which started on June 2013, aims to improve the capacity of the scientific institutions, end users and SME forming the project consortium to assess the volcanic hazards at Italian Supersites, i.e. Mt. Etna and Campi Flegrei/Vesuvius. The Project activities will focus on the optimisation and integration of ground and space monitoring systems, the breakthrough in understanding of volcanic processes, and on the increase of the effectiveness of the coordination between the scientific and end-user communities in the hazard management. The overall goal of the project is to apply the rationale of the Supersites GEO initiative to Mt. Etna and Campi Flegrei/Vesuvius, considered as cluster of Supersites. For the purpose MED-SUV will integrate long-term observations of ground-based multidisciplinary data available for these volcanoes, i.e. geophysical, geochemical, and volcanological datasets, with Earth Observation (EO) data. Merging of different parameters over a long period will provide better understanding of the volcanic processes. In particular, given the variety of styles and intensities of the volcanic activity observed at these volcanoes, and which make them sort of archetypes for 'closed conduit ' and 'open conduit' volcanic systems, the combination of different data will allow discrimination between peculiar volcano behaviours associated with pre-, syn- and post-eruptive phases. Indeed, recognition of specific volcano patterns will allow broadening of the spectrum of knowledge of geo-hazards, as well as better parameterisation and modelling of the eruptive phenomena and of the processes occurring in the volcano supply system; thus improving the capability of carrying out volcano surveillance activities. Important impacts on the European industrial sector, arising from a partnership integrating the scientific community and SMEs to implement together new observation/monitoring sensors/systems, are

  15. Looking inside volcanoes with the Imaging Atmospheric Cherenkov Telescopes

    Science.gov (United States)

    Del Santo, M.; Catalano, O.; Cusumano, G.; La Parola, V.; La Rosa, G.; Maccarone, M. C.; Mineo, T.; Sottile, G.; Carbone, D.; Zuccarello, L.; Pareschi, G.; Vercellone, S.

    2017-12-01

    Cherenkov light is emitted when charged particles travel through a dielectric medium with velocity higher than the speed of light in the medium. The ground-based Imaging Atmospheric Cherenkov Telescopes (IACT), dedicated to the very-high energy γ-ray Astrophysics, are based on the detection of the Cherenkov light produced by relativistic charged particles in a shower induced by TeV photons interacting with the Earth atmosphere. Usually, an IACT consists of a large segmented mirror which reflects the Cherenkov light onto an array of sensors, placed at the focal plane, equipped by fast electronics. Cherenkov light from muons is imaged by an IACT as a ring, when muon hits the mirror, or as an arc when the impact point is outside the mirror. The Cherenkov ring pattern contains information necessary to assess both direction and energy of the incident muon. Taking advantage of the muon detection capability of IACTs, we present a new application of the Cherenkov technique that can be used to perform the muon radiography of volcanoes. The quantitative understanding of the inner structure of a volcano is a key-point to monitor the stages of the volcano activity, to forecast the next eruptive style and, eventually, to mitigate volcanic hazards. Muon radiography shares the same principle as X-ray radiography: muons are attenuated by higher density regions inside the target so that, by measuring the differential attenuation of the muon flux along different directions, it is possible to determine the density distribution of the interior of a volcano. To date, muon imaging of volcanic structures has been mainly achieved with detectors made up of scintillator planes. The advantage of using Cherenkov telescopes is that they are negligibly affected by background noise and allow a consistently improved spatial resolution when compared to the majority of the current detectors.

  16. Multiresolution pattern recognition of small volcanos in Magellan data

    Science.gov (United States)

    Smyth, P.; Anderson, C. H.; Aubele, J. C.; Crumpler, L. S.

    1992-01-01

    The Magellan data is a treasure-trove for scientific analysis of venusian geology, providing far more detail than was previously available from Pioneer Venus, Venera 15/16, or ground-based radar observations. However, at this point, planetary scientists are being overwhelmed by the sheer quantities of data collected--data analysis technology has not kept pace with our ability to collect and store it. In particular, 'small-shield' volcanos (less than 20 km in diameter) are the most abundant visible geologic feature on the planet. It is estimated, based on extrapolating from previous studies and knowledge of the underlying geologic processes, that there should be on the order of 10(exp 5) to 10(exp 6) of these volcanos visible in the Magellan data. Identifying and studying these volcanos is fundamental to a proper understanding of the geologic evolution of Venus. However, locating and parameterizing them in a manual manner is very time-consuming. Hence, we have undertaken the development of techniques to partially automate this task. The goal is not the unrealistic one of total automation, but rather the development of a useful tool to aid the project scientists. The primary constraints for this particular problem are as follows: (1) the method must be reasonably robust; and (2) the method must be reasonably fast. Unlike most geological features, the small volcanos of Venus can be ascribed to a basic process that produces features with a short list of readily defined characteristics differing significantly from other surface features on Venus. For pattern recognition purposes the relevant criteria include the following: (1) a circular planimetric outline; (2) known diameter frequency distribution from preliminary studies; (3) a limited number of basic morphological shapes; and (4) the common occurrence of a single, circular summit pit at the center of the edifice.

  17. Forecasting deflation, intrusion and eruption at inflating volcanoes

    Science.gov (United States)

    Blake, Stephen; Cortés, Joaquín A.

    2018-01-01

    A principal goal of volcanology is to successfully forecast the start of volcanic eruptions. This paper introduces a general forecasting method, which relies on a stream of monitoring data and a statistical description of a given threshold criterion for an eruption to start. Specifically we investigate the timing of intrusive and eruptive events at inflating volcanoes. The gradual inflation of the ground surface is a well-known phenomenon at many volcanoes and is attributable to pressurised magma accumulating within a shallow chamber. Inflation usually culminates in a rapid deflation event caused by magma escaping from the chamber to produce a shallow intrusion and, in some cases, a volcanic eruption. We show that the ground elevation during 15 inflation periods at Krafla volcano, Iceland, increased with time towards a limiting value by following a decaying exponential with characteristic timescale τ. The available data for Krafla, Kilauea and Mauna Loa volcanoes show that the duration of inflation (t*) is approximately equal to τ. The distribution of t* / τ values follows a log-logistic distribution in which the central 60% of the data lie between 0.99 deflation event starting during a specified time interval to be estimated. The time window in which there is a specified probability of deflation starting can also be forecast, and forecasts can be updated after each new deformation measurement. The method provides stronger forecasts than one based on the distribution of repose times alone and is transferable to other types of monitoring data and/or other patterns of pre-eruptive unrest.

  18. Hawaiian Volcano Observatory seismic data, January to March 2009

    Science.gov (United States)

    Nakata, Jennifer S.; Okubo, Paul G.

    2010-01-01

    This U.S. Geological Survey (USGS), Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during January–March 2009. The seismic summary offers earthquake hypocenters without interpretation as a source of preliminary data and is complete in that most data for events of M≥1.5 are included. All latitude and longitude references in this report are stated in Old Hawaiian Datum.

  19. Geochemistry of mud volcano fluids in the Taiwan accretionary prism

    International Nuclear Information System (INIS)

    You Chenfeng; Gieskes, Joris M.; Lee, Typhoon; Yui Tzenfu; Chen Hsinwen

    2004-01-01

    Taiwan is located at the collision boundary between the Philippine Sea Plate and the Asian Continental Plate and is one of the most active orogenic belts in the world. Fluids sampled from 9 sub-aerial mud volcanoes distributed along two major geological structures in southwestern Taiwan, the Chishan fault and the Gutingkeng anticline, were analyzed to evaluate possible sources of water and the degree of fluid-sediment interaction at depth in an accretionary prism. Overall, the Taiwanese mud volcano fluids are characterized by high Cl contents, up to 347 mM, suggesting a marine origin from actively de-watering sedimentary pore waters along major structures on land. The fluids obtained from the Gutingkeng anticline, as well as from the Coastal Plain area, show high Cl, Na, K, Ca, Mg and NH 4 , but low SO 4 and B concentrations. In contrast, the Chishan fault fluids are much less saline (1/4 seawater value), but show much heavier O isotope compositions (δ 18 O=5.1-6.5 %o). A simplified scenario of mixing between sedimentary pore fluids and waters affected by clay dehydration released at depth can explain several crucial observations including heavy O isotopes, radiogenic Sr contents ( 87 Sr/ 86 Sr=0.71136-0.71283), and relatively low salinities in the Chishan fluids. Gases isolated from the mud volcanoes are predominantly CH 4 and CO 2 , where the CH 4 -C isotopic compositions show a thermogenic component of δ 13 C=-38 %o. These results demonstrate that active mud volcano de-watering in Taiwan is a direct product of intense sediment accretion and plate collision in the region

  20. Database for volcanic processes and geology of Augustine Volcano, Alaska

    Science.gov (United States)

    McIntire, Jacqueline; Ramsey, David W.; Thoms, Evan; Waitt, Richard B.; Beget, James E.

    2012-01-01

    Augustine Island (volcano) in lower Cook Inlet, Alaska, has erupted repeatedly in late-Holocene and historical times. Eruptions typically beget high-energy volcanic processes. Most notable are bouldery debris avalanches containing immense angular clasts shed from summit domes. Coarse deposits of these avalanches form much of Augustine's lower flanks. This geologic map at 1:25,000 scale depicts these deposits, these processes.

  1. HYPOCENTER DISTRIBUTION OF LOW FREQUENCY EVENT AT PAPANDAYAN VOLCANO

    Directory of Open Access Journals (Sweden)

    Muhammad Mifta Hasan

    2016-10-01

    Full Text Available Papandayan volcano is a stratovolcano with irregular cone-shaped has eight craters around the peak. The most active crater in Papandayan is a Mas crater. Distribution of relocated event calculated using Geiger Adaptive Damping Algorithm (GAD shows that the epicenter of the event centered below Mas crater with maximum rms 0.114. While depth of the hypocenter range between 0-2 km and 5-6 km due to activity of steam and gas.

  2. Ring and Volcano Structures Formed by a Metal Dipyrromethene Complex

    Energy Technology Data Exchange (ETDEWEB)

    Son, Seung Bae; Hahn, Jae Ryang [Chonbuk National Univ., Jeonju (Korea, Republic of); Miao, Qing; Shin, Jiyoung; Dolphin, David [Univ. of British Columbia, Columbia (Canada)

    2014-06-15

    Dichloromethane liquid droplets containing a cobalt dipyrromethene trimer deposited on a graphite surface were found to form coffee ring, toroid ring, or volcano dot structures due to the redistribution of the solute during solvent evaporation. The shapes and size distributions of the ring structures depended on the drying temperature. The shape differences were attributed to the fact that the solvent evaporation rate controlled the self-assembly process that yielded the coffee stain and pinhole structures.

