Sample records for erebus volcano antarctica

  1. Gas discharges in fumarolic ice caves of Erebus volcano, Antarctica

    Fischer, T. P.; Curtis, A. G.; Kyle, P. R.; Sano, Y.


    reactions. We are confident that the atmospheric component is not the result of sampling procedure but intrinsic to the ice cave system. In addition to carbon dioxide, magmatic gases emitted from Erebus lava lake contain significant amounts of SO2, HCl, HF, CO and H2 [1,2]. The acid magmatic gases (SO2, HCl, HF) and a significant amount of the CO2 are likely absorbed by the subsurface ice/water system. The atmospheric components (Ar, nitrogen, oxygen) likely enter the system at shallow levels. The relative abundances of these components reflect degassing fractionation of these volatiles from liquid water at low temperatures, suggesting the presence of liquid water in the subsurface. [1] Oppenheimer, C., Kyle, P.R., 2008. Probing the magma plumbing of Erebus volcano, Antarctica, by open-path FTIR spectroscopy of gas emissions. J. Vol. Geoth. Res. 177, 743-754. [2] Moussallam, Y., Oppenheimer, C., et al., 2012. Hydrogen emission from Erebus volcano, Antarctica. Bull. Volcan 74, 2109-2120.

  2. Mantle to surface degassing of alkalic magmas at Erebus volcano, Antarctica

    Oppenheimer, C.; Moretti, R.; Kyle, P.R.; Eschenbacher, A.; Lowenstern, J. B.; Hervig, R.L.; Dunbar, N.W.


    Continental intraplate volcanoes, such as Erebus volcano, Antarctica, are associated with extensional tectonics, mantle upwelling and high heat flow. Typically, erupted magmas are alkaline and rich in volatiles (especially CO2), inherited from low degrees of partial melting of mantle sources. We examine the degassing of the magmatic system at Erebus volcano using melt inclusion data and high temporal resolution open-path Fourier transform infrared (FTIR) spectroscopic measurements of gas emissions from the active lava lake. Remarkably different gas signatures are associated with passive and explosive gas emissions, representative of volatile contents and redox conditions that reveal contrasting shallow and deep degassing sources. We show that this unexpected degassing signature provides a unique probe for magma differentiation and transfer of CO2-rich oxidised fluids from the mantle to the surface, and evaluate how these processes operate in time and space. Extensive crystallisation driven by CO2 fluxing is responsible for isobaric fractionation of parental basanite magmas close to their source depth. Magma deeper than 4kbar equilibrates under vapour-buffered conditions. At shallower depths, CO2-rich fluids accumulate and are then released either via convection-driven, open-system gas loss or as closed-system slugs that ascend and result in Strombolian eruptions in the lava lake. The open-system gases have a reduced state (below the QFM buffer) whereas the closed-system gases preserve their deep oxidised signatures (close to the NNO buffer). ?? 2011 Elsevier B.V.

  3. Volcanic emissions of metals and halogens from White Island (New Zealand) and Erebus volcano (Antarctica) determined with chemical traps

    Wardell, L. J.; Kyle, P. R.; Counce, D.


    Volcanic emission rates of As, Sb, Pb, Hg, Se, Cl, and F were determined at Erebus volcano, Antarctica and White Island, New Zealand, using chemical traps. The trace metal fluxes were determined by combining the species to S ratios in the solutions with SO 2 emission rates measured by correlation spectrometry at the two volcanoes. At Erebus volcano, fluxes for the metals Pb and Hg were 2.0 × 10 - 4 and 8.1 × 10 - 6 kg s - 11 , respectively. Fluxes for Cl, F, As, Sb and Se (0.35, 0.15, 2.5 × 10 - 4 , 1.2 × 10 - 5 , and 4.5 × 10 - 6 kg s - 1 , respectively) agreed within error limits for values determined previously by the LiOH impregnated filter method [Zreda-Gostynska, G., Kyle, P., Finnegan, D., Prestbo, K., 1997. Volcanic gas emissions from Mount Erebus and their impact on the Antarctic environment. Journal of Geophysical Research, 102(B7): 15039-15055.], demonstrating the utility of the chemical trap method. A fall in the As/S ratio from 7 × 10 - 4 in 1997/1999 to 3 × 10 - 4 in 2000 at Erebus coincided with a change in the frequency and style of eruptive activity that may have been due to injection of magma into the system. At White Island, chemical trap data indicated fluxes of Cl = 0.90, F = 0.0079, Pb = 2.7 × 10 - 4 , Hg = 1.1 × 10 - 5 , As = 1.3 × 10 - 4 , Sb = 1.9 × 10 - 5 and Se = 1.5 × 10 - 5 kg s - 1 . Samples collected 600 m downwind of the active crater were comparable to samples collected adjacent to the main gas vent, showing that this method can still be used at some distance from a degassing vent.

  4. A model of the geochemical and physical fluctuations of the lava lake at Erebus volcano, Antarctica

    Molina, Indira; Burgisser, Alain; Oppenheimer, Clive


    Erebus volcano, Antarctica, exhibits periodical surface fluctuations of both geochemical and physical nature. Modeling the physics driving the lake oscillation is a challenge, even with a relatively simple theoretical framework. We present a quantitative analysis that aims to reconcile both lake level and gas geochemical cycles. Our model is based on the assumption that the periodicity is caused by the regular release of magma batches and/or core annular flow that have a fixed volume of melt and ascend and degas in equilibrium. Results suggest that cycles are not caused by the mixing between magma residing in the lake and a deep magma but by two distinct deep sources that rise separately. These sources of bubbly magma come from at most 2-3 km depth and rise buoyantly. Individual batches detach from the rising magmas at depths of 20-250 m. The two batch types can coexist in a single conduit up to a depth of ~ 30 m, above which they rise alternately to release respectively 19 and 23 kg/s of gas at the lake surface every 10 min. The temperature of the descending flow is between 890 and 950 °C, which is roughly 100 °C colder than the ascending currents. Batch pairs have shapes likely constrained by the conduit width. Regardless of their shapes, the pairs reach very high porosities near the surface and have diameters of 4-14 m that are consistent with video observations showing spreading waves at the lake surface. The alternating arrival of these large batches suggests a lava lake mostly filled with gas-rich magma.

  5. Three-phase flow dynamics in the lava lakes at Mount Erebus, Antarctica

    Qin, Z.; Suckale, J.


    Long-lived, persistently active lava lakes expose the top of a convecting magma column to direct observation and offer a unique window into the cryptic magmatic plumbing system at depth. In this paper, we focus on the lava lake at Mount Erebus, a large intraplate stratovolcano at Ross Island, Antarctica, to gain new insights into the multi-phase interactions between gas bubbles, crystals and magmatic liquid in basaltic volcanoes. Early studies of magmatic convection have considered multi-phase magmas as perfectly homogeneous mixtures. The high proportion of erupted gas relative to magma, however, suggests that gas separates from the flow and drives eruptive activity. Similarly, the large size (up to 10cm) of the megacrysts that make up 97% of the crystal cargo at Erebus begs the question whether these crystals are likely to remain entrained and how crystal segregation in the lava lakes and conduit alters eruptive behavior. We study the multiphase behavior of magmatic convection at Mount Erebus through two dimensional numerical simulations. Our model was developed with Mount Erebus in mind, but we argue that it could also serve as a virtual laboratory for studying multiphase flow in other basaltic systems. To accurately capture the deformability, breakup and coalescence of large gas bubbles, we track the gas-liquid interfaces with level-set functions. The crystal phase is incorporated using distributed Lagrange multipliers. We discretize the multiphase Stokes and energy equation through an iterative finite difference method that captures the potentially discontinuous jumps in the pressure, stresses, density and viscosity through a Ghost-Fluid approach. We have benchmarked and validated our numerical approach against analytical results and laboratory experiments. We synthesize observations of thermal flux, seismic behavior, geodesy and geochemistry to deduce constraints on the mass flux, conduit dimensions, reservoir size, and crystal growth as a basis for our

  6. Microbial communities in dark oligotrophic volcanic ice cave ecosystems of Mt. Erebus, Antarctica

    Bradley M. Tebo


    Full Text Available The Earth’s crust hosts a subsurface, dark, and oligotrophic biosphere that is poorly understood in terms of the energy supporting its biomass production and impact on food webs at the Earth’s surface. Dark oligotrophic volcanic ecosystems (DOVEs are good environments for investigations of life in the absence of sunlight as they are poor in organics, rich in chemical reactants and well known for chemical exchange with Earth’s surface systems. Ice caves near the summit of Mt. Erebus (Antarctica offer DOVEs in a polar alpine environment that is starved in organics and with oxygenated hydrothermal circulation in highly reducing host rock. We surveyed the microbial communities using PCR, cloning, sequencing and analysis of the small subunit (16S ribosomal and Ribulose-1,5-bisphosphate Carboxylase/Oxygenase (RubisCO genes in sediment samples from three different caves, two that are completely dark and one that receives snow-filtered sunlight seasonally. The microbial communities in all three caves are composed primarily of Bacteria and fungi; Archaea were not detected. The bacterial communities from these ice caves display low phylogenetic diversity, but with a remarkable diversity of RubisCO genes including new deeply branching Form I clades, implicating the Calvin-Benson-Bassham cycle as a pathway of CO2 fixation. The microbial communities in one of the dark caves, Warren Cave, which has a remarkably low phylogenetic diversity, were analyzed in more detail to gain a possible perspective on the energetic basis of the microbial ecosystem in the cave. Atmospheric carbon (CO2 and CO, including from volcanic emissions, likely supplies carbon and/or some of the energy requirements of chemoautotrophic microbial communities in Warren Cave and probably other Mt. Erebus ice caves. Our work casts a first glimpse at Mt. Erebus ice caves as natural laboratories for exploring carbon, energy and nutrient sources in the subsurface biosphere and the

  7. Distinguishing styles of explosive eruptions at Erebus, Redoubt and Taupo volcanoes using multivariate analysis of ash morphometrics

    Avery, Meredith R.; Panter, Kurt S.; Gorsevski, Pece V.


    The style and dynamics of volcanic eruptions control the level and type of hazards posed for local populations and can have a temporary long-range impact on climate if eruptions are extremely energetic. The purpose of this study is to provide a statistical approach to ash morphometrics in order to provide a means by which to evaluate diverse eruption styles and mechanisms of fragmentation. The methodology presented can be applied to tephra deposits worldwide and may aid volcanic hazard mitigation by better defining a volcano's history of explosive behavior. Ash-sized grains were collected from tephra deposits on Mount Erebus, Antarctica (imaged by scanning electron microscopy. Morphometric properties were determined using image processing software and then evaluated by several statistical methods. Discriminant analysis of all parameters was found to be the best at differentiating the tephra deposits and allowing for interpretation of eruptive styles in conjunction with field observations. A linear array of data forming a positive slope in factor space, which explains > 99% of the total data variance, is interpreted to represent a continuum between fragmentations involving water-magma interaction ("wet") to grains that were formed predominately by magmatic ("dry") fragmentation mechanisms. The Taupo Hatepe ash, which was deposited from a phreatoplinian eruption column, has the highest factor values in the array, which signifies, in part, more rectangular/blocky morphologies with smooth grain edges. Factor values for the 2009 Redoubt eruption (events 2-4) are nearly as high as Hatepe ash and based on this we suggest that it was produced, in part, by phreatomagmatic fragmentation. This is supported by field observations that document melting and eruption through glacial ice during the early phases of the 2009 activity. Redoubt ash grains from later stages of the same eruption (events 9-18) show a significant shift to lower values in factor space (more irregular

  8. A Technique to Measure Energy Partitioning and Absolute Gas Pressures of Strombolian Explosions Using Doppler Radar at Erebus Volcano

    Gerst, A.; Hort, M.; Kyle, P. R.; Voege, M.


    In 2005/06 we deployed three 24GHz (K-Band) continuous wave Doppler radar instruments at the crater rim of Erebus volcano in Antarctica. At the time there was a ~40 m wide, ~1000°C hot convecting phonolite lava lake, which was the source of ~0-6 Strombolian gas bubble explosions per day. We measured the velocities of ~50 explosions using a sample rate of 1-15 Hz. Data were downloaded in real-time through a wireless network. The measurements provide new insights into the still largely unknown mechanism of Strombolian eruptions, and help improve existing eruption models. We present a technique for a quasi in-situ measurement of the absolute pressure inside an eruption gas bubble. Pressures were derived using a simple eruption model and measured high resolution bubble surface velocities during explosions. Additionally, this technique allows us to present a comprehensive energy budget of a volcanic explosion as a time series of all important energy terms (i.e. potential, kinetic, dissipative, infrasonic, surface, seismic and thermal energy output). The absolute gas pressure inside rising expanding gas bubbles rapidly drops from ~3-10 atm (at the time when the lake starts to bulge) to ~1 atm before the bubble bursts, which usually occurs at radii of ~15-20m. These pressures are significantly lower than previously assumed for such explosions. The according internal energy of the gas agrees well with the observed total energy output. The results show that large explosions released about 109 to 1010 J each (equivalent to about 200-2000 kg of TNT), at a peak discharge rate frequently exceeding 109 W (the power output of a typical nuclear power plant). This dynamic output is mainly controlled by the kinetic and potential energy of the exploding magma shell, while other energy types were found to be much smaller (with the exception of thermal energy). Remarkably, most explosions at Erebus show two distinct surface acceleration peaks separated by ~0.3 seconds. This suggests

  9. Microbial biodiversity of thermophilic communities in hot mineral soils of Tramway Ridge, Mount Erebus, Antarctica.

    Soo, Rochelle M; Wood, Susanna A; Grzymski, Joseph J; McDonald, Ian R; Cary, S Craig


    Tramway Ridge, located near the summit of Mount Erebus in Antarctica, is probably the most remote geothermal soil habitat on Earth. Steam fumaroles maintain moist, hot soil environments creating extreme local physicochemical differentials. In this study a culture-independent approach combining automated rRNA intergenic spacer analysis (ARISA) and a 16S rRNA gene library was used to characterize soil microbial (Bacterial and Archaeal) diversity along intense physicochemical gradients. Statistical analysis of ARISA data showed a clear delineation between bacterial community structure at sites close to fumaroles and all other sites. Temperature and pH were identified as the primary drivers of this demarcation. A clone library constructed from a high-temperature site led to the identification of 18 novel bacterial operational taxonomic units (OTUs). All 16S rRNA gene sequences were deep branching and distantly (85-93%) related to other environmental clones. Five of the signatures branched with an unknown group between candidate division OP10 and Chloroflexi. Within this clade, sequence similarity was low, suggesting it contains several yet-to-be described bacterial groups. Five archaeal OTUs were obtained and exhibited high levels of sequence similarity (95-97%) with Crenarchaeota sourced from deep-subsurface environments on two distant continents. The novel bacterial assemblage coupled with the unique archaeal affinities reinvigorates the hypotheses that Tramway Ridge organisms are relics of archaic microbial lineages specifically adapted to survive in this harsh environment and that this site may provide a portal to the deep-subsurface biosphere.

  10. Targeting Autotrophic and Lithotrophic Microorganisms from Fumarolic Ice Caves of Mt. Erebus, Antarctica

    Anitori, R.; Davis, R.; Connell, L.; Kelley, M.; Staudigel, H.; Tebo, B. M.


    Terrestrial and aquatic volcanic oligotrophic environments can host microorganisms that obtain their energy from reduced inorganic chemicals present in volcanic rocks and soils. We sampled basaltic rock from terrestrial Dark Oligotrophic Volcanic Ecosystems (DOVEs) located in two fumarole ice caves, Warren and Warren West, located near the summit of Mt. Erebus, Antarctica. For reference, we sampled a similar cave, Harry's Dream, which receives continuous light during the Austral summer. We report here culturing data for bacterial and eukaryotic microbes from rocky soils in these caves when targeting lithotrophic organisms using media containing reduced inorganic compounds (Mn2+, Fe2+, NH4+). In addition, to test for the possible presence of inorganic carbon fixation, we screened samples for the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) gene. Culturing of soil samples on media targeting both autotrophs and heterotrophs yielded a diverse collection of generally slow-growing colonies of bacteria (majority), fungi and non-fungal eukaryotes. Manganese(II)-oxidizing colonies were identified in Warren and Harry's Dream, and these exhibited two colony morphotypes upon subculturing. Sequencing of the PCR amplified 16S rRNA gene identified a bacterium distantly related to Pseudonocardia sp., a genus with known manganese oxidizers. Other bacteria enriched included members of the Actinobacteria, Alphaproteobacteria and Betaproteobacteria. There was a low diversity in cultured eukaryotes representing several potential undescribed species (Geomyces sp., Penicillium sp.) and isolates that may represent alternate, previously undescribed habitats and forms (Psilolechia leprosa, Alternaria alternata). One Warren isolate was a 99% 16S rRNA match to the N2 fixer Bradyrhizobium sp.; when inoculated into liquid medium specific for N2 fixers, growth was maintained upon subculture. Putative iron oxidizers were also enriched from the two DOVE caves, using slush agar iron

  11. Fungal Diversity in a Dark Oligotrophic Volcanic Ecosystem (DOVE on Mount Erebus, Antarctica

    Hubert Staudigel


    Full Text Available Fumarolic Ice caves on Antarctica’s Mt. Erebus contain a dark oligotrophic volcanic ecosystem (DOVE and represent a deep biosphere habitat that can provide insight into microbial communities that utilize energy sources other than photosynthesis. The community assembly and role of fungi in these environments remains largely unknown. However, these habitats could be relatively easily contaminated during human visits. Sixty-one species of fungi were identified from soil clone libraries originating from Warren Cave, a DOVE on Mt. Erebus. The species diversity was greater than has been found in the nearby McMurdo Dry Valleys oligotrophic soil. A relatively large proportion of the clones represented Malassezia species (37% of Basidomycota identified. These fungi are associated with skin surfaces of animals and require high lipid content for growth, indicating that contamination may have occurred through the few and episodic human visits in this particular cave. These findings highlight the importance of fungi to DOVE environments as well as their potential use for identifying contamination by humans. The latter offers compelling evidence suggesting more strict management of these valuable research areas.

  12. Rheology of phonolitic magmas - the case of the Erebus lava lake

    Le Losq, Charles; Neuville, Daniel R.; Moretti, Roberto; Kyle, Philip R.; Oppenheimer, Clive


    Long-lived active lava lakes are comparatively rare and are typically associated with low-viscosity basaltic magmas. Erebus volcano, Antarctica, is unique today in hosting a phonolitic lava lake. Phonolitic magmas can erupt explosively, as in the 79 CE Plinian eruption of Vesuvius volcano, Italy, and it is therefore important to understand their physical properties. The phonolite at Erebus has slightly higher silica content than that at Vesuvius yet its present activity is predominantly non-explosive. As a contribution to understanding such contrasting eruptive behaviour, we focus on the rheological differences between these comparable magmas. In particular, we evaluate the viscosity of the Erebus phonolite magma by integrating new experimental data within a theoretical and empirical framework. The resulting model enables estimation of the Erebus melt viscosity as a function of temperature, crystal and water concentrations, with an uncertainty of, at most, ± 0.45 log (Pa s). Using reported ranges for these parameters, we predict that the magma viscosity in the upper region of the plumbing system of Erebus ranges between 105 and 107 Pas. This is substantially higher than has been hitherto considered with significant implications for modelling the dynamics of the lava lake, conduit and magma reservoir system. Our analysis highlights the generic challenges encountered in calculation of magma viscosity and presents an approach that can be applied to other cases.

  13. Advances in seismic monitoring at Deception Island volcano (Antarctica since the International Polar Year

    Enrique Carmona


    Full Text Available Deception Island is an active volcano located in the south Shetland Islands, Antarctica. It constitutes a natural laboratory to test geophysical instruments in extreme conditions, since they have to endure not only the Antarctic climate but also the volcanic environment. Deception is one of the most visited places in Antarctica, both by scientists and tourists, which emphasize the importance of volcano monitoring. Seismic monitoring has been going on since 1986 during austral summer surveys. The recorded data include volcano-tectonic earthquakes, long-period events and volcanic tremor, among others. The level of seismicity ranges from quiet periods to seismic crises (e.g. 1992-1993, 1999. Our group has been involved in volcano monitoring at Deception Island since 1994. Based on this experience, in recent years we have made the most of the opportunities of the International Polar Year 2007-2008 to introduce advances in seismic monitoring along four lines: (1 the improvement of the seismic network installed for seismic monitoring during the summer surveys; (2 the development and improvement of seismic arrays for the detection and characterization of seismo-volcanic signals; (3 the design of automated event recognition tools, to simplify the process of data interpretation; and (4 the deployment of permanent seismic stations. These advances help us to obtain more data of better quality, and therefore to improve our interpretation of the seismo-volcanic activity at Deception Island, which is a crucial step in terms of hazards assessment.

  14. Embedded ARM System for Volcano Monitoring in Remote Areas: Application to the Active Volcano on Deception Island (Antarctica

    Luis Miguel Peci


    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.

  15. Embedded ARM system for volcano monitoring in remote areas: application to the active volcano on Deception Island (Antarctica).

    Peci, Luis Miguel; Berrocoso, Manuel; Fernández-Ros, Alberto; García, Alicia; Marrero, José Manuel; Ortiz, Ramón


    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.

  16. A Benthic Invertebrate Survey of Jun Jaegyu Volcano: An active undersea volcano in Antarctic Sound, Antarctica

    Quinones, G.; Brachfeld, S.; Gorring, M.; Prezant, R. S.; Domack, E.


    Jun Jaegyu volcano, an Antarctic submarine volcano, was dredged in May 2004 during cruise 04-04 of the RV Laurence M. Gould to determine rock, sediment composition and marine macroinvertebrate diversity. The objectives of this study are to examine the benthic assemblages and biodiversity present on a young volcano. The volcano is located on the continental shelf of the northeastern Antarctic Peninsula, where recent changes in surface temperature and ice shelf stability have been observed. This volcano was originally swath-mapped during cruise 01-07 of the Research Vessel-Ice Breaker Nathaniel B. Palmer. During LMG04-04 we also studied the volcano using a SCUD video camera, and performed temperature surveys along the flanks and crest. Both the video and the dredge indicate a seafloor surface heavily colonized by benthic organisms. Indications of fairly recent lava flows are given by the absence of marine life on regions of the volcano. The recovered dredge material was sieved, and a total of thirty-three invertebrates were extracted. The compilation of invertebrate community data can subsequently be compared to other benthic invertebrate studies conducted along the peninsula, which can determine the regional similarity of communities over time, their relationship to environmental change and health, if any, and their relationship to geologic processes in Antarctic Sound. Twenty-two rock samples, all slightly weathered and half bearing encrusted organisms, were also analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES). Except for one conglomerate sample, all are alkali basalts and share similar elemental compositions with fresh, unweathered samples from the volcano. Two of the encrusted basalt samples have significantly different compositions than the rest. We speculate this difference could be due to water loss during sample preparation, loss of organic carbon trapped within the vesicles of the samples and/or elemental uptake by the

  17. Antarctica



  18. Seismic monitoring at Deception Island volcano (Antarctica): the 2010-2011 survey

    Martín, R.; Carmona, E.; Almendros, J.; Serrano, I.; Villaseñor, A.; Galeano, J.


    As an example of the recent advances introduced in seismic monitoring of Deception Island volcano (Antarctica) during recent years, we describe the instrumental network deployed during the 2010-2011 survey by the Instituto Andaluz de Geofísica of University of Granada, Spain (IAG-UGR). The period of operation extended from December 19, 2010 to March 5, 2011. We deployed a wireless seismic network composed by four three-component seismic stations. These stations are based on 24-bit SL04 SARA dataloggers sampling at 100 sps. They use a PC with embedded linux and SEISLOG data acquisition software. We use two types of three-component seismometers: short-period Mark L4C with natural frequency of 1 Hz and medium-period Lennartz3D/5s with natural frequency of 0.2 Hz. The network was designed for an optimum spatial coverage of the northern half of Deception, where a magma chamber has been reported. Station locations include the vicinity of the Spanish base "Gabriel de Castilla" (GdC), Obsidianas Beach, a zone near the craters from the 1970 eruptions, and the Chilean Shelter located south of Pendulum Cove. Continuous data from the local seismic network are received in real-time in the base by wifi transmission. We used Ubiquiti Networks Nanostation2 antennas with 2.4 GHz, dual-polarity, 10 dBi gain, and 54 Mbps transmission rate. They have shown a great robustness and speed for real-time applications. To prioritize data acquisition when the battery level is low, we have designed a circuit that allows independent power management for the seismic station and wireless transmission system. The reception antenna located at GdC is connected to a computer running SEISCOMP. This software supports several transmission protocols and manages the visualization and recording of seismic data, including the generation of summary plots to show the seismic activity. These twelve data channels are stored in miniseed format and displayed in real time, which allows for a rapid evaluation of

  19. A search for the volcanomagnetic signal at Deception volcano (South Shetland I., Antarctica

    J. M. Ibáñez


    Full Text Available After the increase in seismic activity detected during the 1991-1992 summer survey at Deception Island, the continuous measurement of total magnetic intensity was included among the different techniques used to monitor this active volcano. The Polish geomagnetic observatory Arctowski, located on King George Island, served as a reference station, and changes in the differences between the daily mean values at both stations were interpreted as indicators of volcanomagnetic effects at Deception. A magnetic station in continuous recording mode was also installed during the 1993-1994 and 1994-1995 surveys. During the latter, a second magnetometer was deployed on Deception Island, and a third one in the vicinity of the Spanish Antarctic Station on Livingston Island (at a distance of 35 km and was used as a reference station. The results from the first survey suggest that a small magma injection, responsible for the seismic re-activation, could produce a volcanomagnetic effect, detected as a slight change in the difference between Deception and Arctowski. On the other hand, a long term variation starting at that moment seems to indicate a thermomagnetic effect. However the short register period of only two stations do not allow the sources to be modelled. The future deployment of a magnetic array during the austral summer surveys, throughout the volcano, and of a permanent geomagnetic observatory at Livingston I. is aimed at further observations of magnetic transients of volcanic origin at Deception Island.

  20. Volcanoes

    ... or more from a volcano. Before a Volcanic Eruption The following are things you can do to ... in case of an emergency. During a Volcanic Eruption Follow the evacuation order issued by authorities and ...

  1. Volcanoes


    In the past thousand years,volcanoes have claimed more than 300,000 lives. Volcanology is ayoung and dangerous science that helps us against the power of the Earth itself.We live on a fiery planet. Nearly 2000 miles beneath our feet, the Earth's inner core reachestemperatures of 12,000 degrees Fahrenheit. Molten rock or magma, rises to the earth's surface. Acold, rigid crust fractured into some twenty plates. When magma breaks through crust it becomes

  2. Emission rates of sulfur dioxide, trace gases and metals from Mount Erebus, Antartica

    Kyle, P.R.; Meeker, K. (New Mexico Institute of Mining and Technology, Socorro (USA)); Finnegan, D. (Los Alamos National Lab., NM (USA))


    SO{sub 2} emission rates have been measured annually since 1983 at Mount Erebus, Antarctica by correlation spectrometer (COSPEC V). Following a 4 month period of sustained strombolian activity in late 1984, SO{sub 2} emissions declined from 230 Mg/day in 1983 to 25 Mg/day and then slowly increased from 16 Mg/day in 1985 to 51 Mg/day in 1987. Nine sets of filter packs containing partcle and {sup 7}LiOH treated filters were collected in the plume in 1986 and analyzed by neutron activation. Using the COSPEC data and measured element/S ratios on the filters, emission rates have been determined for trace gases and metals. The authors infer HCl and HF emissions in 1983 to be about 1200 and 500 Mg/day, respectively. Mt Erebus has therefore been an important source of halogens to the Anarctic atmosphere and could be responsible for excess Cl found in Central Antarctica snow.

  3. Multiplets and Detection of Seismic Velocity Changes During the 1998-99 Seismic Series at Deception Island Volcano, Antarctica

    Carmona, E.; Martini, F.; Ibanez, J. M.; Bean, C. J.


    During the 1998-1999 Antarctic summer, the pattern of seismicity at Deception Island Volcano changed significantly with respect to previous years. This was characterized by the occurrence of an intense swarm of local earthquakes. More than 2000 local earthquakes were recorded in the period January-February 1999. The average moment magnitude was around 0.5, with the exception of two earthquakes of magnitude 2.3 and 3.4; array analysis was used to establish the hypocentral distribution of the earthquakes. A regional origin of the seismicity, or direct involvement of magmatic fluids, was demonstrated to be unlikely. Most earthquakes in the series were found to be related to small (pressurized fluids (Ibanez et al. 2003). The presence of fluids in the source area could explain the fracturing process and is supported by the observation of hybrid events in the same source region. The study of the spatial distribution of the first motion of the P waves suggests that different source mechanisms acted in a very small volume, and often at the same time. Many distinct families of events with very similar waveforms were identified. When recorded at the same station, the similarity of repeating earthquakes indicates that source and wavepath are the same, and therefore any observed difference in waveforms is related to a change in the medium. Employing Coda Wave Interferometry (Snieder et al., 2002), the families of events identified in the series show a drop in the velocity over a short time period around the two events with bigger magnitudes. These variations may be related to cracking and/or fluid influx. After the seismic crisis, a change in the composition of the fumarolic gases was observed with the appearance of sulfur deposits around the fumaroles, and a clear uplift and inflation of a few centimeters was detected (Garcia et al., 2001). The seismic characteristics and the spatial and temporal behavior of the series, associated with other geochemical, bathymetric and

  4. Volcano Preparedness

    ... You might feel better to learn that an ‘active’ volcano is one that has erupted in the past ... miles away. If you live near a known volcano, active or dormant, following these tips will help you ...

  5. Hello Antarctica


    China has made 25 expeditions to the Antarctic over a quarter century Exactly 17,501.949 km-that’s the distance from Beijing to Changcheng (lit-erally meaning the Great Wall) Station,the first little piece of China on the continent of Antarctica. Twenty-five years ago, when the country was conceiving its first journey to the South Pole, that distance meant nothing

  6. UAV Antarctica

    Dahl, David; Stetler, Fredrik


    One of the biggest problems of our time is the global warming. A direct result of this phenomena is the melting of ice of the glaciers on the north and the south pole. As this continues, the melted ice will contribute to an increase of the sea level, and may cause enormous natural disasters. To be able to prevent this, it’s important to study its affects. This reports contains a concept study of a Unmanned Aerial Vehicle, a UAV, set on the coast of Antarctica by the Australian owned base Davi...

  7. Vanishing Volcano



    Mauna Loa, the world’s largest active volcano,is sinking into the Pacific Ocean——and it’s taking the main island of Hawaii with it! The problem:The mighty volcano has gained too much weight, says Peter Lipman of the U. S. Geological Survey.

  8. Dante's volcano


    This video contains two segments: one a 0:01:50 spot and the other a 0:08:21 feature. Dante 2, an eight-legged walking machine, is shown during field trials as it explores the inner depths of an active volcano at Mount Spurr, Alaska. A NASA sponsored team at Carnegie Mellon University built Dante to withstand earth's harshest conditions, to deliver a science payload to the interior of a volcano, and to report on its journey to the floor of a volcano. Remotely controlled from 80-miles away, the robot explored the inner depths of the volcano and information from onboard video cameras and sensors was relayed via satellite to scientists in Anchorage. There, using a computer generated image, controllers tracked the robot's movement. Ultimately the robot team hopes to apply the technology to future planetary missions.

  9. What Are Volcano Hazards?

    ... 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. Mineral resources of Antarctica

    Compiled and edited by Wright, Nancy A.; Williams, Paul L.


    Although the existence of mineral deposits in Antarctica is highly probable, the chances of finding them are quite small. Minerals have been found there in great variety but only as occurrences. Manganese nodules, water (as ice), geothermal energy, coal, petroleum, and natural gas are potential resources that could perhaps be exploited in the future. On the basis of known mineral occurrences in Antarctica and relationships between geologic provinces of Antarctica and those of neighboring Gondwana continents, the best discovery probability for a base-metal deposit in any part of Antarctica is in the Andean orogen; it is estimated to be 0.075 (75 chances in 1,000).

  11. On the mechanism of explosive eruption of mount erebus volcano: the dynamics of the rupture structure in a cavitating layer

    Bol'shakova, E. S.; Kedrinskiy, V. K.


    This paper presents the results of an experimental simulation of rupture development in heavily cavitating magma melt flow in volcanic conduits and its effect on the structure of explosive volcanic eruptions. The dynamics of the state of a layer of distilled water (similar in the density of cavitation nuclei to magma melt) under shock-wave loading was studied. The experiments were performed using electromagnetic hydrodynamic shock tubes (EM HST) with maximum capacitor bank energy of up to 100 J and 5 kJ. It was found that the topology of the rupture formed on the membrane surface did not change during its development. Empirical estimates were obtained for the proportion of the capacitor bank energy expended in the development of the rupture and the characteristic time of its existence. The study revealed a number of fundamentally new physical effects in the cavity dynamics in a cavitating medium: a cavitation “boundary layer” is formed on the surface of the quasi-empty rupture, which is transformed into a cluster of high energy density upon closure of the flow.

  12. Bringing Antarctica Home

    Constible, Juanita; Williams, Lauren; Faure, Jaime; Lee, Richard E., Jr.


    When one thinks of the amazing creatures of Antarctica, an insect probably does not come to mind. But this unlikely animal, and a scientific expedition to Antarctica, was the foundation for a learning event that created a community of learners spanning kindergarten through sixth grade and extended beyond the classroom. Miami University's Antarctic…

  13. Santorini Volcano

    Druitt, T.H.; Edwards, L.; Mellors, R.M.; Pyle, D.M.; Sparks, R.S.J.; Lanphere, M.; Davies, M.; Barreirio, B.


    Santorini is one of the most spectacular caldera volcanoes in the world. It has been the focus of significant scientific and scholastic interest because of the great Bronze Age explosive eruption that buried the Minoan town of Akrotiri. Santorini is still active. It has been dormant since 1950, but there have been several substantial historic eruptions. Because of this potential risk to life, both for the indigenous population and for the large number of tourists who visit it, Santorini has been designated one of five European Laboratory Volcanoes by the European Commission. Santorini has long fascinated geologists, with some important early work on volcanoes being conducted there. Since 1980, research groups at Cambridge University, and later at the University of Bristol and Blaise Pascal University in Clermont-Ferrand, have collected a large amount of data on the stratigraphy, geochemistry, geochronology and petrology of the volcanics. The volcanic field has been remapped at a scale of 1:10 000. A remarkable picture of cyclic volcanic activity and magmatic evolution has emerged from this work. Much of this work has remained unpublished until now. This Memoir synthesizes for the first time all the data from the Cambridge/Bristol/Clermont groups, and integrates published data from other research groups. It provides the latest interpretation of the tectonic and magmatic evolution of Santorini. It is accompanied by the new 1:10 000 full-colour geological map of the island.

  14. The conquest of Antarctica; A la conquista de la Antartida

    Tristan, R. M.


    The information obtained in the more than 15 projects designed for the XXVIII campaign to Antarctica, and in the they involved a total of 80 researchers, will serve to learn more about terrestrial magnetism, changes occurring in the climate, the behavior of the volcanoes, the evolution of the glaciers, the rate of thaw, the weather variations, characteristics of the lichens, the progress of pollution... Even know the past that remains frozen under the ice to predict what might happen in the future. (Author)

  15. Antarctica - Ross Ice Shelf


    This color picture of Antarctica is one part of a mosaic of pictures covering the entire polar continent taken during the hours following Galileo's historic first encounter with its home planet. The view shows the Ross Ice Shelf to the right and its border with the sea. An occasional mountain can be seen poking through the ice near the McMurdo Station. It is late spring in Antarctica, so the sun never sets on the frigid, icy continent. This picture was taken about 6:20 p.m. PST on December 8, 1990. From top to bottom, the frame looks across about half of Antarctica.

  16. Living and Working in Antarctica.

    Kemp, Noel

    This source book, designed for 11- to 14-year-old students, seeks to describe what life is like in Antarctica. In spite of extreme weather conditions, people go to Antarctica to work every summer. Some of them stay there during the winter as well. This book seeks to supply answers to such questions as: How do people get to Antarctica? Why do they…

  17. Global Volcano Locations Database

    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...

  18. A Scientific Excursion: Volcanoes.

    Olds, Henry, Jr.


    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)

  19. Antarctica: Discovery & Exploration.

    Gascoigne, Toss; Collett, Peter

    An examination of Antarctica, from the first sightings to the heroic explorations of the late 18th and early 19th centuries to modern-day research, is presented in this book. Twelve chapters are as follows: (1) The search begins; (2) Whalers and sealers: bites and nibbles; (3) The new continent: first sight; (4) Wintering: the first party; (5)…

  20. Tectonics of Antarctica

    Hamilton, W.


    Antarctica consists of large and wholly continental east Antarctica and smaller west Antarctica which would form large and small islands, even after isostatic rebound, if its ice cap were melted. Most of east Antarctica is a Precambrian Shield, in much of which charnockites are characteristic. The high Transantarctic Mountains, along the Ross and Weddell Seas, largely follow a geosyncline of Upper Precambrian sedimentary rocks that were deformed, metamorphosed and intruded by granitic rocks during Late Cambrian or Early Ordovician time. The rocks of the orogen were peneplained, then covered by thin and mostly continental Devonian-Jurassic sediments, which were intruded by Jurassic diabase sheets and overlain by plateau-forming tholeiites. Late Cenozoic doming and block-faulting have raised the present high mountains. Northeastern Victoria Land, the end of the Transantarctic Mountains south of New Zealand, preserves part of a Middle Paleozoic orogen. Clastic strata laid unconformably upon the Lower Paleozoic plutonic complex were metamorphosed at low grade, highly deformed and intruded by Late Devonian or Early Carboniferous granodiorites. The overlying Triassic continental sedimentary rocks have been broadly folded and normal-faulted. Interior west Antarctica is composed of miogeosynclinal clastic and subordinate carbonate rocks which span the Paleozoic Era and which were deformed, metamorphosed at generally low grade, and intruded by granitic rocks during Early Mesozoic time and possibly during other times also. Patterns of orogenic belts, if systematic, cannot yet be defined; but fragmentation and rotation of crustal blocks by oroclinal folding and strike-slip faulting can be suggested. The Ellsworth Mountains, for example, consist of Cambrian-Permian metasedimentary rocks that strike northward toward the noncorrelative and latitudinally striking Mesozoic terrane of the Antarctic Peninsula in one direction and southward toward that of the Lower Paleozoic: terrane

  1. Volcano seismology

    Chouet, B.


    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

  2. Volcanoes: Nature's Caldrons Challenge Geochemists.

    Zurer, Pamela S.


    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.…

  3. Astronomy in Antarctica

    Burton, Michael G


    Antarctica provides a unique environment for astronomy. The cold, dry and stable air found above the high plateau, as well as the pure ice below, offers new opportunities across the photon & particle spectrum. The summits of the plateau provide the best seeing conditions, the darkest skies and the most transparent atmosphere of any earth-based observing site. Astronomical activities are now underway at four plateau sites: the Amundsen-Scott South Pole Station, Concordia Station at Dome C, Kunlun Station at Dome A and Fuji Station at Dome F, in addition to long duration ballooning from the coastal station of McMurdo. Astronomy conducted includes optical, IR, THz & sub-mm, measurements of the CMBR, solar, as well as high energy astrophysics involving measurement of cosmic rays, gamma rays and neutrinos. Antarctica is also the richest source of meteorites on our planet. An extensive range of site testing measurements have been made over the high plateau. We summarise the facets of Antarctica that are dri...

  4. Foci of Volcanoes

    Yokoyama, I.


    One may assume a center of volcanic activities beneath the edifice of an active volcano, which is here called the focus of the volcano. Sometimes it may be a ''magma reservoir''. Its depth may differ with types of magma and change with time. In this paper, foci of volcanoes are discussed from the viewpoints of four items: (1) Geomagnetic changes related with volcanic activities; (2) Crustal deformations related with volcanic activities; (3) Magma transfer through volcanoes; and (4) Subsurface structure of calderas.

  5. Informal STEM Education in Antarctica

    Chell, K.


    Tourism in Antarctica has increased dramatically with tens of thousands of tourists visiting the White Continent each year. Tourism cruises to Antarctica offer a unique educational experience for lay people through informal science-technology-engineering-mathematics (STEM) education. Passengers attend numerous scientific lectures that cover topics such as the geology of Antarctica, plate tectonics, glaciology, and climate change. Furthermore, tourists experience the geology and glaciology first hand during shore excursions. Currently, the grand challenges facing our global society are closely connected to the Earth sciences. Issues such as energy, climate change, water security, and natural hazards, are consistently on the legislative docket of policymakers around the world. However, the majority of the world’s population is uninformed about the role Earth sciences play in their everyday lives. Tourism in Antarctica provides opportunities for informal STEM learning and, as a result, tourists leave with a better understanding and greater appreciation for both Antarctica and Earth sciences.

  6. Hovercraft experience in Antarctica

    Cook, Harvey C.

    The Model 1500 TD air-cushion vehicle (ACV) has been modified for the extreme conditions encountered in Antarctic operations; these operations began in the 1988-1989 austral summer. Performance evaluations covering 300 hours of engine operations have been obtained which demonstrate the basic soundness of this ACV's design and construction, and its applicability to Antarctic operations, where it was able to reduce travel time and fuel consumption in excess of 40 percent. In addition, passenger comfort was increased manyfold over wheeled and tracked vehicles for comparable missions. The ACV is judged capable of solving many of the transportation problems experienced in Antarctica.

  7. Antarctica Day: An International Celebration

    Pope, A.; Hambrook Berkman, J.; Berkman, P. A.


    For more than half a century, the 1959 Antarctic Treaty continues to shine as a rare beacon of international cooperation. To celebrate this milestone of peace in our civilization with hope and inspiration for future generations, Antarctica Day is celebrated each year on December 1st , the anniversary of the Antarctic Treaty signing. As an annual event - initiated by the Foundation for the Good Governance of International Spaces ( in collaboration with the Association of Polar Early Carer Scientists ( - Antarctica Day encourages participation from around the world. The Antarctic Treaty set aside 10% of the earth, 'forever to be used exclusively for peaceful purposes in the interest of mankind.' It was the first nuclear arms agreement and the first institution to govern all human activities in an international region beyond sovereign jurisdictions. In this spirit, Antarctica Day aims to: - Demonstrate how diverse nations can work together peacefully, using science as a global language of cooperation for decision making beyond national boundaries, - Provide strategies for students learning about Antarctica through art, science and history at all school levels, - Increase collaboration and communication between classrooms, communities, researchers and government officials around the world, and - Provide a focus for polar educators to build on each year. Through close collaboration with a number of partners. Antarctica Day activities have included: a Polar Film Festival convened by The Explorers Club; live sessions connecting classrooms with scientists in Antarctica thanks to PolarTREC and ARCUS; an international activity that involved children from 13 countries who created over 600 flags which exemplify Antarctica Day (these were actually flown in Antarctica with signed certificates then returned to the classes); a map where Antarctica Day participants all over the world could share what they were doing; an Antarctic bird count

  8. Antarctic volcanoes: A remote but significant hazard

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


    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).

  9. Glaciers of Antarctica

    Williams, Richard S.; Ferrigno, Jane G.


    Of all the world?s continents Antarctica is the coldest, the highest, and the least known. It is one and a half times the size of the United States, and on it lies 91 percent (30,109,800 km3) of the estimated volume of all the ice on Earth. Because so little is known about Antarctic glaciers compared with what is known about glaciers in populated countries, satellite imagery represents a great leap forward in the provision of basic data. From the coast of Antarctica to about 81?south latitude, there are 2,514 Landsat nominal scene centers (the fixed geographic position of the intersection of orbital paths and latitudinal rows). If there were cloud-free images for all these geographic centers, only about 520 Landsat images would be needed to provide complete coverage. Because of cloud cover, however, only about 70 percent of the Landsat imaging area, or 55 percent of the continent, is covered by good quality Landsat images. To date, only about 20 percent of Antarctica has been mapped at scales of 1:250,000 or larger, but these maps do include about half of the coastline. The area of Antarctica that could be planimetrically mapped at a scale of 1:250,000 would be tripled if the available Landsat images were used in image map production. This chapter contains brief descriptions and interpretations of features seen in 62 carefully selected Landsat images or image mosaics. Images were chosen on the basis of quality and interest; for this reason they are far from evenly spaced around the continent. Space limitations allow less than 15 percent of the Landsat imaging area of Antarctica to be shown in the illustrations reproduced in this chapter. Unfortunately, a wealth of glaciological and other features of compelling interest is present in the many hundreds of images that could not be included. To help show some important features beyond the limit of Landsat coverage, and as an aid to the interpretation of certain features seen in the images, 38 oblique aerial photographs

  10. Cosmology from Antarctica

    Wilson, Robert W


    Observation of the CMB is central to observational cosmology, and the Antarctic Plateau is an exceptionally good site for this work. The first attempt at CMB observations from the Plateau was an expedition to the South Pole in December 1986 by the Radio Physics Research group at Bell Laboratories. Sky noise and opacity were measured. The results were sufficiently encouraging that in the Austral summer of 1988-1989, three CMB groups participated in the "Cucumber" campaign, where a temporary site dedicated to CMB anisotropy measurements was set up 2 km from South Pole Station. Winter-time observations became possible with the establishment in 1990 of the Center for Astrophysical Research in Antarctica (CARA), a National Science Foundation Science and Technology Center. CARA developed year-round observing facilities in the "Dark Sector", a section of Amundsen-Scott South Pole Station dedicated to astronomical observations. CARA scientists fielded several astronomical instruments: AST/RO, SPIREX, White Dish, Pyth...

  11. Antarctica: The Next Decade

    Rowley, Peter D.

    Laurence M. Gould, in charge of United States efforts during the International Geophysical Year (IGY, 1957-1958) and a longterm spokesman for Antarctic science, once remarked that it was the cooperative efforts during the IGY in Antarctica, “coldest of all the continents, that witnessed the first thawing of the cold war.”The Antarctic Treaty, which governs all activities on the continent, was an outgrowth of the IGY. The Treaty—the model international agreement for peaceful cooperation—was signed in 1959 and became effective in 1961. As it nears its historic 30-year anniversary, it has been the subject of a blitz of recent publications, partly because of a general misapprehension that the Treaty might “expire” then and partly the result of controversial negotiations on the recently (June 1988) adopted Convention on the Regulation of Antarctic Mineral Resource Activities (CRAMRA).

  12. Landscape evolution of Antarctica

    Jamieson, S.S.R.; Sugden, D.E.


    The relative roles of fluvial versus glacial processes in shaping the landscape of Antarctica have been debated since the expeditions of Robert Scott and Ernest Shackleton in the early years of the 20th century. Here we build a synthesis of Antarctic landscape evolution based on the geomorphology of passive continental margins and former northern mid-latitude Pleistocene ice sheets. What makes Antarctica so interesting is that the terrestrial landscape retains elements of a record of change that extends back to the Oligocene. Thus there is the potential to link conditions on land with those in the oceans and atmosphere as the world switched from a greenhouse to a glacial world and the Antarctic ice sheet evolved to its present state. In common with other continental fragments of Gondwana there is a fluvial signature to the landscape in the form of the coastal erosion surfaces and escarpments, incised river valleys, and a continent-wide network of river basins. A selective superimposed glacial signature reflects the presence or absence of ice at the pressure melting point. Earliest continental-scale ice sheets formed around 34 Ma, growing from local ice caps centered on mountain massifs, and featured phases of ice-sheet expansion and contraction. These ice masses were most likely cold-based over uplands and warm-based across lowlands and near their margins. For 20 million years ice sheets fluctuated on Croll-Milankovitch frequencies. At ~14 Ma the ice sheet expanded to its maximum and deepened a preexisting radial array of troughs selectively through the coastal mountains and eroded the continental

  13. Earth - Ross Ice Shelf, Antarctica


    This color picture of Antarctica is one part of a mosaic of pictures covering the entire Antarctic continent taken during the hours following Galileo's historic first encounter with its home planet. The view shows the Ross Ice Shelf. An occasional mountain can be seen poking through the ice. It is late spring in Antarctica, so the sun never sets on the frigid, icy continent. This picture was taken on December 8, 1990.

  14. Solar Eclipses Observed from Antarctica


    Aspects of the solar corona are still best observed during totality of solar eclipses, and other high-resolution observations of coronal active regions can be observed with radio telescopes by differentiation of occultation observations, as we did with the Jansky Very Large Array for the annular solar eclipse of 2012 May 20 in the US. Totality crossing Antarctica included the eclipse of 2003 November 23, and will next occur on 2021 December 4; annularity crossing Antarctica included the eclip...

  15. Volcanoes - Direct Download

    U.S. Geological Survey, Department of the Interior — This map layer includes Holocene volcanoes, which are those thought to be active in the last 10,000 years, that are within an extended area of the northern...

  16. Italian active volcanoes

    RobertoSantacroce; RenawCristofolini; LuigiLaVolpe; GiovanniOrsi; MauroRosi


    The eruptive histories, styles of activity and general modes of operation of the main active Italian volcanoes,Etna, Vulcano, Stromboli, Vesuvio, Campi Flegrei and Ischia, are described in a short summary.

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

    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....