  3. Monitoring Active Volcanos Using Aerial Images and the Orthoview Tool

    OpenAIRE

    Maria Marsella; Carla Nardinocchi; Cristina Proietti; Leonardo Daga; Mauro Coltelli

    2014-01-01

    In volcanic areas, where it can be difficult to perform direct surveys, digital photogrammetry techniques are rarely adopted for routine volcano monitoring. Nevertheless, they have remarkable potentialities for observing active volcanic features (e.g., fissures, lava flows) and the connected deformation processes. The ability to obtain accurate quantitative data of definite accuracy in short time spans makes digital photogrammetry a suitable method for controlling the evolution of rapidly cha...

  4. Mutnovsky and Gorely Volcanoes, Kamchatka as Planetary Analogue Sites

    Science.gov (United States)

    Evdokimova, N.; Izbekov, P. E.; Krupskaya, V.; Muratov, A.

    2016-12-01

    Recent advances in Mars studies suggest that volcanic rocks, which dominated Martian surface in the past, have been exposed to alteration processes in a water-bearing environment during Noachian, before 3.7 Gy. Active volcanoes on Earth are natural laboratories, where volcanic processes and their associated products can be studied directly. This is particularly important for studying of alteration of juvenile volcanic products in aqueous environment because of the transient nature of some of the alteration products, as well as the environment itself. Terrestrial analogues help us to better understand processes on Mars; they are particularly useful as a test sites for preparation to future Mars missions. In this presentation we describe planetary analogue sites at Mutnovsky and Gorely Volcanoes in Kamchatka, which might be helpful for comparative studies and preparation to future Mars missions. Mutnovsky and Gorely Volcanoes are located 75 km south of Petropavlovsk-Kamchatsky, in the southern part of the Kamchatka Peninsula, Russia. The modern volcanic landscape in the area was shaped in Holocene (recent 10,000 years) through intermittent eruption of magmas ranging in composition from basalts to dacites and rhyodacites, with basaltic andesite lavas dominating in the modern relief. Two localities could be of a particular interest: (1) Mutnovsky NW thermal field featuring processes of active hydrothermal alteration of lavas of basaltic andesite and (2) dry lake at the bottom of Gorely caldera featuring products of mechanical disintegration of basaltic andesite lavas by eolian processes with short seasonal sedimentation in aqueous environment.

  5. Pb-210 and Po-210 from active volcanoes in Japan

    International Nuclear Information System (INIS)

    Komura, K.; Uchida, K.; Yamamoto, M.; Ueno, K.

    1991-01-01

    The concentration of Pb-210 and Po-210 in the surface air of volcanic areas is of considerable interest from the viewpoints of geochemistry, geophysics and also health physics, because these nuclides are the useful tracers for the estimation of the residence time or life time of aerosols, and give the significant radiation dose due to inhalation and ingestion through food stuffs. Since the establishment of Low Level Radioactivity Laboratory, Kanazawa University, in 1976, the measurement of environmental radioactivity has been one of the main subjects, and the measurement of Pb-210 and Po-210 in the surface air of Kagoshima was begun in 1987 to estimate the contribution from Volcano Sakurajima. In this study, the measurement of Pb-210 and Po-210 in air borne particles collected with air samplers, volcanic ash and lava of volcano Sakurajima of which the age of eruption is known. Moreover, the Po-210 in the volcanic gas and sulfur sublimate in the samples collected in four active volcanoes in Hokkaido was measured. The experiment and the results are reported. (K.I.)

  6. Design of Deformation Monitoring System for Volcano Mitigation

    International Nuclear Information System (INIS)

    Islamy, M R F; Salam, R A; Khairurrijal; Munir, M M; Irsyam, M

    2016-01-01

    Indonesia has many active volcanoes that are potentially disastrous. It needs good mitigation systems to prevent victims and to reduce casualties from potential disaster caused by volcanoes eruption. Therefore, the system to monitor the deformation of volcano was built. This system employed telemetry with the combination of Radio Frequency (RF) communications of XBEE and General Packet Radio Service (GPRS) communication of SIM900. There are two types of modules in this system, first is the coordinator as a parent and second is the node as a child. Each node was connected to coordinator forming a Wireless Sensor Network (WSN) with a star topology and it has an inclinometer based sensor, a Global Positioning System (GPS), and an XBEE module. The coordinator collects data to each node, one a time, to prevent collision data between nodes, save data to SD Card and transmit data to web server via GPRS. Inclinometer was calibrated with self-built in calibrator and tested in high temperature environment to check the durability. The GPS was tested by displaying its position in web server via Google Map Application Protocol Interface (API v.3). It was shown that the coordinator can receive and transmit data from every node to web server very well and the system works well in a high temperature environment. (paper)

  7. Design of Deformation Monitoring System for Volcano Mitigation

    Science.gov (United States)

    Islamy, M. R. F.; Salam, R. A.; Munir, M. M.; Irsyam, M.; Khairurrijal

    2016-08-01

    Indonesia has many active volcanoes that are potentially disastrous. It needs good mitigation systems to prevent victims and to reduce casualties from potential disaster caused by volcanoes eruption. Therefore, the system to monitor the deformation of volcano was built. This system employed telemetry with the combination of Radio Frequency (RF) communications of XBEE and General Packet Radio Service (GPRS) communication of SIM900. There are two types of modules in this system, first is the coordinator as a parent and second is the node as a child. Each node was connected to coordinator forming a Wireless Sensor Network (WSN) with a star topology and it has an inclinometer based sensor, a Global Positioning System (GPS), and an XBEE module. The coordinator collects data to each node, one a time, to prevent collision data between nodes, save data to SD Card and transmit data to web server via GPRS. Inclinometer was calibrated with self-built in calibrator and tested in high temperature environment to check the durability. The GPS was tested by displaying its position in web server via Google Map Application Protocol Interface (API v.3). It was shown that the coordinator can receive and transmit data from every node to web server very well and the system works well in a high temperature environment.

  8. Vulnerability mapping in kelud volcano based on village information

    Science.gov (United States)

    Hisbaron, D. R.; Wijayanti, H.; Iffani, M.; Winastuti, R.; Yudinugroho, M.

    2018-04-01

    Kelud Volcano is a basaltic andesitic stratovolcano, situated at 27 km to the east of Kediri, Indonesia. Historically, Kelud Volcano has erupted with return period of 9-75 years, had caused nearly 160,000 people living in Tulungagung, Blitar and Kediri District to be in high-risk areas. This study aims to map vulnerability towards lava flows in Kediri and Malang using detailed scale. There are four major variables, namely demography, asset, hazard, and land use variables. PGIS (Participatory Geographic Information System) is employed to collect data, while ancillary data is derived from statistics information, interpretation of high resolution satellite imagery and Unmanned Aerial Vehicles (UAVs). Data were obtained from field checks and some from high resolution satellite imagery and UAVs. The output of this research is village-based vulnerability information that becomes a valuable input for local stakeholders to improve local preparedness in areas prone to improved disaster resilience. The results indicated that the highest vulnerability to lava flood disaster in Kelud Volcano is owned by Kandangan Hamlet, Pandean Hamlet and Kacangan Hamlet, because these two hamlets are in the dominant high vulnerability position of 3 out of 4 scenarios (economic, social and equal).

  9. Climbing in the high volcanoes of central Mexico

    Science.gov (United States)

    Secor, R. J.

    1984-01-01

    A chain of volcanoes extends across central Mexico along the 19th parallel, a line just south of Mexico City. The westernmost of these peaks is Nevado de Colima at 4,636 feet above sea level. A subsidiary summit of Nevado de Colima is Volcan de Colima, locally called Fuego (fire) it still emits sulphurous fumes and an occasional plume of smoke since its disastrous eruption in 1941. Parictuin, now dormant, was born in the fall of 1943 when a cornfield suddenly erupted. Within 18 months, the cone grew more than 1,700 feet. Nevado de Toluca is a 15,433-foot volcanic peak south of the city of Toluca. Just southeast of Mexico City are two high volcanoes that are permanently covered by snow: Iztaccihuatl (17,342 fet) and Popocatepetl (17,887 feet) Further east is the third highest mountain in North America: 18,700-foot Citlateptl, or El Pico de Orizaba. North of these high peaks are two volcanoes, 14, 436-foot La Malinche and Cofre de Perote at 14,048 feet. This range of mountains is known variously as the Cordillera de Anahuac, the Sierra Volcanica Transversal, or the Cordillera Neovolcanica. 

  10. Forecasting magma-chamber rupture at Santorini volcano, Greece.

    Science.gov (United States)

    Browning, John; Drymoni, Kyriaki; Gudmundsson, Agust

    2015-10-28

    How much magma needs to be added to a shallow magma chamber to cause rupture, dyke injection, and a potential eruption? Models that yield reliable answers to this question are needed in order to facilitate eruption forecasting. Development of a long-lived shallow magma chamber requires periodic influx of magmas from a parental body at depth. This redistribution process does not necessarily cause an eruption but produces a net volume change that can be measured geodetically by inversion techniques. Using continuum-mechanics and fracture-mechanics principles, we calculate the amount of magma contained at shallow depth beneath Santorini volcano, Greece. We demonstrate through structural analysis of dykes exposed within the Santorini caldera, previously published data on the volume of recent eruptions, and geodetic measurements of the 2011-2012 unrest period, that the measured 0.02% increase in volume of Santorini's shallow magma chamber was associated with magmatic excess pressure increase of around 1.1 MPa. This excess pressure was high enough to bring the chamber roof close to rupture and dyke injection. For volcanoes with known typical extrusion and intrusion (dyke) volumes, the new methodology presented here makes it possible to forecast the conditions for magma-chamber failure and dyke injection at any geodetically well-monitored volcano.

  11. Peeking Beneath the Caldera: Communicating Subsurface Knowledge of Newberry Volcano

    Science.gov (United States)

    Mark-Moser, M.; Rose, K.; Schultz, J.; Cameron, E.

    2016-12-01

    "Imaging the Subsurface: Enhanced Geothermal Systems and Exploring Beneath Newberry Volcano" is an interactive website that presents a three-dimensional subsurface model of Newberry Volcano developed at National Energy Technology Laboratory (NETL). Created using the Story Maps application by ArcGIS Online, this format's dynamic capabilities provide the user the opportunity for multimedia engagement with the datasets and information used to build the subsurface model. This website allows for an interactive experience that the user dictates, including interactive maps, instructive videos and video capture of the subsurface model, and linked information throughout the text. This Story Map offers a general background on the technology of enhanced geothermal systems and the geologic and development history of Newberry Volcano before presenting NETL's modeling efforts that support the installation of enhanced geothermal systems. The model is driven by multiple geologic and geophysical datasets to compare and contrast results which allow for the targeting of potential EGS sites and the reduction of subsurface uncertainty. This Story Map aims to communicate to a broad audience, and provides a platform to effectively introduce the model to researchers and stakeholders.

  12. InSAR observations of active volcanoes in Latin America

    Science.gov (United States)

    Morales Rivera, A. M.; Chaussard, E.; Amelung, F.

    2012-12-01

    Over the last decade satellite-based interferometric synthetic aperture radar (InSAR) has developed into a well-known technique to gauge the status of active volcanoes. The InSAR technique can detect the ascent of magma to shallow levels of the volcanic plumbing system because new arriving magma pressurizes the system. This is likely associated with the inflation of the volcanic edifice and the surroundings. Although the potential of InSAR to detect magma migration is well known, the principal limitation was that only for few volcanoes frequent observations were acquired. The ALOS-1 satellite of the Japanese Aerospace Exploration Agency (JAXA) acquired a global L-band data set of 15-20 acquisitions during 2006-2011. Here we use ALOS InSAR and Small Baseline (SB) time-series methods for a ground deformation survey of Latin America with emphasis on the northern Andes. We present time-dependent ground deformation data for the volcanoes in Colombia, Ecuador and Peru and interpret the observations in terms of the dynamics of the volcanic systems.

  13. Pb-210 and Po-210 from active volcanoes in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Komura, K; Uchida, K; Yamamoto, M; Ueno, K [Kanazawa Univ. (Japan)

    1991-01-01

    The concentration of Pb-210 and Po-210 in the surface air of volcanic areas is of considerable interest from the viewpoints of geochemistry, geophysics and also health physics, because these nuclides are the useful tracers for the estimation of the residence time or life time of aerosols, and give the significant radiation dose due to inhalation and ingestion through food stuffs. Since the establishment of Low Level Radioactivity Laboratory, Kanazawa University, in 1976, the measurement of environmental radioactivity has been one of the main subjects, and the measurement of Pb-210 and Po-210 in the surface air of Kagoshima was begun in 1987 to estimate the contribution from Volcano Sakurajima. In this study, the measurement of Pb-210 and Po-210 in air borne particles collected with air samplers, volcanic ash and lava of volcano Sakurajima of which the age of eruption is known. Moreover, the Po-210 in the volcanic gas and sulfur sublimate in the samples collected in four active volcanoes in Hokkaido was measured. The experiment and the results are reported. (K.I.).

  14. Monitoring Active Volcanos Using Aerial Images and the Orthoview Tool

    Directory of Open Access Journals (Sweden)

    Maria Marsella

    2014-12-01

    Full Text Available In volcanic areas, where it can be difficult to perform direct surveys, digital photogrammetry techniques are rarely adopted for routine volcano monitoring. Nevertheless, they have remarkable potentialities for observing active volcanic features (e.g., fissures, lava flows and the connected deformation processes. The ability to obtain accurate quantitative data of definite accuracy in short time spans makes digital photogrammetry a suitable method for controlling the evolution of rapidly changing large-area volcanic phenomena. The systematic acquisition of airborne photogrammetric datasets can be adopted for implementing a more effective procedure aimed at long-term volcano monitoring and hazard assessment. In addition, during the volcanic crisis, the frequent acquisition of oblique digital images from helicopter allows for quasi-real-time monitoring to support mitigation actions by civil protection. These images are commonly used to update existing maps through a photo-interpretation approach that provide data of unknown accuracy. This work presents a scientific tool (Orthoview that implements a straightforward photogrammetric approach to generate digital orthophotos from single-view oblique images provided that at least four Ground Control Points (GCP and current Digital Elevation Models (DEM are available. The influence of the view geometry, of sparse and not-signalized GCP and DEM inaccuracies is analyzed for evaluating the performance of the developed tool in comparison with other remote sensing techniques. Results obtained with datasets from Etna and Stromboli volcanoes demonstrate that 2D features measured on the produced orthophotos can reach sub-meter-level accuracy.

  15. Large submarine sand-rubble flow on Kilauea volcano, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Fornari, D J [Columbia Univ., Palisades, NY; Moore, J G; Calk, L

    1979-05-01

    Papa'u seamount on the south submarine slope of Kilauea volcano is a large landslide about 19 km long, 6 km wide, and up to 1 km thick with a volume of about 39 km/sup 3/. Dredge hauls, remote camera photographs, and submersible observations indicate that it is composed primarily of unconsolidated angular glassy basalt sand with scattered basalt blocks up to 1 m in size; no lava flows were seen. Sulfur contents of basalt glass from several places on the sand-rubble flow and nearby areas are low (< 240 ppm), indicating that the clastic basaltic material was all erupted on land. The Papa'u sandrubble flow was emplaced during a single flow event fed from a large near-shore bank of clastic basaltic material which in turn was formed as lava flows from the summit area of Kilauea volcano disintegrated when they entered the sea. The current eruptive output of the volcano suggests that the material in the submarine sand-rubble flow represents about 6000 years of accumulation, and that the flow event occurred several thousand years ago.

  16. A repeatable seismic source for tomography at volcanoes

    Directory of Open Access Journals (Sweden)

    A. Ratdomopurbo

    1999-06-01

    Full Text Available One major problem associated with the interpretation of seismic signals on active volcanoes is the lack of knowledge about the internal structure of the volcano. Assuming a 1D or a homogeneous instead of a 3D velocity structure leads to an erroneous localization of seismic events. In order to derive a high resolution 3D velocity model ofMt. Merapi (Java a seismic tomography experiment using active sources is planned as a part of the MERAPI (Mechanism Evaluation, Risk Assessment and Prediction Improvement project. During a pre-site survey in August 1996 we tested a seismic source consisting of a 2.5 l airgun shot in water basins that were constructed in different flanks of the volcano. This special source, which in our case can be fired every two minutes, produces a repeatable, identical source signal. Using this source the number of receiver locations is not limited by the number of seismometers. The seismometers can be moved to various receiver locations while the source reproduces the same source signal. Additionally, at each receiver location we are able to record the identical source signal several times so that the disadvantage of the lower energy compared to an explosion source can be reduced by skipping disturbed signals and stacking several recordings.

  17. Stratigraphic reconstruction of the 13 ka BP debris avalanche deposit at Colima volcano (Mexico): effect of climatic conditions on the flow mobility

    Science.gov (United States)

    Roverato, M.; Capra, L.

    2010-12-01

    Colima volcano is an andesitic stratovolcano located in the western part of the Trans-Mexican Volcanic Belt (TMVB) and at the southern end of the N-S trending Colima graben, about 70 km from the Pacific Ocean coast. It is probably the most active Mexican volcano in historic time and one of the most active of North America. Colima volcano yielded numerous partial edifice collapses with emplacement of debris avalanche deposits (DADs) of contrasting volume, morphology, texture and origin. This work has the aim to provide the evidences of how the climatic condition during the 13 ka flank collapse of the Colima volcano affected the textural characteristic and the mobility of the debris avalanche and debris flow originated from this event that occurred just after the Last Glacial Maximum in Mexico (18.4-14.5 ka 14C BP with snow line at 3600 m a.s.l. up to 13 ka BP). The 13,000 yrs old debris avalanche deposit, here named Tonila (TDAD) presents the typical debris avalanche textural characteristics (angular to sub-angular clasts, coarse matrix, jigsaw fit) but at approximately 13 km from the source, the deposit transforms to an hybrid phase with debris avalanche fragments imbedded in a finer, homogenous and indurated matrix more similar to a debris flow deposit. The debris avalanche deposit is directly overly by debris flows, often more than 10 m thick that contains large amount of logs from pine tree, mostly accumulated toward the base and imbricated down flow. Fluvial deposits also occur throughout all successions, representing periods of stream and river reworking highly localized and re-establishment. All these evidences point to the presence of water in the mass previous to the failure. The event here described represent an anomalous event between the previously described deposit associated to volcanic complex, and evidence as climatic condition can alter and modifies the depositional sequences incrementing the hazard.

  18. New Perspectives on the Climatic Impact of the 1600 Eruption of Huaynaputina Volcano, Peru

    Science.gov (United States)

    Verosub, K. L.; Lippman, J.

    2007-05-01

    A critical test of the new understanding of volcanic aerosols developed since 1982 is to determine if it can predict the effects of larger eruptions than those that have occurred since El Chichon. To do that, requires detailed information about the effects of specific large eruptions. We have been investigating the human and climatic impacts of the 1600 eruption of Huaynaputina volcano in Peru. The estimated Volcanic Explosivity Index for this eruption is 6, which is comparable to that of the 1815 eruption of Tambora volcano in Indonesia, which produced global cooling and led to crop failures, famine and social unrest. On the basis of tree-ring data, Briffa et al. (1998) suggested that the most severe short-term Northern Hemisphere cooling event of the past 600 years occurred in 1601, the year following the Huaynaputina eruption. In order gain a better understanding of the nature and extent of this cooling, we have been collecting annual time series that provide information about climatic conditions during time intervals that bracket the Huaynaputina eruption. Among the time series that we have examined (or plan to examine) are ice conditions in the harbors of Tallinn, Estonia, and Riga, Latvia and in Lake Suwa in Japan: cherry blossom blooming (sakura) dates from Kyoto, Japan; records of agricultural production from China and Russia; tithe records from the Spanish colonial empire; dates of the beginning of the wine harvest in France and the rye harvest in Sweden; prices of agricultural commodities in Europe; and river flows from the Nile and the Colorado. Often, in the records we have examined, 1601 shows up as one of the coldest years, if not the coldest year. In addition, the worst famines in Russian history took place between 1601 and 1603, which eventually led to the overthrow of Tsar Boris Gudonov. Thus, there is considerable evidence that the climatic impacts of the Huaynaputina eruption were comparable to those from the Tambora eruption. This result is

  19. The eruption of Mount Pagan volcano, Mariana Islands, 15 May 1981

    Science.gov (United States)

    Banks, N.G.; Koyanagi, R.Y.; Sinton, J.M.; Honma, K.T.