  18. My IGY in Antarctica

    Bentley, Charles


    Dr Charles Bentley is the A.P. Crary Professor Emeritus of Geophysics, Department of Geology and Geophysics, University of Wisconsin-Madison. Dr. Bentley joined the Arctic Institute of North America in 1956 to participate in International Geophysical Year (IGY)-related activities in the Antarctic. He wintered over consecutively in 1957 and 1958 at Byrd Station, a station in the interior of West Antarctica that housed 24 men each winter - 12 Navy support people and 12 civilian scientists/technicians. During the austral summers, he also participated in over-snow traverses, first as co-leader, then leader (the other coleader went home after the first year). These traverses consisted of six men and three vehicles, and lasted several months. These traverses covered more than 1609 kilometers (1000 miles) of largely unmapped and unphotographed terrain. During these traverses, connections to Byrd Station were by radio (daily, when the transmission conditions were good enough) and roughly every 2 weeks by resupply flight.

  19. New determinations of 40Ar/39Ar isotopic ages and flow volumes for Cenozoic volcanism in the Terror Rift, Ross Sea, Antarctica

    Rilling, S.; Mukasa, S.; Wilson, T.; Lawver, L.; Hall, C.


    This study provides new determinations of 40Ar/39Ar isotopic ages and flow volumes for submarine and subaerial Neogene volcanism developed within the Terror Rift, Ross Sea, Antarctica, the youngest segment of the West Antarctic Rift System. The study is based on the first dredged samples from seven seamounts north of Ross Island, as well as new data from Franklin and Beaufort Islands. The sampled foidite and basanitic lavas range in age from Quaternary (90 ± 66 ka) on a small seamount ˜10 km north of Franklin Island to 6.80 ± 0.05 Ma on Beaufort Island. These ages are consistent with ages of volcanism in both the Melbourne and Erebus Volcanic Provinces and significantly expand the documented area of Neogene magmatism in Victoria Land. There is no geographic progression of volcanism through time, but volcanism was voluminous in the Pliocene and particularly widespread during the Pleistocene. Two of the dredges sampled edifices comprised of less than 0.2 km3 of volcanic materials. The largest seamount in the study area has 58.8 km3 of volcanic material and represents growth over a period of several thousand years. Estimated minimum eruption rates range from 2 × 10-4 km3 y-1 to 2 × 10-3 km3 y-1, consistent with rates proposed for other rift systems and nearby Mt. Erebus. Recent estimates of extension magnitude for the Terror Rift correspond to minimal decompression of only 0.10 to 0.22 GPa and therefore limited melt output of a typical peridotite source.

  20. Pulsating star research from Antarctica

    Chadid, Merieme


    This invited talk discusses the pulsating star research from the heart of Antarctica and the scientific polar challenges in the extreme environment of Antarctica, and how the new polar technology could cope with unresolved stellar pulsation enigmas and evolutionary properties challenges towards an understanding of the mysteries of the Universe. PAIX, the first robotic photometer Antarctica program, has been successfully launched during the polar night 2007. This ongoing program gives a new insight to cope with unresolved stellar enigmas and stellar oscillation challenges with a great opportunity to benefit from an access to the best astronomical site on Earth, Dome C. PAIX achieves astrophysical measurement time-series of stellar fields, challenging photometry from space. A continuous and an uninterrupted series of multi-color photometric observations has been collected each polar night - 150 days - without regular interruption, Earth's rotation effect. PAIX shows the first light curve from Antarctica and first step for the astronomy in Antarctica giving new insights in remote polar observing runs and robotic instruments towards a new technology.

  1. Volcanoes: Coming Up from Under.

    Science and Children, 1980


    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)

  2. Organizational changes at Earthquakes & Volcanoes

    Gordon, David W.


    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).

  3. Hawaii's volcanoes revealed

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


    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

  4. Description and morphology of the “Juan de Fuca vent mussel”, Benthomodiolus erebus sp. n. (Bivalvia, Mytilidae, Bathymodiolinae: “Phylogenetically basal but morphologically advanced”

    P. Graham Oliver


    Full Text Available The Juan de Fuca vent mussel first found in 1990 is formally described as Benthomodiolus erebus sp. n. Comparisons are made with the three other species previously assigned to Benthomodiolus namely B. lignocola, B. geikotsucola and B. abyssicola. The anatomies of all four species are examined and are shown to share the arrangement of pedal and byssus musculature, having largely un-fused mantle margins and a hind gut with a very short loop. The ctenidia were examined using both light and scanning electron microscopy. B. erebus and B. geikotsucola were found to have lamellar filaments with extensive abfrontal expansion and fusion of the ascending and descending arms. In this there is similarity with Bathymodiolus. B. lignocola and B. abyssicola were found to have linear filaments with narrow abfrontal surfaces with little fusion. All four species were shown to have the abfrontal surfaces covered by polygonal cushions of microvilli although these were much less apparent in B. lignocola and B. abyssicola. Although Benthomodiolus was shown by a number of previous studies, using molecular data alone, to be phylogenetically basal to all other Bathymodiolinae the anatomy is highly adapted for chemosymbiosis. Species of Benthomodiolus are found on wood-falls, whale-falls and vent sites and thus mirror the habits of the Bathymodiolus/Idas clade.

  5. Santa Maria Volcano, Guatemala


    The eruption of Santa Maria volcano in 1902 was one of the largest eruptions of the 20th century, forming a large crater on the mountain's southwest flank. Since 1922, a lava-dome complex, Santiaguito, has been forming in the 1902 crater. Growth of the dome has produced pyroclastic flows as recently as the 2001-they can be identified in this image. The city of Quezaltenango (approximately 90,000 people in 1989) sits below the 3772 m summit. The volcano is considered dangerous because of the possibility of a dome collapse such as one that occurred in 1929, which killed about 5000 people. A second hazard results from the flow of volcanic debris into rivers south of Santiaguito, which can lead to catastrophic flooding and mud flows. More information on this volcano can be found at web sites maintained by the Smithsonian Institution, Volcano World, and Michigan Tech University. ISS004-ESC-7999 was taken 17 February 2002 from the International Space Station using a digital camera. The image is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Searching and viewing of additional images taken by astronauts and cosmonauts is available at the NASA-JSC Gateway to

  6. Anatomy of a volcano

    Wassink, J.


    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. “W

  7. Catalogue of Icelandic Volcanoes

    Ilyinskaya, Evgenia; Larsen, Gudrun; Gudmundsson, Magnus T.; Vogfjord, Kristin; Pagneux, Emmanuel; Oddsson, Bjorn; Barsotti, Sara; Karlsdottir, Sigrun


    The Catalogue of Icelandic Volcanoes is a newly developed open-access web resource in English intended to serve as an official source of information about active volcanoes in Iceland and their characteristics. The Catalogue forms a part of an integrated volcanic risk assessment project in Iceland GOSVÁ (commenced in 2012), as well as being part of the effort of FUTUREVOLC (2012-2016) on establishing an Icelandic volcano supersite. Volcanic activity in Iceland occurs on volcanic systems that usually comprise a central volcano and fissure swarm. Over 30 systems have been active during the Holocene (the time since the end of the last glaciation - approximately the last 11,500 years). In the last 50 years, over 20 eruptions have occurred in Iceland displaying very varied activity in terms of eruption styles, eruptive environments, eruptive products and the distribution lava and tephra. Although basaltic eruptions are most common, the majority of eruptions are explosive, not the least due to magma-water interaction in ice-covered volcanoes. Extensive research has taken place on Icelandic volcanism, and the results reported in numerous scientific papers and other publications. In 2010, the International Civil Aviation Organisation (ICAO) funded a 3 year project to collate the current state of knowledge and create a comprehensive catalogue readily available to decision makers, stakeholders and the general public. The work on the Catalogue began in 2011, and was then further supported by the Icelandic government and the EU through the FP7 project FUTUREVOLC. The Catalogue of Icelandic Volcanoes is a collaboration of the Icelandic Meteorological Office (the state volcano observatory), 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. The Catalogue is built up of chapters with texts and various

  8. Antarctica: Chile’s Claim,


    Marie Byrd Land is be- low sea level and covered by a sheath of ice 600 to 4,000 meters (1,968 to 13,120 feet) thick. * This sheath of ice extends below...Channel to sulphurs lead, silver stratiform bodies Spring Point, Trans- in sedimentary Antarctica Mountain and volcanic rocks Ultra- Chrome , Stratified en

  9. Surface winds over West Antarctica

    Bromwich, David


    Five winter months (April-August 1988) of thermal infrared satellite images were examined to investigate the occurrence of dark (warm) signatures across the Ross Ice Shelf in the Antarctic continent. These features are inferred to be generated by katabatic winds that descend from southern Marie Byrd Land and then blow horizontally across the ice shelf. Significant mass is added to this airstream by katabatic winds blowing from the major glaciers that flow through the Transantarctic Mountains from East Antarctica. These negatively buoyant katabatic winds can reach the northwestern edge of the shelf - a horizontal propagation distance of up to 1,000 km - 14 percent of the time. Where the airstream crosses from the ice shelf to the ice-covered Ross Sea, a prominent coastal polynya is formed. Because the downslope buoyancy force is near zero over the Ross Ice Shelf, the northwestward propagation of the katabatic air mass requires pressure gradient support. The study shows that the extended horizontal propagation of this atmospheric density current occurred in conjunction with the passage of synoptic cyclones over the southern Amundsen Sea. These cyclones can strengthen the pressure gradient in the interior of West Antarctica and make the pressure field favorable for northwestward movement of the katabatic winds from West Antarctica across the ice shelf in a geostrophic direction. The glacier winds from East Antarctica are further accelerated by the synoptic pressure gradient, usually undergo abrupt adjustment beyond the exit to the glacier valley, and merge into the mountain-parallel katabatic air mass.

  10. Pine Island Glacier, Antarctica


    This pair of MISR images of the Pine Island Glacier in western Antarctica was acquired on December 12, 2000 during Terra orbit 5246. At left is a conventional, true-color image from the downward-looking (nadir) camera. The false-color image at right is a composite of red band data taken by the MISR forward 60-degree, nadir, and aftward 60-degree cameras, displayed in red, green, and blue colors, respectively. Color variations in the left (true-color) image highlight spectral differences. In the multi-angle composite, on the other hand, color variations act as a proxy for differences in the angular reflectance properties of the scene. In this representation, clouds show up as light purple. Blue to orange gradations on the surface indicate a transition in ice texture from smooth to rough. For example, the bright orange 'carrot-like' features are rough crevasses on the glacier's tongue. In the conventional nadir view, the blue ice labeled 'rough crevasses' and 'smooth blue ice' exhibit similar coloration, but the multi-angle composite reveals their different textures, with the smoother ice appearing dark purple instead of orange. This could be an indicator of different mechanisms by which this ice is exposed. The multi-angle view also reveals subtle roughness variations on the frozen sea ice between the glacier and the open water in Pine Island Bay.To the left of the 'icebergs' label are chunks of floating ice. Additionally, smaller icebergs embedded in the frozen sea ice are visible below and to the right of the label. These small icebergs are associated with dark streaks. Analysis of the illumination geometry suggests that these streaks are surface features, not shadows. Wind-driven motion and thinning of the sea ice in the vicinity of the icebergs is one possible explanation.Recently, Robert Bindschadler, a glaciologist at the NASA Goddard Space Flight Center discovered in Landsat 7 imagery a newly-formed crack traversing the Pine Island Glacier. This crack is

  11. Catalogue of Icelandic volcanoes

    Ilyinskaya, Evgenia; Larsen, Gudrun; Vogfjörd, Kristin; Tumi Gudmundsson, Magnus; Jonsson, Trausti; Oddsson, Björn; Reynisson, Vidir; Barsotti, Sara; Karlsdottir, Sigrun


    Volcanic activity in Iceland occurs on volcanic systems that usually comprise a central volcano and fissure swarm. Over 30 systems have been active during the Holocene. In the last 100 years, over 30 eruptions have occurred displaying very varied activity in terms of eruption styles, eruptive environments, eruptive products and their distribution. Although basaltic eruptions are most common, the majority of eruptions are explosive, not the least due to magma-water interaction in ice-covered volcanoes. Extensive research has taken place on Icelandic volcanism, and the results reported in scientific papers and other publications. In 2010, the International Civil Aviation Organisation funded a 3 year project to collate the current state of knowledge and create a comprehensive catalogue readily available to decision makers, stakeholders and the general public. The work on the Catalogue began in 2011, and was then further supported by the Icelandic government and the EU. The Catalogue forms a part of an integrated volcanic risk assessment project in Iceland (commenced in 2012), and the EU FP7 project FUTUREVOLC (2012-2016), establishing an Icelandic volcano Supersite. The Catalogue is a collaborative effort between the Icelandic Meteorological Office (the state volcano observatory), the Institute of Earth Sciences at the University of Iceland, and the Icelandic Civil Protection, with contributions from a large number of specialists in Iceland and elsewhere. The catalogue is scheduled for opening in the first half of 2015 and once completed, it will be an official publication intended to serve as an accurate and up to date source of information about active volcanoes in Iceland and their characteristics. The Catalogue is an open web resource in English and is composed of individual chapters on each of the volcanic systems. The chapters include information on the geology and structure of the volcano; the eruption history, pattern and products; the known precursory signals

  12. Volcano-hazard zonation for San Vicente volcano, El Salvador

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


    San Vicente volcano, also known as Chichontepec, is one of many volcanoes along the volcanic arc in El Salvador. This composite volcano, located about 50 kilometers east of the capital city San Salvador, has a volume of about 130 cubic kilometers, rises to an altitude of about 2180 meters, and towers above major communities such as San Vicente, Tepetitan, Guadalupe, Zacatecoluca, and Tecoluca. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and major transportation routes are located near the lowermost southern and eastern flanks of the volcano. The population density and proximity around San Vicente volcano, as well as the proximity of major transportation routes, increase the risk that even small landslides or eruptions, likely to occur again, can have serious societal consequences. The eruptive history of San Vicente volcano is not well known, and there is no definitive record of historical eruptive activity. The last significant eruption occurred more than 1700 years ago, and perhaps long before permanent human habitation of the area. Nevertheless, this volcano has a very long history of repeated, and sometimes violent, eruptions, and at least once a large section of the volcano collapsed in a massive landslide. The oldest rocks associated with a volcanic center at San Vicente are more than 2 million years old. The volcano is composed of remnants of multiple eruptive centers that have migrated roughly eastward with time. Future eruptions of this volcano will pose substantial risk to surrounding communities.



    This paper makes an analysis and study on altogether 8 palyniferous samples from the volcano-sedimentary rock series in the Half Three Point area of the Fildes Peninsula, King George Island, Antarctica, the rock series being grey tuffaceous siltstone in lithological characters, about 5m in thickness. Only after making a number of analyses, could we find the relatively abundant sporopollen fossils from 4 samples (Nos. GWP 4—7). But the fossils are poorly preserved, and most of them can hardly be identifi...

  14. Geology of Kilauea volcano

    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)


    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.

  15. 4D volcano gravimetry

    Battaglia, Maurizio; Gottsmann, J.; Carbone, D.; Fernandez, J.


    Time-dependent gravimetric measurements can detect subsurface processes long before magma flow leads to earthquakes or other eruption precursors. The ability of gravity measurements to detect subsurface mass flow is greatly enhanced if gravity measurements are analyzed and modeled with ground-deformation data. Obtaining the maximum information from microgravity studies requires careful evaluation of the layout of network benchmarks, the gravity environmental signal, and the coupling between gravity changes and crustal deformation. When changes in the system under study are fast (hours to weeks), as in hydrothermal systems and restless volcanoes, continuous gravity observations at selected sites can help to capture many details of the dynamics of the intrusive sources. Despite the instrumental effects, mainly caused by atmospheric temperature, results from monitoring at Mt. Etna volcano show that continuous measurements are a powerful tool for monitoring and studying volcanoes.Several analytical and numerical mathematical models can beused to fit gravity and deformation data. Analytical models offer a closed-form description of the volcanic source. In principle, this allows one to readily infer the relative importance of the source parameters. In active volcanic sites such as Long Valley caldera (California, U.S.A.) and Campi Flegrei (Italy), careful use of analytical models and high-quality data sets has produced good results. However, the simplifications that make analytical models tractable might result in misleading volcanological inter-pretations, particularly when the real crust surrounding the source is far from the homogeneous/ isotropic assumption. Using numerical models allows consideration of more realistic descriptions of the sources and of the crust where they are located (e.g., vertical and lateral mechanical discontinuities, complex source geometries, and topography). Applications at Teide volcano (Tenerife) and Campi Flegrei demonstrate the

  16. Pairing the Volcano

    Ionica, Sorina


    Isogeny volcanoes are graphs whose vertices are elliptic curves and whose edges are $\\ell$-isogenies. Algorithms allowing to travel on these graphs were developed by Kohel in his thesis (1996) and later on, by Fouquet and Morain (2001). However, up to now, no method was known, to predict, before taking a step on the volcano, the direction of this step. Hence, in Kohel's and Fouquet-Morain algorithms, many steps are taken before choosing the right direction. In particular, ascending or horizontal isogenies are usually found using a trial-and-error approach. In this paper, we propose an alternative method that efficiently finds all points $P$ of order $\\ell$ such that the subgroup generated by $P$ is the kernel of an horizontal or an ascending isogeny. In many cases, our method is faster than previous methods. This is an extended version of a paper published in the proceedings of ANTS 2010. In addition, we treat the case of 2-isogeny volcanoes and we derive from the group structure of the curve and the pairing ...

  17. Italian Volcano Supersites

    Puglisi, G.


    Volcanic eruptions are among the geohazards that may have a substantial economic and social impact, even at worldwide scale. Large populated regions are prone to volcanic hazards worldwide. Even local phenomena may affect largely populated areas and in some cases even megacities, producing severe economic losses. On a regional or global perspective, large volcanic eruptions may affect the climate for years with potentially huge economic impacts, but even relatively small eruptions may inject large amounts of volcanic ash in the atmosphere and severely affect air traffic over entire continents. One of main challenges of the volcanological community is to continuously monitor and understand the internal processes leading to an eruption, in order to give substantial contributions to the risk reduction. Italian active volcanoes constitute natural laboratories and ideal sites where to apply the cutting-edge volcano observation systems, implement new monitoring systems and to test and improve the most advanced models and methods for investigate the volcanic processes. That's because of the long tradition of volcanological studies resulting into long-term data sets, both in-situ and from satellite systems, among the most complete and accurate worldwide, and the large spectrum of the threatening volcanic phenomena producing high local/regional/continental risks. This contribution aims at presenting the compound monitoring systems operating on the Italian active volcanoes, the main improvements achieved during the recent studies direct toward volcanic hazard forecast and risk reductions and the guidelines for a wide coordinated project aimed at applying the ideas of the GEO Supersites Initiative at Mt. Etna and Campi Flegrei / Vesuvius areas.

  18. Ruiz Volcano: Preliminary report

    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.

  19. Potential methane reservoirs beneath Antarctica.

    Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H


    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage.

  20. Preliminary volcano-hazard assessment for Iliamna Volcano, Alaska

    Waythomas, Christopher F.; Miller, Thomas P.


    Iliamna Volcano is a 3,053-meter-high, ice- and snow-covered stratovolcano in the southwestern Cook Inlet region about 225 kilometers southwest of Anchorage and about 100 kilometers northwest of Homer. Historical eruptions of Iliamna Volcano have not been positively documented; however, the volcano regularly emits steam and gas, and small, shallow earthquakes are often detected beneath the summit area. The most recent eruptions of the volcano occurred about 300 years ago, and possibly as recently as 90-140 years ago. Prehistoric eruptions have generated plumes of volcanic ash, pyroclastic flows, and lahars that extended to the volcano flanks and beyond. Rock avalanches from the summit area have occurred numerous times in the past. These avalanches flowed several kilometers down the flanks and at least two large avalanches transformed to cohesive lahars. The number and distribution of known volcanic ash deposits from Iliamna Volcano indicate that volcanic ash clouds from prehistoric eruptions were significantly less voluminous and probably less common relative to ash clouds generated by eruptions of other Cook Inlet volcanoes. Plumes of volcanic ash from Iliamna Volcano would be a major hazard to jet aircraft using Anchorage International Airport and other local airports, and depending on wind direction, could drift at least as far as the Kenai Peninsula and beyond. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Because Iliamna Volcano has not erupted for several hundred years, a future eruption could involve significant amounts of ice and snow that could lead to the formation of large lahars and downstream flooding. The greatest hazards in order of importance are described below and shown on plate 1.

  1. A novel adenovirus in Chinstrap penguins (Pygoscelis antarctica) in Antarctica.

    Lee, Sook-Young; Kim, Jeong-Hoon; Park, Yon Mi; Shin, Ok Sarah; Kim, Hankyeom; Choi, Han-Gu; Song, Jin-Won


    Adenoviruses (family Adenoviridae) infect various organ systems and cause diseases in a wide range of host species. In this study, we examined multiple tissues from Chinstrap penguins (Pygoscelis antarctica), collected in Antarctica during 2009 and 2010, for the presence of novel adenoviruses by PCR. Analysis of a 855-bp region of the hexon gene of a newly identified adenovirus, designated Chinstrap penguin adenovirus 1 (CSPAdV-1), showed nucleotide (amino acid) sequence identity of 71.8% (65.5%) with South Polar skua 1 (SPSAdV-1), 71% (70%) with raptor adenovirus 1 (RAdV-1), 71.4% (67.6%) with turkey adenovirus 3 (TAdV-3) and 61% (61.6%) with frog adenovirus 1 (FrAdV-1). Based on the genetic and phylogenetic analyses, CSPAdV-1 was classified as a member of the genus, Siadenovirus. Virus isolation attempts from kidney homogenates in the MDTC-RP19 (ATCC® CRL-8135™) cell line were unsuccessful. In conclusion, this study provides the first evidence of new adenovirus species in Antarctic penguins.

  2. A Novel Adenovirus in Chinstrap Penguins (Pygoscelis antarctica in Antarctica

    Sook-Young Lee


    Full Text Available Adenoviruses (family Adenoviridae infect various organ systems and cause diseases in a wide range of host species. In this study, we examined multiple tissues from Chinstrap penguins (Pygoscelis antarctica, collected in Antarctica during 2009 and 2010, for the presence of novel adenoviruses by PCR. Analysis of a 855-bp region of the hexon gene of a newly identified adenovirus, designated Chinstrap penguin adenovirus 1 (CSPAdV-1, showed nucleotide (amino acid sequence identity of 71.8% (65.5% with South Polar skua 1 (SPSAdV-1, 71% (70% with raptor adenovirus 1 (RAdV-1, 71.4% (67.6% with turkey adenovirus 3 (TAdV-3 and 61% (61.6% with frog adenovirus 1 (FrAdV-1. Based on the genetic and phylogenetic analyses, CSPAdV-1 was classified as a member of the genus, Siadenovirus. Virus isolation attempts from kidney homogenates in the MDTC-RP19 (ATCC® CRL-8135™ cell line were unsuccessful. In conclusion, this study provides the first evidence of new adenovirus species in Antarctic penguins.

  3. Elementary analysis of data from Tianchi Volcano

    LIU Guo-ming; ZHANG Heng-rong; KONG Qing-jun; WU Cheng-zhi; GUO Feng; ZHANG Chao-fan


    Tianchi Volcano is the largest potential erupticve volcano in China. Analyzing these data on seismic monitoring, deformation observation and water chemistry investigation gained from the Tianchi Volcano Observatory (TVO), the authors consider that the Tianchi Volcano is in going into a new flourishing time.

  4. Mount Rainier active cascade volcano


    Mount Rainier is one of about two dozen active or recently active volcanoes in the Cascade Range, an arc of volcanoes in the northwestern United States and Canada. The volcano is located about 35 kilometers southeast of the Seattle-Tacoma metropolitan area, which has a population of more than 2.5 million. This metropolitan area is the high technology industrial center of the Pacific Northwest and one of the commercial aircraft manufacturing centers of the United States. The rivers draining the volcano empty into Puget Sound, which has two major shipping ports, and into the Columbia River, a major shipping lane and home to approximately a million people in southwestern Washington and northwestern Oregon. Mount Rainier is an active volcano. It last erupted approximately 150 years ago, and numerous large floods and debris flows have been generated on its slopes during this century. More than 100,000 people live on the extensive mudflow deposits that have filled the rivers and valleys draining the volcano during the past 10,000 years. A major volcanic eruption or debris flow could kill thousands of residents and cripple the economy of the Pacific Northwest. Despite the potential for such danger, Mount Rainier has received little study. Most of the geologic work on Mount Rainier was done more than two decades ago. Fundamental topics such as the development, history, and stability of the volcano are poorly understood.

  5. Mount Rainier active cascade volcano

    Mount Rainier is one of about two dozen active or recently active volcanoes in the Cascade Range, an arc of volcanoes in the northwestern United States and Canada. The volcano is located about 35 kilometers southeast of the Seattle-Tacoma metropolitan area, which has a population of more than 2.5 million. This metropolitan area is the high technology industrial center of the Pacific Northwest and one of the commercial aircraft manufacturing centers of the United States. The rivers draining the volcano empty into Puget Sound, which has two major shipping ports, and into the Columbia River, a major shipping lane and home to approximately a million people in southwestern Washington and northwestern Oregon. Mount Rainier is an active volcano. It last erupted approximately 150 years ago, and numerous large floods and debris flows have been generated on its slopes during this century. More than 100,000 people live on the extensive mudflow deposits that have filled the rivers and valleys draining the volcano during the past 10,000 years. A major volcanic eruption or debris flow could kill thousands of residents and cripple the economy of the Pacific Northwest. Despite the potential for such danger, Mount Rainier has received little study. Most of the geologic work on Mount Rainier was done more than two decades ago. Fundamental topics such as the development, history, and stability of the volcano are poorly understood.

  6. Soufriere Hills Volcano


    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

  7. Characteristics of Hawaiian volcanoes

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


    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.

  8. Recent accumulation rate at Dome A, Antarctica

    HOU ShuGui; LI YuanSheng; XIAO CunDe; REN JiaWen


    Based on the horizon of β activity and the density profiles, recent accumulation rate at Dome A, Antarctica is calculated to be 0.023 m water equivalent per year. This value is comparative to the accumulation rates deduced from the other inland sites of Antarctica. Clear-sky precipitation (or diamond dust) dominates the total precipitation at Dome A region. We speculate Dome A as a potential site to discover the oldest ice in Antarctica due to its tremendous ice thickness (>3000 m), extremely low accumulation rate, and low ice velocity.

  9. Volcanoes in Eruption - Set 1

    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...

  10. Volcanoes in Eruption - Set 2

    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...

  11. USGS Volcano Notification Service (VNS)

    U.S. Geological Survey, Department of the Interior — Website provides a subscription service to receive an email when changes occur in the activity levels for monitored U.S. volcanoes and/or when information releases...


    T. M. Manevich


    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.

  13. Mahukona: The missing Hawaiian volcano

    Garcia, M.O.; Muenow, D.W. (Univ. of Hawaii, Honolulu (USA)); Kurz, M.D. (Woods Hole Oceanographic Institution, MA (USA))


    New bathymetric and geochemical data indicate that a seamount west of the island of Hawaii, Mahukona, is a Hawaiian shield volcano. Mahukona has weakly alkalic lavas that are geochemically distinct. They have high {sup 3}He/{sup 4}He ratios (12-21 times atmosphere), and high H{sub 2}O and Cl contents, which are indicative of the early state of development of Hawaiian volcanoes. The He and Sr isotopic values for Mahukona lavas are intermediate between those for lavas from Loihi and Manuna Loa volcanoes and may be indicative of a temporal evolution of Hawaiian magmas. Mahukona volcano became extinct at about 500 ka, perhaps before reaching sea level. It fills the previously assumed gap in the parallel chains of volcanoes forming the southern segment of the Hawaiian hotspot chain. The paired sequence of volcanoes was probably caused by the bifurcation of the Hawaiian mantle plume during its ascent, creating two primary areas of melting 30 to 40 km apart that have persisted for at least the past 4 m.y.

  14. Iron Meteorites and Upwelling in Antarctica

    Gourlay, B. S.; Behr, E.; Mardon, A.; Behr, E.


    In Antarctica, a meteorite stranding zone, stone meteorites are more common than iron. Dr. Evatt's team suggests that the heat conductivity of iron may be opposing the upwelling effects so iron meteorites sink under the ice unlike the stone ones.

  15. Geoethical approach to mineral activities in Antarctica

    Talalay, Pavel


    Antarctica is the outermost from civilization space continent. From 14.0 million km2 of surface area about 98% of Antarctica is covered by ice that averages at least 1.6 km in thickness. Geologically, the continent is the least explored in the world, and it is almost absolutely unknown what mineral resources Antarctica has as they are buried in rock that is covered by a thick ice sheet. It is thought to have large and valuable mineral deposits under the ice. This is because of what has been found in samples taken from the small areas of rock that are exposed, and also from what has been found in South Africa and South America. Up until 180 million years ago, Antarctica was a part of the Gondwanaland super continent, attached to South America, the Southern part of Africa, India and Australia, these continents then drifted apart until they reached their current positions. This leads to a possibility that Antarctica may also share some of the mineral wealth of these continents. Right now on the ice-free areas of Antarctica iron ore, chromium, copper, gold, nickel, platinum, coal and hydrocarbons have been found. The Protocol on Environmental Protection to the Antarctic Treaty, also known as the Madrid Protocol, was signed in 1991 by the signatories to the Antarctic Treaty and became law in January 1998. The Protocol provides for comprehensive protection of the Antarctic environment and associated ecosystems and includes a ban on all commercial mining for at least fifty years (this is up for review in 2041). Current climate change and melting ice in Polar Regions is opening up new opportunities to exploit mineral and oil resources. Even Antarctica's weather, ice and distance from any industrialized areas mean that mineral extraction would be extremely expensive and also extremely dangerous, the depletion of mineral recourses on the Earth can reverse banning of mining in Antarctica in future. There is no question that any resource exploitation in Antarctica will cause

  16. Potential seaways across West Antarctica

    Vaughan, David G.; Barnes, David K. A.; Fretwell, Peter T.; Bingham, Robert G.


    The West Antarctic ice sheet (WAIS) has long been considered vulnerable to rapid retreat and today parts are rapidly losing ice. Projection of future change in WAIS is, however, hampered by our poor understanding of past changes, especially during interglacial periods that could be analogs for the future, but which undoubtedly provide an opportunity for testing predictive models. We consider how ice-loss would open seaways across WAIS; these would likely alter Southern Ocean circulation and climate, and would broadly define the de-glacial state, but they may also have left evidence of their existence in the coastal seas they once connected. We show the most likely routes for such seaways, and that a direct seaway between Weddell and Ross seas, which did not pass through the Amundsen Sea sector, is unlikely. Continued ice-loss at present rates would open seaways between Amundsen and Weddell seas (A-W), and Amundsen and Bellingshausen seas (A-B), in around one thousand years. This timescale indicates potential future vulnerability, but also suggests seaways may have opened in recent interglacial periods. We attempt to test this hypothesis using contemporary bryozoan species assemblages around Antarctica, concluding that anomalously high similarity in assemblages in the Weddell and Amundsen seas supports recent migration through A-W. Other authors have suggested opening of seaways last occurred during Marine Isotope Stage 7a (209 ka BP), but we conclude that opening could have occurred in MIS 5e (100 ka BP) when Antarctica was warmer than present and likely contributed to global sea levels higher than today.

  17. The separation of Ceylon from Antarctica

    Schreider, Al. A.; Schreider, A. A.; Boiko, A. N.; Kashintsev, G. L.; Evsenko, E. I.


    The geometry of the junction between Ceylon and Antarctica during the Gondwanaland breakup is still under discussion. Analysis of the available geological-geophysical materials has allowed the peculiarities of Ceylon separation from Antarctica to be characterized, the new paleogeodynamical reconstruction to be elaborated, and a prognosis of the tectonic structure and mineral resources in the areas of Antarctic coast that were adjacent to Ceylon to be made.

  18. A volcano-seismic event spotting system for the use in rapid response systems

    Hammer, Conny; Ohrnberger, Matthias


    Toolkit (HTK), a software package which has been developed in the realm of speech recognition research. The training procedure can be described as follows: First, we extract a valuable set of wave field parameters in a sliding window fashion from an unlabeled continuous data stream. Here, we use polarization and spectral attributes as those are well known to provide good discrimination between different seismic event classes. In the following these parameters are used to extract a fixed number of clusters in the feature space. Each cluster corresponds to a mixture component of the overall output distribution which is modeled by Gaussian mixture densities. Based on this general multivariate description of the overall data set we start building particular event classifiers from a single waveform example based on the cluster description learned before. For the classification task we use context dependent hidden Markov models which represent a stochastic description observations and hence are able to handle the great variabilities of volcano-seismic signal characteristics. To show the capabilities of this new approach tests were performed on two different datasets. Based on the results of the automatic classification process of seismic signals recorded at Soufrière Hills volcano and continuous data recorded at Mt. Erebus volcano we show that the system is able to provide a robust event classification without previously existing training events. For this reason we conclude that the suggested approach is a valuable tool for rapid response action.

  19. "Mediterranean volcanoes vs. chain volcanoes in the Carpathians"

    Chivarean, Radu


    Volcanoes have always represent an attractive subject for students. Europe has a small number of volcanoes and Romania has none active ones. The curricula is poor in the study of volcanoes. We want to make a parallel between the Mediterranean active volcanoes and the old extinct ones in the Oriental Carpathians. We made an comparison of the two regions in what concerns their genesis, space and time distribution, the specific relief and the impact in the landscape, consequences of their activities, etc… The most of the Mediterranean volcanoes are in Italy, in the peninsula in Napoli's area - Vezuviu, Campi Flegrei, Puzzoli, volcanic islands in Tirenian Sea - Ischia, Aeolian Islands, Sicily - Etna and Pantelleria Island. Santorini is located in Aegean Sea - Greece. Between Sicily and Tunisia there are 13 underwater volcanoes. The island called Vulcano, it has an active volcano, and it is the origin of the word. Every volcano in the world is named after this island, just north of Sicily. Vulcano is the southernmost of the 7 main Aeolian Islands, all volcanic in origin, which together form a small island arc. The cause of the volcanoes appears to be a combination of an old subduction event and tectonic fault lines. They can be considered as the origin of the science of volcanology. The volcanism of the Carpathian region is part of the extensive volcanic activity in the Mediterranean and surrounding regions. The Carpathian Neogene/Quaternary volcanic arc is naturally subdivided into six geographically distinct segments: Oas, Gutai, Tibles, Calimani, Gurghiu and Harghita. It is located roughly between the Carpathian thrust-and-fold arc to the east and the Transylvanian Basin to the west. It formed as a result of the convergence between two plate fragments, the Transylvanian micro-plate and the Eurasian plate. Volcanic edifices are typical medium-sized andesitic composite volcanoes, some of them attaining the caldera stage, complicated by submittal or peripheral domes

  20. Mud Volcanoes Formation And Occurrence

    Guliyev, I. S.


    Mud volcanoes are natural phenomena, which occur throughout the globe. They are found at a greater or lesser scale in Azerbaijan, Turkmenistan, Georgia, on the Kerch and Taman peninsulas, on Sakhalin Island, in West Kuban, Italy, Romania, Iran, Pakistan, India, Burma, China, Japan, Indonesia, Malaysia, New Zealand, Mexico, Colombia, Trinidad and Tobago, Venezuela and Ecuador. Mud volcanoes are most well-developed in Eastern Azerbaijan, where more than 30% of all the volcanoes in the world are concentrated. More than 300 mud volcanoes have already been recognized here onshore or offshore, 220 of which lie within an area of 16,000 km2. Many of these mud volcanoes are particularly large (up to 400 m high). The volcanoes of the South Caspian form permanent or temporary islands, and numerous submarine banks. Many hypotheses have been developed regarding the origin of mud volcanoes. Some of those hypotheses will be examined in the present paper. Model of spontaneous excitation-decompaction (proposed by Ivanov and Guliev, 1988, 2002). It is supposed that one of major factors of the movement of sedimentary masses and formation of hydrocarbon deposits are phase transitions in sedimentary basin. At phase transitions there are abnormal changes of physical and chemical parameters of rocks. Abnormal (high and negative) pressure takes place. This process is called as excitation of the underground environment with periodicity from several tens to several hundreds, or thousand years. The relationship between mud volcanism and the generation of hydrocarbons, particularly methane, is considered to be a critical factor in mud volcano formation. At high flow rates the gas and sediment develops into a pseudo-liquid state and as flow increases the mass reaches the "so-called hover velocity" where mass transport begins. The mass of fluid moves as a quasi-uniform viscous mass through the sediment pile in a piston like manner until expelled from the surface as a "catastrophic eruption

  1. Global Volcano Model

    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.


    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.

  2. Remote Sensing of Active Volcanoes

    Francis, Peter; Rothery, David

    The synoptic coverage offered by satellites provides unparalleled opportunities for monitoring active volcanoes, and opens new avenues of scientific inquiry. Thermal infrared radiation can be used to monitor levels of activity, which is useful for automated eruption detection and for studying the emplacement of lava flows. Satellite radars can observe volcanoes through clouds or at night, and provide high-resolution topographic data. In favorable conditions, radar inteferometery can be used to measure ground deformation associated with eruptive activity on a centimetric scale. Clouds from explosive eruptions present a pressing hazard to aviation; therefore, techniques are being developed to assess eruption cloud height and to discriminate between ash and meterological clouds. The multitude of sensors to be launched on future generations of space platforms promises to greatly enhance volcanological studies, but a satellite dedicated to volcanology is needed to meet requirements of aviation safety and volcano monitoring.

  3. Mount Rainier: A decade volcano

    Swanson, Donald A.; Malone, Stephen D.; Samora, Barbara A.

    Mount Rainier, the highest (4392 m) volcano in the Cascade Range, towers over a population of more than 2.5 million in the Seattle-Tacoma metropolitan area, and its drainage system via the Columbia River potentially affects another 500,000 residents of southwestern Washington and northwestern Oregon (Figure 1). Mount Rainier is the most hazardous volcano in the Cascades in terms of its potential for magma-water interaction and sector collapse. Major eruptions, or debris flows even without eruption, pose significant dangers and economic threats to the region. Despite such hazard and risk, Mount Rainier has received little study; such important topics as its petrologic and geochemical character, its proximal eruptive history, its susceptibility to major edifice failure, and its development over time have been barely investigated. This situation may soon change because of Mount Rainier's recent designation as a “Decade Volcano.”

  4. Systematic radon survey over active volcanoes

    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)


    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.

  5. Space analogue studies in Antarctica

    Lugg, D.; Shepanek, M.


    Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mitogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

  6. Space analogue studies in Antarctica

    Lugg, D.; Shepanek, M.


    Medical research has been carried out on the Australian National Antarctic Research Expeditions (ANARE) for 50 years. As an extension of this program collaborative Australian/United States research on immunology, microbiology, psychology and remote medicine has produced important data and insight on how humans adapt to the stress of extreme isolation, confinement and the harsh environment of Antarctica. An outstanding analogue for the isolation and confinement of space missions (especially planetary outposts), ANARE has been used as an international research platform by Australia and the United States since 1993. Collaborative research has demonstrated a lowered responsiveness of the immune system under the isolation and confinement of Antarctic winter-over; a reduction of almost 50% in T cell proliferation to mitogen phytohaemogglutinin, as well as changes in latent herpesvirus states and the expansion of the polyclonal latent Epstein-Barr virus infected B cell populations. Although no clinically significant disease has been found to result from these immune changes, research is currently assessing the effects of psychological factors on the immune system. This and associated research performed to date and its relevance to both organisations is discussed, and comment made on possible extensions to the program in both medical and other fields.

  7. Alaska volcanoes guidebook for teachers

    Adleman, Jennifer N.


    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

  8. Preliminary volcano-hazard assessment for Augustine Volcano, Alaska

    Waythomas, Christopher F.; Waitt, Richard B.


    Augustine Volcano is a 1250-meter high stratovolcano in southwestern Cook Inlet about 280 kilometers southwest of Anchorage and within about 300 kilometers of more than half of the population of Alaska. Explosive eruptions have occurred six times since the early 1800s (1812, 1883, 1935, 1964-65, 1976, and 1986). The 1976 and 1986 eruptions began with an initial series of vent-clearing explosions and high vertical plumes of volcanic ash followed by pyroclastic flows, surges, and lahars on the volcano flanks. Unlike some prehistoric eruptions, a summit edifice collapse and debris avalanche did not occur in 1812, 1935, 1964-65, 1976, or 1986. However, early in the 1883 eruption, a portion of the volcano summit broke loose forming a debris avalanche that flowed to the sea. The avalanche initiated a small tsunami reported on the Kenai Peninsula at English Bay, 90 kilometers east of the volcano. Plumes of volcanic ash are a major hazard to jet aircraft using Anchorage International and other local airports. Ashfall from future eruptions could disrupt oil and gas operations and shipping activities in Cook Inlet. Eruptions similar to the historical and prehistoric eruptions are likely in Augustine's future.

  9. Tilt signals at Mount Melbourne, Antarctica: evidence of a shallow volcanic source

    Salvatore Gambino


    Full Text Available Mount Melbourne (74°21′ S, 164°43′ E is a quiescent volcano located in northern Victoria Land, Antarctica. Tilt signals have been recorded on Mount Melbourne since early 1989 by a permanent shallow borehole tiltmeter network comprising five stations. An overall picture of tilt, air and permafrost temperatures over 15 years of continuous recording data is reported. We focused our observations on long-term tilt trends that at the end of 1997 showed coherent changes at the three highest altitude stations, suggesting the presence of a ground deformation source whose effects are restricted to the summit area of Mount Melbourne. We inverted these data using a finite spherical body source, thereby obtaining a shallow deflation volume source located under the summit area. The ground deformation observed corroborates the hypothesis that the volcanic edifice of Mount Melbourne is active and should be monitored multidisciplinarily.

  10. The Landsat Image Mosaic of Antarctica (LIMA): A Cutting-Edge Way for Students and Teachers to Learn about Antarctica

    Campbell, Brian; Bindschadler, Robert


    By studying Antarctica via satellite and through ground-truthing research, we can learn where the ice is melting and why. The Landsat Image Mosaic of Antarctica (LIMA), a new and cutting-edge way for scientists, researchers, educators, students, and the public to look at Antarctica, supports this research and allows for unprecedented views of our…

  11. Mount Rainier, a decade volcano

    Kuehn, S.C.; Hooper, P.R. (Washington State Univ., Pullman, WA (United States). Dept. of Geology); Eggers, A.E. (Univ. of Puget Sound, Tacoma, WA (United States). Dept. of Geology)


    Mount Rainier, recently designated as a decade volcano, is a 14,410 foot landmark which towers over the heavily populated southern Puget Sound Lowland of Washington State. It last erupted in the mid-1800's and is an obvious threat to this area, yet Rainier has received little detailed study. Previous work has divided Rainier into two distinct pre-glacial eruptive episodes and one post-glacial eruptive episode. In a pilot project, the authors analyzed 253 well-located samples from the volcano for 27 major and trace elements. Their objective is to test the value of chemical compositions as a tool in mapping the stratigraphy and understanding the eruptive history of the volcano which they regard as prerequisite to determining the petrogenesis and potential hazard of the volcano. The preliminary data demonstrates that variation between flows is significantly greater than intra-flow variation -- a necessary condition for stratigraphic use. Numerous flows or groups of flows can be distinguished chemically. It is also apparent from the small variation in Zr abundances and considerable variation in such ratios as Ba/Nb that fractional crystallization plays a subordinate role to some form of mixing process in the origin of the Mount Rainier lavas.

  12. Acting Antarctica: science on stage

    Ciceri, Piera; Tizzoni, Paola; Pierro, Luigia


    Key-words: Polar science, Earth science, Theatre, Hands on activities The legendary Antarctic Expedition of sir E. Shackleton and his crew of 27 aboard the Endurance (1914/16) trapped in the Antarctic ice has become the starting point to learn about Polar Science and Climate Change. While the students were involved into this incredible adventure by the astonishing images of the Australian photographer Frank Hurley (who joined the crew), they discovered the world in which this story happened. Students were then involved in hands-on activities and role plays and have become the writers of the play "Uomini a scienza ai confini del mondo". They act the story of Shackelton's expedition and they tell at the same time to the audience about ice pack, ice cores and their role in understanding the past of the climate, physical and geographical characteristic of polar regions, thermal phenomena related to adaptations of polar animals, solar radiation at different latitude, day/night duration. The theater was the place to "stage" some scientific experiments and to explain the current research carried out in polar regions and their importance in climate change studies and to stress some similarities between Antarctica and space. The project was carried out from teachers of science, letters and geography and was born in collaboration with the "Piccolo Teatro di Milano" and the association "Science Under 18" with the support of a professional actor and director and was played for other schools at "EXPO 2015" in Milano (Italy). In our opinion drama activities improve reading comprehension, and both verbal and non-verbal communication skills. To be able to write and to act, students need a deep understanding of contents. Arts, including theatre, are a good key to involve emotionally students. To have an audience different from their own teachers and classmates offers a real task and the opportunity to play and let grow real skills.

  13. Degassing dynamics of basaltic lava lake at a top-ranking volatile emitter: Ambrym volcano, Vanuatu arc

    Allard, Patrick; Burton, Mike; Sawyer, Georgina; Bani, Philipson


    Persistent lava lakes are rare on Earth and provide volcanologists with a remarkable opportunity to directly investigate magma dynamics and degassing at the open air. Ambrym volcano, in Vanuatu, is one of the very few basaltic arc volcanoes displaying such an activity and voluminous gas emission, but whose study has long remained hampered by challenging accessibility. Here we report the first high temporal resolution (every 5 s) measurements of vigorous lava lake degassing inside its 300 m deep Benbow crater using OP-FTIR spectroscopy. Our results reveal a highly dynamic degassing pattern involving (i) recurrent (100-200 s) short-period oscillations of the volcanic gas composition and temperature, correlating with pulsated gas emission and sourced in the upper part of the lava lake, (ii) a continuous long period (∼8 min) modulation probably due to the influx of fresh magma at the bottom of the lake, and (iii) discrete CO2 spike events occurring in coincidence with the sequential bursting of meter-sized bubbles, which indicates the separate ascent of large gas bubbles or slugs in a feeder conduit with estimated diameter of 6 ± 1 m. This complex degassing pattern, measured with unprecedented detail and involving both coupled and decoupled magma-gas ascent over short time scales, markedly differs from that of quieter lava lakes at Erebus and Kilauea. It can be accounted for by a modest size of Benbow lava lake and its very high basalt supply rate (∼20 m3 s-1), favouring its rapid overturn and renewal. We verify a typical basaltic arc signature for Ambrym volcanic gas and, based on contemporaneous SO2 flux measurements, we evaluate huge emission rates of 160 Gg d-1 of H2O, ∼10 Gg d-1 of CO2 and ∼8 Gg d-1 of total acid gas (SO2, HCl and HF) during medium activity of the volcano in 2008. Such rates make Ambrym one of the three most powerful volcanic gas emitters at global scale, whose atmospheric impact at local and regional scale may be considerable.

  14. ULF fluctuations at Terra Nova Bay (Antarctica

    A. Meloni


    Full Text Available ULF geomagnetic field measurements in Antarctica are a very important tool for better understanding the dynamics of the Earth’s magnetosphere and its response to the variable solar wind conditions. We review the results obtained in the last few years at the Italian observatory at Terra Nova Bay

  15. Sterile soil from Antarctica: organic analysis.

    Horowitz, N H; Bauman, A J; Cameron, R E; Geiger, P J; Hubbard, J S; Shulman, G P; Simmonds, P G; Westberg, K


    Soils from the dry-valley region of Antarctica can be sterile by the usual microbiological criteria and yet contain significant amounts of organic carbon. Examination of one such soil shows that the organic material is finely divided anthracite coal. These findings have significant implications for the biological exploration of Mars.

  16. Antarctica: Is It More Than Just Ice?

    Johnson, Cheryl; Gutierrez, Melida


    The authors introduced polar science in a fourth-grade classroom by means of 3 hands-on activities that addressed (1) the melting of glaciers and ice, (2) the differences between the North and the South Pole, and (3) the geography and landforms of Antarctica. An assessment 4 months after the original activity showed that students remembered the…

  17. Antarctica: Is It More Than Just Ice?

    Johnson, Cheryl; Gutierrez, Melida


    The authors introduced polar science in a fourth-grade classroom by means of 3 hands-on activities that addressed (1) the melting of glaciers and ice, (2) the differences between the North and the South Pole, and (3) the geography and landforms of Antarctica. An assessment 4 months after the original activity showed that students remembered the…

  18. First airborne transient em survey in antarctica

    Auken, Esben; Mikucki, J. J.; Sørensen, Kurt Ingvard K.I.


    A first airborne transient electromagnetic survey was flown in Antarctica in December 2011 with the SkyTEM system. This transient airborne EM system has been optimized in Denmark for almost ten years and was specially designed for ground water mapping. The SkyTEM tool is ideal for mapping...

  19. Read--and Walk--to Antarctica

    Harr, Natalie; Doneyko, Kathleen; Lee, Richard E., Jr.


    The students at Crestwood Primary School proved that they have what it takes to exercise their bodies and their minds. In an effort to support their teacher's scientific expedition to Antarctica, students from kindergarten to second grade pledged to read books and do physical activity that equated to the 12,900 km (8,000-mile) journey to the…

  20. Ostracoda from Vestfold Hill lake terraces, Antarctica

    Setty, M.G.A.P.

    Six species of ostracodes are recorded from two transects of terraces of Deep Lake, Vestfold Hills, Antarctica. Two species (@iXesteleberis@@ sp. and @iBradleya dictyon@@) range from Cretaceous to Recent, @iPoseidonamicus aff. P. major@@ ranges from...