    1984-01-01

    A major explosive eruption occurred 15 May 1981 at Mount Pagan Volcano, the larger of two historic eruptive centers on Pagan Island, Mariana Islands. The eruption was preceded by increased numbers of locally felt earthquakes beginning in late March or early April and by new ground cracks, new sublimates, and increased gas emissions. A swarm of felt earthquakes began at 0745h (local time = UCT+10 hours) 15 May, and at 0915 h, closely following a loud sonic boom, a strong plinian column issued from the volcano. The high-altitude ash cloud (at least 13.5 km) travelled south-southeast, but ash and scoria deposits were thickest (> 2 m) in the NW sector of the island because of the prevailing low-altitude southeasterly winds. The early activity of 15 May probably involved magmatic eruption along a fissure system oriented about N10??E. However, the eruption became hydromagmatic, possibly within minutes, and was largely restricted to three long-lived vents. The northernmost of these built a substantial new scoria-ash cinder cone. Flows and air-fall deposits, consisting almost entirely of juvenile material, exceeded 105 ?? 106 m3 in volume (75 ?? 106 m3 of magma) on land and at least 70-100 ?? 606 m3 at sea. An unknown volume was carried away by stratospheric winds. Lithic blocks and juvenile bombs as large as 1 m in diameter were thrown more than 2 km from the summit, and evidence for base-surge was observed in restricted corridors as low as 200 m elevation on the north and south slopes of the volcano. Neither of these events resulted in serious injuries to the 54 residents of the island, nor did the eruption produce serious chemical hazards in their water supply. Weak eruptions occurred during the ensuing month, and some of these were monitored by ground observations, seismic monitoring, and deformation studies. Precursory seismicity and possibly deformation occurred with some of the observed eruptions. More vigorous eruptions were reported by visiting residents in late

  20. Volcano monitoring using GPS: Developing data analysis strategies based on the June 2007 Kīlauea Volcano intrusion and eruption

    Science.gov (United States)

    Larson, Kristine M.; Poland, Michael; Miklius, Asta

    2010-01-01

    The global positioning system (GPS) is one of the most common techniques, and the current state of the art, used to monitor volcano deformation. In addition to slow (several centimeters per year) displacement rates, GPS can be used to study eruptions and intrusions that result in much larger (tens of centimeters over hours-days) displacements. It is challenging to resolve precise positions using GPS at subdaily time intervals because of error sources such as multipath and atmospheric refraction. In this paper, the impact of errors due to multipath and atmospheric refraction at subdaily periods is examined using data from the GPS network on Kīlauea Volcano, Hawai'i. Methods for filtering position estimates to enhance precision are both simulated and tested on data collected during the June 2007 intrusion and eruption. Comparisons with tiltmeter records show that GPS instruments can precisely recover the timing of the activity.

  1. Tracking the movement of Hawaiian volcanoes; Global Positioning System (GPS) measurement

    Science.gov (United States)

    Dvorak, J.J.

    1992-01-01

    Most, if not all, volcanic eruptions are preceded by surface movements near the volcano. These ground movements are the response of the shallow crust to the accumulation of the magma or the buildup of magma pressure within a subterranean reservoir beneath the volcano. As the magma reservoir expands, the summit and the flanks of the volcano rise and spread apart. Measurements made at many volcanoes show that slow ground movement may precede an eruption by as many as several years. Sudden increases in the rate of ground movement often precede an eruption by a few hours or days.

  2. 2014 volcanic activity in Alaska: Summary of events and response of the Alaska Volcano Observatory

    Science.gov (United States)

    Cameron, Cheryl E.; Dixon, James P.; Neal, Christina A.; Waythomas, Christopher F.; Schaefer, Janet R.; McGimsey, Robert G.

    2017-09-07

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest or suspected unrest, and seismic events at 18 volcanic centers in Alaska during 2014. The most notable volcanic activity consisted of intermittent ash eruptions from long-active Cleveland and Shishaldin Volcanoes in the Aleutian Islands, and two eruptive episodes at Pavlof Volcano on the Alaska Peninsula. Semisopochnoi and Akutan volcanoes had seismic swarms, both likely the result of magmatic intrusion. The AVO also installed seismometers and infrasound instruments at Mount Cleveland during 2014.

  3. Geophysical research on structure of partly eroded maar volcanoes: Miocene Hnojnice and Oligocene Rychnov volcanoes (northern Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Skácelová, Z.; Rapprich, V.; Valenta, Jan; Hartvich, Filip; Šrámek, J.; Radoň, M.; Gaždová, Renata; Nováková, Lucie; Kolínský, Petr; Pécskay, Z.

    2010-01-01

    Roč. 55, č. 4 (2010), s. 299-310 ISSN 1802-6222 R&D Projects: GA AV ČR IAA300460602 Institutional research plan: CEZ:AV0Z30460519 Keywords : maar–diatreme volcano * ground magnetometry * ground gravity measurements Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.026, year: 2010 www.jgeosci.org/content/jgeosci.072_2010_4_skacelova.pdf

  4. Body Wave and Ambient Noise Tomography of Makushin Volcano, Alaska

    Science.gov (United States)

    Lanza, F.; Thurber, C. H.; Syracuse, E. M.; Ghosh, A.; LI, B.; Power, J. A.

    2017-12-01

    Located in the eastern portion of the Alaska-Aleutian subduction zone, Makushin Volcano is among the most active volcanoes in the United States and has been classified as high threat based on eruptive history and proximity to the City of Unalaska and international air routes. In 2015, five individual seismic stations and three mini seismic arrays of 15 stations each were deployed on Unalaska island to supplement the Alaska Volcano Observatory (AVO) permanent seismic network. This temporary array was operational for one year. Taking advantage of the increased azimuthal coverage and the array's increased earthquake detection capability, we developed body-wave Vp and Vp/Vs seismic images of the velocity structure beneath the volcano. Body-wave tomography results show a complex structure with the upper 5 km of the crust dominated by both positive and negative Vp anomalies. The shallow high-Vp features possibly delineate remnant magma pathways or conduits. Low-Vp regions are found east of the caldera at approximately 6-9 km depth. This is in agreement with previous tomographic work and geodetic models, obtained using InSAR data, which had identified this region as a possible long-term source of magma. We also observe a high Vp/Vs feature extending between 7 and 12 km depth below the caldera, possibly indicating partial melting, although the resolution is diminished at these depths. The distributed stations allow us to further complement body-wave tomography with ambient noise imaging and to obtain higher quality of Vs images. Our data processing includes single station data preparation and station-pair cross-correlation steps (Bensen et al., 2007), and the use of the phase weighted stacking method (Schimmel and Gallart, 2007) to improve the signal-to-noise ratio of the cross-correlations. We will show surface-wave dispersion curves, group velocity maps, and ultimately a 3D Vs image. By performing both body wave and ambient noise tomography, we provide a high

  5. Update of the volcanic risk map of Colima volcano, Mexico

    Science.gov (United States)

    Suarez-Plascencia, C.; Nuñez Cornu, F. J.; Marquez-Azua, B.

    2010-12-01

    The Colima volcano, located in western Mexico (19° 30.696 N, 103° 37.026 W) began its current eruptive process in February 10, 1999. This event was the basis for the development of two volcanic hazard maps: one for ballistics (rock fall) lahars, and another one for ash fall. During the period of 2003 to 2008 this volcano has had an intense effusive-explosive activity, similar to the one that took place during the period of 1890 through 1900. Intense pre-Plinian eruption in January 20, 1913, generated little economic losses in the lower parts of the volcano thanks to the low population density and low socio-economic activities at the time The current volcanic activity has triggered ballistic projections, pyroclastic and ash flows, and lahars, all have exceeded the maps limits established in 1999. Vulnerable elements within these areas have gradually changed due to the expansion of the agricultural frontier on the east and southeast sides of the Colima volcano. On the slopes of the northwest side, new blue agave Tequilana weber and avocado orchard crops have emerged along with important production of greenhouse tomato, alfalfa and fruit (citrus) crops that will eventually be processed and dried for exportation to the United States and Europe. Also, in addition to the above, large expanses of corn and sugar cane have been planted on the slopes of the volcano since the nineteenth century. The increased agricultural activity has had a direct impact in the reduction of the available forest land area. Coinciding with this increased activity, the 0.8% growth population during the period of 2000 - 2005, - due to the construction of the Guadalajara-Colima highway-, also increased this impact. The growth in vulnerability changed the level of risk with respect to the one identified in the year 1999 (Suarez, 2000), thus motivating us to perform an update to the risk map at 1:25,000 using vector models of the INEGI, SPOT images of different dates, and fieldwork done in order

  6. Mechanism of the 1996-97 non-eruptive volcano-tectonic earthquake swarm at Iliamna Volcano, Alaska

    Science.gov (United States)

    Roman, D.C.; Power, J.A.

    2011-01-01

    A significant number of volcano-tectonic(VT) earthquake swarms, some of which are accompanied by ground deformation and/or volcanic gas emissions, do not culminate in an eruption.These swarms are often thought to represent stalled intrusions of magma into the mid- or shallow-level crust.Real-time assessment of the likelihood that a VTswarm will culminate in an eruption is one of the key challenges of volcano monitoring, and retrospective analysis of non-eruptive swarms provides an important framework for future assessments. Here we explore models for a non-eruptive VT earthquake swarm located beneath Iliamna Volcano, Alaska, in May 1996-June 1997 through calculation and inversion of fault-plane solutions for swarm and background periods, and through Coulomb stress modeling of faulting types and hypocenter locations observed during the swarm. Through a comparison of models of deep and shallow intrusions to swarm observations,we aim to test the hypothesis that the 1996-97 swarm represented a shallow intrusion, or "failed" eruption.Observations of the 1996-97 swarm are found to be consistent with several scenarios including both shallow and deep intrusion, most likely involving a relatively small volume of intruded magma and/or a low degree of magma pressurization corresponding to a relatively low likelihood of eruption. ?? 2011 Springer-Verlag.

  7. Embedded ARM system for volcano monitoring in remote areas: application to the active volcano on Deception Island (Antarctica).