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

    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...

  2. Trace metal suites in Antarctic pre-industrial ice are consistent with emissions from quiescent degassing of volcanoes worldwide

    Matsumoto, A.; Hinkley, T.K.


    Trace metals are more abundant in atmospheric load and deposition material than can be due to rock and soil dusts and ocean salt. In pre-industrial ice from coastal west Antarctica, dust and salt account for only a few percent of the lead, cadmium, and indium that is present in most samples, less than half in any sample. For these trace metals, the deposition rate to the pre-industrial ice is approximately matched by the output rate to the atmosphere by quiescent (non-explosive) degassing of volcanoes worldwide, according to a new estimate. The basis of the match is the masses and proportions of the metals, and the proportions of Pb isotopes, in ice and in volcano emissions. The isotopic compositions of Pb in ice are similar to those of a suite of ocean island volcanoes, mostly in the southern hemisphere. The natural baseline values for pre-industrial atmospheric deposition fluxes of trace metal suites at Taylor Dome, and the worldwide quiescent volcano emissions fluxes to which they are linked, constitute a reasonably well-constrained baseline component for deposition fluxes of metals in modern times. ?? 2001 Elsevier Science B.V. All rights reserved.

  3. Volcano Monitoring Using Google Earth

    Bailey, J. E.; Dehn, J.; Webley, P.; Skoog, R.


    At the Alaska Volcano Observatory (AVO), Google Earth is being used as a visualization tool for operational satellite monitoring of the region's volcanoes. Through the abilities of the Keyhole Markup Language (KML) utilized by Google Earth, different datasets have been integrated into this virtual globe browser. Examples include the ability to browse thermal satellite image overlays with dynamic control, to look for signs of volcanic activity. Webcams can also be viewed interactively through the Google Earth interface to confirm current activity. Other applications include monitoring the location and status of instrumentation; near real-time plotting of earthquake hypocenters; mapping of new volcanic deposits; and animated models of ash plumes within Google Earth, created by a combination of ash dispersion modeling and 3D visualization packages. The globe also provides an ideal interface for displaying near real-time information on detected thermal anomalies or "hotspot"; pixels in satellite images with elevated brightness temperatures relative to the background temperature. The Geophysical Institute at the University of Alaska collects AVHRR (Advanced Very High Resolution Radiometer) and MODIS (Moderate Resolution Imaging Spectroradiometer) through its own receiving station. The automated processing that follows includes application of algorithms that search for hotspots close to volcano location, flagging those that meet certain criteria. Further automated routines generate folders of KML placemarkers, which are linked to Google Earth through the network link function. Downloadable KML files have been created to provide links to various data products for different volcanoes and past eruptions, and to demonstrate examples of the monitoring tools developed. These KML files will be made accessible through a new website that will become publicly available in December 2006.

  4. Modeling eruptions of Karymsky volcano

    Ozerov, A.; Ispolatov, I.; Lees, J.


    A model is proposed to explain temporal patterns of activity in a class of periodically exploding Strombolian-type volcanos. These patterns include major events (explosions) which follow each other every 10-30 minutes and subsequent tremor with a typical period of 1 second. This two-periodic activity is thought to be caused by two distinct mechanisms of accumulation of the elastic energy in the moving magma column: compressibility of the magma in the lower conduit and viscoelastic response of...

  5. Earthquakes - Volcanoes (Causes and Forecast)

    Tsiapas, E.


    EARTHQUAKES - VOLCANOES (CAUSES AND FORECAST) ELIAS TSIAPAS RESEARCHER NEA STYRA, EVIA,GREECE TEL.0302224041057 The earthquakes are caused by large quantities of liquids (e.g. H2O, H2S, SO2, ect.) moving through lithosphere and pyrosphere (MOHO discontinuity) till they meet projections (mountains negative projections or projections coming from sinking lithosphere). The liquids are moved from West Eastward carried away by the pyrosphere because of differential speed of rotation of the pyrosphere by the lithosphere. With starting point an earthquake which was noticed at an area and from statistical studies, we know when, where and what rate an earthquake may be, which earthquake is caused by the same quantity of liquids, at the next east region. The forecast of an earthquake ceases to be valid if these components meet a crack in the lithosphere (e.g. limits of lithosphere plates) or a volcano crater. In this case the liquids come out into the atmosphere by the form of gasses carrying small quantities of lava with them (volcano explosion).

  6. Active Deformation of Etna Volcano Combing IFSAR and GPS data

    Lundgren, Paul


    The surface deformation of an active volcano is an important indicator of its eruptive state and its hazard potential. Mount Etna volcano in Sicily is a very active volcano with well documented eruption episodes.

  7. Campgrounds in Hawaii Volcanoes National Park

    National Park Service, Department of the Interior — This dataset provides campground locations in Hawaii Volcanoes National Park. Information about facilities, water availability, permit requirements and type of...

  8. Research on Methods for Building Volcano Disaster Information System--taking Changbai Mountain as an example

    ZHANG Xuexia; BO Liqun; LU Xingchang


    Volcano eruption is one of the most serious geological disasters in the world. There are volcanoes in every territory on the earth, about a thousand in China, among which Changbai Mountain Volcano, Wudalianchi Volcano and Tengchong Volcano are the most latent catastrophic eruptive active volcanoes. The paper, following an instance of Changbai Mountain Volcano, expounds that monitoring, forecasting and estimating volcano disaster by building Volcano Disaster Information System (VDIS) is feasible to alleviate volcano disaster.

  9. Volcanic hazards at Atitlan volcano, Guatemala

    Haapala, J.M.; Escobar Wolf, R.; Vallance, James W.; Rose, William I.; Griswold, J.P.; Schilling, S.P.; Ewert, J.W.; Mota, M.


    Atitlan Volcano is in the Guatemalan Highlands, along a west-northwest trending chain of volcanoes parallel to the mid-American trench. The volcano perches on the southern rim of the Atitlan caldera, which contains Lake Atitlan. Since the major caldera-forming eruption 85 thousand years ago (ka), three stratovolcanoes--San Pedro, Toliman, and Atitlan--have formed in and around the caldera. Atitlan is the youngest and most active of the three volcanoes. Atitlan Volcano is a composite volcano, with a steep-sided, symmetrical cone comprising alternating layers of lava flows, volcanic ash, cinders, blocks, and bombs. Eruptions of Atitlan began more than 10 ka [1] and, since the arrival of the Spanish in the mid-1400's, eruptions have occurred in six eruptive clusters (1469, 1505, 1579, 1663, 1717, 1826-1856). Owing to its distance from population centers and the limited written record from 200 to 500 years ago, only an incomplete sample of the volcano's behavior is documented prior to the 1800's. The geologic record provides a more complete sample of the volcano's behavior since the 19th century. Geologic and historical data suggest that the intensity and pattern of activity at Atitlan Volcano is similar to that of Fuego Volcano, 44 km to the east, where active eruptions have been observed throughout the historical period. Because of Atitlan's moderately explosive nature and frequency of eruptions, there is a need for local and regional hazard planning and mitigation efforts. Tourism has flourished in the area; economic pressure has pushed agricultural activity higher up the slopes of Atitlan and closer to the source of possible future volcanic activity. This report summarizes the hazards posed by Atitlan Volcano in the event of renewed activity but does not imply that an eruption is imminent. However, the recognition of potential activity will facilitate hazard and emergency preparedness.

  10. The oldest plesiosaur (Reptilia, Sauropterygia from Antarctica

    Alexander Wilhelm Armin Kellner


    Full Text Available Antarctic plesiosaurs are known from the Upper Cretaceous López de Bertodano and Snow Hill Island formations (Campanian to upper Maastrichtian, which crop out within the James Ross Basin region of the Antarctic Peninsula. Here we describe the first plesiosaur fossils from the Lachman Crags Member of the Santa Marta Formation, north-western James Ross Island. This material constitutes the stratigraphically oldest plesiosaur occurrence presently known from Antarctica, extending the occurrence of plesiosaurians in this continent back to Santonian times (86.3–83.5 Mya. Furthermore, MN 7163-V represents the first plesiosaur from this region not referable to the Elasmosauridae nor Aristonectes, indicating a greater diversity of this group of aquatic reptiles in Antarctica than previously suspected.

  11. Predictability of Volcano Eruption: lessons from a basaltic effusive volcano

    Grasso, J R


    Volcano eruption forecast remains a challenging and controversial problem despite the fact that data from volcano monitoring significantly increased in quantity and quality during the last decades.This study uses pattern recognition techniques to quantify the predictability of the 15 Piton de la Fournaise (PdlF) eruptions in the 1988-2001 period using increase of the daily seismicity rate as a precursor. Lead time of this prediction is a few days to weeks. Using the daily seismicity rate, we formulate a simple prediction rule, use it for retrospective prediction of the 15 eruptions,and test the prediction quality with error diagrams. The best prediction performance corresponds to averaging the daily seismicity rate over 5 days and issuing a prediction alarm for 5 days. 65% of the eruptions are predicted for an alarm duration less than 20% of the time considered. Even though this result is concomitant of a large number of false alarms, it is obtained with a crude counting of daily events that are available fro...

  12. Newberry Volcano's youngest lava flows

    Robinson, Joel E.; Donnelly-Nolan, Julie M.; Jensen, Robert A.


    Most of Newberry Volcano's youngest lava flows are found within the Newberry National Volcanic Monument in central Oregon. Established November 5, 1990, the monument is managed by the U.S. Forest Service as part of the Deschutes National Forest. Since 2011, a series of aerial surveys over the monument collected elevation data using lidar (light detection and ranging) technology, which uses lasers to directly measure the ground surface. These data record previously unseen detail in the volcano’s numerous lava flows and vents. On average, a laser return was collected from the ground’s surface every 2.17 feet (ft) with ±1.3 inches vertical precision.

  13. Managing Human Activities in Antarctica : Should Wilderness Protection Count?

    Bastmeijer, C.J.


    Antarctica is often described as one of the world's last wildernesses. In harmony with this general perception, the wilderness values of Antarctica received legal status with the adoption of the Protocol on Environmental Protection to the Antarctic Treaty. Article 3(1) of the Protocol obliges each C

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

    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.


    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

  15. Continental Scale Antarctic deposition of sulphur and black carbon from anthropogenic and volcanic sources

    H.-F. Graf


    Full Text Available While Antarctica is often described as a pristine environment, the potential threats from local pollution sources including tourist ships and emissions associated with scientific activities have recently been raised. However, to date there has been no systematic attempt to model the impacts of such pollutants at the continental scale. Indeed, until very recently there was not even a sulphur emission budget available for Antarctica. Here we present the first comprehensive study of atmospheric pollution in Antarctica using a limited area chemistry climate model, and a monthly emissions inventory for sulphur from maintenance of research stations, ground and air traffic, shipping and the active volcano Mt. Erebus. We find that ship emissions, both sulphurous and black carbon, dominate anthropogenic pollution near the ground. These are likely to rise considerably if recent trends in tourism continue.

  16. Continental scale Antarctic deposition of sulphur and black carbon from anthropogenic and volcanic sources

    H.-F. Graf


    Full Text Available While Antarctica is often described as a pristine environment, there is an increasing awareness of the potential threats from local pollution sources including tourist ships and emissions associated with scientific activities. However, to date there has been no systematic attempt to model the impacts of such pollutants at the continental scale. Indeed, until very recently there was not even a sulphur emission budget available for Antarctica. Here we present the first comprehensive study of atmospheric pollution in Antarctica using a limited area chemistry climate model, and a monthly emissions inventory for sulphur from maintenance of research stations, ground and air traffic, shipping and the active Erebus volcano. We find that ship emissions, both sulphurous and black carbon, dominate anthropogenic pollution near the ground. Their prevalence is likely to rise dramatically if recent trends in tourism continue.

  17. Volcanoes

    ... Part 3 of 3) Hot Weather Tips Heat Stress in Older Adults FAQs Extreme Heat PSAs Related Links MMWR Bibliography CDC's Program Floods Flood Readiness Personal Hygiene After a Disaster Cleanup of Flood Water After a Flood Worker Safety Educational Materials Floods ...

  18. Redoubt Volcano: 2009 Eruption Overview

    Bull, K. F.


    Redoubt Volcano is a 3110-m glaciated stratovolcano located 170 km SW of Anchorage, Alaska, on the W side of Cook Inlet. The edifice comprises a oil production in Cook Inlet was halted for nearly five months. Unrest began in August, 2008 with reports of H2S odor. In late September, the Alaska Volcano Observatory (AVO)’s seismic network recorded periods of volcanic tremor. Throughout the fall, AVO noted increased fumarolic emissions and accompanying ice- and snow-melt on and around the 1990 dome, and gas measurements showed elevated H2S and CO2 emissions. On January 23, seismometers recorded 48 hrs of intermittent tremor and discrete, low-frequency to hybrid events. Over the next 6 weeks, seismicity waxed and waned, an estimated 5-6 million m3 of ice were lost due to melting, volcanic gas emissions increased, and debris flows emerged repeatedly from recently formed ice holes near the 1990 dome, located on the crater’s N (“Drift”) side. On March 15, a phreatic explosion deposited non-juvenile ash from a new vent in the summit ice cap just S of the 1990 dome. Ash from the explosion rose to ~4500 m above sea level (asl). The plume was accompanied by weak seismicity. The first magmatic explosion occurred on March 22. Over the next two weeks, more than 19 explosions destroyed at least two lava domes and produced ash plumes that reached 6-18 km asl. Tephra was deposited along variable azimuths including trace to minor amounts on Anchorage and Kenai Peninsula communities, and reached Fairbanks, ~800 km to the N. Several lahars were produced by explosive disruption and melting of the “Drift” glacier. The largest lahars followed explosions on March 23 and April 4 and inundated the Drift River valley to the coast, causing temporary evacuation of the Drift River Oil Terminal, ~40 km from the vent. Time-lapse images captured pyroclastic flows and lahars in the “Drift” glacier valley during several of the explosions. Ballistics and pyroclastic flow deposits were

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

    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.


    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.

  20. The genus Bryoerythrophyllum (Musci, Pottiaceae in Antarctica

    Sollman Philip


    Full Text Available Antarctic material of the genus Bryoerythrophyllum P. C. Chen was studied from all specimens present in KRAM. Bryoerythrophyllum recurvirostrum (Hedw. P. C. Chen var. antarcticum L. I. Savicz & Smirnova is treated as a distinct species: B. antarcticum (L. I. Savicz & Smirnova P. Sollman, stat. nov. Three species are now known in the Antarctic region: B. antarcticum, B. recurvirostrum and B. rubrum (Jur. ex Geh. P. C. Chen. Bryoerythrophyllum rubrum is reported for the first time from the Antarctic. It is a bipolar species. A key to the taxa is given. These species are described and briefly discussed, with notes on illustrations, reproduction, habitat, world range, distribution and elevation in Antarctica.

  1. Autonomous Observations in Antarctica with AMICA

    Di Rico, Gianluca; Dolci, Mauro; Straniero, Oscar; Valentini, Angelo; Valentini, Gaetano; Di Cianno, Amico; Giuliani, Croce; Magrin, Demetrio; Bonoli, Carlotta; Bortoletto, Favio; D'Alessandro, Maurizio; Corcione, Leonardo; Riva, Alberto


    The Antarctic Multiband Infrared Camera (AMICA) is a double channel camera operating in the 2-28 micron infrared domain (KLMNQ bands) that will allow to characterize and exploit the exceptional advantages for Astronomy, expected from Dome C in Antarctica. The development of the camera control system is at its final stage. After the investigation of appropriate solutions against the critical environment, a reliable instrumentation has been developed. It is currently being integrated and tested to ensure the correct execution of automatic operations. Once it will be mounted on the International Robotic Antarctic Infrared Telescope (IRAIT), AMICA and its equipment will contribute to the accomplishment of a fully autonomous observatory.

  2. Antarctica and the strategic plan for biodiversity.

    Chown, Steven L; Brooks, Cassandra M; Terauds, Aleks; Le Bohec, Céline; van Klaveren-Impagliazzo, Céline; Whittington, Jason D; Butchart, Stuart H M; Coetzee, Bernard W T; Collen, Ben; Convey, Peter; Gaston, Kevin J; Gilbert, Neil; Gill, Mike; Höft, Robert; Johnston, Sam; Kennicutt, Mahlon C; Kriesell, Hannah J; Le Maho, Yvon; Lynch, Heather J; Palomares, Maria; Puig-Marcó, Roser; Stoett, Peter; McGeoch, Melodie A


    The Strategic Plan for Biodiversity, adopted under the auspices of the Convention on Biological Diversity, provides the basis for taking effective action to curb biodiversity loss across the planet by 2020-an urgent imperative. Yet, Antarctica and the Southern Ocean, which encompass 10% of the planet's surface, are excluded from assessments of progress against the Strategic Plan. The situation is a lost opportunity for biodiversity conservation globally. We provide such an assessment. Our evidence suggests, surprisingly, that for a region so remote and apparently pristine as the Antarctic, the biodiversity outlook is similar to that for the rest of the planet. Promisingly, however, much scope for remedial action exists.

  3. Antarctica: measuring glacier velocity from satellite images.

    Lucchitta, B K; Ferguson, H M


    Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.

  4. Exhumation of the Shackleton Range, Antarctica

    Lucka, Nicole; Lisker, Frank; Läufer, Andreas; Spiegel, Cornelia


    The Shackleton Range is situated between 80° - 81°S and 19° - 31°W, where it forms the continuation of the Transantarctic Mountains in the Weddell Sea sector of Antarctica. There, Precambrian igneous and metamorphic basement is overlain by (meta-) sedimentary rocks of an Early Paleozoic nappe stack and post-orogenic red beds. Nappe stacking resulted from the collision of East and West Gondwana due to the closure of the Mozambique Ocean in pan-African times. The uplift and exhumation history of the Shackleton Range has been analysed earlier based on a series of vertical fission track profiles (Schäfer, 1998; Lisker et al., 1999). Zircon ages range from ~160 to 210 Ma while apatite ages between ~95 and ~170 Ma comprise a break in slope of the altitude regression at ~110 Ma, and are accompanied by mean track lengths of 12.7 - 14.1 µm (standard deviation 1.0 - 1.4 µm). These data have been interpreted qualitatively in terms of two cooling/ exhumation stages during Jurassic and mid-Cretaceous times. However, the recognition of Jurassic volcaniclastic rocks associated with the ~180 Ma Ferrar event in the vicinity of the sample locations (Buggisch et al., 1994) challenges this exhumation concept. Moreover, new fission track proxy data (Dpar) and apatite (U-Th-Sm)/He ages between 88 and 171 Ma allow thermal history modelling of the combined thermochronological data. First tentative thermal history models suggest early Mesozoic cooling followed by (post-) Jurassic heating and final cooling since the Late Cretaceous. This scenario requires burial of the Shackleton Range region, and therefore the existence of a sedimentary basin at least during the Jurassic-Early Cretaceous, and subsequent basin inversion. The thickness of the now vanished sedimentary strata did unlikely exceed 2 - 3 km. Future work including additional apatite fission track analyses will help to quantifying geometry, depth and timing of this depocentre and evaluating potential links with the coeval

  5. Volcano Monitoring Using Google Earth

    Cameron, W.; Dehn, J.; Bailey, J. E.; Webley, P.


    At the Alaska Volcano Observatory (AVO), remote sensing is an important component of its daily monitoring of volcanoes. AVO’s remote sensing group (AVORS) primarily utilizes three satellite datasets; Advanced Very High Resolution Radiometer (AVHRR) data, from the National Oceanic and Atmospheric Administration’s (NOAA) Polar Orbiting Satellites (POES), Moderate Resolution Imaging Spectroradiometer (MODIS) data from the National Aeronautics and Space Administration’s (NASA) Terra and Aqua satellites, and NOAA’s Geostationary Operational Environmental Satellites (GOES) data. AVHRR and MODIS data are collected by receiving stations operated by the Geographic Information Network of Alaska (GINA) at the University of Alaska’s Geophysical Institute. An additional AVHRR data feed is supplied by NOAA’s Gilmore Creek satellite tracking station. GOES data are provided by the Naval Research Laboratory (NRL), Monterey Bay. The ability to visualize these images and their derived products is critical for the timely analysis of the data. To this end, AVORS has developed javascript web interfaces that allow the user to view images and metadata. These work well for internal analysts to quickly access a given dataset, but they do not provide an integrated view of all the data. To do this AVORS has integrated its datasets with Keyhole Markup Language (KML) allowing them to be viewed by a number of virtual globes or other geobrowsers that support this code. Examples of AVORS’ use of KML include the ability to browse thermal satellite image overlays to look for signs of volcanic activity. Webcams can also be viewed interactively through KML to confirm current activity. Other applications include monitoring the location and status of instrumentation; near real-time plotting of earthquake hypocenters; mapping of new volcanic deposits using polygons; and animated models of ash plumes, created by a combination of ash dispersion modeling and 3D visualization packages.

  6. Parallel System Architecture (PSA): An efficient approach for automatic recognition of volcano-seismic events

    Cortés, Guillermo; García, Luz; Álvarez, Isaac; Benítez, Carmen; de la Torre, Ángel; Ibáñez, Jesús


    Automatic recognition of volcano-seismic events is becoming one of the most demanded features in the early warning area at continuous monitoring facilities. While human-driven cataloguing is time-consuming and often an unreliable task, an appropriate machine framework allows expert technicians to focus only on result analysis and decision-making. This work presents an alternative to serial architectures used in classic recognition systems introducing a parallel implementation of the whole process: configuration, feature extraction, feature selection and classification stages are independently carried out for each type of events in order to exploit the intrinsic properties of each signal class. The system uses Gaussian Mixture Models (GMMs) to classify the database recorded at Deception Volcano Island (Antarctica) obtaining a baseline recognition rate of 84% with a cepstral-based waveform parameterization in the serial architecture. The parallel approach increases the results to close to 92% using mixture-based parameterization vectors or up to 91% when the vector size is reduced by 19% via the Discriminative Feature Selection (DFS) algorithm. Besides the result improvement, the parallel architecture represents a major step in terms of flexibility and reliability thanks to the class-focused analysis, providing an efficient tool for monitoring observatories which require real-time solutions.

  7. Lahar hazards at Agua volcano, Guatemala

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


    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.

  8. Volcanoes muon imaging using Cherenkov telescopes

    Catalano, Osvaldo; Mineo, Teresa; Cusumano, Giancarlo; Maccarone, Maria Concetta; Pareschi, Giovanni


    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 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 energ...

  9. Radial anisotropy ambient noise tomography of volcanoes

    Mordret, Aurélien; Rivet, Diane; Shapiro, Nikolai; Jaxybulatov, Kairly; Landès, Matthieu; Koulakov, Ivan; Sens-Schönfelder, Christoph


    The use of ambient seismic noise allows us to perform surface-wave tomography of targets which could hardly be imaged by other means. The frequencies involved (~ 0.5 - 20 s), somewhere in between active seismic and regular teleseismic frequency band, make possible the high resolution imaging of intermediate-size targets like volcanic edifices. Moreover, the joint inversion of Rayleigh and Love waves dispersion curves extracted from noise correlations allows us to invert for crustal radial anisotropy. We present here the two first studies of radial anisotropy on volcanoes by showing results from Lake Toba Caldera, a super-volcano in Indonesia, and from Piton de la Fournaise volcano, a hot-spot effusive volcano on the Réunion Island (Indian Ocean). We will see how radial anisotropy can be used to infer the main fabric within a magmatic system and, consequently, its dominant type of intrusion.

  10. A field guide to Newberry Volcano, Oregon

    Jenson, Robert A.; Donnelly-Nolan, Julie M.; McKay, Daniele


    Newberry Volcano is located in central Oregon at the intersection of the Cascade Range and the High Lava Plains. Its lavas range in age from ca. 0.5 Ma to late Holocene. Erupted products range in composition from basalt through rhyolite and cover ~3000 km2. The most recent caldera-forming eruption occurred ~80,000 years ago. This trip will highlight a revised understanding of the volcano's history based on new detailed geologic work. Stops will also focus on evidence for ice and flooding on the volcano, as well as new studies of Holocene mafic eruptions. Newberry is one of the most accessible U.S. volcanoes, and this trip will visit a range of lava types and compositions including tholeiitic and calc-alkaline basalt flows, cinder cones, and rhyolitic domes and tuffs. Stops will include early distal basalts as well as the youngest intracaldera obsidian flow.

  11. Cenozoic geodynamics of the Ross Sea region, Antarctica: Crustal extension, intraplate strike-slip faulting, and tectonic inheritance

    Salvini, Francesco; Brancolini, Giuliano; Busetti, Martina; Storti, Fabrizio; Mazzarini, Francesco; Coren, Franco


    An integrated study of onshore and offshore geology of the Ross Sea region (namely, Victoria Land, north of Ross Island, and the Ross Sea, Antarctica) has revealed a complex, post-Eocene tectonic framework. Regional NW-SE right-lateral, strike-slip faults are the outstanding feature of this framework and overprint an older Mesozoic extensional event, responsible for formation of N-S basins in the Ross Sea. The Cenozoic framework includes kinematic deformation and reactivation along the NW-SE faults, including formation of pull-apart basins, both positive and negative flower structures, and push-up ridges. N-S extensional faults are well developed between NW-SE faults and indicate E-W extension during the Cenozoic, produced by the NW-SE right-lateral strike-slip motion together with regional crustal extension. NNW-SSE compression, induced by the right-lateral, strike-slip kinematics, is indicated by locally inverted NE-SW faults and basins. The evolution, geometry, and location of the Rennick Graben and the Lanterman Range fit well into this model. Variations in the deformational style across the region can be linked to corresponding variations in the bulk crustal rheology, from brittle behavior in the west, to ductile deformation (at subseismic-scale resolution) near the Eastern Basin. A semibrittle region that favors N-S clustering of Cenozoic magmatic activity lies in between. In this region, Cenozoic volcanoes develop at the intersections of the NW-SE and the major N-S faults. The NW-SE faults cut almost continually from the Ross Sea to East Antarctica through lithospheric sectors with different rheology and thickness. At least two of the NW-SE faults correspond to older Paleozoic terrane boundaries in northern Victoria Land. The NW-SE faults link in the Southern Ocean with major transform faults related to the plate motions of Australia, New Zealand, and Antarctica.

  12. Deglacial temperature history of West Antarctica

    Cuffey, Kurt M.; Clow, Gary D.; Steig, Eric J.; Buizert, Christo; Fudge, T. J.; Koutnik, Michelle; Waddington, Edwin D.; Alley, Richard B.; Severinghaus, Jeffrey P.


    The most recent glacial to interglacial transition constitutes a remarkable natural experiment for learning how Earth’s climate responds to various forcings, including a rise in atmospheric CO2. This transition has left a direct thermal remnant in the polar ice sheets, where the exceptional purity and continual accumulation of ice permit analyses not possible in other settings. For Antarctica, the deglacial warming has previously been constrained only by the water isotopic composition in ice cores, without an absolute thermometric assessment of the isotopes’ sensitivity to temperature. To overcome this limitation, we measured temperatures in a deep borehole and analyzed them together with ice-core data to reconstruct the surface temperature history of West Antarctica. The deglacial warming was 11.3±1.8∘11.3±1.8∘C, approximately two to three times the global average, in agreement with theoretical expectations for Antarctic amplification of planetary temperature changes. Consistent with evidence from glacier retreat in Southern Hemisphere mountain ranges, the Antarctic warming was mostly completed by 15 kyBP, several millennia earlier than in the Northern Hemisphere. These results constrain the role of variable oceanic heat transport between hemispheres during deglaciation and quantitatively bound the direct influence of global climate forcings on Antarctic temperature. Although climate models perform well on average in this context, some recent syntheses of deglacial climate history have underestimated Antarctic warming and the models with lowest sensitivity can be discounted.

  13. The Landsat Image Mosaic of Antarctica

    Bindschadler, R.; Vornberger, P.; Fleming, A.; Fox, A.; Mullins, J.; Binnie, D.; Paulsen, S.J.; Granneman, B.; Gorodetzky, D.


    The Landsat Image Mosaic of Antarctica (LIMA) is the first true-color, high-spatial-resolution image of the seventh continent. It is constructed from nearly 1100 individually selected Landsat-7 ETM+ scenes. Each image was orthorectified and adjusted for geometric, sensor and illumination variations to a standardized, almost seamless surface reflectance product. Mosaicing to avoid clouds produced a high quality, nearly cloud-free benchmark data set of Antarctica for the International Polar Year from images collected primarily during 1999-2003. Multiple color composites and enhancements were generated to illustrate additional characteristics of the multispectral data including: the true appearance of the surface; discrimination between snow and bare ice; reflectance variations within bright snow; recovered reflectance values in regions of sensor saturation; and subtle topographic variations associated with ice flow. LIMA is viewable and individual scenes or user defined portions of the mosaic are downloadable at Educational materials associated with LIMA are available at

  14. Lahar-hazard zonation for San Miguel volcano, El Salvador

    Major, J.J.; Schilling, S.P.; Pullinger, C.R.; Escobar, C.D.; Chesner, C.A.; Howell, M.M.


    San Miguel volcano, also known as Chaparrastique, is one of many volcanoes along the volcanic arc in El Salvador. The volcano, located in the eastern part of the country, rises to an altitude of about 2130 meters and towers above the communities of San Miguel, El Transito, San Rafael Oriente, and San Jorge. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and the PanAmerican and coastal highways cross the lowermost northern and southern flanks of the volcano. The population density around San Miguel volcano coupled with the proximity of major transportation routes increases the risk that even small volcano-related events, like landslides or eruptions, may have significant impact on people and infrastructure. San Miguel volcano is one of the most active volcanoes in El Salvador; it has erupted at least 29 times since 1699. Historical eruptions of the volcano consisted mainly of relatively quiescent emplacement of lava flows or minor explosions that generated modest tephra falls (erupted fragments of microscopic ash to meter sized blocks that are dispersed into the atmosphere and fall to the ground). Little is known, however, about prehistoric eruptions of the volcano. Chemical analyses of prehistoric lava flows and thin tephra falls from San Miguel volcano indicate that the volcano is composed dominantly of basalt (rock having silica content

  15. EARTHQUAKES - VOLCANOES (Causes - Forecast - Counteraction)

    Tsiapas, Elias


    Earthquakes and volcanoes are caused by: 1)Various liquid elements (e.g. H20, H2S, S02) which emerge from the pyrosphere and are trapped in the space between the solid crust and the pyrosphere (Moho discontinuity). 2)Protrusions of the solid crust at the Moho discontinuity (mountain range roots, sinking of the lithosphere's plates). 3)The differential movement of crust and pyrosphere. The crust misses one full rotation for approximately every 100 pyrosphere rotations, mostly because of the lunar pull. The above mentioned elements can be found in small quantities all over the Moho discontinuity, and they are constantly causing minor earthquakes and small volcanic eruptions. When large quantities of these elements (H20, H2S, SO2, etc) concentrate, they are carried away by the pyrosphere, moving from west to east under the crust. When this movement takes place under flat surfaces of the solid crust, it does not cause earthquakes. But when these elements come along a protrusion (a mountain root) they concentrate on its western side, displacing the pyrosphere until they fill the space created. Due to the differential movement of pyrosphere and solid crust, a vacuum is created on the eastern side of these protrusions and when the aforementioned liquids overfill this space, they explode, escaping to the east. At the point of their escape, these liquids are vaporized and compressed, their flow accelerates, their temperature rises due to fluid friction and they are ionized. On the Earth's surface, a powerful rumbling sound and electrical discharges in the atmosphere, caused by the movement of the gasses, are noticeable. When these elements escape, the space on the west side of the protrusion is violently taken up by the pyrosphere, which collides with the protrusion, causing a major earthquake, attenuation of the protrusions, cracks on the solid crust and damages to structures on the Earth's surface. It is easy to foresee when an earthquake will occur and how big it is

  16. Spreading and collapse of big basaltic volcanoes

    Puglisi, Giuseppe; Bonforte, Alessandro; Guglielmino, Francesco; Peltier, Aline; Poland, Michael


    Among the different types of volcanoes, basaltic ones usually form the most voluminous edifices. Because volcanoes are growing on a pre-existing landscape, the geologic and structural framework of the basement (and earlier volcanic landforms) influences the stress regime, seismicity, and volcanic activity. Conversely, the masses of these volcanoes introduce a morphological anomaly that affects neighboring areas. Growth of a volcano disturbs the tectonic framework of the region, clamps and unclamps existing faults (some of which may be reactivated by the new stress field), and deforms the substratum. A volcano's weight on its basement can trigger edifice spreading and collapse that can affect populated areas even at significant distance. Volcano instability can also be driven by slow tectonic deformation and magmatic intrusion. The manifestations of instability span a range of temporal and spatial scales, ranging from slow creep on individual faults to large earthquakes affecting a broad area. In the frame of MED-SVU project, our work aims to investigate the relation between basement setting and volcanic activity and stability at three Supersite volcanoes: Etna (Sicily, Italy), Kilauea (Island of Hawaii, USA) and Piton de la Fournaise (La Reunion Island, France). These volcanoes host frequent eruptive activity (effusive and explosive) and share common features indicating lateral spreading and collapse, yet they are characterized by different morphologies, dimensions, and tectonic frameworks. For instance, the basaltic ocean island volcanoes of Kilauea and Piton de la Fournaise are near the active ends of long hotspot chains while Mt. Etna has developed at junction along a convergent margin between the African and Eurasian plates and a passive margin separating the oceanic Ionian crust from the African continental crust. Magma supply and plate velocity also differ in the three settings, as to the sizes of the edifices and the extents of their rift zones. These

  17. The seismicity of Marapi volcano, West Sumatra.

    D'Auria, L.


    Marapi is one of the active volcanoes in West Sumatra. It is a stratovolcano with an edifice that is elongated in the ENE-WSW direction. Its elevation is about 2,900 m a.s.l. The summit area is characterized by a caldera that contains some active craters aligned along the ENE-WSW direction. The Marapi volcano is an attractive region for tourists and hosts many small communities its surrounding areas. The recent history of Mt. Marapi is characterized by explosive activity at the summit craters. No lava flows have passed the rim of the summit caldera in recent times. The last eruption occurred on August 5, 2004, and consisted of moderate explosive activity from the central crater. In 1975 an eruption with magmatic and phreatic explosive phases and mudflows and lahars occurred that caused fatalities in the surrounding areas. Since 1980 other eruptions have occurred at Marapi volcano. Even if the explosive intensities of those eruptions have been small to moderate, in some cases, there were fatalities. A cooperation project started between Italy and Indonesia (COVIN) for the monitoring of volcanoes in West Sumatra. In the context of this project a monitoring centre has been set up at the Bukittinggi Observatory and a seismological monitoring system for Marapi volcano has been realized. This system is based on a broadband seismic network including 4 three-component stations. The data acquired by the broadband network of Marapi volcano are continuous recordings of the seismic signals starting from 19/10/2006. Volcano-Tectonic and Long Period events of Marapi volcano together with regional and teleseismic earthquakes are recorded. Several events of high magnitude located at short distances from the network were also recorded such as on March 6, 2007, when two events of Magnitudes Mw 6.4 and 6.3 were recorded with the epicentres near the Marapi volcano. During the following days, there was a sequence of hundreds of aftershocks. The preliminary analysis of the seismicity of

  18. Molecular variation of antarctic grass Deschampsia antarctica Desv. from King George Island (Antarctica

    Katarzyna J. Chwedorzewska


    Full Text Available Deschampsia antarctica Desv. plants collected on King George Islands (Antarctica at two localities that differ in topographic and nutrition conditions exhibited morphological variation that differentiated plants of both locations. The molecular variation characteristic to individuals of both sites was tested using AFLP approach in order to verify whether morphological variation characteristic to the plants resulted from environmental factors or possibly from differences at the DNA level. Four primer pair combinations were used to generate 339 AFLP fragments, 132 of which were polymorphic and allowed evaluation of genetic relationships among D. antarctica individuals. Chi-square test revealed that only 12 signals were discriminative for the plants from both locations. Cluster analysis conducted on these AFLP fragments demonstrated that plants from the location rich in biogenes were more polymorphic than those from poor one. Our data suggest that the phenotypic variation specific to plants of both locations seem to be the result of adaptation to the environmental conditions like soil and moisture rather than reflect genetic differences.

  19. Environmental controls of marine productivity hot spots around Antarctica

    Arrigo, Kevin R; van Dijken, Gert L; Strong, Aaron L


    ...) in 46 coastal polynyas around Antarctica. Data presented here suggest that melting ice shelves are a primary supplier of Fe to coastal polynyas, with basal melt rates explaining 59% of the between...

  20. Volcanic ash layers in blue ice fields (Beardmore Glacier Area, Antarctica): Iridium enrichments

    Koeberl, Christian


    Dust bands on blue ice fields in Antarctica have been studied and have been identified to originate from two main sources: bedrock debris scraped up from the ground by the glacial movement (these bands are found predominantly at fractures and shear zones in the ice near moraines), and volcanic debris deposited on and incorporated in the ice by large-scale eruptions of Antarctic (or sub-Antractic) volcanoes. Ice core studies have revealed that most of the dust layers in the ice cores are volcanic (tephra) deposits which may be related to some specific volcanic eruptions. These eruptions have to be related to some specific volcanic eruptions. These eruptions have to be relatively recent (a few thousand years old) since ice cores usually incorporate younger ice. In contrast, dust bands on bare blue ice fields are much older, up to a few hundred thousand years, which may be inferred from the rather high terrestrial age of meteorites found on the ice and from dating the ice using the uranium series method. Also for the volcanic ash layers found on blue ice fields correlations between some specific volcanoes (late Cenozoic) and the volcanic debris have been inferred, mainly using chemical arguments. During a recent field expedition samples of several dust bands found on blue ice fields at the Lewis Cliff Ice Tongue were taken. These dust band samples were divided for age determination using the uranium series method, and chemical investigations to determine the source and origin of the dust bands. The investigations have shown that most of the dust bands found at the Ice Tongue are of volcanic origin and, for chemical and petrological reasons, may be correlated with Cenozoic volcanoes in the Melbourne volcanic province, Northern Victoria Land, which is at least 1500 km away. Major and trace element data have been obtained and have been used for identification and correlation purposes. Recently, some additional trace elements were determined in some of the dust band

  1. Antarctica and the strategic plan for biodiversity

    Chown, Steven L.; Brooks, Cassandra M.; Terauds, Aleks; Le Bohec, Céline; van Klaveren-Impagliazzo, Céline; Whittington, Jason D.; Butchart, Stuart H. M.; Coetzee, Bernard W. T.; Collen, Ben; Convey, Peter; Gaston, Kevin J.; Gilbert, Neil; Gill, Mike; Höft, Robert; Johnston, Sam; Kennicutt, Mahlon C.; Kriesell, Hannah J.; Le Maho, Yvon; Lynch, Heather J.; Palomares, Maria; Puig-Marcó, Roser; Stoett, Peter; McGeoch, Melodie A.


    The Strategic Plan for Biodiversity, adopted under the auspices of the Convention on Biological Diversity, provides the basis for taking effective action to curb biodiversity loss across the planet by 2020—an urgent imperative. Yet, Antarctica and the Southern Ocean, which encompass 10% of the planet’s surface, are excluded from assessments of progress against the Strategic Plan. The situation is a lost opportunity for biodiversity conservation globally. We provide such an assessment. Our evidence suggests, surprisingly, that for a region so remote and apparently pristine as the Antarctic, the biodiversity outlook is similar to that for the rest of the planet. Promisingly, however, much scope for remedial action exists. PMID:28350825

  2. Caloplaca coeruleofrigida sp. nova, a species from continental Antarctica

    Søchting, Ulrik; Seppelt, R.


    Caloplaca coeruleofrigida Søchting & Seppelt is described from Southern Victoria Land, continental Antarctica. It is characterized by vertically elongated papillae and a pale orange pigmentation on shaded parts, and black thallus and apothecia on exposed parts of the thallus......Caloplaca coeruleofrigida Søchting & Seppelt is described from Southern Victoria Land, continental Antarctica. It is characterized by vertically elongated papillae and a pale orange pigmentation on shaded parts, and black thallus and apothecia on exposed parts of the thallus...

  3. Occurrence and Diversity of Marine Yeasts in Antarctica Environments

    ZHANG Xue; HUA Mingxia; SONG Chunli; CHI Zhenming


    A total of 28 yeast strains were obtained from the sea sediment of Antarctica.According to the results of routine identification and molecular characterization,the strains belonged to species of Yarrowia lipolytica,Debaryomyces hansenii,Rhodotorula slooffiae,Rhodotorula mucilaginosa,Sporidiobolus salmonicolor,Aureobasidium pullulans,Mrakia frigida and Guehomyces pullulans,respectively.The Antarctica yeasts have wide potential applications in biotechnology,for some of them can produce β-galactosidase and killer toxins.

  4. Occurrence and diversity of marine yeasts in Antarctica environments

    Zhang, Xue; Hua, Mingxia; Song, Chunli; Chi, Zhenming


    A total of 28 yeast strains were obtained from the sea sediment of Antarctica. According to the results of routine identification and molecular characterization, the strains belonged to species of Yarrowia lipolytica, Debaryomyces hansenii, Rhodotorula slooffiae, Rhodotorula mucilaginosa, Sporidiobolus salmonicolor, Aureobasidium pullulans, Mrakia frigida and Guehomyces pullulans, respectively. The Antarctica yeasts have wide potential applications in biotechnology, for some of them can produce β-galactosidase and killer toxins.

  5. Seismic unrest at Katla Volcano- southern Iceland

    jeddi, zeinab; Tryggvason, Ari; Gudmundsson, Olafur; Bödvarsson, Reynir; SIL Seismology Group


    Katla volcano is located on the propagating Eastern Volcanic Zone (EVZ) in South Iceland. It is located beneath Mýrdalsjökull ice-cap which covers an area of almost 600 km2, comprising the summit caldera and the eruption vents. 20 eruptions between 930 and 1918 with intervals of 13-95 years are documented at Katla which is one of the most active subglacial volcanoes in Iceland. Eruptions at Katla are mainly explosive due to the subglacial mode of extrusion and produce high eruption columns and catastrophic melt water floods (jökulhlaups). The present long Volcanic repose (almost 96 years) at Katla, the general unrest since 1955, and the 2010 eruption of the neighbouring Eyjafjallajökull volcano has prompted concerns among geoscientists about an imminent eruption. Thus, the volcano has been densely monitored by seismologists and volcanologists. The seismology group of Uppsala University as a partner in the Volcano Anatomy (VA) project in collaboration with the University of Iceland and the Icelandic Meteorological Office (IMO) installed 9 temporary seismic stations on and around the Mýrdalsjökull glacier in 2011. Another 10 permanent seismic stations are operated by IMO around Katla. The project's data collection is now finished and temporary stations were pulled down in August 2013. According to seismicity maps of the whole recording period, thousands of microearthquakes have occurred within the caldera region. At least three different source areas are active in Katla: the caldera region, the western Godaland region and a small cluster at the southern rim of Mýrdalsjökull near the glacial stream of Hafursarjökull. Seismicity in the southern flank has basically started after June 2011. The caldera events are mainly volcano-tectonic, while western and southern events are mostly long period (lp) and can be related to glacial or magmatic movement. One motivation of the VA Katla project is to better understand the physical mechanism of these lp events. Changes

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

    Thompson, Susan A.; Thompson, Keith S.


    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)

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

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


    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.

  8. USGS U.S. Volcanoes with Elevated Status

    U.S. Geological Survey, Department of the Interior — Website provides list of elevated status volcanoes with access to activity updates and/or information releases for changes in activity at the volcanoes. activity at...

  9. The Cenozoic Volcanoes in Northeast China

    LIU Jiaqi; HAN Jingtai; GUO Zhengfu


    There are more than 600 Cenozoic volcanic cones and craters with abeut 50 000 km2of lava flows in northeast China, which formed many volcanic clusters and shown the features of the continental rift - type volcanoes. Most volcanic activities in this area, especially in the east part of Songliao graben, were usually controlled by rifts and faults with the main direction of NE / NNE in parallel and become younger from the central graben towards its both sides, especially to the east continental margin. It is revealed that the volcanism occurred in northeast China was as strong as that occurred in Japan during the Miocene and the Quaternary. The Quaternary basalt that is usually distributed along river valley is called "valley basalt"while Neogene basalt usually distributed in the top of mounts is called "high position basalt". These volcanoes and volcanic rocks are usually composed of alkaline basalts with ultramafic inclusions, except Changbaishan volcano that is built by trachyte and pantellerite.

  10. Renewed unrest at Mount Spurr Volcano, Alaska

    Power, John A.


    The Alaska Volcano Observatory (AVO),a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys, has detected unrest at Mount Spurr volcano, located about 125 km west of Anchorage, Alaska, at the northeast end of the Aleutian volcanic arc.This activity consists of increased seismicity melting of the summit ice cap, and substantial rates of C02 and H2S emission.The current unrest is centered beneath the volcano's 3374-m-high summit, whose last known eruption was 5000–6000 years ago. Since then, Crater Peak, 2309 m in elevation and 4 km to the south, has been the active vent. Recent eruptions occurred in 1953 and 1992.

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

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


    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)

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

    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…

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

    Russo, Joseph; Mattox, Stephen; Kildau, Nicole


    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…

  14. Volcanoes muon imaging using Cherenkov telescopes

    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: [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)


    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.

  15. Applications of geophysical methods to volcano monitoring

    Wynn, Jeff; Dzurisin, Daniel; Finn, Carol A.; Kauahikaua, James P.; Lahusen, Richard G.


    The array of geophysical technologies used in volcano hazards studies - some developed originally only for volcano monitoring - ranges from satellite remote sensing including InSAR to leveling and EDM surveys, campaign and telemetered GPS networks, electronic tiltmeters and strainmeters, airborne magnetic and electromagnetic surveys, short-period and broadband seismic monitoring, even microphones tuned for infrasound. They include virtually every method used in resource exploration except large-scale seismic reflection. By “geophysical ” we include both active and passive methods as well as geodetic technologies. Volcano monitoring incorporates telemetry to handle high-bandwith cameras and broadband seismometers. Critical geophysical targets include the flux of magma in shallow reservoir and lava-tube systems, changes in active hydrothermal systems, volcanic edifice stability, and lahars. Since the eruption of Mount St. Helens in Washington State in 1980, and the eruption at Pu’u O’o in Hawai’i beginning in 1983 and still continuing, dramatic advances have occurred in monitoring technology such as “crisis GIS” and lahar modeling, InSAR interferograms, as well as gas emission geochemistry sampling, and hazards mapping and eruption predictions. The on-going eruption of Mount St. Helens has led to new monitoring technologies, including advances in broadband Wi-Fi and satellite telemetry as well as new instrumentation. Assessment of the gap between adequate monitoring and threat at the 169 potentially dangerous Holocene volcanoes shows where populations are dangerously exposed to volcanic catastrophes in the United States and its territories . This paper focuses primarily on Hawai’ian volcanoes and the northern Pacific and Cascades volcanoes. The US Geological Survey, the US National Park System, and the University of Utah cooperate in a program to monitor the huge Yellowstone volcanic system, and a separate observatory monitors the restive Long Valley

  16. Volcanoes muon imaging using Cherenkov telescopes

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


    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.

  17. Unusual seismic activity in 2011 and 2013 at the submarine volcano Rocard, Society hot spot (French Polynesia)

    Talandier, Jacques; Hyvernaud, Olivier; Maury, René C.


    We analyze two seismic events that occurred on 27 May 2011 and 29 April 2013 at the Rocard submarine volcano which overlies the Society hot spot. The Polynesian Seismic Network recorded for the first time unusual associated short- and long-period signals, with perfectly monochromatic (0.0589 Hz) Rayleigh wave trains of long period and duration. None of the numerous observations of long-period (10-30 s) signals previously associated with volcanic activity in Japan, Italy, Mexico, Indonesia, Antarctica, and the Hawaiian Islands have the characteristics we observed at Rocard. We propose a tentative model for these unusual and rather enigmatic signals, in which the movement of lava excited the resonance of a shallow open conduit under a high hydrostatic pressure of ~400 bars.

  18. The origin of the Hawaiian Volcano Observatory

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


    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.

  19. Volcano geodesy in the Cascade arc, USA

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


    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

  20. Volcano geodesy in the Cascade arc, USA

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


    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. Volcano shapes, entropies, and eruption probabilities

    Gudmundsson, Agust; Mohajeri, Nahid


    We propose that the shapes of polygenetic volcanic edifices reflect the shapes of the associated probability distributions of eruptions. In this view, the peak of a given volcanic edifice coincides roughly with the peak of the probability (or frequency) distribution of its eruptions. The broadness and slopes of the edifices vary widely, however. The shapes of volcanic edifices can be approximated by various distributions, either discrete (binning or histogram approximation) or continuous. For a volcano shape (profile) approximated by a normal curve, for example, the broadness would be reflected in its standard deviation (spread). Entropy (S) of a discrete probability distribution is a measure of the absolute uncertainty as to the next outcome/message: in this case, the uncertainty as to time and place of the next eruption. A uniform discrete distribution (all bins of equal height), representing a flat volcanic field or zone, has the largest entropy or uncertainty. For continuous distributions, we use differential entropy, which is a measure of relative uncertainty, or uncertainty change, rather than absolute uncertainty. Volcano shapes can be approximated by various distributions, from which the entropies and thus the uncertainties as regards future eruptions can be calculated. We use the Gibbs-Shannon formula for the discrete entropies and the analogues general formula for the differential entropies and compare their usefulness for assessing the probabilities of eruptions in volcanoes. We relate the entropies to the work done by the volcano during an eruption using the Helmholtz free energy. Many factors other than the frequency of eruptions determine the shape of a volcano. These include erosion, landslides, and the properties of the erupted materials (including their angle of repose). The exact functional relation between the volcano shape and the eruption probability distribution must be explored for individual volcanoes but, once established, can be used to

  2. Comparative account of benthic community at two different locations in the continental Antarctica

    Ingole, B.S.; Dhargalkar, V.K.

    Data on faunal communities, abundance and biomass were collected from seven stations in the Queen Maud Land shelf, Lazarev Sea, East Antarctica and three stations in Atca Ice Port, Weddell Sea, West Antarctica. The sampling depth ranged from 70...

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

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


    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.

  4. Muons reveal the interior of volcanoes

    Francesco Poppi


    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...

  5. The reawakening of Alaska's Augustine volcano

    Power, John A.; Nye, Christopher J.; Coombs, Michelle L.; Wessels, Rick L.; Cervelli, Peter F.; Dehn, Jon; Wallace, Kristi L.; Freymueller, Jeffrey T.; Doukas, Michael P.


    Augustine volcano, in south central Alaska, ended a 20-year period of repose on 11 January 2006 with 13 explosive eruptions in 20 days. Explosive activity shifted to a quieter effusion of lava in early February, forming a new summit lava dome and two short, blocky lava flows by late March (Figure 1).

  6. Volcano hazards at Fuego and Acatenango, Guatemala

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


    The Fuego-Acatenango massif comprises a string of five or more volcanic vents along a north-south trend that is perpendicular to that of the Central American arc in Guatemala. From north to south known centers of volcanism are Ancient Acatenango, Yepocapa, Pico Mayor de Acatenango, Meseta, and Fuego. Volcanism along the trend stretches back more than 200,000 years. Although many of the centers have been active contemporaneously, there is a general sequence of younger volcanism, from north to south along the trend. This massive volcano complex towers more than 3500 meters (m) above the Pacific coastal plain to the south and 2000 m above the Guatemalan Highlands to the north. The volcano complex comprises remnants of multiple eruptive centers, which periodically have collapsed to form huge debris avalanches. The largest of these avalanches extended more than 50 kilometers (km) from its source and covered more than 300 square km. The volcano has potential to produce huge debris avalanches that could inundate large areas of the Pacific coastal plain. In areas around the volcanoes and downslope toward the coastal plain, more than 100,000 people are potentially at risk from these and other flowage phenomena.

  7. New volcanoes discovered in southeast Australia

    Wendel, JoAnna


    Scientists have discovered three new active volcanoes in the Newer Volcanics Province (NVP) in southeast Australia. Researchers from Monash University in Melbourne describe in the Australian Journal of Earth Sciences how they used a combination of satellite photographs, detailed topography models from NASA, the distribution of magnetic minerals in the rocks, and site visits to analyze the region.

  8. Carbonate assimilation at Merapi volcano, Java Indonesia

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


    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...

  9. Degassing and differentiation in subglacial volcanoes, Iceland

    Moore, J.G.; Calk, L.C.


    Within the neovolcanic zones of Iceland many volcanoes grew upward through icecaps that have subsequently melted. These steep-walled and flat-topped basaltic subglacial volcanoes, called tuyas, are composed of a lower sequence of subaqueously erupted, pillowed lavas overlain by breccias and hyaloclastites produced by phreatomagmatic explosions in shallow water, capped by a subaerially erupted lava plateau. Glass and whole-rock analyses of samples collected from six tuyas indicate systematic variations in major elements showing that the individual volcanoes are monogenetic, and that commonly the tholeiitic magmas differentiated and became more evolved through the course of the eruption that built the tuya. At Herdubreid, the most extensively studies tuya, the upward change in composition indicates that more than 50 wt.% of the first erupted lavas need crystallize over a range of 60??C to produce the last erupted lavas. The S content of glass commonly decreases upward in the tuyas from an average of about 0.08 wt.% at the base to crystallization that generates the more evolved, lower-temperature melts during the growth of the tuyas, apparently results from cooling and degassing of magma contained in shallow magma chambers and feeders beneath the volcanoes. Cooling may result from percolation of meltwater down cracks, vaporization, and cycling in a hydrothermal circulation. Degassing occurs when progressively lower pressure eruption (as the volcanic vent grows above the ice/water surface) lowers the volatile vapour pressure of subsurface melt, thus elevating the temperature of the liquidus and hastening liquid-crystal differentiation. ?? 1991.

  10. Social, occupational and cultural adaptation in Antarctica

    Nicolas, Michel; Bishop, Sheryl; Weiss, Karine; Gaudino, Marvin


    Life in isolated and confined environments (ICEs, e.g., polar stations, submarine or space missions), is subject to important constraints which can generate psychosociological impaired outcomes. This study investigated psychological, social, occupational and cultural variables which are among the most important determinants in adaptation to a one-year wintering in Antarctica with 13 international participants. Our findings confirm and give further insight into the role of social (Cohesiveness, Social Support) and occupational (Implementation / Preparedness, Counterproductive Activity, Decision Latitude and Psychological Job Demands) dimensions of adaptation to ICE environments. Relationships between various social and occupational dimensions studies reflected detrimental effects ranging from decrements in cohesiveness, social support and work performance which differed across professional status and multicultural factors. These psychosocial issues have important implications for pre-mission selection and training, monitoring and support of crews during the mission and post-mission readaptation. Operational recommendations are suggested to improve adaptation, success and well-being for long-term ICE missions, e.g., to Mars and beyond.

  11. AGB Star Variability Observed from Antarctica

    Briguglio, Runa


    We present here a short account of the first observations done at the Italo-French base of Dome C, Antarctica, in the field of Mira variability. The observations aimed at improving our knowledge of the variability period of some important Long Period Variables (LPV), to be used in Period-Luminosity criteria for determining in a reliable way the absolute magnitudes and hence the distances of AGB stars. The observations were taken during the 2007 winter campaign, using the small-IRAIT telescope, a 25 cm Cassegrain instrument capable of multiband photometry. The telescope was equipped with a reliable remote control system, which allowed us to get very high duty-cycle observations (the highest efficient was obtained in July 2007, with more than 98% of on-source time, over 9 ``solar'' days during the long polar night). The experiments done with small IRAIT will be precious as a pathfinder, for defining the observational strategies of the larger IRAIT (International Robotic Antarctic Infrared Telescope [1]), an 80-cm aperture telescope, working mainly in IR, that will be installed in Dome C next year.

  12. Phytoplankton Bloom Phenology near Palmer Station Antarctica

    Crews, L.; Doney, S. C.; Kavanaugh, M.; Ducklow, H. W.; Schofield, O.; Glover, D. M.


    West Antarctic Peninsula (WAP) phytoplankton bloom phenology is coupled to growing season water column stratification precipitated by seasonal warming and the melting of winter sea-ice. Previous studies document declining bloom magnitude over decadal timescales in conjunction with decreasing sea-ice extent and duration in the Northern WAP, but less work has been to done explain the observed inter-annual variability in this region. Here we use a high-resolution in situ time series collected by the Palmer Station Antarctica Long Term Ecological Research program and satellite ocean color imagery to investigate the underlying mechanisms controlling phytoplankton bloom timing and magnitude near Palmer Station. We pair chlorophyll and CTD measurements collected twice per week during the austral summer, 1992—2003, with satellite ocean color and ice fractional cover data to examine bloom development and within-season trends in mixed layer depth. Initial results suggest a possible shift over time with spring/summer blooms occurring earlier in the growing season reflecting earlier sea-ice free conditions. Net phytoplankton accumulation rates are also computed and compared against growth estimates. Our results can be used to develop and validate models of coastal Antarctic primary production that better represent inter-annual primary production variability.

  13. Physical properties of aerosols at Maitri, Antarctica

    C G Deshpande; A K Kamra


    Measurements of the submicron aerosol size distribution made at the Indian Antarctic station, Maitri (70° 45′S, 11° 44′E) from January 10th to February 24th, 1997, are reported. Total aerosol concentrations normally range from 800 to 1200 particles cm-3 which are typical values for the coastal stations at Antarctica in summer. Aerosol size distributions are generally trimodal and open- ended with a peak between 75 and 133nm and two minima at 42 and 420 nm. Size distributions remain almost similar for several hours or even days in absence of any meteorological disturbance. Total aerosol concentration increases by approximately an order of magnitude whenever a low pressure system passes over the station. Based on the evolution of aerosol size-distributions during such aerosol enhancement periods, three types of cases have been identified. The nucleation mode in all three cases has been suggested to result from the photochemical conversion of the DMS emissions transported either by the marine air or by the air from the ice-melt regions around Maitri. Subsidence of midtropospheric air during the weakening of radiative inversion is suggested as a possible source of the nucleation mode particles in the third case. Growth of the nucleation mode particles by condensation, coagulation and/or by cloud processes has been suggested to be responsible for other modes in size distributions.

  14. Ozone profiles above Palmer Station, Antarctica

    Torres, Arnold L.; Brothers, George


    NASA's Goddard Space Flight Center/Wallops Flight Facility conducted a series of 52 balloon-borne measurements of vertical ozone profiles over the National Science Foundation (NSF) research facility at Palmer Station, Antarctica (64 deg 46 S, 64 deg 3 W) between August 9 and October 24, 1987. High resolution measurements were made from ground level to an average of 10 mb. While much variation was seen in the profile amounts of ozone, it is clear that a progressive depletion of ozone occurred during the measurement period, with maximum depletion taking place in the 17 to 19 km altitude region. Ozone partial pressures dropped by about 95 percent in this region. Shown here are plotted time dependences of ozone amounts observed at 17 km and at arbitrarily selected altitudes below (13 km) and above (24 km) the region of maximum depletion. Ozone partial pressure at 17 km is about 150nb in early August, and has decreased to less than 10nb in the minimums in October. The loss rate is of the order of 1.5 percent/day. In summary, a progressive depletion in stratospheric ozone over Palmer Station was observed from August to October, 1987. Maximum depletion occurred in the 17 to 19 km range, and amounted to 95 percent. Total ozone overburden decreased by up to 50 percent during the same period.

  15. Hazard maps of Colima volcano, Mexico

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


    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

  16. 45 CFR 674.4 - Restrictions on collection of meteorites in Antarctica.


    ... Antarctica. 674.4 Section 674.4 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ANTARCTIC METEORITES § 674.4 Restrictions on collection of meteorites in Antarctica. No person may collect meteorites in Antarctica for other than scientific research purposes....

  17. Where does CO2 in Antarctica cool the atmosphere ?

    Schmithüsen, Holger; Notholt, Justus; König-Langlo, Gert; Lemke, Peter; Jung, Thomas


    In a recent study we have shown that for the high altitude plateau in Antarctica CO2 causes a surplus in infrared emission to space compared to what is emitted from the surface. This corresponds to a negative greenhouse effect, and is due to the fact that for this region the surface is typically colder than the atmosphere above, opposite to the rest of the world. As a consequence, for this region an increase in CO2 leads to an increase in the energy loss to space, leading to an increase in the negative greenhouse effect. We now studied in more detail the radiative effect of CO2 and compared the results with available measurements from Antarctica. H. Schmithüsen, J. Notholt, G. Köngig-Langlo, T, Jung. How increasing CO2 leads to an increased negative greenhouse effect in Antarctica. Geophysical Research Letters, in press, 2015. doi: 10.1002/2015GL066749.

  18. Provenance of dust to Antarctica: A lead isotopic perspective

    Gili, Stefania; Gaiero, Diego M.; Goldstein, Steven L.; Chemale, Farid, Jr.; Koester, Edinei; Jweda, Jason; Vallelonga, Paul; Kaplan, Michael R.


    Antarctic ice preserves an ~800 kyr record of dust activity in the Southern Hemisphere. Major efforts have been dedicated to elucidate the origin of this material in order to gain greater insight into the atmospheric dust cycle. On the basis of Pb isotopes in Antarctic dust samples and potential sources, this contribution demonstrates for the first time that Patagonia is the main contributor of dust to Antarctica during interglacial periods as well as glacials, although the potential importance of Tierra del Fuego remains unclear because of its geochemical similarities to Patagonia. An important new finding is that the Puna-Altiplano sector of the continent is a second important dust source to eastern Antarctica during both glacials and interglacials, being more prominent during interglacials. The data indicate South America is the primary dust source to Antarctica during both glacials and interglacials.

  19. Permafrost and periglacial research in Antarctica: New results and perspectives

    Guglielmin, Mauro; Vieira, Gonçalo


    In the last two years the research within the Antarctic Permafrost, Periglacial Environments and Soils (ANTPAS) Expert Group of the Scientific Committee on Antarctic Research (SCAR) and Working Group of the International Permafrost Association (IPA) provided new results on the dynamics of periglacial environments both in Maritime and Continental Antarctica. In continental Antarctica despite the absence of air warming, in the last 15 years an active layer thickening and acceleration of permafrost degradation erosional phenomena were reported, these being mainly related to the increase of solar radiation. On the other hand, in Maritime Antarctica, with a dramatic air warming, permafrost degradation has been observed, but the role of snow cover on the ground energy balance and consequently on permafrost and active layer has been underlined. Moreover, many contributions on the knowledge on the characteristics of the Antarctic soils were carried out in several areas along a wide latitudinal range.

  20. Ongoing deformation of Antarctica following recent Great Earthquakes

    King, Matt; Santamaría-Gómez, Alvaro


    The secular motion of Antarctica is thought to be almost everywhere governed by horizontal rigid plate rotation plus three-dimensional deformations due to past and present changes in ice-ocean loading, known as glacial isostatic adjustment (GIA). We use geodetic data to investigate deformation following the 1998 magnitude ~8.1 Antarctic intra-plate Earthquake, and show sustained three-dimensional deformation along East Antarctica's coastline, 600 km from the rupture location. Using a model of viscoelastic deformation we are able to match observed northward velocity changes, and either east or height, but not all three directions simultaneously, apparently partly due to lateral variations in mantle rheology. Our modeling predicts much of Antarctica may still be deforming, with further deformation possible from the 2004 Macquarie Ridge Earthquake. This previously unconsidered mode of Antarctic deformation affects geodetic estimates of plate motion and GIA; its viscous nature raises the prospect of further present-day deformation due to earlier Great Earthquakes.

  1. Space Radar Image of Colombian Volcano


    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

  2. Molecular Cytogenetic Analysis of Deschampsia antarctica Desv. (Poaceae), Maritime Antarctic.

    Amosova, Alexandra V; Bolsheva, Nadezhda L; Samatadze, Tatiana E; Twardovska, Maryana O; Zoshchuk, Svyatoslav A; Andreev, Igor O; Badaeva, Ekaterina D; Kunakh, Viktor A; Muravenko, Olga V


    Deschampsia antarctica Desv. (Poaceae) (2n = 26) is one of the two vascular plants adapted to the harshest environment of the Antarctic. Although the species is a valuable model for study of environmental stress tolerance in plants, its karyotype is still poorly investigated. We firstly conducted a comprehensive molecular cytogenetic analysis of D. antarctica collected on four islands of the Maritime Antarctic. D. antarctica karyotypes were studied by Giemsa C- and DAPI/C-banding, Ag-NOR staining, multicolour fluorescence in situ hybridization with repeated DNA probes (pTa71, pTa794, telomere repeats, pSc119.2, pAs1) and the GAA simple sequence repeat probe. We also performed sequential rapid in situ hybridization with genomic DNA of D. caespitosa. Two chromosome pairs bearing transcriptionally active 45S rDNA loci and five pairs with 5S rDNA sites were detected. A weak intercalary site of telomere repeats was revealed on the largest chromosome in addition to telomere hybridization signals at terminal positions. This fact confirms indirectly the hypothesis that chromosome fusion might have been the cause of the unusual for cereals chromosome number in this species. Based on patterns of distribution of the examined molecular cytogenetic markers, all chromosomes in karyotypes were identified, and chromosome idiograms of D. antarctica were constructed. B chromosomes were found in most karyotypes of plants from Darboux Island. A mixoploid plant with mainly triploid cells bearing a Robertsonian rearrangement was detected among typical diploid specimens from Great Jalour Island. The karyotype variability found in D. antarctica is probably an expression of genome instability induced by environmental stress factors. The differences in C-banding patterns and in chromosome distribution of rDNA loci as well as homologous highly repeated DNA sequences detected between genomes of D. antarctica and its related species D. caespitosa indicate that genome reorganization involving

  3. Ice plug prevents irreversible discharge from East Antarctica

    Mengel, M.; Levermann, A.


    Changes in ice discharge from Antarctica constitute the largest uncertainty in future sea-level projections, mainly because of the unknown response of its marine basins. Most of West Antarctica's marine ice sheet lies on an inland-sloping bed and is thereby prone to a marine ice sheet instability. A similar topographic configuration is found in large parts of East Antarctica, which holds marine ice equivalent to 19 m of global sea-level rise, that is, more than five times that of West Antarctica. Within East Antarctica, the Wilkes Basin holds the largest volume of marine ice that is fully connected by subglacial troughs. This ice body was significantly reduced during the Pliocene epoch. Strong melting underneath adjacent ice shelves with similar bathymetry indicates the ice sheet's sensitivity to climatic perturbations. The stability of the Wilkes marine ice sheet has not been the subject of any comprehensive assessment of future sea level. Using recently improved topographic data in combination with ice-dynamic simulations, we show here that the removal of a specific coastal ice volume equivalent to less than 80 mm of global sea-level rise at the margin of the Wilkes Basin destabilizes the regional ice flow and leads to a self-sustained discharge of the entire basin and a global sea-level rise of 3-4 m. Our results are robust with respect to variation in ice parameters, forcing details and model resolution as well as increased surface mass balance, indicating that East Antarctica may become a large contributor to future sea-level rise on timescales beyond a century.

  4. Common processes at unique volcanoes – a volcanological conundrum

    Katharine eCashman


    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.

  5. Mean thermospheric winds observed from Halley, Antarctica

    R. I. Crickmore

    Full Text Available Thermospheric winds on a total of 237 nights have been studied for the effects due to geomagnetic activity, solar flux, and season. The observations have been made from 1988 to 1992 by a Fabry-Perot interferometer (FPI operating at Halley (75.5°S, 26.6°W, Antarctica. This is the first statistical study of thermospheric winds near the southern auroral zone. The main factor affecting the wind velocities is the geomagnetic activity. Increases in activity cause an increase in the maximum equatorward wind, and cause the zonal wind in the evening to become more westward. Smaller changes in the mean wind occur with variations in season and solar flux. The small variation with solar flux is more akin to the situation found at mid-latitudes than at high latitudes. Since the geomagnetic latitude of Halley is only 61°, it suggests that the variability of the wind with solar flux may depend more on geomagnetic than geographic latitude. These observations are in good agreement with the empirical Horizontal Wind Model (HWM90. However, comparisons with predictions of the Vector Spherical Harmonic Model (VSH show that for low geomagnetic activity the predicted phases of the two components of the wind closely resemble the observations but the modelled amplitudes are too small by a factor of two. At high geomagnetic activity the major differences are that modelled zonal velocity is too westward in the evening and too eastward after 04 UT. The modelled ion densities at the F-region peak are a factor of up to 9 too large, whilst the predicted mean value and diurnal variation of the altitude of the peak are significantly lower than those observed. It is suggested that these differences result from the ion loss rate being too low, and an inaccurate model of the magnetic field.

  6. Soils of Marie Byrd Land, West Antarctica

    Lupachev, A. V.; Abakumov, E. V.


    Soils of Marie Byrd Land-one of the remotest and difficultly accessible regions of Antarctica-were investigated in the area of the mothballed Russkaya station located to the south of 74° S. Despite the extremely severe wind regime (the average wind velocity is 13 m/s, and the maximum wind velocity is up to 60 m/s), the projective cover of vegetation in the area of the station averages 25-40% and reaches 60-80% in some places. The phenomena of physical weathering of the bedrock-exfoliation, stone pavements, residual rocks exposed by wind (hoodoos), and others-are clearly manifested. In most of the described soils, normal organic and organomineral horizons are absent. The soil profiles represent the mixture of the residues of mosses and lichens and the gravelly eluvium. The fine earth material is blown out of the surface horizons by strong winds; its residual accumulation takes place in the middle and lower parts of the profiles. The classification position of these soils is open to argument; they are close to Petrozems and Lithozems. Most of the profiles are underlain by the massive or slightly disintegrated bedrock with dry permafrost at a depth of 20 to 50 cm. Soils with dry permafrost comprise about 75% of the surveyed area. In separate loci in the depressions of the local mesorelief and on gentle slopes, the soils with clearly expressed cryoturbation features are developed; their profiles are underlain by the ice-rich permafrost and compose about 15% of the surveyed area. Anthropogenically disturbed soils and soils polluted with petroleum hydrocarbons, heavy metals, and other pollutants occupy about 10% of the surveyed area.

  7. Electric field measurements from Halley, Antarctica

    Nicoll, Keri; Harrison, R. Giles


    Antarctica is a unique location for the study of atmospheric electricity. Not only is it one of the most pollutant free places on Earth, but its proximity to the south magnetic pole means that it is an ideal location to study the effects of solar variability on the atmospheric electric field. This is due to the reduced shielding effect of the geomagnetic field at the poles which leads to a greater flux of incoming Galactic Cosmic Rays (GCRs) as well as an increased probability of energetic particle precipitation from SEPs and relativistic electrons. To investigate such effects, two electric field mills of different design were installed at the British Antarctic Survey Halley base in February 2015 (75. 58 degrees south, 26.66 degrees west). Halley is situated on the Brunt Ice Shelf in the south east of the Weddell Sea and has snow cover all year round. Preliminary analysis has focused on selection of fair weather criteria using wind speed and visibility measurements which are vital to assess the effects of falling snow, blowing snow and freezing fog on the electric field measurements. When the effects of such adverse weather conditions are removed clear evidence of the characteristic Carnegie Curve diurnal cycle exists in the Halley electric field measurements (with a mean value of 50V/m and showing a 40% peak to peak variation in comparison to the 34% variation in the Carnegie data). Since the Carnegie Curve represents the variation in thunderstorm activity across the Earth, its presence in the Halley data confirms the presence of the global atmospheric electric circuit signal at Halley. The work presented here will discuss the details of the Halley electric field dataset, including the variability in the fair weather measurements, with a particular focus on magnetic field fluctuations.

  8. Darwin's triggering mechanism of volcano eruptions

    Galiev, Shamil


    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

  9. Voluminous submarine lava flows from Hawaiian volcanoes

    Holcomb, R.T.; Moore, J.G.; Lipman, P.W.; Belderson, R.H.


    The GLORIA long-range sonar imaging system has revealed fields of large lava flows in the Hawaiian Trough east and south of Hawaii in water as deep as 5.5 km. Flows in the most extensive field (110 km long) have erupted from the deep submarine segment of Kilauea's east rift zone. Other flows have been erupted from Loihi and Mauna Loa. This discovery confirms a suspicion, long held from subaerial studies, that voluminous submarine flows are erupted from Hawaiian volcanoes, and it supports an inference that summit calderas repeatedly collapse and fill at intervals of centuries to millenia owing to voluminous eruptions. These extensive flows differ greatly in form from pillow lavas found previously along shallower segments of the rift zones; therefore, revision of concepts of volcano stratigraphy and structure may be required.

  10. Vulcan's fury: Man against the volcano

    Varekamp, Johan C.

    I read this book on an 11-hour flight back from a field trip in the Andes, where I got first-hand insight into how people live with a volcano that now and then explodes. Appropriate reading, I felt, especially as the fascination of the human world with volcanoes and eruptive disasters is indeed long standing. This book is a recent addition to a list of titles in this genre (e.g., the new book by Sigurdsson to be reviewed in Eos shortly). The scope of the book is summarized in the introductory sentence of the preface: “This book is about an unequal contest. It describes human reactions to volcanic eruptions.” This is the perspective of the book's descriptions of 16 large and not-so-large eruptions over the last two millennia.

  11. Decision Analysis Tools for Volcano Observatories

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


    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.

  12. On the morphometry of terrestrial shield volcanoes

    Grosse, Pablo; Kervyn, Matthieu


    Shield volcanoes are described as low angle edifices that have convex up topographic profiles and are built primarily by the accumulation of lava flows. This generic view of shields' morphology is based on a limited number of monogenetic shields from Iceland and Mexico, and a small set of large oceanic islands (Hawaii, Galapagos). Here, the morphometry of over 150 monogenetic and polygenetic shield volcanoes, identified inthe Global Volcanism Network database, are analysed quantitatively from 90-meter resolution DEMs using the MORVOLC algorithm. An additional set of 20 volcanoes identified as stratovolcanoes but having low slopes and being dominantly built up by accumulation of lava flows are documented for comparison. Results show that there is a large variation in shield size (volumes range from 0.1 to >1000 km3), profile shape (height/basal width ratios range from 0.01 to 0.1), flank slope gradients, elongation and summit truncation. Correlation and principal component analysis of the obtained quantitative database enables to identify 4 key morphometric descriptors: size, steepness, plan shape and truncation. Using these descriptors through clustering analysis, a new classification scheme is proposed. It highlights the control of the magma feeding system - either central, along a linear structure, or spatially diffuse - on the resulting shield volcano morphology. Genetic relationships and evolutionary trends between contrasted morphological end-members can be highlighted within this new scheme. Additional findings are that the Galapagos-type morphology with a central deep caldera and steep upper flanks are characteristic of other shields. A series of large oceanic shields have slopes systematically much steeper than the low gradients (<4-8°) generally attributed to large Hawaiian-type shields. Finally, the continuum of morphologies from flat shields to steeper complex volcanic constructs considered as stratovolcanoes calls for a revision of this oversimplified

  13. Buried caldera of mauna kea volcano, hawaii.

    Porter, S C


    An elliptical caldera (2.1 by 2.8 kilometers) at the summit of Mauna Kea volcano is inferred to lie buried beneath hawaiite lava flows and pyroclastic cones at an altitude of approximately 3850 meters. Stratigraphic relationships indicate that hawaiite eruptions began before a pre-Wisconsin period of ice-cap glaciation and that the crest of the mountain attained its present altitude and gross form during a glaciation of probable Early Wisconsin age.

  14. Publications of the Volcano Hazards Program 2014

    Nathenson, Manuel


    The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Natural Hazards activity, as funded by Congressional appropriation. Investigations are carried out by the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaiʻi Mānoa and Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all of these institutions.

  15. Monitoring active volcanoes: The geochemical approach

    Takeshi Ohba


    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.

  16. Geothermal Exploration of Newberry Volcano, Oregon

    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)


    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.

  17. Seismic and infrasound monitoring at Cotopaxi volcano

    Ruiz, M.; Yepes, H.; Palacios, P.; Troncoso, L.; Mothes, P.; Kumagai, H.


    Cotopaxi is an active ice-capped volcano (5967m) located 60 km SE from Quito and is one of the largest and more hazardous volcanoes in the Northern Andes. Monitoring of Cotopaxi, using seismic and infrasound techniques has improving significantly since 1976, when three short-period stations were deployed temporarily in response to an increase of fumarolic activity. Later in May 1977, a short-period vertical seismometer was installed on the NW flank at 7 km from the crater. Since 1986 a short-period seismic station is working at the northern flank of Cotopaxi and transmitting analog data to the Instituto Geofisico. In 1993 a network of 4 short-period seismic stations were installed on all flanks of the volcano. Between March 1996 and June 1997 a temporal network of 16 stations were deployed for several months in order to study local seismicity and internal structure (Metaxian et al., 1999). Since 2006, a network of five broad band stations (0.02-60 s) and low-frequency infrasound sensors (0.01-10 s) were installed through a JICA Cooperation Project (Kumagai et al., 2007). Data is transmitted to the Instituto Geofisico via a digital radio system. Through this network, LP and VLP events have been recorded and analyzed (Molina et al., 2008). VLP events were located beneath the north and north-eastern flank using waveform inversion and amplitude distribution methods (Kumagai et al., 2010).

  18. Detecting Blackholes and Volcanoes in Directed Networks

    Li, Zhongmou; Liu, Yanchi


    In this paper, we formulate a novel problem for finding blackhole and volcano patterns in a large directed graph. Specifically, a blackhole pattern is a group which is made of a set of nodes in a way such that there are only inlinks to this group from the rest nodes in the graph. In contrast, a volcano pattern is a group which only has outlinks to the rest nodes in the graph. Both patterns can be observed in real world. For instance, in a trading network, a blackhole pattern may represent a group of traders who are manipulating the market. In the paper, we first prove that the blackhole mining problem is a dual problem of finding volcanoes. Therefore, we focus on finding the blackhole patterns. Along this line, we design two pruning schemes to guide the blackhole finding process. In the first pruning scheme, we strategically prune the search space based on a set of pattern-size-independent pruning rules and develop an iBlackhole algorithm. The second pruning scheme follows a divide-and-conquer strategy to fur...

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

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


    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.

  20. Citizen empowerment in volcano monitoring, communication and decision-making at Tungurahua volcano, Ecuador

    Bartel, B. A.; Mothes, P. A.


    Trained citizen volunteers called vigías have worked to help monitor and communicate warnings about Tungurahua volcano, in Ecuador, since the volcano reawoke in 1999. The network, organized by the scientists of Ecuador's Instituto Geofísico de la Escuela Politécnica Nacional (Geophysical Institute) and the personnel from the Secretaría Nacional de Gestión de Riesgos (Risk Management, initially the Civil Defense), has grown to more than 20 observers living around the volcano who communicate regularly via handheld two-way radios. Interviews with participants conducted in 2010 indicate that the network enables direct communication between communities and authorities; engenders trust in scientists and emergency response personnel; builds community; and empowers communities to make decisions in times of crisis.

  1. A comparison of coincident GRACE and ICESat data over Antarctica

    Gunter, B.; Urban, T.; Riva, R.E.M.; Helsen, M.M.; Harpold, R.; Poole, S.; Nagel, P.; Schutz, B.; Tapley, B.


    In this study, we present a comparison of coincident GRACE and ICESat data over Antarctica. The analysis focused on the secular changes over a 4-year period spanning from 2003 to 2007, using the recently reprocessed and publicly available data sets for both missions. The results show that the two in

  2. P-band radar ice sounding in Antarctica

    Dall, Jørgen; Kusk, Anders; Kristensen, Steen Savstrup


    In February 2011, the Polarimetric Airborne Radar Ice Sounder (POLARIS) was flown in Antarctica in order to assess the feasibility of a potential space-based radar ice sounding mission. The campaign has demonstrated that the basal return is detectable in areas with up to 3 km thick cold ice...

  3. DOMECair: An Airborne Campaign in Antarctica Supporting SMOS Calibration

    Skou, Niels; Kristensen, Steen Savstrup; Søbjærg, Sten Schmidl


    In search for a stable, well characterized terrestrial calibration target for SMOS, an airborne campaign was carried out in January 2013 over the Dome C area of Antarctica, and the surface was measured by an L-band radiometer. The focus was on homogeneity, and an area of 350 × 350 km around...

  4. Radiocarbon analyses along the EDML ice core in Antarctica

    van de Wal, R.S.W.; Meijer, H.A.J.; van Rooij, M.; van der Veen, C.


    Samples, 17 in total, from the EDML core drilled at Kohnen station Antarctica are analysed for 14CO and 14CO2 with a dry-extraction technique in combination with accelerator mass spectrometry. Results of the in situ produced 14CO fraction show a very low concentration of in situ produced 14CO. Despi

  5. Radiocarbon analyses along the EDML ice core in Antarctica

    Van de Wal, R. S. W.; Meijer, H. A. J.; De Rooij, M.; Van der Veen, C.


    Samples, 17 in total, from the EDML core drilled at Kohnen station Antarctica are analysed for (CO)-C-14 and (CO2)-C-14 with a dry-extraction technique in combination with accelerator mass spectrometry. Results of the in situ produced (CO)-C-14 fraction show a very low concentration of in situ produ

  6. The Twelfth Indian Scientific Expedition to Antarctica: Events and achievements

    Dhargalkar, V

    Delhi and Dr. B.N. Desai, Director, National Institute of Oceanography, Goa, families of the expedition members and friends. This was the smallest team M.V. Thuleland ever carried to Antarctica. On very next day of sailing the members were briefed about...

  7. Abrupt climate warming in East Antarctica during the early Holocene

    Cremer, H.; Heiri, O.; Wagner, B.; Wagner-Cremer, F.


    We report a centennial-scale warming event between 8600 and 8400 cal BP from Amery Oasis, East Antarctica, that is documented by the geochemical record in a lacustrine sediment sequence. The organic carbon content, the C/S ratio, and the sedimentation rate in this core have distinctly elevated value

  8. An evolutionary insight into Newcastle disease viruses isolated in Antarctica.

    Soñora, Martin; Moreno, Pilar; Echeverría, Natalia; Fischer, Sabrina; Comas, Victoria; Fajardo, Alvaro; Cristina, Juan


    The disease caused by Newcastle disease virus (NDV) is a severe threat to the poultry industry worldwide. Recently, NDV has been isolated in the Antarctic region. Detailed studies on the mode of evolution of NDV strains isolated worldwide are relevant for our understanding of the evolutionary history of NDV. For this reason, we have performed Bayesian coalescent analysis of NDV strains isolated in Antarctica to study evolutionary rates, population dynamics, and patterns of evolution. Analysis of F protein cleavage-site sequences of NDV isolates from Antarctica suggested that these strains are lentogenic. Strains isolated in Antarctica and genotype I reference strain Ulster/67 diverged from ancestors that existed around 1958. The time of the most recent common ancestor (MRCA) was established to be around 1883 for all class II viruses. A mean rate of evolution of 1.78 × 10(-3) substitutions per site per year (s/s/y) was obtained for the F gene sequences of NDV strains examined in this study. A Bayesian skyline plot indicated a decline in NDV population size in the last 25 years. The results are discussed in terms of the possible role of Antarctica in emerging or re-emerging viruses and the evolution of NDV populations worldwide.

  9. Ross Ice Shelf and the Queen Maude Mounains, Antarctica


    Part of the Ross Ice Shelf and the Queen Maude Mounains of Antarctica (55.5N, 178.0W) are in the background of this scene, oriented toward the south. Low stratocumulus clouds are predominant throughout most of the scene.

  10. Origin(s) of Antarctica's Wilkes subglacial basin

    Weihaupt, J.G.; Van der Hoeven, F.G.; Lorius, C.; Chambers, F.B.


    The Wilkes Subglacial Basin (WSB), the largest subglacial basin in East Antarctica, is a topographic depression of continental proportions that lies beneath the East Antarctic continental ice sheet. Discovered by the US Victoria Land Traverse 1959–60, the origin of the WSB and the influence of palae

  11. Surface and snowdrift sublimation at Princess Elisabeth station, East Antarctica

    Thiery, W.; Gorodetskaya, I.V.; Bintanja, R.; van Lipzig, N.P.M.; van den Broeke, M.R.; Reijmer, C.H.; Kuipers Munneke, P.


    In the near-coastal regions of Antarctica, a significant fraction of the snow precipitating onto the surface is removed again through sublimation – either directly from the surface or from drifting snow particles. Meteorological observations from an Automatic Weather Station (AWS) near the Belgian r

  12. Antarctica: Arena for South American Cooperation or Conflict.

    Child, Jack

    A number of converging circumstances suggest that Antarctica may be a major object of geopolitical attention in South America in the decade to come. The Malvinas/Falklands crisis focused geopolitical attention on the South Atlantic and the chain of Southern (Austral) Islands which link the southern tip of South America to the Antarctic Peninsula.…

  13. Triassic leech cocoon from Antarctica contains fossil bell animal

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.


    , exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica...

  14. Mass Casualty Incident Response and Aeromedical Evacuation in Antarctica

    Mills, Christopher N


    Full Text Available Antarctica is one of the most remote regions on Earth. Mass casualty incident (MCI responses in Antarctica are prone to complications from multiple environmental and operational challenges. This review of the current status of MCI risks and response strategies for Antarctica focuses on aeromedical evacuation, a critical component of many possible MCI scenarios. Extreme cold and weather, a lack of medical resources and a multitude of disparate international bases all exert unique demands on MCI response planning. Increasing cruise ship traffic is also escalating the risk of MCI occurrence. To be successful, MCI response must be well coordinated and undertaken by trained rescuers, especially in the setting of Antarctica. Helicopter rescue or aeromedical evacuation of victims to off-continent facilities may be necessary. Currently, military forces have the greatest capacity for mass air evacuation. Specific risks that are likely to occur include structure collapses, vehicle incapacitations, vehicle crashes and fires. All of these events pose concomitant risks of hypothermia among both victims and rescuers. Antarctica’s unique environment requires flexible yet robust MCI response planning among the many entities in operation on the continent. [West J Emerg Med. 2011;12(1:37-42.

  15. Microbial Energetics Beneath the Taylor Glacier, Antarctica

    Mikucki, J. A.; Turchyn, A. V.; Farquhar, J.; Priscu, J. C.; Schrag, D. P.; Pearson, A.


    Subglacial microbiology is controlled by glacier hydrology, bedrock lithology, and the preglacial ecosystem. These factors can all affect metabolic function by influencing electron acceptor and donor availability in the subglacial setting leaving biogeochemical signatures that can be used to determine ecosystem processes. Blood Falls, an iron-rich, episodic subglacial outflow from the Taylor Glacier in the McMurdo Dry Valleys Antarctica provides an example of how microbial community structure and function can provide insight into subglacial hydrology. This subglacial outflow contains cryoconcentrated, Pliocene-age seawater salts that pooled in the upper Taylor Valley and was subsequently covered by the advance of the Taylor Glacier. Biogeochemical measurements, culture-based techniques, and genomic analysis were used to characterize microbes and chemistry associated with the subglacial outflow. The isotopic composition of important geochemical substrates (i.e., δ34Ssulfate, Δ33Ssulfate, δ18Osulfate, δ18Owater, Δ14SDIC) were also measured to provide more detail on subglacial microbial energetics. Typically, subglacial systems, when driven to anoxia by the hydrolysis of organic matter, will follow a continuum of redox chemistries utilizing electron acceptors with decreasing reduction potential (e.g., Fe (III), sulfate, CO2). Our data provide no evidence for sulfate reduction below the Taylor Glacier despite high dissolved organic carbon (450 μM C) and measurable metabolic activity. We contend that, in the case of the Taylor Glacier, the in situ bioenergetic reduction potential has been 'short-circuited' at Fe(III)-reduction and excludes sulfate reduction and methanogenesis. Given the length of time that this marine system has been isolated from phototrophic production (~2 Mya) the ability to degrade and consume increasingly recalcitrant organic carbon is likely an important component to the observed redox chemistry. Our work indicates that glacier hydrology

  16. July 1973 ground survey of active Central American volcanoes

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.


    The author has identified the following significant results. Ground survey has shown that thermal anomalies of various sizes associated with volcanic activity at several Central American volcanoes should be detectable from Skylab. Anomalously hot areas of especially large size (greater than 500 m in diameter) are now found at Santiaguito and Pacaya volcanoes in Guatemala and San Cristobal in Nicaragua. Smaller anomalous areas are to be found at least seven other volcanoes. This report is completed after ground survey of eleven volcanoes and ground-based radiation thermometry mapping at these same points.

  17. The critical role of volcano monitoring in risk reduction

    R. I. Tilling


    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.

  18. Geologic map of Medicine Lake volcano, northern California

    Donnelly-Nolan, Julie M.


    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.

  19. Seismic Constraints on the Mantle Viscosity Structure beneath Antarctica

    Wiens, Douglas; Heeszel, David; Aster, Richard; Nyblade, Andrew; Wilson, Terry


    Lateral variations in upper mantle viscosity structure can have first order effects on glacial isostatic adjustment. These variations are expected to be particularly large for the Antarctic continent because of the stark geological contrast between ancient cratonic and recent tectonically active terrains in East and West Antarctica, respectively. A large misfit between observed and predicted GPS rates for West Antarctica probably results in part from the use of a laterally uniform viscosity structure. Although not linked by a simple relationship, mantle seismic velocities can provide important constraints on mantle viscosity structure, as they are both largely controlled by temperature and water content. Recent higher resolution seismic models for the Antarctic mantle, derived from data acquired by new seismic stations deployed in the AGAP/GAMSEIS and ANET/POLENET projects, offer the opportunity to use the seismic velocity structure to place new constraints on the viscosity of the Antarctic upper mantle. We use an Antarctic shear wave velocity model derived from array analysis of Rayleigh wave phase velocities [Heeszel et al, in prep] and examine a variety of methodologies for relating seismic, thermal and rheological parameters to compute a suite of viscosity models for the Antarctic mantle. A wide variety of viscosity structures can be derived using various assumptions, but they share several robust common elements. There is a viscosity contrast of at least two orders of magnitude between East and West Antarctica at depths of 80-250 km, reflecting the boundary between cold cratonic lithosphere in East Antarctica and warm upper mantle in West Antarctica. The region beneath the Ellsworth-Whitmore Mtns and extending to the Pensacola Mtns. shows intermediate viscosity between the extremes of East and West Antarctica. There are also significant variations between different parts of West Antarctica, with the lowest viscosity occurring beneath the Marie Byrd Land (MBL

  20. Magma Supply System at Batur Volcano Inferred from Volcano-Tectonic Earthquakes and Their Focal Mechanism

    Sri Hidayati


    Full Text Available DOI: 10.17014/ijog.v8i2.159The Volcano-Tectonic (VT earthquakes occurring during September - November 2009 were analyzed. The result shows that the epicentres aligning in NE- SW direction coincided with the weak zone of Batur Volcano Complex. The focal zone is located at the depth around 1.5 - 5.5 km beneath the summit. Migration of magma was detected by ground deformation measured by GPS and focal mechanism. Mechanism of VT earthquake shows mostly normal fault types during the swarm in November 2009.

  1. The petrological relationship between Kamen volcano and adjacent volcanoes of Klyuchevskaya group

    Churikova, Tatiana; Gordeychik, Boris; Wörner, Gerhard; Ivanov, Boris; Maximov, Alexander; Lebedev, Igor; Griban, Andrey


    The Klyuchevskaya Group (KG) of volcanoes has the highest magma production rate across the Kamchatka arc and in fact for any arc worldwide. However, modern geochemical studies of Kamen volcano, which is located between Klyuchevskoy, Bezymianny and Ploskie Sopky volcanoes, were not carried out and its relation and petrogenesis in comparison to other KG volcanoes is unknown. Space-time proximity of KG volcanoes and the common zone of seismicity below them may suggest a common source and genetic relationship. However, the lavas of neighboring volcanoes are rather different: high-Mg and high-Al basalts occur at Klyuchevskoy volcano, Hbl-bearing andesites and dаcites dominate at Bezymianny and medium-high-K subalkaline rocks at Ploskie Sopky volcano. Moreover, previously it was shown that distinct fluid signatures were observed in different KG volcanoes. In this report we present geological, petrographical, mineralogical and petrochemical data on the rocks of Kamen volcano in comparison with other KG volcanoes. Three consecutive periods of volcano activity were recognized in geological history of Kamen volcano: stratovolcano formation, development of a dike complex and formation of numerous cinder and cinder-lava monogenetic cones. The rock series of volcano are divided into four groups: olivine-bearing (Ol-2Px and Ol-Cpx), olivine-free (2Px-Pl, Cpx-Pl and abundant Pl), Hb-bearing and subaphyric rocks. While olivine-bearing rocks are observed in all volcanic stages, olivine-free lavas are presented only in the stratovolcano edifice. Lavas of the monogenetic cones are presented by olivine-bearing and subaphyric rocks. Dikes are olivine-bearing and hornblende-bearing rocks. Olivines of the Kamen stratovolcano and dikes vary from Fo60 to Fo83, clinopyroxenes are augites in composition and plagioclases have a bimodal distribution with maximum modes at An50 and An86. Oxides are represented by high-Al spinel, magnetite and titaniferous magnetite. Mineral compositions of the

  2. Reconciling the shadow of a subduction signature with rift geochemistry and tectonic environment in Eastern Marie Byrd Land, Antarctica

    LeMasurier, Wesley E.; Choi, Sung Hi; Hart, Stanley R.; Mukasa, Sam; Rogers, Nick


    Basalt-trachyte volcanoes in the Marie Byrd Land (MBL) Cenozoic province lie along the Amundsen Sea coast on the north flank of the West Antarctic rift. Basalts here are characterized by OIB-like geochemistry, restricted ranges of 87Sr/86Sr (0.702535-0.703284) and 143Nd/144Nd (0.512839-0.513008) and a wide range of 206Pb/204Pb (19.357-20.934). Basalts at three MBL volcanoes display two anomalies compared with the above and with all other basalts in West Antarctica. They include 143Nd/144Nd (0.512778-0.512789) values at Mt. Takahe and Mt. Siple that are 2σ lower than other West Antarctic basalts, and Ba/Nb, Ba/La, and Ba/Th values at Mt. Murphy and Mt. Takahe that are 3-8 times higher than normal OIB. Isotope and trace element data do not support crustal and lithospheric mantle contamination, or the presence of residual mantle amphibole or phlogopite as explanations of these anomalies. The apparent coincidence of these anomalies with the site of a pre-Cenozoic convergence zone along the Gondwanaland margin suggests a subduction influence. Major episodes of subduction and granitic plutonism took place in MBL during the Devonian, Permian, and Late Cretaceous. Relicts in the source region, of components from these subducted slabs, provide a credible explanation for the uncoupling of Ba from other large ion lithophile elements (LILE), for its erratic distribution, and for the anomalously low 143Nd/144Nd at Mt. Takahe. The last episode of subduction ended ~ 85 Ma, and was followed by continental break-up, rifting and lithospheric attenuation that produced the West Antarctic rift as we know it today. Thus, the enigmatic geochemical signatures in these three volcanoes seem to have been preserved roughly 61-85 m.y. after subduction ended. New calculations of source melting depth and a new determination of lithospheric thickness suggest that the source of the anomalies resides in a fossil mélange diapir that rose from the Cretaceous subducting slab, became attached to the

  3. Instability of Hawaiian volcanoes: Chapter 4 in Characteristics of Hawaiian volcanoes

    Denlinger, Roger P.; Morgan, Julia K.; Poland, Michael P.; Takahashi, T. Jane; Landowski, Claire M.


    Hawaiian volcanoes build long rift zones and some of the largest volcanic edifices on Earth. For the active volcanoes on the Island of Hawai‘i, the growth of these rift zones is upward and seaward and occurs through a repetitive process of decades-long buildup of a magma-system head along the rift zones, followed by rapid large-scale displacement of the seaward flank in seconds to minutes. This large-scale flank movement, which may be rapid enough to generate a large earthquake and tsunami, always causes subsidence along the coast, opening of the rift zone, and collapse of the magma-system head. If magma continues to flow into the conduit and out into the rift system, then the cycle of growth and collapse begins again. This pattern characterizes currently active Kīlauea Volcano, where periods of upward and seaward growth along rift zones were punctuated by large (>10 m) and rapid flank displacements in 1823, 1868, 1924, and 1975. At the much larger Mauna Loa volcano, rapid flank movements have occurred only twice in the past 200 years, in 1868 and 1951.

  4. Breakup of the Larsen Ice Shelf, Antarctica


    Recent Moderate-resolution Imaging Spectroradiometer (MODIS) satellite imagery analyzed at the University of Colorado's National Snow and Ice Data Center revealed that the northern section of the Larsen B ice shelf, a large floating ice mass on the eastern side of the Antarctic Peninsula, has shattered and separated from the continent. This particular image was taken on March 5, 2002. The shattered ice formed a plume of thousands of icebergs adrift in the Weddell Sea. A total of about 3,250 square kilometers of shelf area disintegrated in a 35-day period beginning on January 31, 2002. Over the last five years, the shelf has lost a total of 5,700 square kilometers and is now about 40 percent the size of its previous minimum stable extent. Ice shelves are thick plates of ice, fed by glaciers, that float on the ocean around much of Antarctica. The Larsen B shelf was about 220 meters thick. Based on studies of ice flow and sediment thickness beneath the ice shelf, scientists believe that it existed for at least 400 years prior to this event and likely existed since the end of the last major glaciation 12,000 years ago. For reference, the area lost in this most recent event dwarfs Rhode Island (2,717 square kilometers) in size. In terms of volume, the amount of ice released in this short time is 720 billion tons--enough ice for about 12 trillion 10-kilogram bags. This is the largest single event in a series of retreats by ice shelves along the peninsula over the last 30 years. The retreats are attributed to a strong climate warming in the region. The rate of warming is approximately 0.5 degrees Celsius per decade, and the trend has been present since at least the late 1940s. Overall in the peninsula, the extent of seven ice shelves has declined by a total of about 13,500 square kilometers since 1974. This value excludes areas that would be expected to calve under stable conditions. Ted Scambos, a researcher with the National Snow and Ice Data Center (NSIDC) at

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

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


    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

  6. SO2 camera measurements at Lastarria volcano and Lascar volcano in Chile

    Lübcke, Peter; Bobrowski, Nicole; Dinger, Florian; Klein, Angelika; Kuhn, Jonas; Platt, Ulrich


    The SO2 camera is a remote-sensing technique that measures volcanic SO2 emissions via the strong SO2 absorption structures in the UV using scattered solar radiation as a light source. The 2D-imagery (usually recorded with a frame rate of up to 1 Hz) allows new insights into degassing processes of volcanoes. Besides the large advantage of high frequency sampling the spatial resolution allows to investigate SO2 emissions from individual fumaroles and not only the total SO2 emission flux of a volcano, which is often dominated by the volcanic plume. Here we present SO2 camera measurements that were made during the CCVG workshop in Chile in November 2014. Measurements were performed at Lastarria volcano, a 5700 m high stratovolcano and Lascar volcano, a 5600 m high stratovolcano both in northern Chile on 21 - 22 November, 2014 and on 26 - 27 November, 2014, respectively. At both volcanoes measurements were conducted from a distance of roughly 6-7 km under close to ideal conditions (low solar zenith angle, a very dry and cloudless atmosphere and an only slightly condensed plume). However, determination of absolute SO2 emission rates proves challenging as part of the volcanic plume hovered close to the ground. The volcanic plume therefore is in front of the mountain in our camera images. An SO2 camera system consisting of a UV sensitive CCD and two UV band-pass filters (centered at 315 nm and 330 nm) was used. The two band-pass filters are installed in a rotating wheel and images are taken with both filter sequentially. The instrument used a CCD with 1024 x 1024 pixels and an imaging area of 13.3 mm x 13.3 mm. In combination with the focal length of 32 mm this results in a field-of-view of 25° x 25°. The calibration of the instrument was performed with help of a DOAS instrument that is co-aligned with the SO2 camera. We will present images and SO2 emission rates from both volcanoes. At Lastarria gases are emitted from three different fumarole fields and we will attempt

  7. Imaging magma plumbing beneath Askja volcano, Iceland

    Greenfield, Tim; White, Robert S.