    Science.gov (United States)

    Peci, Luis Miguel; Berrocoso, Manuel; Fernández-Ros, Alberto; García, Alicia; Marrero, José Manuel; Ortiz, Ramón

    2014-01-02

    This paper describes the development of a multi-parameter system for monitoring volcanic activity. The system permits the remote access and the connection of several modules in a network. An embedded ARM™ processor has been used, allowing a great flexibility in hardware configuration. The use of a complete Linux solution (Debian™) as Operating System permits a quick, easy application development to control sensors and communications. This provides all the capabilities required and great stability with relatively low energy consumption. The cost of the components and applications development is low since they are widely used in different fields. Sensors and commercial modules have been combined with other self-developed modules. The Modular Volcano Monitoring System (MVMS) described has been deployed on the active Deception Island (Antarctica) volcano, within the Spanish Antarctic Program, and has proved successful for monitoring the volcano, with proven reliability and efficient operation under extreme conditions. In another context, i.e., the recent volcanic activity on El Hierro Island (Canary Islands) in 2011, this technology has been used for the seismic equipment and GPS systems deployed, thus showing its efficiency in the monitoring of a volcanic crisis.

  8. Embedded ARM System for Volcano Monitoring in Remote Areas: Application to the Active Volcano on Deception Island (Antarctica

    Directory of Open Access Journals (Sweden)

    Luis Miguel Peci

    2014-01-01

    Full Text Available This paper describes the development of a multi-parameter system for monitoring volcanic activity. The system permits the remote access and the connection of several modules in a network. An embedded ARMTM processor has been used, allowing a great flexibility in hardware configuration. The use of a complete Linux solution (DebianTM as Operating System permits a quick, easy application development to control sensors and communications. This provides all the capabilities required and great stability with relatively low energy consumption. The cost of the components and applications development is low since they are widely used in different fields. Sensors and commercial modules have been combined with other self-developed modules. The Modular Volcano Monitoring System (MVMS described has been deployed on the active Deception Island (Antarctica volcano, within the Spanish Antarctic Program, and has proved successful for monitoring the volcano, with proven reliability and efficient operation under extreme conditions. In another context, i.e., the recent volcanic activity on El Hierro Island (Canary Islands in 2011, this technology has been used for the seismic equipment and GPS systems deployed, thus showing its efficiency in the monitoring of a volcanic crisis.

  9. Characterization of volcanic deposits and geoarchaeological studies from the 1815 eruption of Tambora volcano

    Directory of Open Access Journals (Sweden)

    Igan Supriatman Sutawidjaja

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol1no1.20066aThe eruption of Tambora volcano on the island of Sumbawa in 1815 is generally considered as the largest and the most violent volcanic event in recorded history. The cataclysmic eruption occurred on 11 April 1815 was initiated by Plinian eruption type on 5 April and killed more than 90,000 people on Sumbawa and nearby Lombok. The type plinian eruptions occurred twice and ejected gray pumice and ash, to form stratified deposits as thick as 40-150 cm on the slopes and mostly distributed over the district west of the volcano. Following this, at about 7 pm, on 11 April the first pyroclastic surge was generated and progressively became greater extending to almost whole direction, mainly to the north, west, and south districts from the eruption center. The deadliest volcanic eruption buried ancient villages by pyroclastic surge and flow deposits in almost intact state, thus preserving important archaeological evidence for the period. High preservation in relatively stable conditions and known date of the eruptions provide approximate dating for the archaeological remains. Archaeological excavations on the site uncovered a variety of remains were relieved by ground penetrating radar (GPR to map structural remains of the ancient villages under the pyroclastic surge and flow deposits. These traverses showed that GPR could define structures as deep as 10 m (velocity 0.090 m/ns and could accurately map the thickness of the stratified volcanic deposits in the Tambora village area.    

  10. The 1793 Eruption of San Martin Volcano (Los Tuxtlas, Veracruz, Mexico)

    Science.gov (United States)

    Espindola, J. M.; Zamora-Camacho, A.; Godinez, M. L.; Rodriguez-Elizarraras, S.

    2007-12-01

    San Martin Tuxtla Volcano is located in the State of Veracruz, Eastern Mexico (18.572N, 95.169W, 1650 masl). Its last eruption, which occurred 1793, was described by D. Jose Moziño, a naturalist sent by the Viceroy-of the then New Spain-to report on the eruption. The activity lasted for several months with distinct events of explosive character, which produced thick ash fall deposits in its vicinity. The explosions were heard, among other places, in the coasts of Tampico some 500km NW from the volcano. The ash fall reached distances up to 200 Km from the crater and covered an area of about 112,000 Km2. Following the description of Moziño and the results of field studies we make a reconstruction of the eruption. We identified the air fall deposit from this eruption and present an isopach map. We present radiocarbon ages of the paleosoils under the ash bed as an indirect evidence of its age. This data together with present day wind velocities, and a diffusion-advection model of the dispersion of ashes allow to estimate in at least 10km the altitude reached by some of the eruptive plumes. An estimation of the minimum volume of ash erupted, based on the reconstructed isopachs, is of about 1.3 x 108 m3. Microphotographs of the ashes suggest that the activity was of phreatomagmatic and strombolian nature. Finally, we address some aspects of the volcanic risk in the area derived from our study.

  11. Characterising hydrothermal fluid pathways beneath Aluto volcano, Main Ethiopian Rift, using shear wave splitting

    Science.gov (United States)

    Nowacki, Andy; Wilks, Matthew; Kendall, J.-Michael; Biggs, Juliet; Ayele, Atalay

    2018-05-01

    Geothermal resources are frequently associated with silicic calderas which show evidence of geologically-recent activity. Hence development of geothermal sites requires both an understanding of the hydrothermal system of these volcanoes, as well as the deeper magmatic processes which drive them. Here we use shear wave splitting to investigate the hydrothermal system at the silicic peralkaline volcano Aluto in the Main Ethiopian Rift, which has experienced repeated uplift and subsidence since at least 2004. We make over 370 robust observations of splitting, showing that anisotropy is confined mainly to the top ∼3 km of the volcanic edifice. We find up to 10% shear wave anisotropy (SWA) is present with a maximum centred at the geothermal reservoir. Fast shear wave orientations away from the reservoir align NNE-SSW, parallel to the present-day minimum compressive stress. Orientations on the edifice, however, are rotated NE-SW in a manner we predict from field observations of faults at the surface, providing fluid pressures are sufficient to hold two fracture sets open. These fracture sets may be due to the repeated deformation experienced at Aluto and initiated in caldera formation. We therefore attribute the observed anisotropy to aligned cracks held open by over-pressurised gas-rich fluids within and above the reservoir. This study demonstrates that shear wave splitting can be used to map the extent and style of fracturing in volcanic hydrothermal systems. It also lends support to the hypothesis that deformation at Aluto arises from variations of fluid pressures in the hydrothermal system. These constraints will be crucial for future characterisation of other volcanic and geothermal systems, in rift systems and elsewhere.

  12. Automatic readout for nuclear emulsions in muon radiography of volcanoes

    Science.gov (United States)

    Aleksandrov, A.; Bozza, C.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Kose, U.; Lauria, A.; Medinaceli, E.; Miyamoto, S.; Montesi, C.; Pupilli, F.; Rescigno, R.; Russo, A.; Sirignano, C.; Stellacci, S. M.; Strolin, P.; Tioukov, V.

    2012-04-01

    Nuclear emulsions are an effective choice in many scenarios of volcano radiography by cosmic-ray muons. They are cheap and emulsion-based detectors require no on-site power supply. Nuclear emulsion films provide sub-micrometric tracking precision and intrinsic angular accuracy better than 1 mrad. Imaging the inner structure of a volcano requires that the cosmic-ray absorption map be measured on wide angular range. High-absorption directions can be probed by allowing for large statistics, which implies a large overall flux, i.e. wide surface for the detector. A total area of the order of a few m2 is nowadays typical, thanks to the automatic readout tools originally developed for high-energy physics experiments such as CHORUS, PEANUT, OPERA. The European Scanning System is now being used to read out nuclear emulsion films exposed to cosmic rays on the side of volcanoes. The structure of the system is described in detail with respect to both hardware and software. Its present scanning speed of 20 cm2/h/side/microscope is suitable to fulfil the needs of the current exposures of nuclear emulsion films for muon radiograph, but it is worth to notice that applications in volcano imaging are among the driving forces pushing to increase the performances of the system. Preliminary results for the Unzen volcano of a joint effort by research groups in Italy and Japan show that the current system is already able to provide signal/background ratio in the range 100÷10000:1, depending on the quality cuts set in the off-line data analysis. The size of the smallest detectable structures in that experimental setup is constrained by the available statistics in the region of highest absorption to about 50 mrad, or 22 m under the top of the mountain. Another exposure is currently taking data at the Stromboli volcano. Readout of the exposed films is expected to begin in March 2012, and preliminary results will be available soon after. An effort by several universities and INFN has

  13. Importance of dust storms in the diagenesis of sandstones: a case study, Entrada sandstone in the Ghost Ranch area, New Mexico, USA

    Science.gov (United States)

    Orhan, Hükmü

    1992-04-01

    The importance of dust storms on geological processes has only been studied recently. Case-hardening, desert-varnish formation, duricrust development, reddening and cementation of sediments and caliche formation, are some important geological processes related to dust storms. Dust storms can also be a major source for cements in aeolian sandstones. The Jurassic aeolian Entrada Formation in the Ghost Ranch area is composed of quartz with minor amounts of feldspar and rock fragments, and is cemented with smectite as grain coatings and calcite and kaolinite as pore fillings. Smectite shows a crinkly and honeycomb-like morphology which points to an authigenic origin. The absence of smectite as framework grains and the presence of partially dissolved grains, coated with smectite and smectite egg-shells, indicate an external source. Clay and fine silt-size particles are believed to be the major source for cements, smectite and calcite in the Entrada Formation. The common association of kaolinite with altered feldspar, and the absence of kaolinite in spots heavily cemented with calcite, lead to the conclusions that the kaolinite formation postdates carbonates and that framework feldspar grains were the source of kaolinite.

  14. Designing an Effective Environmental Education Program that Meets the Needs of Stakeholders: A Case Study of the High Lonesome Ranch in DeBeque, Colorado

    Science.gov (United States)

    Haley, Bethany M.