    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

  8. Lahar Hazard Modeling at Tungurahua Volcano, Ecuador

    Sorensen, O. E.; Rose, W. I.; Jaya, D.


    Tungurahua Volcano (Lat. 01^o28'S; Long. 78^o27'W), located in the central Ecuadorian Andes, is an active edifice that rises more than 3 km above surrounding topography. Since European settlement in 1532, Tungurahua has experienced four major eruptive episodes: 1641-1646, 1773-1781, 1886-1888 and 1916-1918 (Hall et al, JVGR V91; p1-21, 1999). In September 1999, Tungurahua began a new period of activity that continues to the present. During this time, the volcano has erupted daily, depositing ash and blocks on its steep flanks. A pattern of continuing eruptions, coupled with rainfall up to 28 mm in a 6 hour period (rain data collected in Baños at 6-hr intervals, 3000 meters below Tungurahua’s summit), has produced an environment conducive to lahar mobilization. Tungurahua volcano presents an immediate hazard to the town of Baños, an important tourist destination and cultural center with a population of about 25,000 residents located 8 km from the crater. During the current eruptive episode, lahars have occurred as often as 3 times per week on the northern and western slopes of the volcano. Consequently, the only north-south trending highway on the west side of Tungurahua has been completely severed at the intersection of at least ten drainages, where erosion has exceeded 10 m since 1999. The La Pampa quebrada, located 1 km west of Baños, is the most active of Tungurahua's drainages. At this location, where the slope is moderate, lahars continue to inundate the only highway linking Baños to the Pan American Highway. Because of steep topography, the conventional approach of measuring planimetric inundation areas to determine the scale of lahars could not be employed. Instead, cross sections were measured in the channels using volume/cross-sectional inundation relationships determined by (Iverson et al, GSABull V110; no. 8, p972-984, 1998). After field observations of the lahars, LAHARZ, a program used in a geographic information system (GIS) to objectively map

  9. 36 CFR 7.25 - Hawaii Volcanoes National Park.


    ... 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....

  10. A Probabilistic Approach for Real-Time Volcano Surveillance

    Cannavo, F.; Cannata, A.; Cassisi, C.; Di Grazia, G.; Maronno, P.; Montalto, P.; Prestifilippo, M.; Privitera, E.; Gambino, S.; Coltelli, M.


    Continuous evaluation of the state of potentially dangerous volcanos plays a key role for civil protection purposes. Presently, real-time surveillance of most volcanoes worldwide is essentially delegated to one or more human experts in volcanology, who interpret data coming from different kind of monitoring networks. Unfavorably, the coupling of highly non-linear and complex volcanic dynamic processes leads to measurable effects that can show a large variety of different behaviors. Moreover, due to intrinsic uncertainties and possible failures in some recorded data, the volcano state needs to be expressed in probabilistic terms, thus making the fast volcano state assessment sometimes impracticable for the personnel on duty at the control rooms. With the aim of aiding the personnel on duty in volcano surveillance, we present a probabilistic graphical model to estimate automatically the ongoing volcano state from all the available different kind of measurements. The model consists of a Bayesian network able to represent a set of variables and their conditional dependencies via a directed acyclic graph. The model variables are both the measurements and the possible states of the volcano through the time. The model output is an estimation of the probability distribution of the feasible volcano states. We tested the model on the Mt. Etna (Italy) case study by considering a long record of multivariate data from 2011 to 2015 and cross-validated it. Results indicate that the proposed model is effective and of great power for decision making purposes.

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

    Schipper, Stacia; Mattox, Stephen


    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…

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

    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...

  13. Monte Carlo Volcano Seismic Moment Tensors

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


    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.

  14. VALVE: Volcano Analysis and Visualization Environment

    Cervelli, D. P.; Cervelli, P.; Miklius, A.; Krug, R.; Lisowski, M.


    Modern volcano observatories collect data using a wide variety of instruments. Visualizing these disparate data on a common time base is critical to interpreting and reacting to geophysical changes. With this in mind, the Hawaiian Volcano Observatory (HVO) created Valve, the Volcano Analysis and Visualization Environment. Valve integrates a wide range of both continuous and discontinuous data sources into a common, internet web-browser based interface that allows scientists to interactively select and visualize these data on a common time base and, if appropriate, in three dimensions. Advances in modern internet browser technology allow for a truly interactive user-interface experience that could previously only be found in stand-alone applications--all while maintaining client platform independence and network portability. This system aids more traditional in-depth analysis by providing a common front-end to retrieving raw data. In most cases, the raw data are being served from an SQL database, a system that lends itself to quickly retrieving, logically arranging, and safely storing data. Beyond Valve's visualization capabilities, the system also provides a variety of tools for time series analysis and source modeling. For example, a user could load several tilt and GPS time series, estimate co-seismic or co-intrusive deformation, and then model the event with an elastic point source or dislocation. From the source model, Coulomb stress changes could be calculated and compared to pre- and post-event hypocenter distribution. Employing a heavily object-oriented design, Valve is easily extensible, modular, portable, and remarkably cost efficient. Quickly visualizing arbitrary data is a trivial matter, while implementing methods for permanent, continuous data streams requires only minimal programming. Portability is ensured by using software that is readily available on a wide variety of operating systems; cost efficiency is achieved by using software that is open

  15. Copahue volcano and its regional magmatic setting

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


    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.

  16. Mechanical coupling between earthquakes, volcanos and landslides

    Feigl, K. L.; Retina Team


    "The eruption began as a large earthquake that triggered a massive landslide that culminated in a violent lateral explosion" [Malone et al., USGS 1981]. The 1980 eruption of Mount St. Helens taught a very powerful lesson -- that one natural hazard can trigger another. For example, earthquakes have triggered landslides in Papua New Guinea. Similarly, eruptions of Vesuvius are mechanically coupled to earthquakes in the Appenines, just as an inflating magma chamber can trigger earthquakes near Hengill volcano in SW Iceland and on the Izu Peninsula in Japan. The Luzon earthquake may have triggered the eruption of Mount Pinatubo. In many of these cases, the second triggered event caused more damage than the initial one. If we can better understand the mechanical coupling underlying the temporal and spatial correlation of such events, we will improve our assessments of the hazards they pose. The RETINA project has been funded by the European Commission's 5th Framework to study couplings between three classes of natural hazards: earthquakes, landslides, and volcanoes. These three phenomena are linked to and by the stress field in the crust. If the stress increases enough, the material will fail catastrophically. For example, magma injection beneath a volcano can trigger an earthquake by increasing stress on a fault. Increasing shear stress on unconsolidated materials on steep slopes can trigger landslides. Such stress change triggers may also be tectonic (from plate driving forces), hydrological (from heavy rain), or volcanic (magmatic injection). Any of these events can perturb the stress field enough to trigger another event. Indeed, stress changes as small as 0.1 bar (0.01 MPa) suffice to trigger an earthquake. If the medium is close to failure, this small change can increase the Coulomb stress beyond the yield threshold, breaking the material. This quantity is the primary means we will use for describing mechanical coupling. In this paper, we will review several case

  17. Geology of El Chichon volcano, Chiapas, Mexico

    Duffield, W.A.; Tilling, R.I.; Canul, R.


    The (pre-1982) 850-m-high andesitic stratovolcano El Chicho??n, active during Pleistocene and Holocene time, is located in rugged, densely forested terrain in northcentral Chiapas, Me??xico. The nearest neighboring Holocene volcanoes are 275 km and 200 km to the southeast and northwest, respectively. El Chicho??n 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 Chicho??n 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 Chicho??n 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 Chicho??n 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

  18. Mud Volcanoes as Exploration Targets on Mars

    Allen, Carlton C.; Oehler, Dorothy Z.


    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.

  19. Galactic Super-volcano in Action


    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

  20. Volcano morphometry and volume scaling on Venus

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


    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

  1. Volcano deformation and subdaily GPS products

    Grapenthin, Ronni

    Volcanic unrest is often accompanied by hours to months of deformation of the ground that is measurable with high-precision GPS. Although GPS receivers are capable of near continuous operation, positions are generally estimated for daily intervals, which I use to infer characteristics of a volcano’s plumbing system. However, GPS based volcano geodesy will not be useful in early warning scenarios unless positions are estimated at high rates and in real time. Visualization and analysis of dynamic and static deformation during the 2011 Tohokuoki earthquake in Japan motivates the application of high-rate GPS from a GPS seismology perspective. I give examples of dynamic seismic signals and their evolution to the final static offset in 30 s and 1 s intervals, which demonstrates the enhancement of subtle rupture dynamics through increased temporal resolution. This stresses the importance of processing data at recording intervals to minimize signal loss. Deformation during the 2009 eruption of Redoubt Volcano, Alaska, suggested net deflation by 0.05 km³ in three distinct phases. Mid-crustal aseismic precursory inflation began in May 2008 and was detected by a single continuous GPS station about 28 km NE of Redoubt. Deflation during the explosive and effusive phases was sourced from a vertical ellipsoidal reservoir at about 7-11.5 km. From this I infer a model for the temporal evolution of a complex plumbing system of at least 2 sources during the eruption. Using subdaily GPS positioning solutions I demonstrate that plumes can be detected and localized by utilizing information on phase residuals. The GPS network at Bezymianny Volcano, Kamchatka, records network wide subsidence at rapid rates between 8 and 12 mm/yr from 2005-2010. I hypothesize this to be caused by continuous deflation of a ˜30 km deep sill under Kluchevskoy Volcano. Interestingly, 1-2 explosive events per year cause little to no deformation at any site other than the summit site closest to the vent. I

  2. Magmatic gas scrubbing: Implications for volcano monitoring

    Symonds, R.B.; Gerlach, T.M.; Reed, M.H.


    Despite the abundance of SO2(g) in magmatic gases, precursory increases in magmatic SO2(g) are not always observed prior to volcanic eruption, probably because many terrestrial volcanoes contain abundant groundwater or surface water that scrubs magmatic gases until a dry pathway to the atmosphere is established. To better understand scrubbing and its implications for volcano monitoring, we model thermochemically the reaction of magmatic gases with water. First, we inject a 915??C magmatic gas from Merapi volcano into 25??C air-saturated water (ASW) over a wide range of gas/water mass ratios from 0.0002 to 100 and at a total pressure of 0.1 MPa. Then we model closed-system cooling of the magmatic gas, magmatic gas-ASW mixing at 5.0 MPa, runs with varied temperature and composition of the ASW, a case with a wide range of magmatic-gas compositions, and a reaction of a magmatic gas-ASW mixture with rock. The modeling predicts gas and water compositions, and, in one case, alteration assemblages for a wide range of scrubbing conditions; these results can be compared directly with samples from degassing volcanoes. The modeling suggests that CO2(g) is the main species to monitor when scrubbing exists; another candidate is H2S(g), but it can be affected by reactions with aqueous ferrous iron. In contrast, scrubbing by water will prevent significant SO2(g) and most HCl(g) emissions until dry pathways are established, except for moderate HCl(g) degassing from pH 100 t/d (tons per day) of SO2(g) in addition to CO2(g) and H2S(g) should be taken as a criterion of magma intrusion. Finally, the modeling suggests that the interpretation of gas-ratio data requires a case-by-case evaluation since ratio changes can often be produced by several mechanisms; nevertheless, several gas ratios may provide useful indices for monitoring the drying out of gas pathways. Published by Elsevier Science B.V.

  3. Slow slip event at Kilauea Volcano

    Poland, Michael P.; Miklius, Asta; Wilson, J. David; Okubo, Paul G.; Montgomery-Brown, Emily; Segall, Paul; Brooks, Benjamin; Foster, James; Wolfe, Cecily; Syracuse, Ellen; Thurbe, Clifford


    Early in the morning of 1 February 2010 (UTC; early afternoon 31 January 2010 local time), continuous Global Positioning System (GPS) and tilt instruments detected a slow slip event (SSE) on the south flank of Kilauea volcano, Hawaii. The SSE lasted at least 36 hours and resulted in a maximum of about 3 centimeters of seaward displacement. About 10 hours after the start of the slip, a flurry of small earthquakes began (Figure 1) in an area of the south flank recognized as having been seismically active during past SSEs [Wolfe et al., 2007], suggesting that the February earthquakes were triggered by stress associated with slip [Segall et al., 2006].

  4. Expressed sequence tag analysis of Antarctic hairgrass Deschampsia antarctica from King George Island, Antarctica.

    Lee, Hyoungseok; Cho, Hyun Hee; Kim, Il-Chan; Yim, Joung Han; Lee, Hong Kum; Lee, Yoo Kyung


    Deschampsia antarctica is the only monocot that thrives in the tough conditions of the Antarctic region. It is an invaluable resource for the identification of genes associated with tolerance to various environmental pressures. In order to identify genes that are differentially regulated between greenhouse-grown and Antarctic field-grown plants, we initiated a detailed gene expression analysis. Antarctic plants were collected and greenhouse plants served as controls. Two different cDNA libraries were constructed with these plants. A total of 2,112 cDNA clones was sequenced and grouped into 1,199 unigene clusters consisting of 243 consensus and 956 singleton sequences. Using similarity searches against several public databases, we constructed a functional classification of the ESTs into categories such as genes related to responses to stimuli, as well as photosynthesis and metabolism. Real-time PCR analysis of various stress responsive genes revealed different patterns of regulation in the different environments, suggesting that these genes are involved in responses to specific environmental factors.

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

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


    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.

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

    Riad Hosein


    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.

  7. Water in volcanoes: evolution, storage and rapid release during landslides.

    Delcamp, Audray; Roberti, Gioachino; van Wyk de Vries, Benjamin


    Volcanoes can store and drain water that is used as a valuable resource by populations living on their slopes. The water drainage and storage pattern depend on the volcano lithologies and structure, as well as the geological and hydrometric settings. The drainage and storage pattern will change according to the hydrometric conditions, the vegetation cover, the eruptive activity and the long- and short-term volcano deformation. Inspired by our field observations and based on geology and structure of volcanic edifices, on hydrogeological studies, and modelling of water flow in opening fractures, we develop a model of water storage and drainage linked with volcano evolution. This paper offers a first-order general model of water evolution in volcanoes.

  8. On the practical convergence of coda-based correlations: a window optimization approach

    Chaput, J.; Clerc, V.; Campillo, M.; Roux, P.; Knox, H.


    We present a novel optimization approach to improve the convergence of interstation coda correlation functions towards the medium's empirical Green's function. For two stations recording a series of impulsive events in a multiply scattering medium, we explore the impact of coda window selection through a Markov Chain Monte Carlo scheme, with the aim of generating a gather of correlation functions that is the most coherent and symmetric over events, thus recovering intuitive elements of the interstation Green's function without any nonlinear post-processing techniques. This approach is tested here for a 2-D acoustic finite difference model, where a much improved correlation function is obtained, as well as for a database of small impulsive icequakes recorded on Erebus Volcano, Antarctica, where similar robust results are shown. The average coda solutions, as deduced from the posterior probability distributions of the optimization, are further representative of the scattering strength of the medium, with stronger scattering resulting in a slightly delayed overall coda sampling. The recovery of singly scattered arrivals in the coda of correlation functions are also shown to be possible through this approach, and surface wave reflections from outer craters on Erebus volcano were mapped in this fashion. We also note that, due to the improvement of correlation functions over subsequent events, this approach can further be used to improve the resolution of passive temporal monitoring.

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

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


    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.

  10. First time-series optical photometry from Antarctica

    Strassmeier, K G; Granzer, T; Tosti, G; DiVarano, I; Savanov, I; Bagaglia, M; Castellini, S; Mancini, A; Nucciarelli, G; Straniero, O; Distefano, E; Messina, S; Cutispoto, G


    Beating the Earth's day-night cycle is mandatory for long and continuous time-series photometry and had been achieved with either large ground-based networks of observatories at different geographic longitudes or when conducted from space. A third possibility is offered by a polar location with astronomically-qualified site characteristics. Aims. In this paper, we present the first scientific stellar time-series optical photometry from Dome C in Antarctica and analyze approximately 13,000 CCD frames taken in July 2007. We conclude that high-precision CCD photometry with exceptional time coverage and cadence can be obtained at Dome C in Antarctica and be successfully used for time-series astrophysics.

  11. Synchronous climate changes in Antarctica and the North Atlantic

    Steig, E.J.; Brook, E.J.; White, J.W.C.; Sucher, C.M.; Bender, M.L.; Lehman, S.J.; Morse, D.L.; Waddington, E.D.; Clow, G.D.


    Central Greenland ice cores provide evidence of abrupt changes in climate over the past 100,000 years. Many of these changes have also been identified in sedimentary and geochemical signatures in deep-sea sediment cores from the North Atlantic, confirming the link between millennial-scale climate variability and ocean thermohaline circulation. It is shown here that two of the most prominent North Atlantic events - the rapid warming that makes the end of the last glacial period and the Bolling/Allerod-Younger Dryas oscillation - are also recorded in an ice core from Taylor Dome, in the western Ross Sea sector of Antarctica. This result contrasts with evidence from ice cores in other regions of Antarctica, which show an asynchronous response between the Northern and Southern Hemispheres.

  12. The establishment of GPS network in Grove Mountains, East Antarctica


    The Grove Mountains are located in Princess Elizabeth Land, East Antarctica, extending from 72° to 73°S latitude and 73° to 76°E longitude, covering approximately 8000 km2 areas. During the 2002/2003 austral summer season, the 19th CHINARE (Chinese National Antarctic Research Expedition) carried out the third expedition in Grove Mountains, East Antarctica. The Geodetic network was established, which can provide ground control for the satellite image map for the multi-discipline expedition in the Grove Mountains where seven permanent GPS benchmarks were set up supported by the helicopter and snow vehicles. All GPS sites besides Z001 were observed at least for one hour using the dual frequencies Trimble 4000ssi GPS receivers. The data were processed by the comprehensive GPS analysis package-GAMIT/GLOBK and the precision is good enough to satisfy with the acquirement of satellite mapping in this area.

  13. VLF wave injection experiments from Siple Station, Antarctica

    R.A., Helliwell


    The background of VLF wave-particle experiments from Siple Station, Antarctica, including wave-induced precipitation is briefly reviewed. Single frequency ducted signals that exceed a certain 'threshold' intensity are observed at the conjugate point (Roberval, Quebec) to be amplified 30-50dB, with temporal growth rates of 30-200dB/s. Following saturation, variable frequency emissions are triggered. When a second signal is added to the first, with a frequency spacing Df

  14. Victoria Land, Ross Sea, and Ross Ice Shelf, Antarctica


    On December 19, 2001, MODIS acquired data that produced this image of Antarctica's Victoria Land, Ross Ice Shelf, and the Ross Sea. The coastline that runs up and down along the left side of the image denotes where Victoria Land (left) meets the Ross Ice Shelf (right). The Ross Ice Shelf is the world's largest floating body of ice, approximately the same size as France. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  15. Transiting planet candidates with ASTEP 400 at Dome C, Antarctica

    Mékarnia, D.; Guillot, T.; Rivet, J.-P.; Schmider, F.-X.; Abe, L.; Gonçalves, I.; Agabi, A.; Crouzet, N.; Fruth, T.; Barbieri, M.; Bayliss, D. D. R.; Zhou, G.; Aristidi, E.; Szulagyi, J.; Daban, J.-B.; Fanteï-Caujolle, Y.; Gouvret, C.; Erikson, A.; Rauer, H.; Bouchy, F.; Gerakis, J.; Bouchez, G.


    ASTEP 400, the main instrument of the ASTEP (Antarctica Search for Transiting ExoPlanets) programme, is a 40 cm telescope, designed to withstand the harsh conditions in Antarctica, achieving a photometric accuracy of a fraction of millimagnitude on hourly time-scales for planet-hosting southern bright (R ˜ 12 mag) stars. We review the performances of this instrument, describe its operating conditions, and present results from the analysis of observations obtained during its first three years (2010-2012) of operation, before its repatriation in 2014. During this time, we observed a total of 22 stellar fields (1° × 1° field of view). Each field, in which we measured stars up to magnitude R = 18 mag, was observed continuously during ˜7 to ˜30 d. More than 200 000 frames were recorded and 310 000 stars processed, using an implementation of the optimal image subtraction photometry algorithm. We found 43 planetary transit candidates. 20 of these candidates were observed using spectroscopic follow-ups including four targets classified as good planet candidates. Our results demonstrate that accurate near-continuous photometric observations are achievable from the Concordia station at Dome C in Antarctica, even if we were not able to reach the nominal photometric precision of the instrument. We conducted a correlation analysis between the rms noise and a large number of external parameters and found that source of the ˜1 mmag correlated noise is not obvious and does not depend on a single parameter. However, our analysis provided some hints and guidance to increase the photometric accuracy of the instrument. These improvements should equip any future telescope operating in Antarctica.

  16. Tidal Energy Resource Assessment for McMurdo Station, Antarctica


    unclear” (U.S. Antarctic Program Blue Ribbon Panel 2012). These studies have predominantly considered solar , wind, geother- mal, and waste wood and paper...tides are called spring tides (Figure 3). When the moon is at a right angle , perpen- dicular to the earth–sun connecting line, the lunar and solar ...capabilities at McMurdo Station, Antarctica, to reduce costs and emissions. Previous assessments considered wind, solar , and geothermal energy

  17. Direct gravimetric determination of aerosol mass concentration in central antarctica.

    Annibaldi, Anna; Truzzi, Cristina; Illuminati, Silvia; Scarponi, Giuseppe


    In Antarctica, experimental difficulties due to extreme conditions have meant that aerosol mass has rarely been measured directly by gravimetry, and only in coastal areas where concentrations were in the range of 1-7 μg m(-3). The present work reports on a careful differential weighing methodology carried out for the first time on the plateau of central Antarctica (Dome C, East Antarctica). To solve problems of accurate aerosol mass measurements, a climatic room was used for conditioning and weighing filters. Measurements were carried out in long stages of several hours of readings with automatic recording of temperature/humidity and mass. This experimental scheme allowed us to sample from all the measurements (up to 2000) carried out before and after exposure, those which were recorded under the most stable humidity conditions and, even more importantly, as close to each other as possible. The automatic reading of the mass allowed us in any case to obtain hundreds of measurements from which to calculate average values with uncertainties sufficiently low to meet the requirements of the differential weighing procedure (±0.2 mg in filter weighing, between ±7% and ±16% both in aerosol mass and concentration measurements). The results show that the average summer aerosol mass concentration (aerodynamic size ≤10 μm) in central Antarctica is about 0.1 μg m(-3), i.e., about 1/10 of that of coastal Antarctic areas. The concentration increases by about 4-5 times at a site very close to the station.

  18. The volcanoes and clouds of Venus

    Prinn, R. G.


    One of the earth's most intriguing features is its geologic activity. However, volcanic eruptions have not been observed on any other body in the solar system, except for a detection of such eruptions on Jupiter's moon Io. As in a number of respects Venus is similar to earth, questions arise regarding the presence of active volcanoes on Venus. In the past, the study of such questions was made difficult or impossible by the layer of clouds surrounding the Venusian surface. In the past half decade the situation has changed. These changes are mainly related to studies based on a utilization of radio waves and microwaves which can pass through the cloud layer. Such studies have been conducted with the aid of terrestrial radio telescopes, the Pioneer Venus satellite orbiting Venus, and two Russian spacecraft. The results of these studies are discussed in detail. It appears that there are active volcanoes on Venus. This volcanism is a key link in the chemical cycle which produces the clouds. The levels of volcanic activity on Venus and earth seem to be roughly comparable.

  19. Volcano-ice interactions on Mars

    Allen, C. C.


    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 composition. 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.

  20. Monitoring Santorini volcano (Greece) breathing from space

    Foumelis, Michael; Trasatti, Elisa; Papageorgiou, Elena; Stramondo, Salvatore; Parcharidis, Issaak


    Since its last eruption in 1950, Santorini volcano (Greece) remained in a dormant state. This is also evidenced for the period 1992-2010 by the gradual deflation signal over Nea Kameni as measured by satellite Synthetic Aperture Radar Interferometry (InSAR) with low rates of about 5-6 mm yr-1 as well as by the absence of seismic activity within the caldera. However, at the beginning of 2011 the volcano showed signs of unrest with increased microseismic activity and significant ground uplift, reaching 14 cm within a year (2011 March-2012 March), according to InSAR time-series. ALOS PALSAR data indicate the onset of the phenomenon in early 2010 where an aseismic pre-unrest phase of increased subsidence (1-3 cm) preceded the uplift. Joint inversions of SAR and GPS velocities using spherical and spheroidal magmatic source types indicate their location offshore at about 1 km north of Nea Kameni and between 3.5 and 3.8 km depth. The estimated volume variation rate is 6 × 106 m3 yr-1 to 9 × 106 m3 yr-1. A gradual slowing in the rate of inflation within the first quarter of 2012 is apparent by ENVISAT data, while subsequent observations from RADARSAT-2 confirm the observed trend.

  1. Space Radar Image of Karisoke & Virunga Volcanoes


    This is a false-color composite of Central Africa, showing the Virunga volcano chain along the borders of Rwanda, Zaire and Uganda. This area is home to the endangered mountain gorillas. The image was acquired on October 3, 1994, on orbit 58 of the space shuttle Endeavour by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR). In this image red is the L-band (horizontally transmitted, vertically received) polarization; green is the C-band (horizontally transmitted and received) polarization; and blue is the C-band (horizontally transmitted and received) polarization. The area is centered at about 2.4 degrees south latitude and 30.8 degrees east longitude. The image covers an area 56 kilometers by 70 kilometers (35 miles by 43 miles). The dark area at the top of the image is Lake Kivu, which forms the border between Zaire (to the right) and Rwanda (to the left). In the center of the image is the steep cone of Nyiragongo volcano, rising 3,465 meters (11,369 feet) high, with its central crater now occupied by a lava lake. To the left are three volcanoes, Mount Karisimbi, rising 4,500 meters (14,800 feet) high; Mount Sabinyo, rising 3,600 meters (12,000 feet) high; and Mount Muhavura, rising 4,100 meters (13,500 feet) high. To their right is Nyamuragira volcano, which is 3,053 meters (10,017 feet) tall, with radiating lava flows dating from the 1950s to the late 1980s. These active volcanoes constitute a hazard to the towns of Goma, Zaire and the nearby Rwandan refugee camps, located on the shore of Lake Kivu at the top left. This radar image highlights subtle differences in the vegetation of the region. The green patch to the center left of the image in the foothills of Karisimbi is a bamboo forest where the mountain gorillas live. The vegetation types in this area are an important factor in the habitat of mountain gorillas. Researchers at Rutgers University in New Jersey and the Dian Fossey Gorilla Fund in London will use this data to produce

  2. Terrestrial Real-Time Volcano Monitoring

    Franke, M.


    As volcano monitoring involves more and different sensors from seismic to GPS receivers, from video and thermal cameras to multi-parameter probes measuring temperature, ph values and humidity in the ground and the air, it becomes important to design real-time networks that integrate and leverage the multitude of available parameters. In order to do so some simple principles need to be observed: a) a common time base for all measurements, b) a packetized general data communication protocol for acquisition and distribution, c) an open and well documented interface to the data permitting standard and emerging innovative processing, and d) an intuitive visualization platform for scientists and civil defense personnel. Although mentioned as simple principles, the list above does not necessarily lead to obvious solutions or integrated systems, which is, however, required to take advantage of the available data. Only once the different data streams are put into context to each other in terms of time and location can a broader view be obtained and additional information extracted. The presentation is a summary of currently available technologies and how they can achieve the goal of an integrated real-time volcano monitoring system. A common time base are standard for seismic and GPS networks. In different projects we extended this to video feeds and time-lapse photography. Other probes have been integrated with vault interface enclosures (VIE) as used in the Transportable Array (TA) of the USArray. The VIE can accommodate the sensors employed in volcano monitoring. The TA has shown that Antelope is a versatile and robust middleware. It provides the required packetized general communication protocol that is independent from the actual physical communication link leaving the network design to adopt appropriate and possible hybrid solutions. This applies for the data acquisition and the data/information dissemination providing both a much needed collaboration platform, as

  3. Igneous Petrogenesis of Tequila Volcano, Western Mexico

    Vázquez-Duarte, A.; Gómez-Tuena, A.; Díaz-Bravo, B.


    Tequila volcano belongs to a Quaternary volcanic chain that runs in parallel to the Middle American Trench, but that have been constructed within the so-called Tepic-Zacoalco rift: an extensional tectonic structure that has been active for the past 3.5 Ma. This unusual tectonic setting, and the existence of a high-resolution stratigraphy for the Tequila Volcanic Field (Lewis-Kenedi, 2005, Bull Volcanol), provide an excellent opportunity to study andesite petrogenesis. New comprehensive geochemical data allow the recognition of at least four different magmatic series around Tequila: 1) The Santa Rosa intraplate basalts (1.0 - 0.2 Ma), a volcanic plateau constructed along the Santiago River Fault north of Tequila volcano. These Na-alkaline basalts are olivine-phyric, have negligible subduction signatures (Ba/Nb= 11.75 - 49.36), and display Sr-Nd-Pb isotopic compositions that correlate with fractionation indexes, probably indicating melt-crust interactions. 2) A group of vitreous domes and flows of dacitic to rhyolitic compositions, mostly contemporaneous to the Santa Rosa basalts, that were emplaced on the periphery of Tequila volcano. These rocks can have very low Sr and Eu contents but their isotopic compositions are remarkably constant and similar to the Santa Rosa basalts, probably indicating a genetic link through low pressure fractionation in the stability field of plagioclase. 3) The main edifice of Tequila volcano (~0.2 Ma) is made of two pyroxene andesites and dacites with strong subduction signatures (Ba/Nb= 53-112), that inversely correlate with MgO contents, but that follow a diverging evolutionary trend as the rest of the sequences. The isotopic compositions of Tequila main edifice can extend to slightly more enriched values, but do not correlate with fractionation indexes, thus indicating provenance from a different source. 4) The youngest activity on Tequila volcano (~0.09 Ma) is represented by amphibole bearing andesites that erupted through the

  4. Ice crystal precipitation at Dome C site (East Antarctica)

    Santachiara, G.; Belosi, F.; Prodi, F.


    For the first time, falling ice crystals were collected on glass slides covered with a thin layer of 2% formvar in chloroform at the Dome Concordia site (Dome C), Antarctica. Samplings were performed in the framework of the 27th Italian Antarctica expedition of the Italian National Program for Research in Antarctica in the period 21 February-6 August 2012. Events of clear-sky precipitations and precipitations from clouds were considered and the replicas obtained were examined under Scanning Electron Microscope (SEM). Several shapes of ice crystals were identified, including "diamond dust" (plates, pyramids, hollow and solid columns), and crystal aggregates varying in complexity. Single events often contained both small (10 μm to 50 μm) and large (hundreds of microns) crystals, suggesting that crystals can form simultaneously near the ground (height of a few hundred metres) and at higher layers (height of thousands of metres). Images of sampled crystal replicas showed that single bullets are not produced separately, but by the disintegration of combinations of bullets. Rimed ice crystals were absent in the Dome C samples, i.e. the only mode of crystal growth was water vapour diffusion. On considering the aerosol in the sampled crystals, we reached the conclusion that inertial impaction, interception and Brownian motion were insufficient to explain the scavenged aerosol. We therefore presume that phoretic forces play a role in scavenging during the crystal growth process.

  5. Antarctica's protected areas are inadequate, unrepresentative, and at risk.

    Shaw, Justine D; Terauds, Aleks; Riddle, Martin J; Possingham, Hugh P; Chown, Steven L


    Antarctica is widely regarded as one of the planet's last true wildernesses, insulated from threat by its remoteness and declaration as a natural reserve dedicated to peace and science. However, rapidly growing human activity is accelerating threats to biodiversity. We determined how well the existing protected-area system represents terrestrial biodiversity and assessed the risk to protected areas from biological invasions, the region's most significant conservation threat. We found that Antarctica is one of the planet's least protected regions, with only 1.5% of its ice-free area formally designated as specially protected areas. Five of the distinct ice-free ecoregions have no specially designated areas for the protection of biodiversity. Every one of the 55 designated areas that protect Antarctica's biodiversity lies closer to sites of high human activity than expected by chance, and seven lie in high-risk areas for biological invasions. By any measure, including Aichi Target 11 under the Convention on Biological Diversity, Antarctic biodiversity is poorly protected by reserves, and those reserves are threatened.

  6. Antarctica's protected areas are inadequate, unrepresentative, and at risk.

    Justine D Shaw


    Full Text Available Antarctica is widely regarded as one of the planet's last true wildernesses, insulated from threat by its remoteness and declaration as a natural reserve dedicated to peace and science. However, rapidly growing human activity is accelerating threats to biodiversity. We determined how well the existing protected-area system represents terrestrial biodiversity and assessed the risk to protected areas from biological invasions, the region's most significant conservation threat. We found that Antarctica is one of the planet's least protected regions, with only 1.5% of its ice-free area formally designated as specially protected areas. Five of the distinct ice-free ecoregions have no specially designated areas for the protection of biodiversity. Every one of the 55 designated areas that protect Antarctica's biodiversity lies closer to sites of high human activity than expected by chance, and seven lie in high-risk areas for biological invasions. By any measure, including Aichi Target 11 under the Convention on Biological Diversity, Antarctic biodiversity is poorly protected by reserves, and those reserves are threatened.

  7. Ground survey of active Central American volcanoes in November - December 1973

    Stoiber, R. E. (Principal Investigator); Rose, W. I., Jr.


    The author has identified the following significant results. Thermal anomalies at two volcanoes, Santiaguito and Izalco, have grown in size in the past six months, based on repeated ground survey. Thermal anomalies at Pacaya volcano have became less intense in the same period. Large (500 m diameter) thermal anomalies exist at 3 volcanoes presently, and smaller scale anomalies are found at nine other volcanoes.

  8. Microtremor study of Gunung Anyar mud volcano, Surabaya, East Java

    Syaifuddin, Firman; Bahri, Ayi Syaeful; Lestari, Wien; Pandu, Juan


    The existence of mud volcano system in East Java is known from the ancient period, especially in Surabaya. Gunung Anyar mud volcano is one of the mud volcano system manifestation was appeared close to the residence. Because of this phenomenon we have to learn about the impact of this mud volcano manifestation to the neighbourhood. The microtremor study was conducted to evaluate the possible influence effect of the mud volcano to the environment and get more information about the subsurface condition in this area. Microtremor is one of the geophysical methods which measure the natural tremor or vibration of the earth, the dominant frequency of the tremor represent thickness of the soft sediment layer overlay above the bed rock or harder rock layer beneath our feet. In this study 90 stations was measured to record the natural tremor. The result from this study shows the direct influenced area of this small mud volcano system is close to 50m from the centre of the mud volcano and bed rock of this area is range between 66 to 140 meter.

  9. Acoustic scattering from mud volcanoes and carbonate mounds.

    Holland, Charles W; Weber, Thomas C; Etiope, Giuseppe


    Submarine mud volcanoes occur in many parts of the world's oceans and form an aperture for gas and fluidized mud emission from within the earth's crust. Their characteristics are of considerable interest to the geology, geophysics, geochemistry, and underwater acoustics communities. For the latter, mud volcanoes are of interest in part because they pose a potential source of clutter for active sonar. Close-range (single-interaction) scattering measurements from a mud volcano in the Straits of Sicily show scattering 10-15 dB above the background. Three hypotheses were examined concerning the scattering mechanism: (1) gas entrained in sediment at/near mud volcano, (2) gas bubbles and/or particulates (emitted) in the water column, (3) the carbonate bio-construction covering the mud volcano edifice. The experimental evidence, including visual, acoustic, and nonacoustic sensors, rules out the second hypothesis (at least during the observation time) and suggests that, for this particular mud volcano the dominant mechanism is associated with carbonate chimneys on the mud volcano. In terms of scattering levels, target strengths of 4-14 dB were observed from 800 to 3600 Hz for a monostatic geometry with grazing angles of 3-5 degrees. Similar target strengths were measured for vertically bistatic paths with incident and scattered grazing angles of 3-5 degrees and 33-50 degrees, respectively.

  10. Preliminary microphysical characterization of precipitation at ground over Antarctica coast

    Roberto, Nicoletta; Adirosi, Elisa; Montopoli, Mario; Baldini, Luca; Dietrich, Stefano; Porcù, Federico


    The primary mass input of the Antarctic ice sheet is snow precipitation which is one of the most direct climatic indicators. Climatic model simulations of precipitations over Antarctica is an important task to assess the variation of ice sheet over long temporal scale. The main source of precipitation information in Antarctica regions derive from satellite observations. However, satellite measurements and products need to be calibrated and validated with observations from ground sensors. In spite of their key role, precipitation measurements at ground are scarce and not appropriate to provide the specific characteristic of precipitation particles that influence the scattering and absorption properties of ice particles. Recently, different stations in Antarctica (Princess Elizabeth, McMurdo, Mario Zucchelli) are equipping observatories for cloud and precipitation observations. The setup of the observatory at the Italian Station, Mario Zucchelli (MZ) plans to integrate the current instrumentation for weather measurements with other instruments specific for precipitation observations, in particular, a 24-GHz vertical pointing radar and a laser disdrometer Parsivel. The synergetic use of the set of instruments allows for characterizing precipitation and studying properties of Antarctic precipitation such as dimension, shapes, fall behavior, density of particles, particles size distribution, particles terminal velocity, reflectivity factor and including some information on their vertical extent. Last November, the OTT Parsivel disdrometer was installed on the roof of a logistic container (at 6 m of height) of the MZ station (Latitude 74° 41' 42" S; Longitude 164° 07' 23E") in the Terranova Bay. The disdrometer measures size and fall velocity of particles, passing through a laser matrix from which the Particle Size Distribution (PSD) is obtained. In addition, some products such as reflectivity factor, snow rate and snow accumulation can be inferred by properly

  11. Development of volcano monitoring technique using repeating earthquakes observed by the Volcano Observation Network of NIED

    Kohno, Y.; Ueda, H.; Kimura, H.; Nagai, M.; Miyagi, Y.; Fujita, E.; Kozono, T.; Tanada, T.


    After the Grate East Japan Earthquake (M9.0) on March 11, 2011, the M6.4 earthquake occurred beneath Mt. Fuji on March 15, 2011. Although the hypocenter seemed to be very close to an assumed magma chamber of Fuji volcano, no anomalies in volcanic activity have been observed until August 2012. As an example, after the M6.1 earthquake occurred in 1998 at southwest of Iwate volcano, a change of seismic velocity structure (e.g. Nishimura et al., 2000) was observed as well as active seismicity and crustal deformation. It had affected waveforms of repeating earthquakes occurring at a plate subduction zone, that is, the waveform similarities were reduced just after the earthquake due to upwelling of magma. In this study, first we analyzed for Mt. Fuji where such changes are expected by the occurrence of the earthquake to try to develop a tool for monitoring active volcanoes using the Volcano Observation network (V-net) data. We used seismic waveform data of repeating earthquakes observed by short period seismometers of V-net and the High Sensitivity Seismograph Network Japan (Hi-net) stations near Fuji volcano after 2007. The seismic data were recorded with a sampling rate of 100 Hz, and we applied 4-8 Hz band pass filter to reduce noise. The repeating earthquakes occurred at the plate subduction zone and their catalog is compiled by Hi-net data (Kimura et al., 2006). We extracted repeating earthquake groups that include earthquakes before and after the M6.4 earthquake on March 15, 2011. A waveform of the first event of the group and waveforms of the other events are compared and calculated cross-correlation coefficients. We adjusted P wave arrivals of each event and calculate the coefficients and lag times of the latter part of the seismic waves with the time window of 1.25 s. We searched the best fit maximizing the cross-correlation coefficients with 0.1 s shift time at each time window. As a result we found three remarkable points at this time. [1] Comparing lag times

  12. Volcano instability induced by strike-slip faulting

    Lagmay, A. M. F.; van Wyk de Vries, B.; Kerle, N.; Pyle, D. M.


    Analogue sand cone experiments were conducted to study instability generated on volcanic cones by basal strike-slip movement. The results of the analogue models demonstrate that edifice instability may be generated when strike-slip faults underlying a volcano move as a result of tectonic adjustment. This instability occurs on flanks of the volcano above the strike-slip shear. On the surface of the volcano this appears as a pair of sigmoids composed of one reverse and one normal fault. In the interior of the cone the faults form a flower structure. Two destabilised regions are created on the cone flanks between the traces of the sigmoidal faults. Bulging, intense fracturing and landsliding characterise these unstable flanks. Additional analogue experiments conducted to model magmatic intrusion show that fractures and faults developed within the volcanic cone due to basal strike-slip motions strongly control the path of the intruding magma. Intrusion is diverted towards the areas where previous development of reverse and normal faults have occurred, thus causing further instability. We compare our model results to two examples of volcanoes on strike-slip faults: Iriga volcano (Philippines), which underwent non-magmatic collapse, and Mount St. Helens (USA), where a cryptodome was emplaced prior to failure. In the analogue and natural examples, the direction of collapse takes place roughly parallel to the orientation of the underlying shear. The model presented proposes one mechanism for strike-parallel breaching of volcanoes, recently recognised as a common failure direction of volcanoes found in regions with transcurrent and transtensional deformation. The recognition of the effect of basal shearing on volcano stability enables prediction of the likely direction of eventual flank failure in volcanoes overlying strike-slip faults.

  13. Turtles to Terabytes: The Ongoing Revolution in Volcano Geodesy

    Dzurisin, D.


    Volcano geodesy is in the midst of a revolution. GPS and InSAR, together with extensive ground-based sensor networks, have enabled major advances in understanding how and why volcanoes deform. Surveying techniques that produced a few bytes of information per benchmark per year have been replaced by continuously operating deformation networks and imaging radar satellites that generate terabytes of data at resolutions unattainable only a few decades ago. These developments have enabled more detailed assessments of volcano hazards, more accurate forecasts of volcanic activity, and better insights into how volcanoes behave over a variety of spatial and temporal scales. Forty years ago, repeated leveling surveys showed that the floor of the Yellowstone caldera had risen more than 70 cm in the past 5 decades. Today a network of GPS stations tracks surface movements continuously with millimeter-scale accuracy and the entire deformation field is imaged frequently by a growing number of SAR satellites, revealing a far more complex style of deformation than was recognized previously. At Mount St. Helens, the 1980-1986 eruption taught us that a seemingly quiescent volcano can suddenly become overtly restless, and that accurate eruption predictions are possible at least in some limited circumstances given sufficient observations. The lessons were revisited during the volcano's 2004-2008 eruption, during which a new generation of geodetic sensors and methods detected a range of co-eruptive changes that enabled new insights into the volcano's magma storage and transport system. These examples highlight volcano deformation styles and scales that were unknown just a few decades ago but now have been revealed by a growing number of data types and modeling methods. The rapid evolution that volcano geodesy is currently experiencing provides an ongoing challenge for geodesists, while also demonstrating that geodetic unrest is common, widespread, and illuminating. Vive la révolution!

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

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


    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.

  15. New Hypocenter Relocation Results From Volcano-Tectonic Events (1995-2006) at Popocatepetl Volcano, Mexico

    Berger, P.; Nava, F. A.; Valdes-Gonzalez, C.


    Popocatepetl, one of the most active strato-volcanoes in Mexico, started a fumarolic and seismic reactivation in December 1994. New hypocenter relocation results have been calculated for some 1,800 volcano-tectonic (VT) events recorded by the seismic network operating at Popocatepetl during 1995-2006, and previously located by the National Center for Disasters Prevention (CENAPRED). We used two location programs to determine hypocenter relocation. One is a recently developed genetic algorithm program, Disloca, which adjusts the differences in arrival times between the recording seismic stations. The second is HypoDD, which uses the double difference earthquake location algorithm. Disloca allowed evaluation of station corrections, plus location of non-clustered hypocenters, while HypoDD refined the locations of clustered ones. Thus, for a given velocity model, hypocenters of clustered events varied slightly depending on the location program. For both programs, four different crustal velocity models were used, two of which include a low velocity zone (LVZ) below 6 km depth. This LVZ represents the presence of magma, which has been suggested to exist at this depth. The spatial distribution of the relocated hypocenters varies from one model to another, but a carefully considered combination of features common to the four distributions, allows a new characterization of the VT activity at Popocatepetl. The distribution of the relocated hypocenters found in this study differs from that of former investigations at Popocatépetl, and gives new insights into the volcano's structures. Hypocenters occur mainly above 10 km depth, with a horizontal range of about 5 km. Features of the spatial distribution allow a tentative interpretation of several internal volcanic structures. Chief among these are branched dike complexes and different sized zones free of volcano-tectonic events, which are in turn surrounded by zones of magma-rock interaction, as indicated by the presence of

  16. The volcano in a gravel pit: Volcano monitoring meets experimental volcanology

    Kueppers, U.; Alatorre-Ibargüengoitia, M. A.; Hort, M.; Kremers, S.; Meier, K.; Scarlato, P. G.; Scheu, B.; Taddeucci, J.; Wagner, R.; Walk, F.; Dingwell, D. B.


    Volcanic eruptions are an inevitable natural threat. During explosive eruptions, gas and pyroclasts are ejected at high speed over variable time spans and at variable intensity. As magma fragmentation inside a volcanic edifice defies direct observation, our mechanistic and quantitative understanding of the syn-eruptive processes is still incomplete. In an attempt to bridge this gap, we used a supra-disciplinary approach and combined experimental volcanology and volcano monitoring devices. We performed 34 field-based fragmentation experiments using cylindrical samples, drilled from natural volcanic rock samples. Decompression and particle ejection were monitored with (1) Doppler Radar (DR), (2) high-speed and high-definition cameras, (3) high-speed thermal camera, (4) acoustic and infrasound sensors and (5) pressure transducers. The experiments were performed at controlled sample porosity (25 to 75 vol.%) and size (60 mm height and 25 mm and 60 mm diameter, respectively), confinement geometry, applied pressure (4 to 18 MPa) and temperature (25 and 850 °C). We present how the velocity of the ejected pyroclasts was measured by and evaluated for the different approaches and how it was affected by the experimental conditions and sample characteristics. We show that all deployed instruments successfully measured the pyroclast ejection, giving coherent results of up to 130 m/s. Close and high-resolution volcano monitoring, spiced with results from our experiments, will allow for "calibrating volcanoes". An enhanced understanding of the pressurisation state of a volcano is an essential factor in ballistic hazard evaluation and eruption energy estimation and will contribute to adequate risk mitigation.

  17. Muon imaging of volcanoes with Cherenkov telescopes

    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


    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

  18. Large-N in Volcano Settings: Volcanosri

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


    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

  19. Degassing Processes at Persistently Active Explosive Volcanoes

    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 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 generates a viscous plug, pressurizes the magma beneath the plug, and

  20. Isotopic evolution of Mauna Loa volcano

    Kurz, M.D.; Kammer, D.P. (Chemistry Dept., Woods Hole Oceanographic Institution, MA (USA))


    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 {sup 3}He/{sup 4}He ({approx equal} 16-20 times atmospheric), higher {sup 206}Pb/{sup 204}Pb ({approx equal} 18.2), and lower {sup 87}Sr/{sup 86}Sr({approx equal} 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 {sup 3}He/{sup 4}He ratios similar to the other young Kau basalt ({approx equal} 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).

  1. Multibeam Bathymetry of Haleakala Volcano, Maui

    Eakins, B. W.; Robinson, J.


    The submarine northeast flank of Haleakala Volcano, Maui was mapped in detail during the summers of 2001 and 2002 by a joint team from the Japan Marine Science and Technology Center (JAMSTEC), Tokyo Institute of Technology, University of Hawaii, and the U.S. Geological Survey. JAMSTEC instruments used included SeaBeam 2112 hull-mounted multibeam sonar (bathymetry and sidescan imagery), manned submersible Shinkai 6500 and ROV Kaiko (bottom video, photographs and sampling of Hana Ridge), gravimeter, magnetometer, and single-channel seismic system. Hana Ridge, Haleakala's submarine east rift zone, is capped by coral-reef terraces for much of its length, which are flexurally tilted towards the axis of the Hawaiian Ridge and delineate former shorelines. Its deeper, more distal portion exhibits a pair of parallel, linear crests, studded with volcanic cones, that suggest lateral migration of the rift zone during its growth. The northern face of the arcuate ridge terminus is a landslide scar in one of these crests, while its southwestern prong is a small, constructional ridge. The Hana slump, a series of basins and ridges analogous to the Laupahoehoe slump off Kohala Volcano, Hawaii, lies north of Hana Ridge and extends down to the Hawaiian moat. Northwest of this slump region a small, dual-crested ridge strikes toward the Hawaiian moat and is inferred to represent a fossil rift zone, perhaps of East Molokai Volcano. A sediment chute along its southern flank has built a large submarine fan with a staircase of contour-parallel folds on its surface that are probably derived from slow creep of sediments down into the moat. Sediments infill the basins of the Hana slump [Moore et al., 1989], whose lowermost layers have been variously back-tilted by block rotation during slumping and flexural loading of the Hawaiian Ridge; the ridges define the outer edges of those down-dropped blocks, which may have subsided several kilometers. An apron of volcaniclastic debris shed from


    S. G. Pugacheva


    Full Text Available In article the basic geological and morphological features of a volcanic relief of a surface of a planet Mars are considered. The volcanic relief of a planet represents relic ancient shield volcanoes, linear forms of volcanic mountains, areal and central lava flooding, radial and concentric breaks. Results of researches of morphology of volcanic and tectonic formations of a relief of Mars are given in article. On materials of shooting of a surface of Mars spacecrafts constructed hypsometric high-rise profiles of volcanoes and average steepness of slopes are defined. The relative age of volcanoes and volcanic plains is estimated on density of shock craters.

  3. Monitoring Thermal Activity of Eastern Anatolian Volcanoes Using MODIS Images

    Diker, Caner; Ulusoy, Inan


    MODIS (Moderate Resolution Imaging Spectroradiometer) instrument is used for imaging atmosphere, land and ocean with 36 bands. Both AQUA and TERRA platforms acquire 2 images daily (daytime and nighttime). Low temperature anomalies on volcanoes comprise important clues. Low temperature anomalies on Holocene volcanoes of Eastern Anatolia were investigated for these clues using MODIS Land Surface Temperature (LST) images. A total of 16800 daily LST images dated between 2001 and 2012 have been processed using a code written in IDL (Interactive Data Language). Factors like shadow, ice/snow and clouds that are affecting the reflectance data are masked. The mask is derived from MODIS reflectance data state image. Various LST images are calculated: Two nested region of interest (ROI) windows (square/rectangular) have been selected on the images. First is the bigger window, which covers the whole area of the volcano (Total volcano area). Second one is a smaller window which circumference the summit (crater and/or caldera) of the volcano (Summit cone) where thermal output is generally higher when compared to the flanks. Two data sets have been calculated using the ROI's for each volcano. The first set contains daytime and nighttime raw data without any correction. The second set contains topographically corrected images; daytime images are corrected using Cosine and Minnaert methods and nighttime images are corrected using three step normalization method. Calculated surface temperatures (Tmax, Tmin, Tmean) are plotted annually. On Nemrut Volcano as an example, maximum and minimum temperatures are between 26.31oC and -44.87oC on nighttime data for twelve years period. Temperature difference between total volcano area ROI and summit cone ROI are calculated (ΔT). High ΔT indicates that there is an increase of temperature at the summit cone when compared to the total volcano area. STA/LTA (Short Term Average/Long Term Average) filter was applied to maximum temperature and

  4. Progresses in geology and hazards analysis of Tianchi Volcano

    WEI Hai-quan; JIN Bo-lu; LIU Yong-shun


    A number of different lahars have been recognized from a systematic survey of a mapping project. The high setting temperature feature of the deposits indicates a relationship between the lahar and the Millennium eruption event of Tianchi Volcano. The lahars caused a dramatic disaster. Recognize of the huge avalanche scars and deposits around Tianchi Volcano imply another highly destructive hazard. Three types of different texture of the avalanche deposits have been recognized. There was often magma mixing processes during the Millennium eruption of Tianchi Volcano, indicating a mixing and co-eruption regime of the eruption.

  5. Volcano-tectonic evolution of the polygenetic Kolumbo submarine volcano/Santorini (Aegean Sea)

    Hübscher, Christian; Ruhnau, M.; Nomikou, P.


    Here we show for the first time the 3D-structural evolution of an explosive submarine volcano by means of reflection seismic interpretation. Four to five vertically stacked circular and cone-shaped units consisting mainly of volcaniclastics build the Kolumbo underwater volcano which experienced its first eruption > 70 ka ago and its last explosive eruption 1650 AD, 7 km NE of Santorini volcano (southern Aegean Sea). The summed volume of volcaniclastics is estimated to range between 13-22 km3. The entire Kolumbo volcanic complex has a height of ≥ 1 km and a diameter of ≥ 11 km. All volcaniclastic units reveal the same transparent reflection pattern strongly suggesting that explosive underwater volcanism was the prevalent process. Growth faults terminate upwards at the base of volcaniclastic units, thus representing a predictor to an eruption phase. Similarities in seismic reflection pattern between Kolumbo and near-by volcanic cones imply that the smaller cones evolved through explosive eruptions as well. Hence, the central Aegean Sea experienced several more explosive eruptions (≥ 23) than previously assumed, thus justifying further risk assessment. However, the eruption columns from the smaller volcanic cones did not reach the air and- consequently - no sub-aerial pyroclastic surge was created. The Anydros basin that hosts Kolumbo volcanic field opened incrementally NW to SE and parallel to the Pliny and Strabo trends during four major tectonic pulses prior to the onset of underwater volcanism.

  6. Space Radar Image of Kilauea Volcano, Hawaii


    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

  7. Shallow velocity imaging of an active volcano

    Fry, B.; Chardot, L.; Jolly, A. D.


    We use a linear array of temporary seismometers to derive a shear-wave velocity model of the upper ~1000m of the crater area of White Island, an active volcano in New Zealand. We use noise interferometry to generate dispersion curves and invert these dispersion curves to obtain a layered 1D model. By exploiting the varying interstation distances along the array, we are able to define a strong shallow impedance contrast in the upper 10 meters as well as a depth to 'effective' bedrock at about 100m. We limit the bandwidth of the measured dispersion using a 2-wave cycle approximation and construct a composite dispersion curve. We then invert the dispersion curves with two separate inversion algorithms in an effort to test the validity of using this broadband approach for monitoring active volcanoes. The first method is a non-linear approach and is useful when an a-priori starting model is poorly known or if a velocity inversion is likely. Unfortunately, this type of non-linear inversion is more sensitive to small perturbations in the recovered Green's Functions, which may be due to non-equipartitioning of the wavefield as well as to velocity changes. The second is a linearized and damped LSQR approach which we envision will be more useful for routine monitoring in situations in which the starting model is well defined. In this case, selective regularization can be used to stablize moving time-window inversion. Lastly, our results will be used as input for hydrothermal fluid flow modelling conducted in a concurrent study.

  8. Geomechanical rock properties of a basaltic volcano

    Lauren N Schaefer


    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.

  9. Submarine volcanoes along the Aegean volcanic arc

    Nomikou, Paraskevi; Papanikolaou, Dimitrios; Alexandri, Matina; Sakellariou, Dimitris; Rousakis, Grigoris


    The Aegean volcanic arc has been investigated along its offshore areas and several submarine volcanic outcrops have been discovered in the last 25 years of research. The basic data including swath bathymetric maps, air-gun profiles, underwater photos and samples analysis have been presented along the four main volcanic groups of the arc. The description concerns: (i) Paphsanias submarine volcano in the Methana group, (ii) three volcanic domes to the east of Antimilos Volcano and hydrothermal activity in southeast Milos in the Milos group, (iii) three volcanic domes east of Christiana and a chain of about twenty volcanic domes and craters in the Kolumbo zone northeast of Santorini in the Santorini group and (iv) several volcanic domes and a volcanic caldera together with very deep slopes of several volcanic islands in the Nisyros group. The tectonic structure of the volcanic centers is described and related to the geometry of the arc and the neotectonic graben structures that usually host them. The NE-SW direction is dominant in the Santorini and Nisyros volcanic groups, located at the eastern part of the arc, where strike-slip is also present, whereas NW-SE direction dominates in Milos and Methana at the western part, where co-existence of E-W disrupting normal faults is observed. The volcanic relief reaches 1100-1200 m in most cases. This is produced from the outcrops of the volcanic centers emerging usually at 400-600 m depth and ending either below sea level or at high altitudes of 600-700 m on the islands. Hydrothermal activity at relatively high temperatures observed in Kolumbo is remarkable whereas low temperature phenomena have been detected in the Santorini caldera around Kameni islands and in the area southeast of Milos. In Methana and Nisyros, hydrothermal activity seems to be limited in the coastal areas without other offshore manifestations.

  10. Embedded multiparametric system for volcano monitoring

    Moure, David; Torres, Pedro A.; Meletlidis, Stavros; Lopez, Carmen; José Blanco, María


    A low cost and low power consumption multiparametric system designed for volcano monitoring is presented. Once tested with various sensors, at present it is installed in two locations in Tenerife, Canary Islands, acquiring and transmitting data in real time. The system is based on a commercial board (Raspberry Pi®, RPi®) that uses an embedded ARMTM processor with a Debian (Wheezy-Raspbian) Linux Operating System. This configuration permits different standard communication systems between devices as USB and ETHERNET, and also communication with integrated circuits is possible. The whole system includes this platform and self-developed hardware and software. Analog signals are acquired at an expansion board with an ADC converter with three 16 bits channels. This board, which is powered directly from the RPi®, provides timing to the sampling data using a Real Time Clock (RTC). Two serial protocols (I2C and SPI) are responsible for communications. Due to the influence of atmospheric phenomena on the volcano monitoring data, the system is complemented by a self-developed meteorological station based on ArduinoCC and low cost commercial sensors (atmospheric pressure, humidity and rainfall). It is powered with the RPi® and it uses a serial protocol for communications. Self-developed software run under Linux OS and handles configuration, signal acquisition, data storage (USB storage or SD card) and data transmission (FTP, web server). Remote configuration, data plotting and downloading is available through a web interface tool. Nowadays, the system is used for gravimetric and oceanic tides data acquisition in Tenerife and soon it will be applied for clinometric data.

  11. Newberry Volcano EGS Demonstration - Phase I Results

    Osborn, William L. [AltaRock Energy, Inc., Seattle, WA (United States); Petty, Susan [AltaRock Energy, Inc., Seattle, WA (United States); Cladouhos, Trenton T. [AltaRock Energy, Inc., Seattle, WA (United States); Iovenitti, Joe [AltaRock Energy, Inc., Seattle, WA (United States); Nofziger, Laura [AltaRock Energy, Inc., Seattle, WA (United States); Callahan, Owen [AltaRock Energy, Inc., Seattle, WA (United States); Perry, Douglas S. [Davenport Newberry Holdings LLC, Stamford, CT (United States); Stern, Paul L. [PLS Environmental, LLC, Boulder, CO (United States)


    Phase I of the Newberry Volcano Enhanced Geothermal System (EGS) Demonstration included permitting, community outreach, seismic hazards analysis, initial microseismic array deployment and calibration, final MSA design, site characterization, and stimulation planning. The multi-disciplinary Phase I site characterization supports stimulation planning and regulatory permitting, as well as addressing public concerns including water usage and induced seismicity. A review of the project's water usage plan by an independent hydrology consultant found no expected impacts to local stakeholders, and recommended additional monitoring procedures. The IEA Protocol for Induced Seismicity Associated with Enhanced Geothermal Systems was applied to assess site conditions, properly inform stakeholders, and develop a comprehensive mitigation plan. Analysis of precision LiDAR elevation maps has concluded that there is no evidence of recent faulting near the target well. A borehole televiewer image log of the well bore revealed over three hundred fractures and predicted stress orientations. No natural, background seismicity has been identified in a review of historic data, or in more than seven months of seismic data recorded on an array of seven seismometers operating around the target well. A seismic hazards and induced seismicity risk assessment by an independent consultant concluded that the Demonstration would contribute no additional risk to residents of the nearest town of La Pine, Oregon. In Phase II of the demonstration, an existing deep hot well, NWG 55-29, will be stimulated using hydroshearing techniques to create an EGS reservoir. The Newberry Volcano EGS Demonstration is allowing geothermal industry and academic experts to develop, validate and enhance geoscience and engineering techniques, and other procedures essential to the expansion of EGS throughout the country. Successful development will demonstrate to the American public that EGS can play a significant role

  12. Fluctuation analysis of the hourly time variability of volcano-magnetic signals recorded at Mt. Etna Volcano, Sicily (Italy)

    Currenti, Gilda [Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma 2, 95123 Catania (Italy); Del Negro, Ciro [Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma 2, 95123 Catania (Italy); Lapenna, Vincenzo [Istituto di Metodologie per l' Analisi Ambientale, Consiglio Nazionale delle Ricerche, IMAA-CNR, C.da S.Loja 5, 85050 Tito, PZ (Italy); Telesca, Luciano [Istituto di Metodologie per l' Analisi Ambientale, Consiglio Nazionale delle Ricerche, IMAA-CNR, C.da S.Loja 5, 85050 Tito, PZ (Italy)]. E-mail:


    The time-correlation properties in the hourly time variability of volcano-magnetic data measured at the active volcano Mt. Etna, Sicily (southern Italy), are investigated by using the detrended fluctuation analysis (DFA). DFA is a data processing method that allows for the detection of scaling behaviors in observational time series even in the presence of nonstationarities. The procedure adopted has revealed unambiguous link between the dynamics of the measured data and the recent eruptive episode of the volcano occurred on October 27, 2002.

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

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


    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.

  14. Influence of persistent wind scour on the surface mass balance of Antarctica

    Das, I.; Bell, R.E.; Lenaerts, J.T.M.; Broeke, M.R. van den


    Accurate quantification of surface snow accumulation over Antarctica is a key constraint for estimates of the Antarctic mass balance, as well as climatic interpretations of ice-core records1,2. Over Antarctica, near-surface winds accelerate down relatively steep surface slopes, eroding and sublimati

  15. Relative sea-level rise around East Antarctica during Oligocene glaciation

    Stocchi, P.; Escutia, C.; Houben, A.J.P.; Vermeersen, B.L.A.; Bijl, P.K.; Brinkhuis, H.; Deconto, R.M.; Galeotti, S.; Passchier, S.; Pollard, D.


    During the middle and late Eocene (∼ 48-34 Myr ago), the Earth's climate cooled and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarctica induced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level rose despite an ove

  16. Relative sea-level rise around East Antarctica during Oligocene glaciation

    Stocchi, P.; Escutia, C.; Houben, A.J.P.; Vermeersen, B.L.A.; Bijl, P.K.; Brinkhuis, H.; DeConto , R.M.; Galeotti, S.; Passchier, S.; Pollard, D.; IODP Expedition 318 Scientists; Houben, A.J.P.


    During the middle and late Eocene (similar to 48-34 Myr ago), the Earth's climate cooled(1,2) and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarctica(3,4) induced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level

  17. Relative sea-level rise around East Antarctica during Oligocene glaciation

    Stocchi, P.; Escutia, C.; Houben, A.J.P.; Vermeersen, B.L.A.; Bijl, P.K.; Brinkhuis, H.; Deconto, R.M.; Galeotti, S.; Passchier, S.; Pollard, D.


    During the middle and late Eocene (∼ 48-34 Myr ago), the Earth's climate cooled and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarctica induced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level rose despite an ove

  18. Relative sea-level rise around East Antarctica during Oligocene glaciation

    Stocchi, P.; Escutia, C.; Houben, A.J.P.; Vermeersen, B.L.A.; Bijl, P.K.; Brinkhuis, H.; DeConto , R.M.; Galeotti, S.; Passchier, S.; Pollard, D.; IODP Expedition 318 Scientists; Houben, A.J.P.


    During the middle and late Eocene (similar to 48-34 Myr ago), the Earth's climate cooled(1,2) and an ice sheet built up on Antarctica. The stepwise expansion of ice on Antarctica(3,4) induced crustal deformation and gravitational perturbations around the continent. Close to the ice sheet, sea level

  19. Antibacterial, antifungal and antiprotozoal activities of fungal communities present in different substrates from Antarctica

    Antarctica is a pristine and extreme environment that represents a unique opportunity for taxonomic, ecological and biotechnological studies of the microorganisms. In the present work, the fungal communities of rhizosphere soil of Deschampsia antarctica, soil, ornithogenic soil, marine and lake sedi...

  20. Antarctica: The Continuing Experiment. Foreign Policy Association Headline Series, No. 273.

    Quigg, Philip W.

    One of a series of booklets on world issues examines the sharpened differences between those nations that have declared sovereignty over parts of Antarctica and those that have not; between those nations that have arbitrarily assumed responsibility for the administration of Antarctica and the smaller, more numerous nations that believe their…

  1. Single-station monitoring of volcanoes using seismic ambient noise

    De Plaen, Raphael S. M.; Lecocq, Thomas; Caudron, Corentin; Ferrazzini, Valérie; Francis, Olivier


    Seismic ambient noise cross correlation is increasingly used to monitor volcanic activity. However, this method is usually limited to volcanoes equipped with large and dense networks of broadband stations. The single-station approach may provide a powerful and reliable alternative to the classical "cross-station" approach when measuring variation of seismic velocities. We implemented it on the Piton de la Fournaise in Reunion Island, a very active volcano with a remarkable multidisciplinary continuous monitoring. Over the past decade, this volcano has been increasingly studied using the traditional cross-correlation technique and therefore represents a unique laboratory to validate our approach. Our results, tested on stations located up to 3.5 km from the eruptive site, performed as well as the classical approach to detect the volcanic eruption in the 1-2 Hz frequency band. This opens new perspectives to successfully forecast volcanic activity at volcanoes equipped with a single three-component seismometer.

  2. Distribution of acidic groundwater around quaternary volcanoes in Japan

    Asamori, Koichi; Ishimaru, Tsuneari; Iwatsuki, Teruki [Japan Nuclear Cycle Development Inst., Toki, Gifu (Japan). Tono Geoscience Center


    One important key issue in the understanding of the long-term stability of the geological environment is the influence of magmatism. In this study, we examined the general spatial distribution of acidic groundwater around Quaternary volcanoes in Japan using a database of groundwater geochemistry. The results may be summarized as follows: Acidic groundwater with pH < 4.8 mainly occur in present volcanic regions and are distributed from several kilometers to about 20 km from Quaternary volcanoes. The pH value of groundwater tends to decrease with increasing distance from a volcano. However, these results may be affected by inhomogeneity of groundwater data distribution and the characteristic activity of each volcano. In order to assess a specific volcanic region, a detailed analysis that considers volcanic activity, using a data set with high spatial density is necessary. (author)

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

    US Fish and Wildlife Service, 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...

  4. Chasing lava: a geologist's adventures at the Hawaiian Volcano Observatory

    Duffield, Wendell A.


    A lively account of the three years (1969-1972) spent by geologist Wendell Duffield working at the Hawaiian Volcano Observatory at Kilauea, one of the world's more active volcanoes. Abundantly illustrated in b&w and color, with line drawings and maps, as well. Volcanologists and general readers alike will enjoy author Wendell Duffield's report from Kilauea--home of Pele, the goddess of fire and volcanoes. Duffield's narrative encompasses everything from the scientific (his discovery that the movements of cooled lava on a lava lake mimic the movements of the earth's crust, providing an accessible model for understanding plate tectonics) to the humorous (his dog's discovery of a snake on the supposedly snake-free island) to the life-threatening (a colleague's plunge into molten lava). This charming account of living and working at Kilauea, one of the world's most active volcanoes, is sure to be a delight.

  5. Mount Rainier: living safely with a volcano in your backyard

    Driedger, Carolyn L.; Scott, William E.


    Majestic Mount Rainier soars almost 3 miles (14,410 feet) above sea level and looms over the expanding suburbs of Seattle and Tacoma, Washington. Each year almost two million visitors come to Mount Rainier National Park to admire the volcano and its glaciers, alpine meadows, and forested ridges. However, the volcano's beauty is deceptive - U.S. Geological Survey (USGS) research shows that Mount Rainier is one of our Nation's most dangerous volcanoes. It has been the source of countless eruptions and volcanic mudflows (lahars) that have surged down valleys on its flanks and buried broad areas now densely populated. To help people live more safely with the volcano, USGS scientists are working closely with local communities, emergency managers, and the National Park Service.

  6. Influence of Persistent Wind Scour on the Surface Mass Balance of Antarctica

    Das, Indrani; Bell, Robin E.; Scambos, Ted A.; Wolovick, Michael; Creyts, Timothy T.; Studinger, Michael; Fearson, Nicholas; Nicolas, Julien P.; Lenaerts, Jan T. M.; vandenBroeke, Michiel R.


    Accurate quantification of surface snow accumulation over Antarctica is a key constraint for estimates of the Antarctic mass balance, as well as climatic interpretations of ice-core records. Over Antarctica, near-surface winds accelerate down relatively steep surface slopes, eroding and sublimating the snow. This wind scour results in numerous localized regions (Antarctica. The scour zones are persistent because they are controlled by bedrock topography. On the basis of our Dome A observations, we develop an empirical model to predict wind-scour zones across the Antarctic continent and find that these zones are predominantly located in East Antarctica. We estimate that approx. 2.7-6.6% of the surface area of Antarctica has persistent negative net accumulation due to wind scour, which suggests that, across the continent, the snow mass input is overestimated by 11-36.5 Gt /yr in present surface-mass-balance calculations.

  7. Sulfur dioxide contributions to the atmosphere by volcanoes.

    Stoiber, R E; Jepsen, A


    The first extensive measurements by remote-sensing correlation spectrometry of the sulfur dioxide emitted by volcanic plumes indicate that on the order of 10(3) metric tons of sulfur dioxide gas enter the atmosphere daily from Central American volcanoes. Extrapolation gives a minimum estimate of the annual amount of sulfur dioxide emitted from the world's volcanoes of about 10(7) metric tons.

  8. Three-dimensional shallow velocity structure beneath Taal Volcano, Philippines

    You, Shuei-Huei; Konstantinou, Konstantinos I.; Gung, Yuancheng; Lin, Cheng-Horng


    Based on its numerous historical explosive eruptions and high potential hazards to nearby population of millions, Taal Volcano is one of the most dangerous "Decade Volcanoes" in the world. To provide better investigation on local seismicity and seismic structure beneath Taal Volcano, we deployed a temporary seismic network consisting of eight stations from March 2008 to March 2010. In the preliminary data processing stage, three periods showing linear time-drifting of internal clock were clearly identified from noise-derived empirical Green's functions. The time-drifting errors were corrected prior to further data analyses. By using VELEST, 2274 local earthquakes were manually picked and located. Two major earthquake groups are noticed, with one lying beneath the western shore of Taal Lake showing a linear feature, and the other spreading around the eastern flank of Taal Volcano Island at shallower depths. We performed seismic tomography to image the 3D structure beneath Taal Volcano using the LOTOS algorithm. Some interesting features are revealed from the tomographic results, including a solidified magma conduit below the northwestern corner of Taal Volcano Island, indicated by high Vp, Vs, and low Vp/Vs ratio, and a large potential hydrothermal reservoir beneath the center of Taal Volcano Island, suggested by low Vs and high Vp/Vs ratio. Furthermore, combining earthquake distributions and tomographic images, we suggest potential existence of a hydrothermal reservoir beneath the southwestern corner of Taal Lake, and a fluid conduit extending to the northwest. These seismic features have never been proposed in previous studies, implying that new hydrothermal activity might be formed in places away from the historical craters on Taal Volcano Island.

  9. U.S. Geological Survey Scientific Activities in the Exploration of Antarctica: Introduction to Antarctica (Including USGS Field Personnel: 1946-59)

    Tony K. Meunier Edited by Williams, Richard S.; Ferrigno, Jane G.


    INTRODUCTION Antarctica is the planet's fifth largest continent [13.2 million km2 (5.1 million mi2)]; it contains the Earth's largest (of two) remaining ice sheets; it is considered to be one of the most important scientific laboratories on Earth. This report is the introduction to a series that covers 60 years of U.S. Geological Survey (USGS) scientific activity in Antarctica. It will concentrate primarily on three major topics:

  10. Special offer-7 days fly and drive Antarctica: The role of wilderness protection in deciding whether (semi) permanent tourist facilities in Antarctica should be prohibited

    Kees Bastmeijer


    Antarctica is often described as one of the world’s last wildernesses. Since 1990, tourism to this wilderness is developing rapidly. In a period of 15 years, the number of tourists that make landings in Antarctica has increased from 2,500 (1990/91) to more than 23,000 (2004/05). The diversity of tourist activities is also increasing. The 1991 Protocol on Environmental...

  11. Geomorphometric comparative analysis of Latin-American volcanoes

    Camiz, Sergio; Poscolieri, Maurizio; Roverato, Matteo


    The geomorphometric classifications of three groups of volcanoes situated in the Andes Cordillera, Central America, and Mexico are performed and compared. Input data are eight local topographic gradients (i.e. elevation differences) obtained by processing each volcano raster ASTER-GDEM data. The pixels of each volcano DEM have been classified into 17 classes through a K-means clustering procedure following principal component analysis of the gradients. The spatial distribution of the classes, representing homogeneous terrain units, is shown on thematic colour maps, where colours are assigned according to mean slope and aspect class values. The interpretation of the geomorphometric classification of the volcanoes is based on the statistics of both gradients and morphometric parameters (slope, aspect and elevation). The latter were used for a comparison of the volcanoes, performed through classes' slope/aspect scatterplots and multidimensional methods. In this paper, we apply the mentioned methodology on 21 volcanoes, randomly chosen from Mexico to Patagonia, to show how it may contribute to detect geomorphological similarities and differences among them. As such, both its descriptive and graphical abilities may be a useful complement to future volcanological studies.

  12. Effects of Basement, Structure, and Stratigraphic Heritages on Volcano Behavior

    Lagmay, Alfredo Mahar Francisco A.


    Effective natural hazard mitigation requires that the science surrounding geophysical events be thoroughly explored. With millions of people living on the flanks of volcanoes, understanding the parameters that effect volcanic behavior is critically important. In particular, basements can influence the occurrence of volcanic eruptions and landslides. This control by the substrate on volcano behavior usually has been considered questionable or less important than the conditions of the deep magma source. However, due to recent findings, this view is changing, specifically with regard to approaches in assessing volcanic hazards. The November 2005 AGU Chapman Conference ``Effects of Basement, Structure, and Stratigraphic Heritages on Volcano Behavior'' brought together geologists and geophysicists from North and South America, Europe, and Asia to discuss the results of their research on the reciprocal effects of the interaction between volcanos and their basements. The conference also highlighted the importance of holding Chapman conferences in developing countries such as the Philippines because many hazardous volcanos are situated in these countries. Apart from having natural field laboratories, these are the very same places that need to promote scientific discourse on volcano research, which can lead to more effective hazard mitigation programs.

  13. Reconstruction of the East Africa and Antarctica continental margins

    Nguyen, Luan C.; Hall, Stuart A.; Bird, Dale E.; Ball, Philip J.


    The Early Jurassic separation of Antarctica from Africa plays an important role in our understanding of the dispersal of Gondwana and Pangea. Previous reconstruction models contain overlaps and gaps in the restored margins that reflect difficulties in accurately delineating the continent-ocean-boundary (COB) and determining the amount and distribution of extended continental crust. This study focuses on the evolution of the African margin adjacent to the Mozambique Basin and the conjugate Antarctic margin near the Riiser-Larsen Sea. Satellite-derived gravity data have been used to trace the orientations and landward limits of fracture zones. A 3-D gravity inversion has produced a crustal thickness model that reliably quantifies the extent and amount of stretched crust. Crustal thicknesses together with fracture zone terminations reveal COBs that are significantly closer to the African and Antarctic coasts than previously recognized. Correlation of fracture zone azimuths and identified COBs suggests Antarctica began drifting away from Africa at approximately 171 Ma in a roughly SSE direction. An areal-balancing method has been used to restore the crust to a uniform prerift thickness so as to perform a nonrigid reconstruction for both nonvolcanic and volcanic margins. Both margins reveal a trend of increasing extension from east to west. Our results suggest Africa underwent extension of 60-120 km, while Antarctic crust was stretched by 105-180 km. Various models tested to determine the direction of extension during rifting suggest that Antarctica moved away from Africa in a WNW-ESE direction during the period between 184 and 171 Ma prior to the onset of seafloor spreading.

  14. Seasonal features of black carbon measured at Syowa Station, Antarctica

    Hara, K.; Osada, K.; Yabuki, M.; Shiobara, M.; Yamanouchi, T.


    Black carbon (BC) is one of important aerosol constituents because the strong light absorption ability. Low concentrations of aerosols and BC let BC make insignificant contribution to aerosol radiative forcing in the Antarctica at the moment. Because of less or negligible source strength of BC in the Antarctic circle, BC can be used as a tracer of transport from the mid-latitudes. This study aims to understand seasonal feature, transport pathway, and origins of black carbon in the Antarctic coats. Black carbon measurement has been made using 7-wavelength aethalometer at Syowa Station, Antarctica since February, 2005. Mass BC concentrations were estimated from light attenuation by Weingartner's correction procedure (Weingartner et al., 2003) in this study. Detection limit was 0.2 - 0.4 ng/m3 in our measurement conditions (2-hour resolution and flow rate of ca. 10LPM). BC concentrations ranged from near detection limit to 55.7 ng/m3 at Syowa Station, Antarctica during the measurements. No trend has been observed since February, 2005. High BC concentrations were coincident with poleward flow from the mid-latitudes under the storm conditions by cyclone approach, whereas low BC concentrations were found in transport from coastal regions and the Antarctic continent. Considering that outflow from South America and Southern Africa affect remarkably air quality in the Southern Ocean of Atlantic and Indian Ocean sectors, BC at Syowa Station might be originated from biomass burning and human activity on South America and Southern Africa. Seasonal features of BC at Syowa Station shows maximum in September - October and lower in December - April. Spring maximum in September - October was obtained at the other Antarctic stations (Neumayer, Halley, South pole, and Ferraz). Although second maximum was found in January at the other stations, the maximum was not observed at Syowa Station.

  15. GlobVolcano pre-operational services for global monitoring active volcanoes

    Tampellini, Lucia; Ratti, Raffaella; Borgström, Sven; Seifert, Frank Martin; Peltier, Aline; Kaminski, Edouard; Bianchi, Marco; Branson, Wendy; Ferrucci, Fabrizio; Hirn, Barbara; van der Voet, Paul; van Geffen, J.


    The GlobVolcano project (2007-2010) is part of the Data User Element programme of the European Space Agency (ESA). The project aims at demonstrating Earth Observation (EO) based integrated services to support the Volcano Observatories and other mandate users (e.g. Civil Protection) in their monitoring activities. The information services are assessed in close cooperation with the user organizations for different types of volcano, from various geographical areas in various climatic zones. In a first phase, a complete information system has been designed, implemented and validated, involving a limited number of test areas and respective user organizations. In the currently on-going second phase, GlobVolcano is delivering pre-operational services over 15 volcanic sites located in three continents and as many user organizations are involved and cooperating with the project team. The set of GlobVolcano offered EO based information products is composed as follows: Deformation Mapping DInSAR (Differential Synthetic Aperture Radar Interferometry) has been used to study a wide range of surface displacements related to different phenomena (e.g. seismic faults, volcanoes, landslides) at a spatial resolution of less than 100 m and cm-level precision. Permanent Scatterers SAR Interferometry method (PSInSARTM) has been introduced by Politecnico of Milano as an advanced InSAR technique capable of measuring millimetre scale displacements of individual radar targets on the ground by using multi-temporal data-sets, estimating and removing the atmospheric components. Other techniques (e.g. CTM) have followed similar strategies and have shown promising results in different scenarios. Different processing approaches have been adopted, according to data availability, characteristic of the area and dynamic characteristics of the volcano. Conventional DInSAR: Colima (Mexico), Nyiragongo (Congo), Pico (Azores), Areanal (Costa Rica) PSInSARTM: Piton de la Fournaise (La Reunion Island

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

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


    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. Psychrotrophic ~Iydrolytic Bacteria from Antarctica &,Other I. Low Temperature Habitats

    K.V. Ramana


    Full Text Available Samples of water, soil,llake sediments and blue-green algal mats from Antarctica were'processed for enumeration, isolation and screening of psychrotrophic hydrolytic bacteria. Amylolytic bacteria were preponderant (75 per cent in the blue-green algal htat samples. Protease, lipase, an1ylase and urerse producing/bacteria were also isolated from the samples. ,Biochemical characteristics indicated that the isolates ;mainly comprised Pseudomonas and Bacillus species. Proteases and lipases of antarctic bacterial strains preferably hydrolysed denatured protein substrate and water soluble monomeric synthetic lipid substrates, respectively.

  18. Meteorites from Grove Mountains, Antarctica:An overview

    王道德; 林杨挺


    Thirty-two meteorites were collected in Grove Mountains area, Antarctica,by the 15th and 16th Chinese Antarctic Research Expeditions (CHINARE). Petrography and mineral chemistry of these meteorites are reviewed, among which there are one Martian lherzolite, one eucrite, one ungrouped iron meteorite, and six unequilibrated and twenty-three equilibrated ordinary chondrites. An equilibrated ordinary chondrite GRV 98004 (H5) has an unusually low cosmic-ray exposure age. Meteorite concentrating processes in Grove Mountains area are discussed. In addition, future studies on Grove Mountains (GRV) meteorites are proposed.

  19. An assessment of forward and inverse GIA solutions for Antarctica

    Bamber, Jonathan L.; Martin, Alba; King, Matt; Zammit-Mangion, Andrew


    GIA has, until recently, been estimated using forward models that attempt to determine how the solid Earth responds to changes in ice-ocean loading through time. These models require knowledge of spatially-varying Earth rheology, including mantle viscosity, and ice load history, both of which have large uncertainties for Antarctica. Recent advances in GIA models include consideration of three-dimensional variations in Earth rheology and power-law rheologies. Such GIA models predict remarkably different patterns of uplift over Antarctica when compared to those using one-dimensional Earth models, such as a shift in the uplift maximum from the Ross to the Wedell Sea (van der Wal et al., 2015). However, large uncertainties still remain in the ice loading history models (A. et al 2014 and van der Wal et al., 2015) and substantial regional differences are found between Antarctic reconstructions. An alternative approach is to use observations of crustal motion from GPS, combined with mass trends from GRACE to invert for GIA. However, this is an undetermined problem which requires assumptions on the density profile of the ice column for which numerical models have been commonly used (Gunter el al., 2014). Here we present a novel solution to the inverse problem using state-of-the-art methods in statistical modelling of spatio-temporal processes. Specifically, we combine observational data, including satellite radar and laser altimetry, GRACE, GPS and InSAR, with prior information on the spatial and temporal smoothness of the underlying process to solve, simultaneously, for ice mass trends and GIA. This is achieved via a spatio-temporal Bayesian hierarchical model and the resulting solution is only dependent on length and smoothness properties obtained from numerical models, but is otherwise entirely data-driven. We compare the most recent forward and inverse GIA solutions for Antarctica with a set of 68 observed vertical velocities over the period 2009 -- 2014 from the GPS

  20. Advanced systems data for mapping Emperor Penguin habitats in Antarctica

    Sanchez, Richard D.; Kooyman, Gerald L.


    Commercial orbital sensor systems combined with other resource data from the U.S. Geological Survey National Civil Applications Program (NCAP) may offer an effective way of mapping Emperor penguin habitats and their response to regional climate change in Antarctica. This project examined these resources to determine their applicability for mapping Emperor penguin habitats to support the National Science Foundation. This work is especially significant to investigate satellite-based imaging as an alternative to intrusive in-the-field enumeration of Emperor penguins and the potential of applying these procedures to support The National Map (TNP).

  1. Wind power in Antarctica - a feasibility study for Wasa

    Lindquist, Anna [Uppsala Univ. (Sweden). Div. for Electricity and Lightning Research


    The Swedish Polar Research Secretariat maintains two research stations in Antarctica, Wasa and Svea. They are both small, summer-only stations that are manned a few months at a time during the regular expeditions to the continent. Recently, Swedish scientists asked for the possibility to make around-the-year measurements with automatic equipment at the two stations. Since Wasa and Svea are only manned occasionally, this request implies the need for a new power supply system. The demands imposed on this new, separate system are hard. The continent is the coldest, windiest and driest on earth and the power supply system must be designed to withstand the harsh conditions. Since there is no personnel present during the Antarctic winter, the system also has to be autonomous and very reliable. The environment in Antarctica is sensitive and protected by strict regulations that all members of the Antarctic Treaty are obliged to follow. More and more nations are revising their power supply systems in order to find substitutions for the conventional diesel generators, and wind power has been installed at several stations and has worked well in many cases. This master thesis project is a feasibility study aimed at investigating whether wind power is a convenient solution in a separate power supply system at Wasa. During the project, wind data from weather stations in Antarctica have been used to map the wind resources at the two research stations. Although more accurate wind measurements would be needed for a complete evaluation of the wind resources, it can be seen that the prerequisites for wind power are good at Wasa. The wind is very directional, the wind speeds are moderate and the temperatures not too low. A wind turbine modified for the climate in Antarctica should function well at Wasa, in combination with a battery bank with NiCd batteries. Two turbines that fulfil most of the demands imposed on them and that seem to perform well in the conditions at Wasa were found

  2. Accelerated sea-level rise from West Antarctica.

    Thomas, R; Rignot, E.; Casassa, G; Kanagaratnam, P; Acuña, C; Akins, T; Brecher, H; E Frederick; Gogineni, P.; Krabill, W.; Manizade, S.; Ramamoorthy, H; Rivera, A.; Russell, R.; Sonntag, J


    Recent aircraft and satellite laser altimeter surveys of the Amundsen Sea sector of West Antarctica show that local glaciers are discharging about 250 cubic kilometers of ice per year to the ocean, almost 60% more than is accumulated within their catchment basins. This discharge is sufficient to raise sea level by more than 0.2 millimeters per year. Glacier thinning rates near the coast during 2002-2003 are much larger than those observed during the 1990s. Most of these glaciers flow into flo...



    A geographic information system (GIS) is a hardware/software tool which is very effective in collecting,storing,searching,handling,and visualizing geographic data together with their descriptive attributes.Such a tool is very helpful to approach a wide range of situations,including many logistic problems.ENEA,as the agency having the task of implementing the Italian Antarctic Program (PNRA),has decided to use a GIS,in order to increase the efficiency in managing the huge amount of data collected in the course of Italian activity in Antarctica,which counts fifteen expeditions up to now.

  4. Detection of evolutionarily distinct avian influenza a viruses in antarctica.

    Hurt, Aeron C; Vijaykrishna, Dhanasekaran; Butler, Jeffrey; Baas, Chantal; Maurer-Stroh, Sebastian; Silva-de-la-Fuente, M Carolina; Medina-Vogel, Gonzalo; Olsen, Bjorn; Kelso, Anne; Barr, Ian G; González-Acuña, Daniel


    ABSTRACT Distinct lineages of avian influenza viruses (AIVs) are harbored by spatially segregated birds, yet significant surveillance gaps exist around the globe. Virtually nothing is known from the Antarctic. Using virus culture, molecular analysis, full genome sequencing, and serology of samples from Adélie penguins in Antarctica, we confirmed infection by H11N2 subtype AIVs. Their genetic segments were distinct from all known contemporary influenza viruses, including South American AIVs, suggesting spatial separation from other lineages. Only in the matrix and polymerase acidic gene phylogenies did the Antarctic sequences form a sister relationship to South American AIVs, whereas distant phylogenetic relationships were evident in all other gene segments. Interestingly, their neuraminidase genes formed a distant relationship to all avian and human influenza lineages, and the polymerase basic 1 and polymerase acidic formed a sister relationship to the equine H3N8 influenza virus lineage that emerged during 1963 and whose avian origins were previously unknown. We also estimated that each gene segment had diverged for 49 to 80 years from its most closely related sequences, highlighting a significant gap in our AIV knowledge in the region. We also show that the receptor binding properties of the H11N2 viruses are predominantly avian and that they were unable to replicate efficiently in experimentally inoculated ferrets, suggesting their continuous evolution in avian hosts. These findings add substantially to our understanding of both the ecology and the intra- and intercontinental movement of Antarctic AIVs and highlight the potential risk of an incursion of highly pathogenic AIVs into this fragile environment. IMPORTANCE Avian influenza viruses (AIVs) are typically maintained and spread by migratory birds, resulting in the existence of distinctly different viruses around the world. However, AIVs have not previously been detected in Antarctica. In this study, we

  5. Summer weather characteristics on the Grove Mountain of East Antarctica


    The summer weather characteristics of the Grove Mountain, East Antarctica, are presented based on the data obtained by Chinese National Antarctic Expedition (CHINARE) in January 1999. The result shows that the pattern of daily variation of temperature and the prevailing wind direction in Grove is similar to that of Zhongshan Station. However, the daily range of temperature and strong wind frequency are much higher than those of Zhongshan Station. The change of wind direction is close to the weather system that impacted the Grove Mountain. The warm and wet air from northern parts often causes the precipitation. The clear weather appears when controlled by eastern winds in January.

  6. Triassic leech cocoon from Antarctica contains fossil bell animal

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.


    Our understanding of the evolution of life on Earth is limited by the imperfection of the fossil record. One reason for this imperfect record is that organisms without hard parts, such as bones, shells, and wood, have a very low potential to enter the fossil record. Occasionally, however......, exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica...

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

    Rashidov, Tofig


    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

  8. 2006-2008 Eruptions and Volcano Hazards Of Soputan Volcano, North Sulawesi, Indonesia

    Hendratno, K.; Pallister, J. S.; McCausland, W. A.; Kristianto, M.; Bina, F. R.; Carn, S. A.; Haerani, N.; Griswold, J.; Keeler, R.


    Soputan is a basalt volcano located in North Sulawesi near the southern margin of the Quaternary Tondano Caldera. Unusual for a basalt volcano, Soputan produces summit lava domes and explosive eruptions, as well as voluminous basaltic tephra deposits and lava flows. Soputan erupted five times during 2006-2008: on 14 December, 2006, 12-15 August, 2007, 25-26 October, 2007, 5-6 June, 2008, and 5-6 October, 2008. The 2006-2007 eruptions destroyed a lava dome at the volcano’s summit and exposed the conduit, resulting in Vulcanian eruptions and St. Vincent type pyroclastic flows from an open vent structure. We used high-resolution satellite images and digital elevation models to make photo-geologic maps of the deposits from the 2006, 2007 and 2008 eruptions, to estimate volumes of deposits using GIS and to model potential flow hazards. In March, 2008 and in March 2009 we conducted reconnaissance geologic field investigations at Soputan. This work was done to field-check our photo-geologic mapping, to reconstruct the sequence of eruptive events in 2006-2008 and to collect samples for geochemical and petrographic analysis. We also analyzed seismic records and SO2 emission data from the eruptions and we interpreted these data in the context of our geologic and geochemical data to provide insights into the ascent and degassing of magmas. On the basis of the eruptive history and modeling of potential lahar inundation areas we present an updated assessment of volcano hazards and a forecast for future eruptions at Soputan. Our analysis of field and petrologic data indicates that Soputan is an open-system volcano, which taps basalt magma from great depth, apparently with little shallow storage of this magma. Degassing of the magma as it rises within the conduit results in growth of micro-phenocrysts, evolution of the matrix melt and a commensurate increase in the viscosity of the magma. This, in turn, results in growth of lava domes and more explosive eruptions than are

  9. Felsic maar-diatreme volcanoes: a review

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


    Felsic maar-diatreme volcanoes host major ore deposits but have been largely ignored in the volcanology literature, especially for the diatreme portion of the system. Here, we use two Mexican tuff rings as analogs for the maar ejecta ring, new observations from one diatreme, and the economic geology literature on four other mineralized felsic maar-diatremes to produce an integrated picture of this type of volcano. The ejecta rings are up to 50 m+ thick and extend laterally up to ˜1.5 km from the crater edge. In two Mexican examples, the lower part of the ejecta ring is dominated by pyroclastic surge deposits with abundant lithic clasts (up to 80% at Hoya de Estrada). These deposits display low-angle cross-bedding, dune bedforms, undulating beds, channels, bomb sags, and accretionary lapilli and are interpreted as phreatomagmatic. Rhyolitic juvenile clasts at Tepexitl have only 0-25% vesicles in this portion of the ring. The upper parts of the ejecta ring sequences in the Mexican examples have a different character: lithic clasts can be less abundant, the grain size is typically coarser, and the juvenile clasts can be different in character (with some more vesicular fragments). Fragmentation was probably shallower at this stage. The post-eruptive maar crater infill is known at Wau and consists of reworked pyroclastic deposits as well as lacustrine and other sediments. Underneath are bedded upper diatreme deposits, interpreted as pyroclastic surge and fall deposits. The upper diatreme and post-eruptive crater deposits have dips larger than 30° at Wau, with approximately centroclinal attitudes. At still lower structural levels, the diatreme pyroclastic infill is largely unbedded; Montana Tunnels and Kelian are good examples of this. At Cerro de Pasco, the pyroclastic infill seems bedded despite about 500 m of post-eruptive erosion relative to the pre-eruptive surface. The contact between the country rocks and the diatreme is sometimes characterized by country rock

  10. Spatial Analysis of Volcanoes at Convergent Margins on Earth

    Roberts, R. V.; de Silva, S. L.; Meyers, M.


    One of the most obvious patterns seen on the surface of the terrestrial planets is the distribution of volcanoes. On Earth, most volcanoes are distributed in volcanic “arcs” that signal the primary relationship between subduction and volcanism. The distributions of major composite volcanoes in volcanic arcs are thought to reflect the primary magmatic pathways from source to surface. Understanding these patterns therefore may allow fundamental controls on the organization of magmatic plumbing in arcs to be identified. Using a control dataset from the Central Volcanic Zone of the Andes (de Silva and Francis, 1991; Springer-Verlag) we have examined several popular approaches to spatial analysis of volcano distribution in several volcanic arcs (Aleutian, Alaskan, Central American, Northern and Southern volcanic zones of the Andes). Restricting our analysis to major volcanoes of similar age, we find that while clustering is visually obvious in many volcanic arcs it has been rejected as a primary signal by previous analytical efforts (e.g. Bremont d'Ars et al (1995)). We show that the fractal box or grid counting method used previously does not detect clusters and statistical methods such as the Kernel Density Analysis or Single-link Cluster Analysis are better suited for cluster detection. Utilizing both ARC GIS and Matlab to conduct density analyses in combination with statistical software SPlus for the appropriate hypothesis testing methods such as the pooled variance t-test, the Welch Modified two sample t-test, and the f-test we find evidence of clustering in four volcanic arcs whose crustal thickness is greater than or equal to 40 kilometres (Central America, CVZ, NVZ, SVZ). We suggest that clustering is the surface manifestation of upper crustal diffusion of primary magmatic pathways, which in other places manifests as a single volcano. The inter-cluster distance is a thus reflection of primary magmatic pathways and thus equivalent to inter-volcano distance

  11. The 2009 eruption of Redoubt Volcano, Alaska

    Bull, Katharine F.; Cameron, Cheryl; Coombs, Michelle L.; Diefenbach, Angie; Lopez, Taryn; McNutt, Steve; Neal, Christina; Payne, Allison; Power, John A.; Schneider, David J.; Scott, William E.; Snedigar, Seth; Thompson, Glenn; Wallace, Kristi; Waythomas, Christopher F.; Webley, Peter; Werner, Cynthia A.; Schaefer, Janet R.