    A successful environmental education (EE) program is one that supports the mission of the parent organization, meets the needs of its audiences, and is effective at increasing environmental literacy. The High Lonesome Ranch (HLR), a private corporation that operates according to a mixed-use landscape model inspired by Aldo Leopold's land ethic, intends to develop an EE program that will operate within an associated nonprofit organization, the High Lonesome Institute (HLI), to further the mission of promoting a contemporary land ethic. Although HLR owners and staff are motivated to develop an EE program, there is currently no clear consensus regarding an overall vision for the program. The purpose of my thesis is to provide HLR owners and their advisors with a recommended design for the education program based on the missions of the HLR and HLI, sound EE theory, stakeholder feedback, and feasibility within the environment of the HLR. To accomplish this, I reviewed pertinent EE literature, reviewed the models used by existing EE programs, and undertook a two-pronged qualitative case study that gathered feedback from the major stakeholders in the HLR/HLI program. The case study included stakeholder interviews and a one-day facilitated charrette. Although feedback from stakeholders on specific program elements ranged widely, there was widespread support for an EE program at the HLR. From this research, I made a series of recommendations regarding how the HLR/HLI should proceed in development, specific program elements, and next steps in the process.

  15. Distribution and demography of San Francisco gartersnakes (Thamnophis sirtalis tetrataenia) at Mindego Ranch, Russian Ridge Open Space Preserve, San Mateo County, California

    Science.gov (United States)

    Kim, Richard; Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

    2018-04-26

    San Francisco gartersnakes (Thamnophis sirtalis tetrataenia) are a subspecies of common gartersnakes endemic to the San Francisco Peninsula of northern California. Because of habitat loss and collection for the pet trade, San Francisco gartersnakes were listed as endangered under the precursor to the Federal Endangered Species Act. A population of San Francisco gartersnakes resides at Mindego Ranch, San Mateo County, which is part of the Russian Ridge Open Space Preserve owned and managed by the Midpeninsula Regional Open Space District (MROSD). Because the site contained non-native fishes and American bullfrogs (Lithobates catesbeianus), MROSD implemented management to eliminate or reduce the abundance of these non-native species in 2014. We monitored the population using capture-mark-recapture techniques to document changes in the population during and following management actions. Although drought confounded some aspects of inference about the effects of management, prey and San Francisco gartersnake populations generally increased following draining of Aquatic Feature 3. Continued management of the site to keep invasive aquatic predators from recolonizing or increasing in abundance, as well as vegetation management that promotes heterogeneous grassland/shrubland near wetlands, likely would benefit this population of San Francisco gartersnakes.

  16. The submarine volcano eruption off El Hierro Island: Effects on the scattering migrant biota and the evolution of the pelagic communities

    KAUST Repository

    Ariza, Alejandro

    2014-07-21

    The submarine volcano eruption off El Hierro Island (Canary Islands) on 10 October 2011 promoted dramatic perturbation of the water column leading to changes in the distribution of pelagic fauna. To study the response of the scattering biota, we combined acoustic data with hydrographic profiles and concurrent sea surface turbidity indexes from satellite imagery. We also monitored changes in the plankton and nekton communities through the eruptive and post-eruptive phases. Decrease of oxygen, acidification, rising temperature and deposition of chemicals in shallow waters resulted in a reduction of epipelagic stocks and a disruption of diel vertical migration (nocturnal ascent) of mesopelagic organisms. Furthermore, decreased light levels at depth caused by extinction in the volcanic plume resulted in a significant shallowing of the deep acoustic scattering layer. Once the eruption ceased, the distribution and abundances of the pelagic biota returned to baseline levels. There was no evidence of a volcano-induced bloom in the plankton community. © 2014 Ariza et al.

  17. Bayesian estimation of magma supply, storage, and eruption rates using a multiphysical volcano model: Kīlauea Volcano, 2000-2012

    Science.gov (United States)

    Anderson, Kyle R.; Poland, Michael P.

    2016-08-01

    Estimating rates of magma supply to the world's volcanoes remains one of the most fundamental aims of volcanology. Yet, supply rates can be difficult to estimate even at well-monitored volcanoes, in part because observations are noisy and are usually considered independently rather than as part of a holistic system. In this work we demonstrate a technique for probabilistically estimating time-variable rates of magma supply to a volcano through probabilistic constraint on storage and eruption rates. This approach utilizes Bayesian joint inversion of diverse datasets using predictions from a multiphysical volcano model, and independent prior information derived from previous geophysical, geochemical, and geological studies. The solution to the inverse problem takes the form of a probability density function which takes into account uncertainties in observations and prior information, and which we sample using a Markov chain Monte Carlo algorithm. Applying the technique to Kīlauea Volcano, we develop a model which relates magma flow rates with deformation of the volcano's surface, sulfur dioxide emission rates, lava flow field volumes, and composition of the volcano's basaltic magma. This model accounts for effects and processes mostly neglected in previous supply rate estimates at Kīlauea, including magma compressibility, loss of sulfur to the hydrothermal system, and potential magma storage in the volcano's deep rift zones. We jointly invert data and prior information to estimate rates of supply, storage, and eruption during three recent quasi-steady-state periods at the volcano. Results shed new light on the time-variability of magma supply to Kīlauea, which we find to have increased by 35-100% between 2001 and 2006 (from 0.11-0.17 to 0.18-0.28 km3/yr), before subsequently decreasing to 0.08-0.12 km3/yr by 2012. Changes in supply rate directly impact hazard at the volcano, and were largely responsible for an increase in eruption rate of 60-150% between 2001 and

  18. Bayesian estimation of magma supply, storage, and eruption rates using a multiphysical volcano model: Kīlauea Volcano, 2000–2012

    Science.gov (United States)

    Anderson, Kyle R.; Poland, Michael

    2016-01-01

    Estimating rates of magma supply to the world's volcanoes remains one of the most fundamental aims of volcanology. Yet, supply rates can be difficult to estimate even at well-monitored volcanoes, in part because observations are noisy and are usually considered independently rather than as part of a holistic system. In this work we demonstrate a technique for probabilistically estimating time-variable rates of magma supply to a volcano through probabilistic constraint on storage and eruption rates. This approach utilizes Bayesian joint inversion of diverse datasets using predictions from a multiphysical volcano model, and independent prior information derived from previous geophysical, geochemical, and geological studies. The solution to the inverse problem takes the form of a probability density function which takes into account uncertainties in observations and prior information, and which we sample using a Markov chain Monte Carlo algorithm. Applying the technique to Kīlauea Volcano, we develop a model which relates magma flow rates with deformation of the volcano's surface, sulfur dioxide emission rates, lava flow field volumes, and composition of the volcano's basaltic magma. This model accounts for effects and processes mostly neglected in previous supply rate estimates at Kīlauea, including magma compressibility, loss of sulfur to the hydrothermal system, and potential magma storage in the volcano's deep rift zones. We jointly invert data and prior information to estimate rates of supply, storage, and eruption during three recent quasi-steady-state periods at the volcano. Results shed new light on the time-variability of magma supply to Kīlauea, which we find to have increased by 35–100% between 2001 and 2006 (from 0.11–0.17 to 0.18–0.28 km3/yr), before subsequently decreasing to 0.08–0.12 km3/yr by 2012. Changes in supply rate directly impact hazard at the volcano, and were largely responsible for an increase in eruption rate of 60–150% between

  19. Modeling volcano growth on the Island of Hawaii: deep-water perspectives

    Science.gov (United States)

    Lipman, Peter W.; Calvert, Andrew T.

    2013-01-01

    Recent ocean-bottom geophysical surveys, dredging, and dives, which complement surface data and scientific drilling at the Island of Hawaii, document that evolutionary stages during volcano growth are more diverse than previously described. Based on combining available composition, isotopic age, and geologically constrained volume data for each of the component volcanoes, this overview provides the first integrated models for overall growth of any Hawaiian island. In contrast to prior morphologic models for volcano evolution (preshield, shield, postshield), growth increasingly can be tracked by age and volume (magma supply), defining waxing alkalic, sustained tholeiitic, and waning alkalic stages. Data and estimates for individual volcanoes are used to model changing magma supply during successive compositional stages, to place limits on volcano life spans, and to interpret composite assembly of the island. Volcano volumes vary by an order of magnitude; peak magma supply also varies sizably among edifices but is challenging to quantify because of uncertainty about volcano life spans. Three alternative models are compared: (1) near-constant volcano propagation, (2) near-equal volcano durations, (3) high peak-tholeiite magma supply. These models define inconsistencies with prior geodynamic models, indicate that composite growth at Hawaii peaked ca. 800–400 ka, and demonstrate a lower current rate. Recent age determinations for Kilauea and Kohala define a volcano propagation rate of 8.6 cm/yr that yields plausible inception ages for other volcanoes of the Kea trend. In contrast, a similar propagation rate for the less-constrained Loa trend would require inception of Loihi Seamount in the future and ages that become implausibly large for the older volcanoes. An alternative rate of 10.6 cm/yr for Loa-trend volcanoes is reasonably consistent with ages and volcano spacing, but younger Loa volcanoes are offset from the Kea trend in age-distance plots. Variable magma flux

  20. Asymmetrical hydrothermal system below Merapi volcano imaged by geophysical data.

    Science.gov (United States)

    Byrdina, Svetlana; Friedel, Sven; Budi-Santoso, Agus; Suryanto, Wiwit; Suhari, Aldjarishy; Vandemeulebrouck, Jean; Rizal, Mohhamed H.; Grandis, Hendra

    2017-04-01

    A high-resolution image of the hydrothermal system of Merapi volcano is obtained using electrical resistivity tomography (ERT), self-potential, and CO2 flux mappings. The ERT inversions identify two distinct low-resistivity bodies, at the base of the south flank and in the summit area, that represent likely two parts of an interconnected hydrothermal system. In the summit area, the extension of the hydrothermal system is clearly limited by the main geological structures which are actual and ancient craters. A sharp resistivity contrast at ancient crater rim Pasar-Bubar separates a conductive hydrothermal system (20 - 50 Ωm) from the resistive andesite lava flows and pyroclastic deposits (2000 - 50 000 Ωm). High diffuse CO2 degassing (with a median value of 400g m -2 d -1) is observed in a narrow vicinity of the active crater rim and close to the Pasar-Bubar. The existence of preferential fluid circulation along this ancient crater rim is also evidenced by self-potential data. The total CO2 degassing across the accessible summit area with a surface of 1.4 · 10 5 m 2 is around 20 td -1. Before the 2010 eruption, Toutain et al. (2009) estimated a higher value of the total diffuse degassing from the summit area (about 200 - 230 td -1). This drop in the diffuse degassing can be related to the decrease in the magmatic activity, to the change of the summit morphology or to a combination of these factors. On the south flank of Merapi, the resistivity model shows spectacular stratification. While surficial recent andesite lava flows are characterized by resistivity exceeding 100 000 Ωm, resistivity as low as 10 Ωm has been encountered at a depth of 200 m at the base of the south flank and was interpreted as a presence of the hydrothermal system. We suggest that a sandwich-like structure of stratified pyroclastic deposits on the flanks of Merapi screen and separate the flow of hydrothermal fluids with the degassing occurring mostly through the fractured crater rims