    Redoubt Volcano, an ice-covered stratovolcano on the west side of Cook Inlet, erupted in March 2009 after several months of escalating unrest. The 2009 eruption of Redoubt Volcano shares many similarities with eruptions documented most recently at Redoubt in 1966–68 and 1989–90. In each case, the eruptive phase lasted several months, consisted of multiple ashproducing explosions, produced andesitic lava and tephra, removed significant amounts of ice from the summit crater and Drift glacier, generated lahars that inundated the Drift River valley, and culminated with the extrusion of a lava dome in the summit crater. Prior to the 2009 explosive phase of the eruption, precursory seismicity lasted approximately six months with the fi rst weak tremor recorded on September 23, 2008. The first phreatic explosion was recorded on March 15, and the first magmatic explosion occurred seven days later, at 22:34 on March 22. The onset of magmatic explosions was preceded by a strong, shallow swarm of repetitive earthquakes that began about 04:00 on March 20, 2009, less than three days before an explosion. Nineteen major ash-producing explosions generated ash clouds that reached heights between 17,000 ft and 62,000 ft (5.2 and 18.9 km) ASL. During ash fall in Anchorage, the Ted Stevens International Airport was shut down for 20 hours, from ~17:00 on March 28 until 13:00 on March 29. On March 23 and April 4, lahars with fl ow depths to 10 m in the upper Drift River valley inundated parts of the Drift River Terminal (DRT). The explosive phase ended on April 4 with a dome collapse at 05:58. The April 4 ash cloud reached 50,000 ft (15.2 km) and moved swiftly to the southeast, depositing up to 2 mm of ash fall in Homer, Anchor Point, and Seldovia. At least two and possibly three lava domes grew and were destroyed by explosions prior to the final lava dome extrusion that began after the April 4 event. The fi nal lava dome ceased growth by July 1, 2009, with an estimated volume of 72

  12. Volcano surveillance by ACR silver fox

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


    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

  13. Geochemistry of the volcano-hydrothermal system of El Chichón Volcano, Chiapas, Mexico

    Taran, Yuri; Fischer, Tobias P.; Pokrovsky, Boris; Sano, Yuji; Armienta, Maria Aurora; Macias, Jose Luis

    The 1982 eruption of El Chichón volcano ejected more than 1km3 of anhydrite-bearing trachyandesite pyroclastic material to form a new 1-km-wide and 300-m-deep crater and uncovered the upper 500m of an active volcano-hydrothermal system. Instead of the weak boiling-point temperature fumaroles of the former lava dome, a vigorously boiling crater spring now discharges / 20kg/s of Cl-rich ( 15 000mg/kg) and sulphur-poor ( / 200mg/kg of SO4), almost neutral (pHup to 6.7) water with an isotopic composition close to that of subduction-type magmatic water (δD=-15‰, δ18O=+6.5‰). This spring, as well as numerous Cl-free boiling springs discharging a mixture of meteoric water with fumarolic condensates, feed the crater lake, which, compared with values in 1983, is now much more diluted ( 3000mg/kg of Cl vs 24 030mg/kg), less acidic (pH=2.6 vs 0.56) and contains much lower amounts of S ( / 200mg/kg of SO4, vs 3550mg/kg) with δ34S=0.5-4.2‰ (+17‰ in 1983). Agua Caliente thermal waters, on the southeast slope of the volcano, have an outflow rate of approximately 100kg/s of 71 °C Na-Ca-Cl water and are five times more concentrated than before the eruption (B. R. Molina, unpublished data). Relative N2, Ar and He gas concentrations suggest extensional tectonics for the El Chichón volcanic centre. The 3He/4He and 4He/20Ne ratios in gases from the crater fumaroles (7.3Ra, 2560) and Agua Caliente hot springs (5.3Ra, 44) indicate a strong magmatic contribution. However, relative concentrations of reactive species are typical of equilibrium in a two-phase boiling aquifer. Sulphur and C isotopic data indicate highly reducing conditions within the system, probably associated with the presence of buried vegetation resulting from the 1982 eruption. All Cl-rich waters at El Chichón have a common source. This water has the appearence of a "partially matured" magmatic fluid: condensed magmatic vapour neutralized by interaction with fresh volcaniclastic deposits and depleted in S

  14. Measurements of spectral snow albedo at Neumayer, Antarctica

    S. Wuttke


    Full Text Available Spectral albedo in high resolution, from 290 to 1050 nm, has been measured at Neumayer, Antarctica, (70°39' S, 8°15' W during the austral summer 2003/2004. At 500 nm, the spectral albedo nearly reaches unity, with slightly lower values below and above 500 nm. Above 600 nm, the spectral albedo decreases to values between 0.45 and 0.75 at 1000 nm. For one cloudless case an albedo up to 1.01 at 500 nm could be determined. This can be explained by the larger directional component of the snow reflectivity for direct incidence, combined with a slightly mislevelled sensor and the snow surface not being perfectly horizontal. A possible explanation for an observed decline in albedo is an increase in snow grain size. The theoretically predicted increase in albedo with increasing solar zenith angle (SZA could not be observed. This is explained by the small range of SZA during albedo measurements, combined with the effect of changing snow conditions outweighing the effect of changing SZA. The measured spectral albedo serves as input for radiative transfer models, describing radiation conditions in Antarctica.

  15. Chemical composition of the sediment from Lake 20 (Antarctica

    Daria ROSSI


    Full Text Available Lake 20 (19,000 m2 is located on the coast of the Ross Sea, in the North-Central part of Victoria Land, and its surface is ice-free between the end of December and early February. Within the framework of the Italian National Research Programme in Antarctica, a study was made of the chemical composition of sediments from the lake, with the intention of using this information to contribute to a better understanding of the processes involved in the long range transport of pollutants and their role in global changes. A sediment core from Lake 20 (Antarctica, 18 cm long, was collected in 1994, sliced into 2 cm sections and analysed using X Ray fluorescence spectrometry for 17 elements (Si, Al, Ca, K, Fe, Mg, Ti, S, P, Pb, Zn, Cu, Ni, Mn, Cr, Na, Cl, by CHN Elemental Analyser for C and N, by Flameless Atomic Absorption Spectrometry for As, and by Cold Vapour Atomic Absorption Spectrometry for Hg. The chemical composition of the sediments is consistent with the known geochemical characteristics of the drainage basin. While the chemical analyses reveal that sedimentation in Lake 20 has changed through time, the variations along the core are most probably related to the climatic evolution of the area, to the consequent changes in weathering processes, and possibly to an increase in the primary productivity of the lake, rather than to anthropogenic influences on the biogeochemical cycles of the elements.

  16. Surface and snowdrift sublimation at Princess Elisabeth station, East Antarctica

    W. Thiery


    Full Text Available In the near-coastal regions of Antarctica, a significant fraction of the snow precipitating onto the surface is removed again through sublimation – either directly from the surface or from drifting snow particles. Meteorological observations from an Automatic Weather Station (AWS near the Belgian research station Princess Elisabeth in Dronning Maud Land, East-Antarctica, are used to study surface and snowdrift sublimation and to assess their impacts on both the surface mass balance and the surface energy balance. Comparison to three other AWSs in Dronning Maud Land shows that sublimation has a significant influence on the surface mass balance at katabatic locations by removing 10–23 % of their total precipitation, but at the same time reveals anomalously low surface and snowdrift sublimation rates at Princess Elisabeth (18 mm w.e. yr–1 compared to 42 mm w.e. yr–1 at Svea Cross and 52 mm w.e. yr–1 at Wasa/Aboa. This anomaly is attributed to local topography, which shields the station from strong katabatic influence, and therefore on the one hand allows for a strong surface inversion to persist throughout most of the year and on the other hand causes a lower probability of occurrence of intermediately strong winds. These wind speed classes turn out to contribute most to the total snowdrift sublimation mass flux, given their ability to lift a high number of particles while still allowing for considerable undersaturation.

  17. Deep Drilling with the ANDRILL Program in Antarctica

    Alex Pyne


    Full Text Available ANDRILL (ANtarctic geological DRILLing is a new international, multi-disciplinary drilling program that targets geological records that lie hidden beneath the icy blanket of Antarctica. The primary objective is to investigate Antarctica’s role in global environmental change over the past sixty-fi ve million years, at various scales of age resolution, and thereby enhance our understanding of Antarctica’s potential response to future global changes. Efforts to understand the infl uence of Antarctica on global climate change require a fundamental knowledge of how the Antarctic cryosphere (ice sheets, ice shelves, and sea ice has evolved, not only in recent times but also during earlier geological periods when global temperature and atmospheric CO2 levels were similar to what might be reached by the end of this century. ANDRILL’s integrated science approach willuse stratigraphic drilling, coring, and multi-proxy core analysis combined with geophysical surveys and numerical modeling to study the Cenozoic history of Antarctic climate and ice sheets, the evolution of polar biota, Antarctic tectonism, and Antarctica’s role in the evolution of Earth’s ocean–climate system.

  18. Chemical composition of fresh snowfalls at Palmer Station, Antarctica

    DeFelice, T. P.

    A first time investigation was performed to establish a chemical baseline for snowfall at Palmer Station Antarctica (64°46'S, 64°05'W) since there was no such record. A chemical baseline for snow could be use to validate climate change studies based on ice core analyses. The snow samples contained (from high to low mass concentration) total organic carbon, chloride, inorganic carbon, sodium, sulfate, magnesium, calcium, potassium, fluoride, ammonium, and nitrate, excluding hydrogen and hydroxide. The pH of these samples ranged between 4.0-6.2. The relatively low nitrate and relatively high sulfate concentrations found in our samples are consistent with the results of other studies for this region of Antarctica. The ions and pH do not appear to favor a particular wind direction during this period. The total deposition of sulfate and flouride via snowfall between 10 January and 10 February is conservatively estimated to be 4.78 and 1.3 kg km -2, respectively.

  19. Ocean mixing beneath Pine Island Glacier ice shelf, West Antarctica

    Kimura, Satoshi; Jenkins, Adrian; Dutrieux, Pierre; Forryan, Alexander; Naveira Garabato, Alberto C.; Firing, Yvonne


    Ice shelves around Antarctica are vulnerable to an increase in ocean-driven melting, with the melt rate depending on ocean temperature and the strength of flow inside the ice-shelf cavities. We present measurements of velocity, temperature, salinity, turbulent kinetic energy dissipation rate, and thermal variance dissipation rate beneath Pine Island Glacier ice shelf, West Antarctica. These measurements were obtained by CTD, ADCP, and turbulence sensors mounted on an Autonomous Underwater Vehicle (AUV). The highest turbulent kinetic energy dissipation rate is found near the grounding line. The thermal variance dissipation rate increases closer to the ice-shelf base, with a maximum value found ˜0.5 m away from the ice. The measurements of turbulent kinetic energy dissipation rate near the ice are used to estimate basal melting of the ice shelf. The dissipation-rate-based melt rate estimates is sensitive to the stability correction parameter in the linear approximation of universal function of the Monin-Obukhov similarity theory for stratified boundary layers. We argue that our estimates of basal melting from dissipation rates are within a range of previous estimates of basal melting.

  20. Properties of soils in Grove Mountains, East Antarctica

    LI; Xiaoli(李潇丽); LIU; Xiaohan(刘小汉); JU; Yitai(琚宜太); HUANG; Feixin(黄费新)


    Three cold desert soil sites were first found in the southern Mount Harding, GroveMountains, East Antarctica. The soils are characteristics of the widespread occurrence of surfacedesert pavement, abundant water-soluble salts, strongly stained upper portion of soil profile,slightly acid and negligible organic matter content. A 1:5 soil-water extracts analysis indicates thatthe dominant cations are Mg2+ and Na+, followed by Ca2+ and K+, and the main anion is SO42-, thenCl- and NO-3. The accumulation of water-soluble salts indicates ion transportation in the frigid andarid Antarctica environment. The distribution of the salts is related to the maximum content ofmoisture and clay mineral. Clay fraction migration occurs in the soils, which is different from that ofother cold desert soils. The upper horizons of some profiles are generally stained, namely rubifica-tion, primarily because of the weathering of iron-bearing minerals. The reddish hues of cold desertsoils have been attributed to relatively high concentrations of dithionite-extractable Fe (Fed). Theweathering features of soils suggest that the soil age of this area is 0.5-3.5 Ma. No remnants ofglaciations were found on the soil sites of Mount Harding, which suggests that the Antarctic glaci-ations have not reached the soil sites since at least 0.5 Ma, even during the Last Glacial Maxi-mum.

  1. The larval alimentary canal of the Antarctic insect, Belgica antarctica.

    Nardi, James B; Miller, Lou Ann; Bee, Charles Mark; Lee, Richard E; Denlinger, David L


    On the Antarctica continent the wingless midge, Belgica antarctica (Diptera, Chironomidae) occurs further south than any other insect. The digestive tract of the larval stage of Belgica that inhabits this extreme environment and feeds in detritus of penguin rookeries has been described for the first time. Ingested food passes through a foregut lumen and into a stomodeal valve representing an intussusception of the foregut into the midgut. A sharp discontinuity in microvillar length occurs at an interface separating relatively long microvilli of the stomodeal midgut region, the site where peritrophic membrane originates, from the midgut epithelium lying posterior to this stomodeal region. Although shapes of cells along the length of this non-stomodeal midgut epithelium are similar, the lengths of their microvilli increase over two orders of magnitude from anterior midgut to posterior midgut. Infoldings of the basal membranes also account for a greatly expanded interface between midgut cells and the hemocoel. The epithelial cells of the hindgut seem to be specialized for exchange of water with their environment, with the anterior two-thirds of the hindgut showing highly convoluted luminal membranes and the posterior third having a highly convoluted basal surface. The lumen of the middle third of the hindgut has a dense population of resident bacteria. Regenerative cells are scattered throughout the larval midgut epithelium. These presumably represent stem cells for the adult midgut, while a ring of cells, marked by a discontinuity in nuclear size at the midgut-hindgut interface, presumably represents stem cells for the adult hindgut.

  2. Transit Search from Antarctica and Chile - Comparison and Combination

    Fruth, T; Csizmadia, Sz; Dreyer, C; Eigmüller, P; Erikson, A; Kabath, P; Pasternacki, T; Rauer, H; Titz-Weider, R; Abe, L; Agabi, A; Gonçalves, I; Guillot, T; Mékarnia, D; Rivet, J -P; Crouzet, N; Chini, R; Lemke, R; Murphy, M


    Observing sites at the East-Antarctic plateau are considered to provide exceptional conditions for astronomy. The aim of this work is to assess its potential for detecting transiting extrasolar planets through a comparison and combination of photometric data from Antarctica with time series from a midlatitude site. During 2010, the two small aperture telescopes ASTEP 400 (Dome C) and BEST II (Chile) together performed an observing campaign of two target fields and the transiting planet WASP-18b. For the latter, a bright star, Dome C appears to yield an advantageous signal-to-noise ratio. For field surveys, both Dome C and Chile appear to be of comparable photometric quality. However, within two weeks, observations at Dome C yield a transit detection efficiency that typically requires a whole observing season in Chile. For the first time, data from Antarctica and Chile have been combined to extent the observational duty cycle. This approach is both feasible in practice and favorable for transit search, as it i...

  3. Reactive chlorine chemistry in the boundary layer of coastal Antarctica

    Zielcke, Johannes; Poehler, Denis; Friess, Udo; Hay, Tim; Eger, Philipp; Kreher, Karin; Platt, Ulrich


    A unique feature of the polar troposphere is the strong impact of halogen photochemistry, in which reactive halogen species are responsible for ozone depletion as well as the oxidation of elemental mercury and dimethyl sulphide. The source, however, as well as release and recycling mechanisms of these halogen species - for some species even abundances - are far from being completely known, especially of chlorine and iodine compounds. Here we present active long-path differential optical absorption spectroscopy (LP-DOAS) measurements conducted during austral spring 2012 at Ross Island, Antarctica, observing several species (BrO, O3, NO2, IO, ClO, OBrO, OClO, OIO, I2, CHOCHO, HCHO, HONO). For the first time, ClO was detected and quantified in the marine boundary layer of coastal Antarctica, with typical mixing ratios around 20 pptv and maxima around 50 pptv. Meteorological controls on the mixing ratio of ClO as well as the interplay with other halogen compounds will be discussed, such as the lack of observed OClO (< 1 pptv). The results seem to reflect previously in chamber studies observed dependences on ozone levels and solar irradiance.

  4. Hydrothermal reservoir beneath Taal Volcano (Philippines): Implications to volcanic activity

    Nagao, T.; Alanis, P. B.; Yamaya, Y.; Takeuchi, A.; Bornas, M. V.; Cordon, J. M.; Puertollano, J.; Clarito, C. J.; Hashimoto, T.; Mogi, T.; Sasai, Y.


    Taal Volcano is one of the most active volcanoes in the Philippines. The first recorded eruption was in 1573. Since then it has erupted 33 times resulting in thousands of casualties and large damages to property. In 1995, it was declared as one of the 15 Decade Volcanoes. Beginning in the early 1990s it has experienced several phases of abnormal activity, including seismic swarms, episodes of ground deformation, ground fissuring and hydrothermal activities, which continues up to the present. However, it has been noted that past historical eruptions of Taal Volcano may be divided into 2 distinct cycles, depending on the location of the eruption center, either at Main Crater or at the flanks. Between 1572-1645, eruptions occurred at the Main Crater, in 1707 to 1731, they occurred at the flanks. In 1749, eruptions moved back to the Main Crater until 1911. During the 1965 and until the end of the 1977 eruptions, eruptive activity once again shifted to the flanks. As part of the PHIVOLCS-JICA-SATREPS Project magnetotelluric and audio-magnetotelluric surveys were conducted on Volcano Island in March 2011 and March 2012. Two-dimensional (2-D) inversion and 3-D forward modeling reveals a prominent and large zone of relatively high resistivity between 1 to 4 kilometers beneath the volcano almost directly beneath the Main Crater, surrounded by zones of relatively low resistivity. This anomalous zone of high resistivity is hypothesized to be a large hydrothermal reservoir filled with volcanic fluids. The presence of this large hydrothermal reservoir could be related to past activities of Taal Volcano. In particular we believe that the catastrophic explosion described during the 1911 eruption was the result of the hydrothermal reservoir collapsing. During the cycle of Main Crater eruptions, this hydrothermal reservoir is depleted, while during a cycle of flank eruptions this reservoir is replenished with hydrothermal fluids.


    Hananto Kurnio


    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.

  6. Research drilling in young silicic volcanoes

    Eichelberger, J.C.


    Magmatic activity, and particularly silicic magmatic activity, is the fundamental process by which continental crust forms and evolves. The transport of magma from deep crustal reservoirs to the surface is a neglected but important aspect of magmatic phenomena. It encompasses problems of eruptive behavior, hydrothermal circulation, and ore deposition, and must be understood in order to properly interpret deeper processes. Drilling provides a means for determining the relationship of shallow intrusive processes to eruption processes at young volcanoes where eruptions are best understood. Drilling also provides a means for directly observing the processes of heat and mass transfer by which recently emplaced intrusions approach equilibrium with their new environment. Drilling in the Inyo Chain, a 600-year-old chain of volcanic vents in California, has shown the close relationship of silicic eruption to shallow dike emplacement, the control of eruptive style by shallow porous-flow degassing, the origin of obsidian by welding, the development of igneous zonation by viscosity segregation, and the character and size of conduits in relation to well-understood magmatic and phreatic eruptions. 36 refs., 9 figs.

  7. Deep Stimulation at Newberry Volcano EGS Demonstration

    Grasso, K.; Cladouhos, T. T.; Petty, S.; Garrison, G. H.; Nordin, Y.; Uddenberg, M.; Swyer, M.


    The Newberry Volcano EGS Demonstration is a 5 year field project designed to demonstrate recent technological advances for engineered geothermal systems (EGS) development. Advances in reservoir stimulation, diverter, and monitoring are being tested in a hot (>300 C), dry well (NWG 55-29) drilled in 2008. These technologies could reduce the cost of electrical power generation. The project began in 2010 with two years of permitting, technical planning, and development of a project-specific Induced Seismicity Mitigation Plan (ISMP), and is funded in part by the Department of Energy. In 2012, the well was hydraulically stimulated with water at pressures below the principle stress for 7 weeks, resulting in hydroshearing. The depth of stimulation was successfully shifted by injection of two pills of Thermally-degradable Zonal Isolation Materials (TZIMs). Injectivity changes, thermal profiles and seismicity indicate that fracture permeability in well NWG 55-29 was enhanced during stimulation. This work successfully demonstrated the viability of large-volume (40,000 m3), low-pressure stimulation coupled with non-mechanical diverter technology, and microseismic monitoring for reservoir mapping. Further analysis and field testing in 2013 indicates further stimulation will be required in order to develop an economically viable reservoir, and is scheduled in 2014. The 2014 stimulation will use improved stimulation and monitoring equipment, better knowledge based on 2012 outcomes, and create a deep EGS reservoir in the hottest part of the wellbore.

  8. Newberry Volcano EGS Demonstration Stimulation Modeling

    Trenton T. Cladouhos, Matthew Clyne, Maisie Nichols,; Susan Petty, William L. Osborn, Laura Nofziger


    As a part of Phase I of the Newberry Volcano EGS Demonstration project, several data sets were collected to characterize the rock volume around the well. Fracture, fault, stress, and seismicity data has been collected by borehole televiewer, LiDAR elevation maps, and microseismic monitoring. Well logs and cuttings from the target well (NWG 55-29) and core from a nearby core hole (USGS N-2) have been analyzed to develop geothermal, geochemical, mineralogical and strength models of the rock matrix, altered zones, and fracture fillings (see Osborn et al., this volume). These characterization data sets provide inputs to models used to plan and predict EGS reservoir creation and productivity. One model used is AltaStim, a stochastic fracture and flow software model developed by AltaRock. The software's purpose is to model and visualize EGS stimulation scenarios and provide guidance for final planning. The process of creating an AltaStim model requires synthesis of geologic observations at the well, the modeled stress conditions, and the stimulation plan. Any geomechanical model of an EGS stimulation will require many assumptions and unknowns; thus, the model developed here should not be considered a definitive prediction, but a plausible outcome given reasonable assumptions. AltaStim is a tool for understanding the effect of known constraints, assumptions, and conceptual models on plausible outcomes.

  9. Genome and transcriptome analysis of the basidiomycetous yeast Pseudozyma antarctica producing extracellular glycolipids, mannosylerythritol lipids.

    Tomotake Morita

    Full Text Available Pseudozyma antarctica is a non-pathogenic phyllosphere yeast known as an excellent producer of mannosylerythritol lipids (MELs, multi-functional extracellular glycolipids, from vegetable oils. To clarify the genetic characteristics of P. antarctica, we analyzed the 18 Mb genome of P. antarctica T-34. On the basis of KOG analysis, the number of genes (219 genes categorized into lipid transport and metabolism classification in P. antarctica was one and a half times larger than that of yeast Saccharomyces cerevisiae (140 genes. The gene encoding an ATP/citrate lyase (ACL related to acetyl-CoA synthesis conserved in oleaginous strains was found in P. antarctica genome: the single ACL gene possesses the four domains identical to that of the human gene, whereas the other oleaginous ascomycetous species have the two genes covering the four domains. P. antarctica genome exhibited a remarkable degree of synteny to U. maydis genome, however, the comparison of the gene expression profiles under the culture on the two carbon sources, glucose and soybean oil, by the DNA microarray method revealed that transcriptomes between the two species were significantly different. In P. antarctica, expression of the gene sets relating fatty acid metabolism were markedly up-regulated under the oily conditions compared with glucose. Additionally, MEL biosynthesis cluster of P. antarctica was highly expressed regardless of the carbon source as compared to U. maydis. These results strongly indicate that P. antarctica has an oleaginous nature which is relevant to its non-pathogenic and MEL-overproducing characteristics. The analysis and dataset contribute to stimulate the development of improved strains with customized properties for high yield production of functional bio-based materials.

  10. Vertical Temperature Simulation of Pegasus Runway, McMurdo Station, Antarctica


    Runway, McMurdo Station, Antarctica Co ld R eg io ns R es ea rc h an d En gi ne er in g La bo ra to ry Steven F. Daly, Robert Haehnel...Vertical Temperature Simulation of Pegasus Runway, McMurdo Station, Antarctica Steven F. Daly, Robert Haehnel, and Christopher Hiemstra Cold Regions...Engineering Support, Continuation” ERDC/CRREL TR-15-2 ii Abstract Pegasus Runway, located 13 km south of McMurdo Station, Antarctica , on the

  11. Dioszegia antarctica sp. nov. and Dioszegia cryoxerica sp. nov., psychrophilic basidiomycetous yeasts from polar desert soils in Antarctica

    Rodriguez, Russell J.; Connell, L.; Redman, R.; Barrett, A.; Iszard, M.; Fonseca, A.


    During a survey of the culturable soil fungal population in samples collected in Taylor Valley, South Victoria Land, Antarctica, 13 basidiomycetous yeast strains with orange-coloured colonies were isolated. Phylogenetic analyses of internal transcribed spacer (ITS) and partial LSU rRNA gene sequences showed that the strains belong to the Dioszegia clade of the Tremellales (Tremellomycetes, Agaricomycotina), but did not correspond to any of the hitherto recognized species. Two novel species, Dioszegia antarctica sp. nov. (type strain ANT-03-116T =CBS 10920T =PYCC 5970T) and Dioszegia cryoxerica sp. nov. (type strain ANT-03-071T =CBS 10919T =PYCC 5967T), are described to accommodate ten and three of these strains, respectively. Analysis of ITS sequences demonstrated intrastrain sequence heterogeneity in D. cryoxerica. The latter species is also notable for producing true hyphae with clamp connections and haustoria. However, no sexual structures were observed. The two novel species can be considered obligate psychrophiles, since they failed to grow above 20 °C and grew best between 10 and 15 °C.

  12. Studying monogenetic volcanoes with Terrestrial Laser Scanner: Case study at Croscat volcano (Garrotxa Volcanic Zone, Spain)

    Geyer Traver, A.; Garcia-Selles, D.; Peddrazzi, D.; Barde-Cabusson, S.; Marti, J.; Muñoz, J.


    Monogenetic basaltic zones are common in many volcanic environments and may develop under very different geodynamic conditions. Despite existing clear similarities between the eruptive activity of different monogenetic volcanic fields, important distinctions may arise when investigating in detail the individual eruptive sequences. Interpretation of the deposits and consequently, the reconstruction and characterization of these eruptive sequences is crucial to evaluate the potential hazard in case of active areas. In diverse occasions, erosional processes (natural and/or anthropogenic) may partly destroy these relatively small-sized volcanic edifices exposing their internal parts. Furthermore, despite human activity in volcanic areas is sometimes unimportant due to the remote location of the monogenetic cones, there are places where this form of erosion is significant, e.g. Croscat volcano (Catalan Volcanic Field, Spain). In any case, when studying monogenetic volcanism, it is usual to find outcrops where the internal structure of the edifices is, for one or other reason, well exposed. However, the access to these outcrops may be extremely difficult or even impossible. During the last years, it has been demonstrated that the study of outcrops with problematic or completely restricted access can be carried out by means of digital representations of the outcrop surface. Digital outcrops make possible the study of those areas with natural access limitations or safety issues and may facilitate visualization of the features of interest over the entire outcrop, as long as the digital outcrop can be analysed while navigated in real- time, with optional displays for perspective, scale distortions, and attribute filtering. In particular, Terrestrial Laser Scanning (TSL) instruments using Light Detection And Ranging technology (LIDAR) are capable of capturing topographic details and achieve modelling accuracy within a few centimetres. The data obtained enables the creation of

  13. A Broadly-Based Training Program in Volcano Hazards Monitoring at the Center for the Study of Active Volcanoes

    Thomas, D. M.; Bevens, D.


    The Center for the Study of Active Volcanoes, in cooperation with the USGS Volcano Hazards Program at HVO and CVO, offers a broadly based volcano hazards training program targeted toward scientists and technicians from developing nations. The program has been offered for 25 years and provides a hands-on introduction to a broad suite of volcano monitoring techniques, rather than detailed training with just one. The course content has evolved over the life of the program as the needs of the trainees have changed: initially emphasizing very basic monitoring techniques (e.g. precise leveling, interpretation of seismic drum records, etc.) but, as the level of sophistication of the trainees has increased, training in more advanced technologies has been added. Currently, topics of primary emphasis have included volcano seismology and seismic networks; acquisition and modeling of geodetic data; methods of analysis and monitoring of gas geochemistry; interpretation of volcanic deposits and landforms; training in LAHARZ, GIS mapping of lahar risks; and response to and management of volcanic crises. The course also provides training on public outreach, based on CSAV's Hawaii-specific hazards outreach programs, and volcano preparedness and interactions with the media during volcanic crises. It is an intensive eight week course with instruction and field activities underway 6 days per week; it is now offered in two locations, Hawaii Island, for six weeks, and the Cascades volcanoes of the Pacific Northwest, for two weeks, to enable trainees to experience field conditions in both basaltic and continental volcanic environments. The survival of the program for more than two decades demonstrates that a need for such training exists and there has been interaction and contribution to the program by the research community, however broader engagement with the latter continues to present challenges. Some of the reasons for this will be discussed.

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

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


    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.

  15. Principal Component Analysis for pattern recognition in volcano seismic spectra

    Unglert, Katharina; Jellinek, A. Mark


    Variations in the spectral content of volcano seismicity can relate to changes in volcanic activity. Low-frequency seismic signals often precede or accompany volcanic eruptions. However, they are commonly manually identified in spectra or spectrograms, and their definition in spectral space differs from one volcanic setting to the next. Increasingly long time series of monitoring data at volcano observatories require automated tools to facilitate rapid processing and aid with pattern identification related to impending eruptions. Furthermore, knowledge transfer between volcanic settings is difficult if the methods to identify and analyze the characteristics of seismic signals differ. To address these challenges we have developed a pattern recognition technique based on a combination of Principal Component Analysis and hierarchical clustering applied to volcano seismic spectra. This technique can be used to characterize the dominant spectral components of volcano seismicity without the need for any a priori knowledge of different signal classes. Preliminary results from applying our method to volcanic tremor from a range of volcanoes including K¯ı lauea, Okmok, Pavlof, and Redoubt suggest that spectral patterns from K¯ı lauea and Okmok are similar, whereas at Pavlof and Redoubt spectra have their own, distinct patterns.

  16. Machine Learning Method for Pattern Recognition in Volcano Seismic Spectra

    Radic, V.; Unglert, K.; Jellinek, M.


    Variations in the spectral content of volcano seismicity related to changes in volcanic activity are commonly identified manually in spectrograms. However, long time series of monitoring data at volcano observatories require tools to facilitate automated and rapid processing. Techniques such as Self-Organizing Maps (SOM), Principal Component Analysis (PCA) and clustering methods can help to quickly and automatically identify important patterns related to impending eruptions. In this study we develop and evaluate an algorithm applied on a set of synthetic volcano seismic spectra as well as observed spectra from Kılauea Volcano, Hawai`i. Our goal is to retrieve a set of known spectral patterns that are associated with dominant phases of volcanic tremor before, during, and after periods of volcanic unrest. The algorithm is based on training a SOM on the spectra and then identifying local maxima and minima on the SOM 'topography'. The topography is derived from the first two PCA modes so that the maxima represent the SOM patterns that carry most of the variance in the spectra. Patterns identified in this way reproduce the known set of spectra. Our results show that, regardless of the level of white noise in the spectra, the algorithm can accurately reproduce the characteristic spectral patterns and their occurrence in time. The ability to rapidly classify spectra of volcano seismic data without prior knowledge of the character of the seismicity at a given volcanic system holds great potential for real time or near-real time applications, and thus ultimately for eruption forecasting.

  17. Negative Magnetic Anomalies Observed in the Central West Antarctica (CWA) Aerogeophysical Survey Over the West Antarctic Ice Sheet (WAIS), Whose Sources are Volcanic Centers (e.g. Mt Resnik) at the Base of the ice >780 Ka

    Behrendt, J. C.; Finn, C. A.; Morse, D. L.; Blankenship, D. D.


    Analysis of a block of coincident aeromagnetic and radar ice-sounding data (from the CWA aerogeophysical survey) over the WAIS reveals ~1000 50->1000-nT, shallow -source, ``volcanic" magnetic anomalies, interpreted as caused by late Cenozoic alkaline magmatism associated with the West Antarctic rift system (WR). About 400 of these anomalies (conservatively selected) have topographic expression at the bed of the WAIS; >80% of these topographic features have Resnik, marked by a complex negative anomaly, is a conical peak 300 m below the surface of the WAIS, and has ~2 km topographic relief. We interpret a magnetic model fit to this anomaly as comprising reversely magnetized (in the present field direction), 0.5-2.5-km thick volcanic flows at the summit overlying normally magnetized flows. Published models (1996) reported for the Hut Point anomaly, at Ross Island, Antarctica, a similar anomaly to Mt. Resnik, also required both normal and reversed magnetizations correlated with drill holes into dated volcanic flows (also part of the late Cenozoic WR) crossing the Brunhes-Matuyama boundary (780 Ka). Because of their form similar to exposed volcanoes in the WAIS area with edifices primarily comprising subaerially-erupted, very magnetic volcanic flows, which have resisted glacial erosion, Behrendt et al. (2004) interpreted that these 18 high-topograpy, high-relief sources are subglacial volcanoes (including the five >780 Ka) erupted subaerially during a period when the WAIS was absent.

  18. Environmental and climate changes in Antarctica in the Geological Past

    G. L. Leitchenkov


    Full Text Available In the Cretaceous time, Antarctica was characterized by subtropical and tropical climate. The Early Eocene was warmest in the Antarctic history but this Climatic Optimum terminated with a long-term cooling trend that culminated in continental-scale glaciation of Antarctica at about 34 Ma ago. There is indirect evidence that small ice caps developed within central Antarctica in the Late Eocene (42−34 Ma. From the Early Oligocene to the Middle Miocene (34−13 Ma ice sheet was wet-based and fluctuated considerably in volume, but about 14 m.y. ago it became dry-based and more stable.  Seismic data collected on the East Antarctic margin give valuable information on dynamics of the past ice sheets. These data shows that the sedimentary cover of the western Wilkes Land margin includes a giant (c. 200 000 km2 deep-water fan which formed between c. 43 and 34 Ma ago. The average rate of sedimentation in the central part of fan was 230–250 m/m.y. Active input of terrigenous sediments into deep-water denotes high-energy fluvial system within the Wilkes Land. Emergence of this fluvial system evidences earliest glaciation in the Antarctic interior which fed full-flowing rivers. The thickness of strata deposited during post-Early Oligocene glaciations on the Antarctic margin generally reflects the averaged energy of depositional environments. The thickest sediments (up to 2.0 km, i.e. almost twice more than in other parts of East Antarctic margin and inferred highest energy are seen in the central Cooperation Sea, on the central Wilkes Land margin and in the D'Urville Sea. The areas with the thickest post-Early Oligocene strata correlate with places where present-day ice discharge is highest, such as via the Lambert, Totten and Mertz/Ninnis Glaciers. The correlation points to high ice (and sediment flux in the same areas since the Early Oligocene.

  19. Crustal structure across the Filchner Ronne Shelf, Antarctica

    Herter, U.; Jokat, W.


    Crustal structure across the Filchner Ronne Shelf, Antarctica U. Herter, W. Jokat One large gap in understanding the tectonic evolution of Antarctica beside the few rock outcrops on the continent is the missing information on crustal thickness along its margins but also in its interior. E.g., the few marine deep seismic lines are located mainly along the Antarctic Peninsula/Pacific margin, but for most of the East Antarctic margins such information is not available. In this contribution we concentrate on one of the most remote areas in Antarctica, the Filchner Ronne Shelf (FRS). The area is underlain by approximately 12 km of sediments, but its crustal fabric is questionable. Thus, some existing deep seismic sounding data were modeled and reinterpreted. Especially, data gathered in 1995 have been analyzed, and a more detailed 2D P-wave velocity model has been calculated. For the profiles in total 12 RefTek stations each with nine geophone chains were placed on the ice shelf and 3175 airgun shots along a 480 km transect were fired by two 32 l BOLT-Airguns each 60 s. Signals were recorded up to distances of 180 km. Due to the ice coverage it was not possible to acquire the data without gaps or along straight lines, which caused some difficulties in the modeling process. Furthermore, in the new model all data from older experiments of the AWI and Soviet Antarctic expeditions acquired with dynamite sources were incorporated. The model shows a sedimentary basin with a thickness up to 12 km and a large velocity inversion in a deeper sediment unit. The crustal thickness varies from 40 km beneath the Antarctic Peninsula, and 14 km of basement in the center part of the profile. Towards Berkner Island the crust thickens again, but the top of the basement is still 11 km deep. The lower crustal velocities range between 6.8 and 7.2 km/s. We interpret the crustal structure as clear evidence for the presence of a failed rift. The initial stretching of the continental crust

  20. Anaerobic psychrophiles from Lake Zub and Lake Untersee, Antarctica

    Townsend, Alisa; Pikuta, Elena V.; Guisler, Melissa; Stahl, Sarah; Hoover, Richard B.


    The study of samples from Antarctica 2008 and 2009 expeditions organized and successfully conducted by Richard Hoover led to the isolation of diverse anaerobic strains with psychrotolerant and psychrophilic physiology. Due to the fact that Lake Untersee has never been subject to microbiological study, this work with the samples has significant and pioneering impact to the knowledge about the biology of this unique ecosystem. Also, the astrobiological significance for the study of these ecosystems is based on new findings of ice covered water systems on other bodies of our solar system. Anaerobic psychrotolerant strain LZ-22 was isolated from a frozen sample of green moss with soils around the rhizosphere collected near Lake Zub in Antarctica. Morphology of strain LZ-22 was observed to be motile, rod shaped and spore-forming cells with sizes 1 x 5-10 μm. This new isolate is a mesophile with the maximum temperature of growth at 40°C. Strain LZ-22 is able to live on media without NaCl and in media with up to 7 % (w/v) NaCl. It is catalase negative and grows only on sugars with the best growth rate being on lactose. The strain is a neutrophile and grows between pH 5 and 9.0 with the optimum at 7.8. Another two strains UL7-96mG and LU-96m7P were isolated from deep water samples of Lake Untersee. Proteolytic strain LU-96m7P had a truly psychrophilic nature and refused to grow at room temperature. Sugarlytic strain UL7-96mG was found to be psychrotolerant, but its rate of growth at 3°C was very high compared with other mesophiles. Two homoacetogenic psychrophilic strains A7AC-96m and AC-DS7 were isolated and purified from samples of Lake Untersee; both of them are able to grow chemolithotrophically on H2+CO2. In the presence of lactate, these strains are able to grow only at 0-18 °C, and growth at 22 °C was observed only with yeast extract stimulation. In this paper, physiological and morphological characteristics of novel psychrophilic and psychrotolerant isolates

  1. Antarctica, supercontinents and the palaeogeography of the Cambrian 'explosion'

    Dalziel, Ian


    Laurentia is bordered by latest Precambrian-Cambrian rifted margins and must therefore have been located within a Precambrian supercontinent. Geochronologic and geochemical evidence indicates that it was attached to parts of the East Antarctic craton within the Rodinian supercontinent in the late Mesoproterozoic. The Mawson craton of Antarctica rifted from the proto-Pacific margin of Laurentia during the Neooproterozoic, colliding with the present 'southern cone' of Laurentia at ~600 Ma along the Shackleton Range suture zone as Gondwana and Laurentia amalgamated to form the ephemeral Pannotia supercontinental assembly at the end of the Precambrian. The abrupt appearance of almost all animal phyla in the fossil record is often colloquially referred to as the Cambrian 'explosion' of life on Earth. It is also named 'Darwin's dilemma,' as he appreciated that this seemingly mysterious event posed a major problem for his theory of evolution by natural selection. It coincided with a time of major marine transgression over all the continents. Although the metazoan 'explosion' is now seen as more protracted than formerly recognized, it is still regarded one of the most critical events in the history of the biosphere. One of the most striking aspects of the earliest Cambrian fossils is geographic differentiation. In particular, the first benthic trilobite faunas on Laurentia, ancestral North America, and the newly amalgamated southern supercontinent of Gondwana are distinctly different. This has led to the suggestion of an unknown vicariant event intervening between an ancestral trilobite clade and higher members that are represented in the fossil record, possibly one related to the breakup of a supercontinent. Igneous rocks along the Panthalassic margin of Gondwana, including South America, southernmost Africa and the Ellsworth-Whitmore crustal block of Antarctica, and along the proto-Appalachian margin of Laurentia indicate that final separation of Laurentia from

  2. New Views of East Antarctica- from Columbia to Gondwana

    Ferraccioli, F.; Forsberg, R.; Aitken, A.; Young, D. A.; Blankenship, D. D.; Bell, R. E.; Finn, C.; Martos, Y. M.; Armadillo, E.; Jacobs, J.; Ebbing, J.; Eagles, G.; Jokat, W.; Jordan, T. A.; Ruppel, A.; Läufer, A.; Dalziel, I. W. D.


    East Antarctica is a keystone in the Gondwana, Rodinia and the Columbia supercontinents. Recent aerogeophysical research, augmented by satellite magnetic, gravity and seismological data is unveiling the crustal architecture of the continent. This is helping comprehend the impact of supercontinental processes such as subduction, accretion, rifting and intraplate tectonics on its evolution. A mosaic of Precambrian basement provinces is apparent in interior East Antarctica (Ferraccioli et al., 2011, Nature). A major suture separates the Archean-Neoproterozoic Ruker Province from an inferred Grenvillian-age orogenic Gamburtsev Province with remarkably thick crust (up to 60 km thick) and thick lithosphere (over 200 km thick). The age of the suturing and its linkages with supercontinental assembly is debated with both Rodinia and Gondwana candidates being proposed. Further east, magnetic highs delineate a Paleo to Mesoproterozoic Nimrod-South Pole igneous province (Goodge and Finn, 2010 JGR) that flanks a composite Mawson Continent- including the Gawler Craton of South Australia (Aitken et al., 2014 GRL). An over 1,900 km long magnetic and gravity lineament is imaged along the western flank of the Wilkes Subglacial Basin and is interpreted here as a major Paleoproterozoic suture zone linked to the collision of Laurentia and East Antarctica within Columbia. The proposed suture played a pivotal role helping localise Neoproterozoic Rodinia rifted margin evolution and forming a backstop for the Ross-Delamerian cycle of Gondwana amalgamation. Aeromagnetic and gravity imaging help determine the extent of a Keweenawan-age (ca 1.1 Ga) large igneous province in the Coats Land Block -isotopically tied with the Mid-Continent Rift System of Laurentia (Loewy et al., 2011 Geology). Imprints of Grenvillian magmatic arc accretion link together the Namaqua-Natal and Maud belts in South Africa and Dronning Maud Land within Rodinia. The aeromagnetically distinct Southeast Dronning Maud

  3. Anaerobic Psychrophiles from Lake Zub and Lake Untersee, Antarctica

    Townsend, Alisa; Pikuta, Elena V.; Guisler, Melissa; Stahl, Sarah; Hoover, Richard B.


    The study of samples from Antarctica 2008 and 2009 expeditions organized and successfully conducted by Richard Hoover led to the isolation of diverse anaerobic strains with psychrotolerant and psychrophilic physiology. Due to the fact that Lake Untersee has never been subject to microbiological study, this work with the samples has significant and pioneering impact to the knowledge about the biology of this unique ecosystem. Also, the astrobiological significance for the study of these ecosystems is based on new findings of ice covered water systems on other bodies of our solar system. Anaerobic psychrotolerant strain LZ-22 was isolated from a frozen sample of green moss with soils around the rhizosphere collected near Lake Zub in Antarctica. Morphology of strain LZ-22 was observed to be motile, rod shaped and spore-forming cells with sizes 1 x 5-10 micron. This new isolate is a mesophile with the maximum temperature of growth at 40C. Strain LZ-22 is able to live on media without NaCl and in media with up to 7% (w/v) NaCl. It is catalase negative and grows only on sugars with the best growth rate being on lactose. The strain is a neutrophile and grows between pH 5 and 9.0 with the optimum at 7.8. Another two strains UL7-96mG and LU-96m7P were isolated from deep water samples of Lake Untersee. Proteolytic strain LU-96m7P had a truly psychrophilic nature and refused to grow at room temperature. Sugarlytic strain UL7-96mG was found to be psychrotolerant, but its rate of growth at 3C was very high compared with other mesophiles. Two homoacetogenic psychrophilic strains A7AC-96m and AC-DS7 were isolated and purified from samples of Lake Untersee; both of them are able to grow chemolithotrophically on H2+CO2. In the presence of lactate, these strains are able to grow only at 0-18C, and growth at 22C was observed only with yeast extract stimulation. In this paper, physiological and morphological characteristics of novel psychrophilic and psychrotolerant isolates from

  4. Distributions of larval and juvenile/adult stages of the Antarctic myctophid fish, Electrona antarctica, off Wilkes Land in East Antarctica

    Moteki, Masato; Fujii, Kentaro; Amakasu, Kazuo; Shimada, Keishi; Tanimura, Atsushi; Odate, Tsuneo


    Myctophid fish are an important component of the Southern Ocean food web because of their very high biomass. This study investigated the spatial distributions of larval and juvenile/adult stages of the Antarctic myctophid Electrona antarctica. Fish were sampled in January 2011 and 2012 on a transect along 140°E and in January 2013 along 110°E using two different opening/closing net systems. In total, 1075 specimens of E. antarctica were collected: 948 larvae, 127 juveniles/adults, and 2 in the transformation stage. Most larvae were collected at 5-200 m depth, with diel vertical migration (DVM) not apparent. Larvae were mainly distributed in the Modified Circumpolar Deep Water (-1.5 °C-2.0 °C). By contrast, an analysis of the echogram at 38 kHz and discrete depth samples implied that juveniles/adults undertook DVM except in the continental slope area (65.5°S). As the distribution of krill is limited to the cold water mass (<-1.5 °C) along the continental slope, E. antarctica and krill populations are spatially separated off Wilkes Land during summer. According to the previously estimated larval period of 30-47 days, E. antarctica may spawn in late November to December in the marginal ice zone or near the sea ice edge. This study suggests that the environment related to sea ice provides a nursery ground for early stage larvae of E. antarctica.

  5. Hunting remnants of maar-diatreme-volcanoes

    Kroner, Corinna; Kämpf, Horst; Matthes, Heidrun; Jahr, Thomas; Markwart, David; Hermann, Tobias; Mrlina, Jan


    In the area of the Rostock-Leipzig-Regensburg fault zone (Germany) several centres of seismic activity are found with seismicity manifesting itself in swarm earthquakes. The occurrence of these earthquakes is globally linked to ascending magma and magmatic fluids. Information is scarce regarding the depth and geometry of the magmatic source, dynamics in the sub-Moho/lower crust region and fluid-tectonic processes in the upper crust in this area. From studies of maar structures located in the seismic active section of the fault zone magma-tectonic phenomena can be reconstructed. For this purpose two relicts of maar volcanoes of different age within a distance of 60 km are investigated by geophysical surveys. Both structures are located in a distance of a few 10 km from recent swarm earthquake centres. The diatreme structure near Ebersbrunn/W-Saxony which is probably of tertiary age is known for several years, the late Quaternary, volcanic palaeo-lake near Mýtina close to the Czech-German border was only recently discovered. Both structures are characterized by distinct gravimetric and magnetic anomalies of about -2 mGal and several 100 nT resp. indicating steeply dipping structures as well as electrical conductivity anomalies. The magnetic total field anomaly of the Ebersbrunn structure has an uncommon rugged appearance. The hypothesis of an origin related to a redistribution of material with high magnetic susceptibility values and saponification of magnetic minerals due to melt water run-off after the last glacial period could not be confirmed. Thus the heterogeneous anomaly character appears to be mainly associated with the degree of weathering of the volcanic material within the diatreme with depth. From 3D gravimetric and magnetic modelling information is gained on geometry and structural composition. Drilling results were used as additional boundary conditions. In both cases modelling reveals an inner zone of significantly reduced density and increased

  6. Dynamics of degassing at Kilauea Volcano, Hawaii

    Vergniolle, Sylvie; Jaupart, Claude


    At Kilauea volcano, Hawaii, the recent long-lived eruptions of Mauna Ulu and Pu'u O'o have occurred in two major stages, defining a characteristic eruptive pattern. The first stage consists of cyclic changes of activity between episodes of "fire fountaining" and periods of quiescence or effusion of vesicular lava. The second stage consists only of continuous effusion of lava. We suggest that these features reflect the dynamics of magma degassing in a chamber which empties into a narrow conduit. In the volcano chamber, gas bubbles rise through magma and accumulate at the roof in a foam layer. The foam flows toward the conduit, and its shape is determined by a dynamic balance between the input of bubbles from below and the output into the conduit. The foam thickness is proportional to (μlQ/ɛ2 ρl g)1/4, where μ l and ρl are the viscosity and density of magma, ɛ is the gas volume fraction in the foam, g is the acceleration of gravity, and Q is the gas flux. The bubbles in the foam deform under the action of buoyancy, and the maximum permissible foam thickness is hc = 2σ/ɛρlgR, where σ is the coefficient of surface tension and R is the original bubble radius. If this critical thickness is reached, the foam collapses into a large gas pocket which erupts into the conduit. Foam accumulation then resumes, and a new cycle begins. The attainment of the foam collapse threshold requires a gas flux in excess of a critical value which depends on viscosity, surface tension, and bubble size. Hence two different eruption regimes are predicted: (1) alternating regimes of foam buildup and collapse leading to the periodic eruption of large gas volumes and (2) steady foam flow at the roof leading to continuous bubbly flow in the conduit. The essential result is that the continuous process of degassing can lead to discontinuous eruptive behavior. Data on eruption rates and repose times between fountaining phases from the 1969 Mauna UIu and the 1983-1986 Pu'u O'o eruptions yield

  7. Basaltic cannibalism at Thrihnukagigur volcano, Iceland

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


    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

  8. Dynamics of degassing at Kilauea Volcano, Hawaii

    Vergniolle, S.; Jaupart, C. (Univ. Paris 7 (France))


    In the volcano chamber, gas bubbles rise through magma and accumulate at the roof in a foam layer. The foam flows toward the conduit, and its shape is determined by a dynamic balance between the input of bubbles from below and the output into the conduit. The bubbles in the foam deform under the action of buoyancy. If the critical thickness is reached, the foam collapses into a large gas pocket which erupts into the conduit. Foam accumulation then resumes, and a new cycle begins. The attainment of the foam collapse threshold requires a gas flux in excess of a critical value which depends on viscosity, suface tension, and bubble size. Hence two different eruption regimes are predicted: (1) alternating regimes of foam buildup and collapse leading to the periodic eruption of large gas volumes and (2) steady foam flow at the roof leading to continuous bubbly flow in the conduit. Data on eruption rates and repose times between fountaining phases from the 1969 Mauna Ulu and the 1983-1986 Pu'u O'o eruptions yield constraints on three key variables. The area of the chamber roof must be a few tens of square kilometers, with a minimum value of about 8 km{sup 2}. Magma reservoirs of similar dimensions are imaged by seismic attenuation tomography below the east rift zone. Close to the roof, the gas volume fraction is a few percent, and the gas bubbles have diameters lying between 0.1 and 0.6 mm. These estimates are close to the predictions of models for bubble nucleation and growth in basaltic melts, as well as to the observations on deep submarine basalts. The transition between cyclic and continuous activity occurs when the mass flux of gas becomes lower than a critical value of the order of 10{sup 3} kg/s. In this model, changes of eruptive regime reflect changes in the amount and size of bubbles which reach the chamber roof.