  1. Geoheritage value of the UNESCO site at Leon Viejo and Momotombo volcano, Nicaragua

    Science.gov (United States)

    van Wyk de Vries, Benjamin; Navarro, Martha; Espinoza, Eveling; Delgado, Hugo

    2017-04-01

    The Momotombo volcano has a special place in the history of Nicaragua. It is perfectly visible from the Capital, Managua, and from the major city of Leon. The old capital "Leon Viejo", founded in 1524 was abandoned in 1610, after a series of earthquakes and some major eruptions from Momotombo. The site was subsequently covered by Momotombo ash. A major geothermal power plant stands at the base of the volcano. Momotombo had been dormant for a hundred years, but had maintained high fumarole temperatures (900°C), indicating magma had been close to the surface for decades. In recent years, seismic activity has increased around the volcano. In December 2015, after a short ash eruption phase the volcano erupted lava, then a string of Vulcanian explosions. The volcano is now in a phase of small Vulcanian explosions and degassing. The Leon Viejo World Heritage site is at risk to mainly ash fall from the volcano, but the abandonment of the old city was primarily due to earthquakes. Additional risks come from high rainfall during hurricanes. There is an obvious link between the cultural site (inscribed under UNESCO cultural criteria) and the geological environment. First, the reactivation of Momotombo volcano makes it more important to revise the hazard of the site. At the same time, Leon Viejo can provide a portal for outreach related to the volcano and for geological risk in general. To maximise this, we provide a geosite inventory of the main features of Momotombo, and it's environs, that can be used as the first base for such studies. The volcano was visited by many adventure tourists before the 2015/2016 eruption, but is out of bounds at present. Alternative routes, around the volcano could be made, to adapt to the new situation and to show to visitors more of the geodiversity of this fascinating volcano-tectonic and cultural area.

  2. Analysis of Distribution of Volcanoes around the Korean Peninsula and the Potential Effects on Korea

    Science.gov (United States)

    Choi, Eun-kyeong; Kim, Sung-wook

    2017-04-01

    Since the scale and disaster characteristics of volcanic eruptions are determined by their geological features, it is important not only to grasp the current states of the volcanoes in neighboring countries around the Korean Peninsula, but also to analyze the tectonic settings, tectonic regions, geological features, volcanic types, and eruption histories of these volcanoes. Volcanic data were based on the volcano information registered with the Global Volcanism Program at the Smithsonian Institute. We created a database of 289 volcanoes around Korea, Japan, China, Taiwan, and the Kamchatka area in Russia, and then identified a high-risk group of 29 volcanoes that are highly likely to affect the region, based on conditions such as volcanic activity, types of rock at risk of eruption, distance from Seoul, and volcanoes having Plinian eruption history with volcanic explosivity index (VEI) of 4 or more. We selected 29 hazardous volcanoes, including Baekdusan, Ulleungdo, and 27 Japanese volcanoes that can cause widespread ashfall on the Korean peninsula by potentially explosive eruptions. In addition, we identified ten volcanoes that should be given the highest priority, through an analysis of data available in literature, such as volcanic ash dispersion results from previous Japanese eruptions, the definition of a large-scale volcano used by Japan's Cabinet Office, and examination of cumulative magma layer volumes from Japan's quaternary volcanoes. We expect that predicting the extent of the spread of ash caused by this hazardous activity and analyzing its impact on the Korean peninsula will be help to predict volcanic ash damage as well as provide direction for hazard mitigation research. Acknowledgements This research was supported by a grant [MPSS-NH-2015-81] through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

  3. Long-term changes in explosive and effusive behaviour at andesitic arc volcanoes: Chronostratigraphy of the Centre Hills Volcano, Montserrat

    Science.gov (United States)

    Coussens, Maya; Cassidy, Michael; Watt, Sebastian F. L.; Jutzeler, Martin; Talling, Peter J.; Barfod, Dan; Gernon, Thomas M.; Taylor, Rex; Hatter, Stuart J.; Palmer, Martin R.; Montserrat Volcano Observatory

    2017-03-01

    Volcanism on Montserrat (Lesser Antilles arc) has migrated southwards since the formation of the Silver Hills 2.5 Ma, and has formed three successively active volcanic centres. The Centre Hills volcano was the focus of volcanism from 1-0.4 Ma, before activity commenced at the currently active Soufrière Hills volcano. The history of activity at these two volcanoes provides an opportunity to investigate the pattern of volcano behaviour on an andesitic arc island over the lifetime of individual volcanoes. Here, we describe the pyroclastic stratigraphy of subaerial exposures around central Montserrat; identifying 11 thick (> 1 m) pumiceous units derived from sustained explosive eruptions of Centre Hills from 0.8-0.4 Ma. Over 10 other, less well- exposed pumiceous units have also been identified. The pumice-rich units are interbedded with andesite lava breccias derived from effusive, dome-forming eruptions of Centre Hills. The stratigraphy indicates that large (up to magnitude 5) explosive eruptions occurred throughout the history of Centre Hills, alongside effusive activity. This behaviour at Centre Hills contrasts with Soufrière Hills, where deposits from sustained explosive eruptions are much less common and restricted to early stages of activity at the volcano, from 175-130 ka. Subsequent eruptions at Soufriere Hills have been dominated by andesitic effusive eruptions. The bulk composition, petrography and mineral chemistry of volcanic rocks from Centre Hills and Soufrière Hills are similar throughout the history of both volcanoes, except for occasional, transient departures to different magma compositions, which mark shifts in vent location or dominant eruption style. For example, the final recorded eruption of Centre Hills, before the initiation of activity at Soufrière Hills, was more silicic than any other identified eruption on Montserrat; and the basaltic South Soufrière Hills episode marked the transition to the current stage of predominantly effusive

  4. Detection, Source Location, and Analysis of Volcano Infrasound

    Science.gov (United States)

    McKee, Kathleen F.

    The study of volcano infrasound focuses on low frequency sound from volcanoes, how volcanic processes produce it, and the path it travels from the source to our receivers. In this dissertation we focus on detecting, locating, and analyzing infrasound from a number of different volcanoes using a variety of analysis techniques. These works will help inform future volcano monitoring using infrasound with respect to infrasonic source location, signal characterization, volatile flux estimation, and back-azimuth to source determination. Source location is an important component of the study of volcano infrasound and in its application to volcano monitoring. Semblance is a forward grid search technique and common source location method in infrasound studies as well as seismology. We evaluated the effectiveness of semblance in the presence of significant topographic features for explosions of Sakurajima Volcano, Japan, while taking into account temperature and wind variations. We show that topographic obstacles at Sakurajima cause a semblance source location offset of 360-420 m to the northeast of the actual source location. In addition, we found despite the consistent offset in source location semblance can still be a useful tool for determining periods of volcanic activity. Infrasonic signal characterization follows signal detection and source location in volcano monitoring in that it informs us of the type of volcanic activity detected. In large volcanic eruptions the lowermost portion of the eruption column is momentum-driven and termed the volcanic jet or gas-thrust zone. This turbulent fluid-flow perturbs the atmosphere and produces a sound similar to that of jet and rocket engines, known as jet noise. We deployed an array of infrasound sensors near an accessible, less hazardous, fumarolic jet at Aso Volcano, Japan as an analogue to large, violent volcanic eruption jets. We recorded volcanic jet noise at 57.6° from vertical, a recording angle not normally feasible

  5. The Origin of Basalt and Cause of Melting Beneath East Antarctica as Revealed by the Southernmost Volcanoes on Earth

    Science.gov (United States)

    Reindel, J. L.; Panter, K. S.; Smellie, J. L.; McIntosh, W. C.

    2017-12-01

    Mt. Early and Sheridan Bluff are two basaltic monogenetic volcanoes located at 87° South latitude at the head of the Scott Glacier. These Early Miocene volcanoes lie 800 km from any other volcano and 200 km inland from the shoulder of the West Antarctic Rift System (WARS), which is the foci of most Cenozoic alkaline volcanism in Antarctica. Preliminary 40Ar/39Ar dates suggest that Mt. Early is older than previously determined and closer in age to Sheridan Bluff ( 19 Ma). Petrography, mineral chemistry and whole rock major and trace element concentrations are used to characterize the basalts and to determine whether they are genetically related to mafic volcanism in the WARS. The basalts are porphyritic with phenocrysts of olivine (Fo 58-84%), plagioclase (An 48-67%) ± clinopyroxene (Wo 43-48%). Whole rock MgO range from 10 to 4 wt.% and have restricted SiO2 (48 to 50 wt.%) contents. The basalts vary from alkaline (up to 6 wt.% Ne-normative) to subalkaline (up to 6 wt.% Hy-normative). The alkaline basalts that occur at both Mt. Early and Sheridan Bluff are more strongly enriched in incompatible elements (La 33-49 ppm, Ba 270-484 ppm, Sr 712-1009 ppm), have LaN/YbN ratios >10 and show prominent Pb negative anomalies with only slight K negative anomalies on primitive mantle normalized, multi-element diagrams. Subalkaline basalts (only at Sheridan Bluff) have lower concentrations of incompatible elements (La 14-16 ppm, Ba 110-144 ppm, and Sr 358-380 ppm), LaN/YbN ratios base of the East Antarctic craton and its replacement by warmer asthenosphere has been proposed for this region based on geophysical evidence (Heeszel et al., 2016). The volcanism may constrain the timing of this event. Heeszel et al. (2016) JGR, 121, 1758-1775.

  6. Climatic fluctuations as a significant contributing factor for volcanic collapses. Evidence from Mexico during the Late Pleistocene

    Science.gov (United States)

    Capra, L.; Bernal-Uruchurtu, J. P.; Carrasco, G.

    2013-05-01

    Climate oscillations have significantly contributed to the planet's evolution, including volcanic activity. Major glaciations have been considered not only as a triggering mechanism for large magmatic eruptions but also inducing volcano instability. Generally, volcano instability can be inferred from detailed volcanological and structural studies of a volcano and its associated depositional sequence, but the triggering mechanism has been always difficult to infer. In this paper, we present evidence of how climatic variations during the Late Pleistocene could have forced sector collapses of the main Mexican stratovolcanoes and enhanced the mobility of associated massive flows inducing the transformation of debris avalanche into debris flows. In particular, the climatic record based on atmospheric moisture content from robustly dated lake record from Guatemala and a U/Th dated speleothem from New Mexico are used here as indicators of summer and winter precipitation. Depositional sequences associated with Late Pleistocene sector collapses of Volcan de Colima, Nevado de Toluca, Citlaltepetl (Pico de Orizaba) and Cofre de Perote volcanoes are here analyzed. Comparing the timing of the event with the climatic record, a combination of summer and/or winter pluvial conditions could have forced and triggered the failure of already unstable volcanoes, even during glacier advances (as for the Citlaltepetl event). Independently of the main cause of the volcano instability (magmatic or tectonic) it is important to highlight that the climatic factor played an important role in enhancing the volcano instability and promoted the lateral transformation of debris avalanches, which under dry conditions would have affected more limited areas.

  7. Models of Hawaiian volcano growth and plume structure: Implications of results from the Hawaii Scientific Drilling Project

    OpenAIRE

    DePaolo, D. J.; Stolper, E. M.

    1996-01-01

    The shapes of typical Hawaiian volcanoes are simply parameterized, and a relationship is derived for the dependence of lava accumulation rates on volcano volume and volumetric growth rate. The dependence of lava accumulation rate on time is derived by estimating the eruption rate of a volcano as it traverses the Hawaiian plume, with the eruption rate determined from a specified radial dependence of magma generation in the plume and assuming that a volcano captures melt from a circular area ce...

  8. Constructing a reference tephrochronology for Augustine Volcano, Alaska

    Science.gov (United States)

    Wallace, Kristi; Coombs, Michelle L.

    2013-01-01

    Augustine Volcano is the most historically active volcano in Alaska's populous Cook Inlet region. Past on-island work on pre-historic tephra deposits mainly focused on using tephra layers as markers to help distinguish among prevalent debris-avalanche deposits on the island (Waitt and Beget, 2009, USGS Prof Paper 1762), or as source material for petrogenetic studies. No comprehensive reference study of tephra fall from Augustine Volcano previously existed. Numerous workers have identified Holocene-age tephra layers in the region surrounding Augustine Island, but without well-characterized reference deposits, correlation back to the source volcano is difficult. The purpose of this detailed tephra study is to provide a record of eruption frequency and magnitude, as well as to elucidate physical and chemical characteristics for use as reference standards for comparison with regionally distributed Augustine tephra layers. Whole rock major- and trace-element geochemistry, deposit componentry, and field context are used to correlate tephra units on the island where deposits are coarse grained. Major-element glass geochemistry was collected for use in correlating to unknown regional tephra. Due to the small size of the volcanic island (9 by 11 km in diameter) and frequent eruptive activity, on-island exposures of tephra deposits older than a couple thousand years are sparse, and the lettered Tephras B, M, C, H, I, and G of Waitt and Beget (2009) range in age from 370-2200 yrs B.P. There are, however, a few exposures on the south side of the volcano, within about 2 km of the vent, where stratigraphic sections that extend back to the late Pleistocene glaciation include coarse pumice-fall deposits. We have linked the letter-named tephras from the coast to these higher exposures on the south side using physical and chemical characteristics of the deposits. In addition, these exposures preserve at least 5 older major post-glacial eruptions of Augustine. These ultra

  9. Catalogue of satellite photography of the active volcanoes of the world

    Science.gov (United States)

    Heiken, G.

    1976-01-01

    A catalogue is presented of active volcanoes as viewed from Earth-orbiting satellites. The listing was prepared of photographs, which have been screened for quality, selected from the earth resources technology satellite (ERTS) and Skylab, Apollo and Gemini spacecraft. There is photography of nearly every active volcano in the world; the photographs are particularly useful for regional studies of volcanic fields.

  10. Soufriere volcano, st. Vincent: observations of its 1979 eruption from the ground, aircraft, and satellites.

    Science.gov (United States)

    Fiske, R S; Sigurdsson, H

    1982-06-04

    Rapid response by earth, atmospheric, and space scientists made possible diverse observations during the explosive phase of the 1979 eruption of Soufriere Volcano. The 11 reports that follow indicate that, with the availability of appropriate personnel, equipment, and logistical support, a significant body of geophysical data can be gathered on short notice at erupting volcanoes in remote parts of the world.

  11. Late Holocene phases of dome growth and Plinian activity at Guagua Pichincha volcano (Ecuador)

    NARCIS (Netherlands)

    Robin, Claude; Samaniego, Pablo; Le Pennec, Jean-Luc; Mothes, Patricia; van der Plicht, Johannes

    2008-01-01

    Since the eruption which affected Quito in AD 1660, Guagua Pichincha has been considered a hazardous volcano. Based on field studies and twenty C-14 dates, this paper discusses the eruptive activity of this volcano, especially that of the last 2000 years. Three major Plinian eruptions with

  12. Elucidation of the Oxygen Reduction Volcano in Alkaline Media using a Copper-Platinum(111) Alloy

    DEFF Research Database (Denmark)

    Jensen, Kim Degn; Tymoczko, Jakub; Rossmeisl, Jan

    2018-01-01

    catalyst should exhibit OH binding circa 0.1 eV weaker than Pt(111), via a Sabatier volcano; this observation suggests that the reaction is mediated via the same surface bound intermediates as in acid, in contrast to previous reports. In 0.1 m KOH, the alloy catalyst at the peak of the volcano exhibits...

  13. Elucidation of the Oxygen Reduction Volcano in Alkaline Media using a Copper-Platinum(111) Alloy

    DEFF Research Database (Denmark)

    Jensen, Kim Degn; Tymoczko, Jakub; Rossmeisl, Jan

    2018-01-01

    catalyst should exhibit OH binding circa 0.1 eV weaker than Pt(111), via a Sabatier volcano; this observation suggests that the reaction is mediated via the same surface bound intermediates as in acid, in contrast to previous reports. In 0.1(M) KOH, the alloy catalyst at the peak of the volcano exhibits...

  14. On the carcinogenic polycyclic aromatic hydrocarbon benzo(a)pyrene in volcano exhausts.

    Science.gov (United States)

    Ilnitsky, A P; Belitsky, G A; Shabad, L M

    1976-05-01

    The content of benzo(a)pyrene in the juvenile ashes of the volcano Tyatya (Kunashir Island, Kuriles) and in the soil, vegetation and volcanic mud collected near volcanos in Kamchatka was studied. It was concluded that volcanic activity does not play a large role in forming the background level of this carcinogen in the human environment.

  15. The added value of time-variable microgravimetry to the understanding of how volcanoes work

    Science.gov (United States)

    Carbone, Daniele; Poland, Michael; Greco, Filippo; Diament, Michel

    2017-01-01

    During the past few decades, time-variable volcano gravimetry has shown great potential for imaging subsurface processes at active volcanoes (including some processes that might otherwise remain “hidden”), especially when combined with other methods (e.g., ground deformation, seismicity, and gas emissions). By supplying information on changes in the distribution of bulk mass over time, gravimetry can provide information regarding processes such as magma accumulation in void space, gas segregation at shallow depths, and mechanisms driving volcanic uplift and subsidence. Despite its potential, time-variable volcano gravimetry is an underexploited method, not widely adopted by volcano researchers or observatories. The cost of instrumentation and the difficulty in using it under harsh environmental conditions is a significant impediment to the exploitation of gravimetry at many volcanoes. In addition, retrieving useful information from gravity changes in noisy volcanic environments is a major challenge. While these difficulties are not trivial, neither are they insurmountable; indeed, creative efforts in a variety of volcanic settings highlight the value of time-variable gravimetry for understanding hazards as well as revealing fundamental insights into how volcanoes work. Building on previous work, we provide a comprehensive review of time-variable volcano gravimetry, including discussions of instrumentation, modeling and analysis techniques, and case studies that emphasize what can be learned from campaign, continuous, and hybrid gravity observations. We are hopeful that this exploration of time-variable volcano gravimetry will excite more scientists about the potential of the method, spurring further application, development, and innovation.

  16. Glaciers of Avacha group of volcanoes in Neoholocene

    Directory of Open Access Journals (Sweden)

    T. M. Manevich

    2016-01-01

    Full Text Available The study of moraines at the Avacha volcano group revealed that glaciers changes at all volcanoes within the group happened almost synchronously. Glacial deposits could be grouped into three generations, corresponding to three periods of glacier fluctuations in Neoholocene. The largest glaciation within the group occurred ~2000 years ago. Fragments of moraine, corresponding to that period were found only in the moraine complex of the Ditmar Glacier which was 15% larger then today at that time. The most of moraines at the Avacha volcano group were formed during the Little Ice Age, which in the studied region continued up to the first decades of XX centuries. The maximal advance of glaciers probably happened in XVII century. The moraine corresponding to that period was found at the Kozelsky Glacier valley. At present time the total area of glaciers which moraines were described and dated approaches 21.46  km2. The area of reconstructed moraines corresponding to the Little Ice Age is estimated to be 2.79 km2, therefore at that period the total glaciation area reaches 24,25 км2 exceeding the present area by 13%. It could be claimed that in general during the time past the Little Ice Age the glaciation nature and glacier types did not change sufficiently. The rate of glacier degradation at various parts of the group is different and depends mainly on exposition. At the valleys of four glaciers we found moraines formed in the middle of XX century. They may appear in 1941–1952 when the unfavorable weather conditions leaded to stable negative anomalies in accumulation have happened.

  17. Geodetic Volcano Monitoring Research in Canary Islands: Recent Results

    Science.gov (United States)

    Fernandez, J.; Gonzalez, P. J.; Arjona, A.; Camacho, A. G.; Prieto, J. F.; Seco, A.; Tizzani, P.; Manzo, M. R.; Lanari, R.; Blanco, P.; Mallorqui, J. J.

    2009-05-01

    The Canarian Archipelago is an oceanic island volcanic chain with a long-standing history of volcanic act