  9. Digging into Augustine Volcano's Silicic Past

    Nadeau, P. A.; Webster, J. D.; Goldoff, B. A.


    Activity at Augustine Volcano, Alaska, has been marked by intermediate composition domes, flows, and tephras during the Holocene. Erosive lahars associated with the 2006 eruption exposed voluminous rhyolite pumice fall beneath glacial tills. The rhyolite is both petrologically and mineralogically different from more recent eruptions, with abundant amphibole (both calcium-amphiboles and cummingtonite) and quartz, both rare in more recent products. Three distinct lithologies are present, with textural and chemical variations between the three. Fe-Ti oxide equilibria indicate temperatures of ~765°C and oxygen fugacities of NNO +1.5. Melt inclusions indicate that the stratigraphically lowest lithology began crystallizing isobarically at ~260 MPa with the contemporary mixed H2O-CO2 fluid phase becoming progressively H2O-rich. The other lithologies were likely crystallized under more H2O-dominated conditions, as indicated by the presence of cummingtonite. Apatites and melt inclusions have generally lower chlorine contents than more recently erupted material, which is typically high in chlorine. Xenocrysts of olivine and clinopyroxene in two of the three lithologies contain mafic (basalt to basaltic andesite) melt inclusions that indicate the likelihood of mixing and/or mingling of magmas as an eruption trigger. We interpret the three lithologies as representative of a smaller pumiceous rhyolite eruption, with subsequent extrusion of a rhyodacite banded lava dome or flow. This was followed by a large-scale rhyolitic pumice eruption that entrained portions of the banded flow as lithic inclusions. The unique qualities of this pre-glacial rhyolite and the potential hazards of a similarly large eruption in modern times indicate that further study is warranted.

  10. The 2013 eruption of Pavlof Volcano, Alaska: a spatter eruption at an ice- and snow-clad volcano

    Waythomas, Christopher F.; Haney, Matthew M.; Fee, David; Schneider, David J.; Wech, Aaron G.


    The 2013 eruption of Pavlof Volcano, Alaska began on 13 May and ended 49 days later on 1 July. The eruption was characterized by persistent lava fountaining from a vent just north of the summit, intermittent strombolian explosions, and ash, gas, and aerosol plumes that reached as high as 8 km above sea level and on several occasions extended as much as 500 km downwind of the volcano. During the first several days of the eruption, accumulations of spatter near the vent periodically collapsed to form small pyroclastic avalanches that eroded and melted snow and ice to form lahars on the lower north flank of the volcano. Continued lava fountaining led to the production of agglutinate lava flows that extended to the base of the volcano, about 3–4 km beyond the vent. The generation of fountain-fed lava flows was a dominant process during the 2013 eruption; however, episodic collapse of spatter accumulations and formation of hot spatter-rich granular avalanches was a more efficient process for melting snow and ice and initiating lahars. The lahars and ash plumes generated during the eruption did not pose any serious hazards for the area. However, numerous local airline flights were cancelled or rerouted, and trace amounts of ash fall occurred at all of the local communities surrounding the volcano, including Cold Bay, Nelson Lagoon, Sand Point, and King Cove.

  11. Expert elicitation for a national-level volcano hazard model

    Bebbington, Mark; Stirling, Mark; Cronin, Shane; Wang, Ting; Jolly, Gill


    The quantification of volcanic hazard at national level is a vital pre-requisite to placing volcanic risk on a platform that permits meaningful comparison with other hazards such as earthquakes. New Zealand has up to a dozen dangerous volcanoes, with the usual mixed degrees of knowledge concerning their temporal and spatial eruptive history. Information on the 'size' of the eruptions, be it in terms of VEI, volume or duration, is sketchy at best. These limitations and the need for a uniform approach lend themselves to a subjective hazard analysis via expert elicitation. Approximately 20 New Zealand volcanologists provided estimates for the size of the next eruption from each volcano and, conditional on this, its location, timing and duration. Opinions were likewise elicited from a control group of statisticians, seismologists and (geo)chemists, all of whom had at least heard the term 'volcano'. The opinions were combined via the Cooke classical method. We will report on the preliminary results from the exercise.

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

    Bruno Massa


    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.

  13. Influence of fortnightly earth tides at Kilauea Volcano, Hawaii.

    Dzurisin, D.


    Analysis of 52 historic eruptions confirms the premise that fortnightly earth tides play a significant role in triggering activity at Kilauea Volcano, Hawaii. Since January 1832, nearly twice as many eruptions have occurred nearer fortnightly tidal maximum than tidal minimum (34 vs. 18). A straightforward significance test indicates that the likelihood of a fortnightly tidal influence on Kilauea eruptions is roughly 90%. This is not the case for Mauna Loa Volcano, where 37 historic eruptions have been distributed randomly with respect to the fortnightly tide. At Kilauea, stresses induced by fortnightly earth tides presumably act in concert with volcanic and tectonic stresses to trigger shallow magma movements along preexisting zones of weakness. Differences in structure or internal plumbing may limit the effectiveness of this mechanism at Mauna Loa. Tidal effects seem to be less marked at shields than at some island-arc volcanoes, possibly because higher average volcanic stress rates in Hawaii more often override the effects of tidal stresses.-Author

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

    Kerlow, Isaac


    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.

  15. The Unexpected Awakening of Chaitén Volcano, Chile

    Carn, Simon A.; Zogorski, John S.; Lara, Luis; Ewert, John W.; Watt, Sebastian; Prata, Alfred J.; Thomas, Ronald J.; Villarosa, Gustavo


    On 2 May 2008, a large eruption began unexpectedly at the inconspicuous Chaitén volcano in Chile's southern volcanic zone. Ash columns abruptly jetted from the volcano into the stratosphere, followed by lava dome effusion and continuous low-altitude ash plumes [Lara, 2009]. Apocalyptic photographs of eruption plumes suffused with lightning were circulated globally. Effects of the eruption were extensive. Floods and lahars inundated the town of Chaitén, and its 4625 residents were evacuated. Widespread ashfall and drifting ash clouds closed regional airports and cancelled hundreds of domestic flights in Argentina and Chile and numerous international flights [Guffanti et al., 2008]. Ash heavily affected the aquaculture industry in the nearby Gulf of Corcovado, curtailed ecotourism, and closed regional nature preserves. To better prepare for future eruptions, the Chilean government has boosted support for monitoring and hazard mitigation at Chaitén and at 42 other highly hazardous, active volcanoes in Chile.

  16. Linking petrology and seismology at an active volcano.

    Saunders, Kate; Blundy, Jon; Dohmen, Ralf; Cashman, Kathy


    Many active volcanoes exhibit changes in seismicity, ground deformation, and gas emissions, which in some instances arise from magma movement in the crust before eruption. An enduring challenge in volcano monitoring is interpreting signs of unrest in terms of the causal subterranean magmatic processes. We examined over 300 zoned orthopyroxene crystals from the 1980-1986 eruption of Mount St. Helens that record pulsatory intrusions of new magma and volatiles into an existing larger reservoir before the eruption occurred. Diffusion chronometry applied to orthopyroxene crystal rims shows that episodes of magma intrusion correlate temporally with recorded seismicity, providing evidence that some seismic events are related to magma intrusion. These time scales are commensurate with monitoring signals at restless volcanoes, thus improving our ability to forecast volcanic eruptions by using petrology.

  17. The Unexpected Awakening of Chaitén Volcano, Chile

    Carn, Simon A.; Pallister, John S.; Lara, Luis; Ewert, John W.; Watt, Sebastian; Prata, Alfred J.; Thomas, Ronald J.; Villarosa, Gustavo


    On 2 May 2008, a large eruption began unexpectedly at the inconspicuous Chaitén volcano in Chile's southern volcanic zone. Ash columns abruptly jetted from the volcano into the stratosphere, followed by lava dome effusion and continuous low-altitude ash plumes [Lara, 2009]. Apocalyptic photographs of eruption plumes suffused with lightning were circulated globally. Effects of the eruption were extensive. Floods and lahars inundated the town of Chaitén, and its 4625 residents were evacuated. Widespread ashfall and drifting ash clouds closed regional airports and cancelled hundreds of domestic flights in Argentina and Chile and numerous international flights [Guffanti et al., 2008]. Ash heavily affected the aquaculture industry in the nearby Gulf of Corcovado, curtailed ecotourism, and closed regional nature preserves. To better prepare for future eruptions, the Chilean government has boosted support for monitoring and hazard mitigation at Chaitén and at 42 other highly hazardous, active volcanoes in Chile.

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

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


    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.

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

    Massa, Bruno; D'Auria, Luca; Cristiano, Elena; De Matteo, Ada


    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.

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

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


    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

  1. Antarctic Single Frames = Frame Level Records of Antarctica Photos: 1946 - 2000

    U.S. Geological Survey, Department of the Interior — Aerial photographs of Antarctica from the United States Antarctic Resource Center (USARC) and the British Antarctic Survey (BAS) are maintained in this collection....

  2. Greenland and Antarctica Ice Sheet Mass Changes and Effects on Global Sea Level

    Forsberg, René; Sørensen, Louise Sandberg; Simonsen, Sebastian Bjerregaard


    Thirteen years of GRACE data provide an excellent picture of the current mass changes of Greenland and Antarctica, with mass loss in the GRACE period 2002–2015 amounting to 265 ± 25 GT/year for Greenland (including peripheral ice caps), and 95 ± 50 GT/year for Antarctica, corresponding to 0.......72 and 0.26 mm/year average global sea level change. A significant acceleration in mass loss rate is found, especially for Antarctica, while Greenland mass loss, after a corresponding acceleration period, and a record mass loss in the summer of 2012, has seen a slight decrease in short-term mass loss trend....... The yearly mass balance estimates, based on point mass inversion methods, have relatively large errors, both due to uncertainties in the glacial isostatic adjustment processes, especially for Antarctica, leakage from unmodelled ocean mass changes, and (for Greenland) difficulties in separating mass signals...

  3. Radiocarbon-dates of snow petrel regurgitations can reveal exposure periods for nunataks in Antarctica

    Ryan, PG


    Full Text Available There are several problems associated with determining radiocarbon dates, particularly for organic material from Antarctica. However, this study attempts to find accurate measure of the length of time these radiocarbon dates have been established...

  4. Characteristics of macrobenthic assemblage from sub-littoral sediment off the Lazarev Sea, East Antarctica

    Ingole, B.S.

    Comparative account of the occurrence and abundance of benthic macro-organisms collected from the Lazarev Sea in Queen Maud Land, (east Antarctica), during austral summer of 1984-85 and 1992-93 (fourth and twelfth Indian Antarctic expeditions...

  5. From sea to land: assessment of the bio-transport of phosphorus by penguins in Antarctica

    Qin, Xianyan; Sun, Liguang; Blais, Jules M.; Wang, Yuhong; Huang, Tao; Huang, Wen; Xie, Zhouqing


    In Antarctica, the marine ecosystem is dynamically interrelated with the terrestrial ecosystem. An example of the link between these two ecosystems is the biogeochemical cycle of phosphorus. Biovectors, such as penguins, transport phosphorus from sea to land, play a key role in this cycle. In this paper, we selected three colonies of penguins, the most important seabirds in Antarctica, and computed the annual quantity of phosphorus transferred from sea to land by these birds. Our results show that adult penguins from colonies at Ardley Island, the Vestfold Hills, and Ross Island could transfer phosphorus in the form of guano at up to 12 349, 167 036, and 97 841 kg/a, respectively, over their breeding period. These quantities are equivalent to an annual input of 3.96×109-1.63×1010 kg of seawater to the land of Antarctica. Finally, we discuss the impact of phosphorus on the ice-free areas of the Antarctica.

  6. Ecobiological assessment of a freshwater lake at Schirmacher Oasis, East Antarctica, with reference to human activities

    Ingole, B.S.; Dhargalkar, V.K.

    The scale and magnitude of probable impact of human activities over a decade (1983-1994) on the freshwater lake Priyadarshini, at Schirmacher Oasis, East Antarctica, was assessed through an ecological study conducted over an annual cycle during...

  7. Mineral dust variability in central West Antarctica associated with ozone depletion

    M. Cataldo


    Full Text Available Here we show that mineral dust retrieved from an ice core in the central West Antarctic sector, spanning the last five decades, provides evidence that northerly air mass incursions into Antarctica, tracked by dust microparticles, have slightly declined. This result contrasts with dust in ice core records reported in West/coastal Antarctica, which show significant increases to the present day. We attribute that difference, in part, to changes in the regional climate regime triggered by the ozone depletion and its consequences for the polar vortex intensity. The vortex maintains the Antarctic central region relatively isolated from mid-latitude air mass incursions with implications to the intensification of the Westerlies and to a persistent positive phase of the Southern Annular Mode. We also show that variability of the diameter of insoluble microparticles in central West Antarctica can be modeled by linear/quadratic functions of both cyclone depth (energy and wind intensity around Antarctica.

  8. Cloning and molecular genetics analyses of Deschampsia antarctica Desv. chloroplast and mitochondrial DNA sequence

    O.P. Savchuk


    Full Text Available Chloroplast and mitochondrial DNA sequences of Deschampsia antarctica were studied. We had made comparison analysis with completely sequenced genomes of other temperateness plants to find homology.

  9. Short term variation in particulate matter in the shelf waters of the Princess Astrid Coast, Antarctica

    Dhargalkar, V.K.; Bhosle, N.B.

    Particulate matter collected at a single station in the shelf waters of Princess Astrid coast (70 degrees S, 11 degrees E) Antarctica, during the austral summer (Jan.-Feb. 1986) was analysed for phytoplankton biomass (Chl @ia@@), living carbon (ATP...

  10. Formation, topography and reactivity of Candida antarctica lipase B immobilized on silicon surface

    Miletic, Nemanja; Fahriansyah, [No Value; Nguyen, Le-Thu T.; Loos, Katja; Miletić, Nemanja


    Candida antarctica lipase B (CaLB) was immobilized on silicon wafers previously modified with aminopropyltriethoxysilane (APTES) and activated with glutaraldehyde (GLA). The various steps of immobilization were characterized using transmission FTIR, AFM, contact angle measurements and XPS. Furthermo

  11. Antarctic Flight Line Maps = Map-Line Indexes of Antarctica Aerial Photos: Pre 1950

    U.S. Geological Survey, Department of the Interior — The Antarctic Fight Line Maps collection is comprised of 1:250,000 scale topographic maps over Antarctica with original hand-drawn flight lines for aerial...

  12. Don Juan Basin, Wright Valley, Antarctica: Model for Surface Processes on Mars

    Englert, P.; Bishop, J. L.; Gibson, E. K.; Patel, S.; Koeberl, C.


    Mineral, chemical, and soluble salt composition of drill core samples from Don Juan Basin, Wright Valley, Antarctica, indicate that the formation of the most saline terrestrial pond may include groundwater discharge and near surface flow processes.

  13. Antarctic Flight Line Maps = Map-Line Indexes of Antarctica Aerial Photos: Pre 1950

    U.S. Geological Survey, Department of the Interior — The Antarctic Fight Line Maps collection is comprised of 1:250,000 scale topographic maps over Antarctica with original hand-drawn flight lines for aerial...

  14. Geodetic and geophysical observations in Antarctica an overview in the IPY perspective

    Capra, Alessandro


    This book is a collection of papers on various aspects of the geodetic and geophysical investigation and observation techniques. It includes material from the Arctic and Antarctica, as well as covering work from both temporary and permanent observatories.

  15. Formation, topography and reactivity of Candida antarctica lipase B immobilized on silicon surface

    Miletic, Nemanja; Fahriansyah, [No Value; Nguyen, Le-Thu T.; Loos, Katja; Miletić, Nemanja


    Candida antarctica lipase B (CaLB) was immobilized on silicon wafers previously modified with aminopropyltriethoxysilane (APTES) and activated with glutaraldehyde (GLA). The various steps of immobilization were characterized using transmission FTIR, AFM, contact angle measurements and XPS.

  16. Interactive Volcano Studies and Education Using Virtual Globes

    Dehn, J.; Bailey, J. E.; Webley, P.


    Internet-based virtual globe programs such as Google Earth provide a spatial context for visualization of monitoring and geophysical data sets. At the Alaska Volcano Observatory, Google Earth is being used to integrate satellite imagery, modeling of volcanic eruption clouds and seismic data sets to build new monitoring and reporting tools. However, one of the most useful information sources for environmental monitoring is under utilized. Local populations, who have lived near volcanoes for decades are perhaps one of the best gauges for changes in activity. Much of the history of the volcanoes is only recorded through local legend. By utilizing the high level of internet connectivity in Alaska, and the interest of secondary education in environmental science and monitoring, it is proposed to build a network of observation nodes around local schools in Alaska and along the Aleutian Chain. A series of interactive web pages with observations on a volcano's condition, be it glow at night, puffs of ash, discolored snow, earthquakes, sounds, and even current weather conditions can be recorded, and the users will be able to see their reports in near real time. The database will create a KMZ file on the fly for upload into the virtual globe software. Past observations and legends could be entered to help put a volcano's long-term activity in perspective. Beyond the benefit to researchers and emergency managers, students and teachers in the rural areas will be involved in volcano monitoring, and gain an understanding of the processes and hazard mitigation efforts in their community. K-12 students will be exposed to the science, and encouraged to participate in projects at the university. Infrastructure at the university can be used by local teachers to augment their science programs, hopefully encouraging students to continue their education at the university level.

  17. Schoolyard Volcanoes: A Unit in Volcanology and Hazards

    Lechner, H. N.; Gochis, E. E.; Brill, K. A.


    How do you teach volcanology and volcanic hazards to students when there is no volcano nearby? You bring the volcano to them! At Michigan Technological University we have developed a four-lesson-unit for middle and high school students which incorporates virtual, analogue and numerical models to increase students' interests in geosciences while simultaneously expanding the community of earth-science-literate individuals necessary for a disaster resilient society. The unit aims to build on students' prior geoscience knowledge by examining the physical properties that influence volcanic eruptions and introduces them to challenges and methods of communicating hazards and risk. Lesson one engages students in a series of hands-on investigations that explore the "3-Vs" of volcanology: Viscosity, Volatiles and Volume. The students learn about the relationship between magma composition and viscosity and the influence on eruption style, behavior and morphology of different volcanoes. Lesson two uses an analogue model of a volcano to demonstrate the forces involved in an explosive eruption and associated hazards. Students think critically about the factors that affect hazards and risk as well as the variables (such as topography) that affect the eruption and the hazard. During lesson three students use Google Earth for a virtual field trip to Pacaya volcano, Guatemala to examine changes in the landscape over time and other evidence of volcanic activity to make interpretations about the volcano. The final lesson has the students use numerical models and GIS to create hazard maps based on probabilistic lahar scenarios. Throughout the unit students are engaged in an inquiry-based exploration that covers several Next Generation Science Standards (NGSS) content and practices. This four lesson unit has been field tested in two school districts and during a summer engineering program. Results from student work and post-surveys show that this strategy raises interests in and

  18. A Study of the Source Processes of Colima Volcano Explosions

    Nunez-Cornu, F. J.; Vargas-Bracamontes, D.; Sanchez, J. J.; Suarez-Plascencia, C.


    Colima volcano, considered as Mexico's most active volcano, has presented several intermittent effusive and explosive phases in recent years. During 2005, a sequence of explosive events with VEI less than or equal to 3 occurred. This activity presented the most intense explosions since the seismic network was deployed. Many of the explosive events were recorded by the digital three-component seismic stations operated by the University of Guadalajara and Jalisco State Civil Defense. These signals were recorded not only by stations located on the volcanic edifice, but also by stations on the northern coast of Jalisco (MCUJ, BSSJ) and Ceboruco Volcano at 184, 182 and 200 km distance, respectively. A study of these signals will be presented. Each explosion was preceded by a seismic event. Nevertheless, the located earthquakes preceding the explosions did not show a common source under the volcano structure, which suggests the existence of a complex structure with possibly more than one conduit, this is also confirmed from a first motion analysis for station F03J, located 12 km at north of the volcano. From analysis of the first ten seconds of the seismic signal on F03J using different representations of the seismic signals, such as waveforms, spectra, time-frequency and time-scale analysis, it is suggested that the source processes are non-stationary, implying that for the case of this period, a general model of the source process of the Colima volcano explosions can not be formulated. The size of the events is evaluated using different criteria. A clear relation between the magnitude of the seismic signals and the amplitude of the sonic and infrasonic waves was not observed.

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

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


    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.

  20. Extraction of intracellular protein from Glaciozyma antarctica for proteomics analysis

    Faizura, S. Nor; Farahayu, K.; Faizal, A. B. Mohd; Asmahani, A. A. S.; Amir, R.; Nazalan, N.; Diba, A. B. Farah; Muhammad, M. Nor; Munir, A. M. Abdul


    Two preparation methods of crude extracts of psychrophilic yeast Glaciozyma antarctica were compared in order to obtain a good recovery of intracellular proteins. Extraction with mechanical procedures using sonication was found to be more effective for obtaining good yield compare to alkaline treatment method. The procedure is simple, rapid, and produce better yield. A total of 52 proteins were identified by combining both extraction methods. Most of the proteins identified in this study involves in the metabolic process including glycolysis pathway, pentose phosphate pathway, pyruyate decarboxylation and also urea cyle. Several chaperons were identified including probable cpr1-cyclophilin (peptidylprolyl isomerase), macrolide-binding protein fkbp12 and heat shock proteins which were postulate to accelerate proper protein folding. Characteristic of the fundamental cellular processes inferred from the expressed-proteome highlight the evolutionary and functional complexity existing in this domain of life.

  1. The Landsat Image Mosaic of the Antarctica Web Portal

    Christopher J Rusanowski


    Full Text Available People believe what they can see. The Poles exist as a frozen dream to most people. The International Polar Year wants to break the ice (so to speak, open up the Poles to the general public, support current polar research, and encourage new research projects.  The IPY officially begins in March, 2007. As part of this effort, the U.S. Geological Survey (USGS and the British Antarctic Survey (BAS, with funding from the National Science Foundation (NSF, are developing three Landsat mosaics of Antarctica and an Antarctic Web Portal with a Community site and an online map viewer. When scientists are able to view the entire scope of polar research, they will be better able to collaborate and locate the resources they need. When the general public more readily sees what is happening in the polar environments, they will understand how changes to the polar areas affect everyone.

  2. An unusual, structurally preserved ovule from the Permian of Antarctica.

    Klavins, S D.; Taylor, E L.; Krings, M; Taylor, T N.


    Anatomically preserved ovules are described from silicified peat of Late Permian age collected from Skaar Ridge in the central Transantarctic Mountains, Antarctica. The small ovules are significant in possessing fleshy apical appendages and a funnel-shaped micropylar extension formed by the sarcotestal layer of the integument, by which they differ from all other Permian ovules described to date. The apical modifications may have functioned in pollination and/or seed dispersal. Similarity with the apical organization of earlier Paleozoic ovules is shown to be superficial, since the analogous structures are developmentally derived from different tissues. Although the ovules occur in rocks in which glossopterids are the only gymnosperms represented, there is insufficient evidence to assign them to a taxonomic group. These ovules are of particular importance because there are so few anatomically preserved gymnosperm reproductive structures known from the Permian and thus provide new data on the diversity of late Paleozoic gymnosperms.

  3. The landsat image mosaic of the Antarctica Web Portal

    Rusanowski, C.J.


    People believe what they can see. The Poles exist as a frozen dream to most people. The International Polar Year wants to break the ice (so to speak), open up the Poles to the general public, support current polar research, and encourage new research projects. The IPY officially begins in March, 2007. As part of this effort, the U.S. Geological Survey (USGS) and the British Antarctic Survey (BAS), with funding from the National Science Foundation (NSF), are developing three Landsat mosaics of Antarctica and an Antarctic Web Portal with a Community site and an online map viewer. When scientists are able to view the entire scope of polar research, they will be better able to collaborate and locate the resources they need. When the general public more readily sees what is happening in the polar environments, they will understand how changes to the polar areas affect everyone.

  4. Aerobiology over Antarctica – a new initiative for atmospheric ecology

    David Anthony Pearce


    Full Text Available The role of aerial dispersal in shaping patterns of biodiversity remains poorly understood, mainly due to a lack of coordinated efforts in gathering data at appropriate temporal and spatial scales. It has been long known that the rate of dispersal to an ecosystem can significantly influence ecosystem dynamics, and that aerial transport has been identified as an important source of biological input to remote locations. With the considerable effort devoted in recent decades to understanding atmospheric circulation in the south polar region, a unique opportunity has emerged to investigate the atmospheric ecology of Antarctica, from local to continental scales. This concept note identifies key questions in Antarctic microbial biogeography and the need for standardized sampling and analysis protocols to address such questions. A consortium of polar aerobiologists is established to bring together researchers with a common interest in the airborne dispersion of microbes and other propagules in the Antarctic, with opportunities for comparative studies in the Arctic.

  5. Surface and snowdrift sublimation at Princess Elisabeth station, East Antarctica

    W. Thiery


    Full Text Available In the near-coastal regions of Antarctica, a significant fraction of the snow precipitating onto the surface is removed again through sublimation – either directly from the surface or from drifting snow particles. Meteorological observations from an Automatic Weather Station (AWS near the Belgian research station Princess Elisabeth in Dronning Maud Land, East-Antarctica, are used to study surface and snowdrift sublimation and to assess their impacts on both the surface mass balance and the surface energy balance during 2009 and 2010. Comparison to three other AWSs in Dronning Maud Land with 11 to 13 yr of observations shows that sublimation has a significant influence on the surface mass balance at katabatic locations by removing 10–23% of their total precipitation, but at the same time reveals anomalously low surface and snowdrift sublimation rates at Princess Elisabeth (17 mm w.e. yr−1 compared to 42 mm w.e. yr−1 at Svea Cross and 52 mm w.e. yr−1 at Wasa/Aboa. This anomaly is attributed to local topography, which shields the station from strong katabatic influence, and, therefore, on the one hand allows for a strong surface inversion to persist throughout most of the year and on the other hand causes a lower probability of occurrence of intermediately strong winds. This wind speed class turns out to contribute most to the total snowdrift sublimation mass flux, given its ability to lift a high number of particles while still allowing for considerable undersaturation.

  6. Uncovering the footprint of former ice streams off Antarctica

    COHIMAR/SEDANO Scientific Party

    Antarctic ice sheets and ice caps have been expanding and contracting following global climatic cycles. The last time the Antarctic ice cover peaked, at least in Western Antarctica, was ca. 21 ky ago during the Last Glacial Maximum (LGM). The strong warming (nearly 2.8°C) over the past 50 years, and the yearly recent collapse of limited portions (hundreds to a few thousands of square miles per event) of ice shelves around the Antarctic Peninsula have brought to the headlines the debate about the potential collapse of the West Antarctic Ice Sheet (WAIS) in the near future under the influence of global warming.Such a catastrophe would substantially contribute to global sea level rise (a resulting 5 m increase is expected); alter water mass conditions, circulation, and productivity around Antarctica and in the world ocean; and modify the Earth's climate.The economic,social, and ecological impacts of these changes would depend greatly on the rate at which they might take place [Bindschadler, 1998” . A detailed knowledge of the past extent of ice sheets and the timing of their advances and retreats thus becomes essential to quantify the rates of change and to properly assess the future stability of the WAIS and nearby ice caps. The stability of ice sheets is largely dependent on ice drainage, which mostly occurs via ice streaming along glacial troughs. Ice streams are thus a key element to solve the puzzle linking ice sheet stability, sea level rise, and climate change at a global scale.

  7. Electrical structure beneath Schirmacher Oasis, East Antarctica: a magnetotelluric study

    D.N. Murthy


    Full Text Available Maitri Station (70.76°S; 11.73°E is located in Schirmacher Oasis, a coastal nunatak in north-central Dronning Maud Land covering an area of 35 km2. Here, we report results from the first magnetotelluric experiments and delineate the deep electrical conductivity structure under Schirmacher Oasis using the data acquired during the 24th Indian Antarctic Scientific Expedition. The magnetotelluric method has the advantage of shallow to deeper level coverage as the data acquisition covers a wide frequency band of 10−3–103 Hz, permitting different penetration depths depending on the frequency and conductivity of the layer under investigation. The modelling results indicate the presence of a highly resistive (8000–10 000 ohm m upper crust, which shows a lateral variation in thickness from 20 km (below site 6 in the east to 10 km (between sites 1 and 2 in the west. It is underlain by a less resistive (500–600 ohm m lower crust. The highly resistive upper crustal structure supports the existing notion that western Dronning Maud Land is a stable, cratonic platform. Results of free-air gravity, seismic, geomagnetic and surface wave dispersion investigations in East Antarctica also indicate a cratonic-type crust. The results of our study allow us to identify a westward thinning of the upper crust with a marked boundary between sites 1 and 2. We also find evidence for the continuity of the Mozambique mobile belt in East Antarctica on the western side of Schirmacher Oasis.

  8. Microzooplankton herbivory and community structure in the Amundsen Sea, Antarctica

    Yang, Eun Jin; Jiang, Yong; Lee, SangHoon


    We examined microzooplankton abundance, community structure, and grazing impact on phytoplankton in the Amundsen Sea, Western Antarctica, during the early austral summer from December 2010 to January 2011. Our study area was divided into three regions based on topography, hydrographic properties, and trophic conditions: (1) the Oceanic Zone (OZ), with free sea ice and low phytoplankton biomass dominated by diatoms; (2) the Sea Ice Zone (SIZ), covered by heavy sea ice with colder water, lower salinity, and dominated by diatoms; and (3) the Amundsen Sea Polynya (ASP), with high phytoplankton biomass dominated by Phaeocystis antarctica. Microzooplankton biomass and communities associated with phytoplankton biomass and composition varied among regions. Heterotrophic dinoflagellates (HDF) were the most significant grazers in the ASP and OZ, whereas ciliates co-dominated with HDF in the SIZ. Microzooplankton grazing impact is significant in our study area, particularly in the ASP, and consumed 55.4-107.6% of phytoplankton production (average 77.3%), with grazing impact increasing with prey and grazer biomass. This result implies that a significant proportion of the phytoplankton production is not removed by sinking or other grazers but grazed by microzooplankton. Compared with diatom-based systems, Phaeocystis-based production would be largely remineralized and/or channeled through the microbial food web through microzooplankton grazing. In these waters the major herbivorous fate of phytoplankton is likely mediated by the microzooplankton population. Our study confirms the importance of herbivorous protists in the planktonic ecosystems of high latitudes. In conclusion, microzooplankton herbivory may be a driving force controlling phytoplankton growth in early summer in the Amundsen Sea, particularly in the ASP.

  9. Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica.

    Radu Herbei

    Full Text Available The McMurdo Dry Valleys constitute the largest ice free area of Antarctica. The area is a polar desert with an annual precipitation of ∼ 3 cm water equivalent, but contains several lakes fed by glacial melt water streams that flow from four to twelve weeks of the year. Over the past ∼20 years, data have been collected on the lakes located in Taylor Valley, Antarctica as part of the McMurdo Dry Valley Long-Term Ecological Research program (MCM-LTER. This work aims to understand the impact of climate variations on the biological processes in all the ecosystem types within Taylor Valley, including the lakes. These lakes are stratified, closed-basin systems and are perennially covered with ice. Each lake contains a variety of planktonic and benthic algae that require nutrients for photosynthesis and growth. The work presented here focuses on Lake Fryxell, one of the three main lakes of Taylor Valley; it is fed by thirteen melt-water streams. We use a functional regression approach to link the physical, chemical, and biological processes within the stream-lake system to evaluate the input of water and nutrients on the biological processes in the lakes. The technique has been shown previously to provide important insights into these Antarctic lacustrine systems where data acquisition is not temporally coherent. We use data on primary production (PPR and chlorophyll-A (CHLfrom Lake Fryxell as well as discharge observations from two streams flowing into the lake. Our findings show an association between both PPR, CHL and stream input.

  10. Climatic Variability in Davis Sea Sector (east Antarctica) Over the Past 250 Years Based on the 105 KM Ice Core Geochemical Data

    Vladimirova, Diana; Ekaykin, Alexey


    In this study we present the air temperature and snow accumulation rate reconstruction in the Davis sea sector of East Antarctica over the past 250 years based on the geochemical investigations of the ice core from 105 km borehole (105 km inland from Mirny Station) drilled in 1988. The core was dated by the counting of the annual layers in the stable water isotope content (dD and d18O) profile and using the absolute date marker (Tambora volcano layer). The accumulation values were deduced from the thickness of the layers multiplied by the core density. The isotope content was transformed into the air temperature by comparing to the instrumental meteorological data from Mirny station. The reconstructed temperature series demonstrates a 0.5°C warming over the last 250 years. At the same time, snow accumulation rate was decreasing at least since the middle of the XIXth century. The climatic characteristics demonstrate cyclic variability with the periods of 6, 9, 19, 32 and about 120 years. Interestingly, in frames of 19-year cycle the temperature and isotope content are negatively related, which could be explained by a zonal shift of the moisture source area. Based on the data of the sodium concentration and "deuterium excess" values in the ice core, we assumed an increased sea ice extent in the XIXth century comparing to the present day.

  11. The environmental impact of sewage and wastewater outfalls in Antarctica: An example from Davis station, East Antarctica.

    Stark, Jonathan S; Corbett, Patricia A; Dunshea, Glenn; Johnstone, Glenn; King, Catherine; Mondon, Julie A; Power, Michelle L; Samuel, Angelingifta; Snape, Ian; Riddle, Martin


    We present a comprehensive scientific assessment of the environmental impacts of an Antarctic wastewater ocean outfall, at Davis station in East Antarctica. We assessed the effectiveness of current wastewater treatment and disposal requirements under the Protocol on Environmental Protection to the Antarctic Treaty. Macerated wastewater has been discharged from an outfall at Davis since the failure of the secondary treatment plant in 2005. Water, sediment and wildlife were tested for presence of human enteric bacteria and antibiotic resistance mechanisms. Epibiotic and sediment macrofaunal communities were tested for differences between sites near the outfall and controls. Local fish were examined for evidence of histopathological abnormalities. Sediments, fish and gastropods were tested for uptake of sewage as measured by stable isotopes of N and C. Escherichia coli carrying antibiotic resistance determinants were found in water, sediments and wildlife (the filter feeding bivalve Laternula eliptica). Fish (Trematomus bernacchii) within close proximity to the outfall had significantly more severe and greater occurrences of histopathological abnormalities than at controls, consistent with exposure to sewage. There was significant enrichment of (15)N in T. bernacchii and the predatory gastropod Neobuccinum eatoni around the outfall, providing evidence of uptake of sewage. There were significant differences between epibiotic and sediment macrofaunal communities at control and outfall sites (environmental drivers such as sea ice. The combined evidence indicated that the discharge of wastewater from the Davis outfall is causing environmental impacts. These findings suggest that conditions in Antarctic coastal locations, such as Davis, are unlikely to be conducive to initial dilution and rapid dispersal of wastewater as required under the Protocol on Environmental Protection to the Antarctic Treaty. Current minimum requirements for wastewater treatment and disposal in

  12. Volcanic Activities of Hakkoda Volcano after the 2011 Tohoku Earthquake

    Yamamoto, M.; Miura, S.


    The 2011 Tohoku Earthquake of 11 March 2011 generated large deformation in and around the Japanese islands, and the large crustal deformation raises fear of further disasters including triggered volcanic activities. In this presentation, as an example of such potential triggered volcanic activities, we report the recent seismic activities of Hakkoda volcano, and discuss the relation to the movement of volcanic fluids. Hakkoda volcano is a group of stratovolcanoes at the northern end of Honshu Island, Japan. There are fumaroles and hot springs around the volcano, and phreatic eruptions from Jigoku-numa on the southwestern flank of Odake volcano, which is the highest peak of the volcanic group, were documented in its history. Since just after the occurrence of the Tohokui Earthquake, the seismicity around the volcano became higher, and the migration of hypocenters of volcano-tectonic (VT) earthquakes was observed.In addition to these VT earthquakes, long-period (LP) events started occurring beneath Odake at a depth of about 2-3 km since February, 2013, and subtle crustal deformation caused by deep inflation source was also detected by the GEONET GNSS network around the same time. The spectra of LP events are common between events irrespective of the magnitude of events, and they have several spectral peaks at 6-7 sec, 2-3 sec, 1 sec, and so on. These LP events sometimes occur like a swarm with an interval of several minutes. The characteristics of observed LP events at Hakkoda volcano are similar to those of LP events at other active volcanoes and hydrothermal area in the world, where abundant fluids exist. Our further analysis using far-field Rayleigh radiation pattern observed by NIED Hi-net stations reveals that the source of LP events is most likely to be a nearly vertical tensile crack whose strike is NE-SW direction. The strike is almost perpendicular to the direction of maximum extensional strain estimated from the geodetic analysis, and is almost parallel to

  13. Output rate of magma from active central volcanoes

    Wadge, G.


    For part of their historic records, nine of the most active volcanoes on earth have each erupted magma at a nearly constant rate. These output rates are very similar and range from 0.69 to 0.26 cu m/s. The volcanoes discussed - Kilauea, Mauna Loa, Fuego, Santiaguito, Nyamuragira, Hekla, Piton de la Fournaise, Vesuvius and Etna - represent almost the whole spectrum of plate tectonic settings of volcanism. A common mechanism of buoyantly rising magma-filled cracks in the upper crust may contribute to the observed restricted range of the rates of output.

  14. OMI Observations of Bromine Monoxide Emissions from Volcanoes

    Suleiman, R. M.; Chance, K.; Liu, X.; Gonzalez Abad, G.; Kurosu, T. P.


    We analyze bromine monoxide (BrO) data from the Ozone Monitoring Instrument (OMI) for emissions from various volcanoes. We use OMI data from 2005 to 2014 to investigate BrO signatures from Galapagos, Kasatochi and Eyjafjallajökull volcanoes. Elevated signatures of BrO daily averages were found over Eyjafjallajökull. SO2 cross sections are updated in the operational BrO algorithm and their effect on the volcanic BrO signature is studied. Comparison between two different sets of SO2 cross sections is made and results still show BrO enhancement over the Eyjafjallajökull region.

  15. Experimental simulation and morphological quantification of volcano growth

    Grosse, Pablo; Kervyn, Matthieu; Gallland, Olivier; Delcamp, Audray; Poppe, Sam


    Volcanoes display very diverse morphologies as a result of a complex interplay of several constructive and destructive processes. Here the role played by the spatial distribution of eruption centre and by an underlying strike-slip fault in controlling the long term growth of volcanoes is investigated with analogue models. Volcano growth was simulated by depositing loads of granular material (sand-kaolin mixtures) from a point source. An individual load deposited at a fixed location produces a simple symmetrical cone with flank slopes at the angle of repose of the granular material (~33°) that can be considered as the building-block for the experiments. Two sets of experiments were undertaken: (1) the location of deposition of the granular material (i.e. the volcano growth location) was shifted with time following specific probability density functions simulating shifts or migrations in vent location; (2) the location of deposition was kept fixed, but the deposition rate (i.e. the volcano growth rate) was varied coupled with the movement of a basal plate attached to a step-motor simulating a strike-slip displacement under the growing cone (and hence deformation of the cone). During the progression of the experiments, the models were photographed at regular time intervals using four digital cameras positioned at slightly different angles over the models. The photographs were used to generate synthetic digital elevation models (DEMs) with 0.2 mm spatial resolution of each step of the models by applying the MICMAC digital stereo-photogrammetry software. Morphometric data were extracted from the DEMs by applying two IDL-language algorithms: NETVOLC, used to automatically calculate the volcano edifice basal outline, and MORVOLC, used to extract a set of morphometric parameters that characterize the volcano edifice in terms of size, plan shape, profile shape and slopes. Analysis of the DEM-derived morphometric parameters allows to quantitatively characterize the growth

  16. Measuring thermal budgets of active volcanoes by satellite remote sensing

    Glaze, L.; Francis, P. W.; Rothery, D. A.


    Thematic Mapper measurements of the total radiant energy flux Q at Lascar volcano in north Chile for December 1984 are reported. The results are consistent with the earlier suggestion that a lava lake is the source of a reported thermal budget anomaly, and with values for 1985-1986 that are much lower, suggesting that fumarolic activity was then a more likely heat source. The results show that satellite remote sensing may be used to monitor the activity of a volcano quantitatively, in a way not possible by conventional ground studies, and may provide a method for predicting eruptions.

  17. Analysis of active volcanoes from the Earth Observing System

    Mouginis-Mark, Peter; Rowland, Scott; Crisp, Joy; Glaze, Lori; Jones, Kenneth; Kahle, Anne; Pieri, David; Zebker, Howard; Krueger, Arlin; Walter, Lou


    The Earth Observing System (EOS) scheduled for launch in 1997 and 1999 is briefly described, and the EOS volcanology investigation objectives are discussed. The volcanology investigation will include long- and short-term monitoring of selected volcanoes, the detection of precursor activity associated with unanticipated eruptions, and a detailed study of on-going eruptions. A variety of instruments on the EOS platforms will enable the study of local- and regional-scale thermal and deformational features of volcanoes, and the chemical and structural features of volcanic eruption plumes and aerosols.

  18. Eyjafjallajökull Volcano Eruption – A Brief Approach



    Full Text Available The paper summarizes the main aspects of the Eyjafjallajökull volcano eruption in Iceland. The process ispresented in the context of Iceland location on tectonic plates’ distribution. Aspects concerning Eyjafjallajökull positionon volcanic landscape of Iceland, both eruption phases and ash composition are briefly described. There are alsoemphasized the effects of the event on main common life aspects it affected (aircraft in Europe and farming in Iceland.The influence of the volcano eruption on the climate change is also discussed.

  19. Tracking Pyroclastic Flows at Soufrière Hills Volcano

    Ripepe, Maurizio; De Angelis, Silvio; Lacanna, Giorgio; Poggi, Pasquale; Williams, Carlisle; Marchetti, Emanuele; Delle Donne, Dario; Ulivieri, Giacomo


    Explosive volcanic eruptions typically show a huge column of ash and debris ejected into the stratosphere, crackling with lightning. Yet equally hazardous are the fast moving avalanches of hot gas and rock that can rush down the volcano's flanks at speeds approaching 280 kilometers per hour. Called pyroclastic flows, these surges can reach temperatures of 400°C. Fast currents and hot temperatures can quickly overwhelm communities living in the shadow of volcanoes, such as what happened to Pompeii and Herculaneum after the 79 C.E. eruption of Italy's Mount Vesuvius or to Saint-Pierre after Martinique's Mount Pelée erupted in 1902.

  20. Antarctica Meta-Analysis: Psychosocial Factors Related to Long Duration Isolation and Confinement

    Leveton, Lauren; Shea, Camille; Slack, Kelley J.; Keeton, Kathryn E.; Palinkas, Lawrence A.


    This meta-analysis is examining the psychological effects of wintering-over in Antarctica. As an isolated, confined, and extreme (ICE) environment, Antarctica provides invaluable opportunities to experience stressors more common to spaceflight than to the average person s everyday life. Increased prevalence of psychological symptoms, syndromes, and psychiatric disorders, as well as positive effects, are expected to be associated with various demographic and environmental factors. Implications for spaceflight are discussed. Findings from statistical review of the Antarctic articles will be shared.

  1. Characterization of Ionosphere Waveguide Propagation by Monitoring HAARP HF Transmissions in Antarctica



  2. Digital filter technology and its application to geomagnetic pulsations in Antarctica


    Digital filter technology is an important method in study of geomagnetic pulsations in Antarctica. The signals received by pulsation magnetometer on the ground include various types of magnetic pulsations. Some types of pulsations or some frequency hands of pulsations can be extracted from the signals by means of digital filter technology because types of pulsations are defined according to their frequency range. In this paper usual digital filter technology is provided for study of magnetic pulsations in Antarctica and some examples are introduced.

  3. Monitoring quiescent volcanoes by diffuse He degassing: case study Teide volcano

    Pérez, Nemesio M.; Melián, Gladys; Asensio-Ramos, María; Padrón, Eleazar; Hernández, Pedro A.; Barrancos, José; Padilla, Germán; Rodríguez, Fátima; Calvo, David; Alonso, Mar


    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

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

    S. Rontogianni


    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.

  5. Tufted hairgrass (Deschampsia caespitosa) exhibits a lower photosynthetic plasticity than Antarctic hairgrass (D. antarctica).

    Bystrzejewska-Piotrowska, Grazyna; Urban, Pawel L


    The aim of our work was to assess photosynthetic plasticity of two hairgrass species with different ecological origins (a temperate zone species, Deschampsia caespitosa (L.) Beauv. and an Antarctic species, D. antarctica) and to consider how the anticipated climate change may affect vitality of these plants. Measurements of chlorophyll fluorescence showed that the photosystem II (PSII) quantum efficiency of D. caespitosa decreased during 4 d of incubation at 4 degrees C but it remained stable in D. antarctica. The fluorescence half-rise times were almost always lower in D. caespitosa than in D. antarctica, irrespective of the incubation temperature. These results indicate that the photosynthetic apparatus of D. caespitosa has poorer performance in these conditions. D. caespitosa reached the maximum photosynthesis rate at a higher temperature than D. antarctica although the values obtained at 8 degrees C were similar in both species. The photosynthetic water-use efficiency (photosynthesis-to-transpiration ratio, P/E) emerges as an important factor demonstrating presence of mechanisms which facilitate functioning of a plant in non-optimal conditions. Comparison of the P/E values, which were higher in D. antarctica than in D. caespitosa at low and medium temperatures, confirms a high degree of adjustability of the photosynthetic apparatus in D. antarctica and unveils the lack of such a feature in D. caespitosa.

  6. Tufted Hairgrass (Deschampsia caespitosa) Exhibits a Lower Photosynthetic Plasticity than Antarctic Hairgrass (D. Antarctica)

    Gra(z)yna Bystrzejewska-Piotrowska; Pawel L. Urban


    The aim of our work was to assess photosynthetic plasticity of two hairgrass species with different ecological origins (a temperate zone species, Deschampsia caespitosa (L.) Beauv. and an Antarctic species, D. antarctica) and to consider how the anticipated climate change may affect vitality of these plants. Measurements of chlorophyll fluorescence showed that the photosystem Ⅱ (PSII) quantum efficiency of D. caespitosa decreased during 4 d of incubation at 4℃ but it remained stable in D. antarctica. The fluorescence half-rise times were almost always lower in D. caespitosa than in D. antarctica,irrespective of the incubation temperature. These results indicate that the photosynthetic apparatus of D. caespitosa has poorer performance in these conditions. D. caespitosa reached the maximum photosynthesis rate at a higher temperature than D. antarctica although the values obtained at 8℃ were similar in both species. The photosynthetic water-use efficiency (photosynthesis-to-transpiration ratio, P/E) emerges as an important factor demonstrating presence of mechanisms which facilitate functioning of a plant in non-optimal conditions. Comparison of the P/E values, which were higher in D. antarctica than in D. caespitosa at low and medium temperatures, confirms a high degree of adjustability of the photosynthetic apparatus in D. antarctica and unveils the lack of such a feature in D. caespitosa.


    Londoño B. John Makario


    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.

  8. Time dependent deformation of Kilauea Volcano, Hawaii

    Montgomery-Brown, Emily Kvietka Desmarais

    In 1997 the continuous Global Positioning System (GPS) network was completed on Kilauea, providing the first network of daily position measurements during eruptions and earthquakes on Kilauea. Kilauea has been studied for many decades with continuous seismic and tilt instruments. Other geodetic data (e.g., campaign GPS, leveling, electronic distance measurements) are also available although they contain only sparse data. Data analysis methods used here include inverting multiple data sets for optimal source parameters and the spatio-temporal distribution of magma volume and fault slip, and combining GPS and seismic observations to understand flank tectonics. The field area for this study, Kilauea Volcano, was chosen because of its frequent activity and potential hazards. The 1997 East Rift Zone eruption (Episode 54) was the first major event to occur after the completion of the continuous GPS network. The event lasted 2 days, but transient deformation continued for six months. This long-duration transient allowed the first spatio-temporal study of transient dike deformation on Kilauea from daily GPS positions. Slow-slip events were discovered on Kilauea during which the southern flank of the volcano would accelerate seaward for approximately 2 days. The discovery was made possible because of the continuously operating GPS network. These slip events were also observed to correlate with small swarms of microearthquakes found to follow temporal pattern consistent with them being co- and aftershocks of the slow-slip event (Segall, 2006). Half-space models of geodetic data favor a shallow fault plane (˜ 5 km), which is much too shallow to have increased the Coulomb stress at the depths of the co- and aftershocks. However, optimizations for the slow-slip source parameters including a layered elastic structure and a topographic correction favor deeper models within the range of the co- and aftershocks. Additionally, the spatial distribution of seaward fault slip, fixed

  9. Decreasing Magmatic Footprints of Individual Volcanos in a Waning Basaltic Field

    G.A> Valentine; F.V. Perry


    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.

  10. Deformation Study of Papandayan Volcano using GPS Survey Method and Its Correlation with Seismic Data Observation

    Dina A. Sarsito


    Full Text Available Papandayan volcano located in the southern part of Garut regency, around 70 km away from Bandung city, West Java. Many methods carried out to monitoring the activities of volcano, both continuously or periodically, one of the monitoring method is periodically GPS survey. Basically those surveys are carried out to understand the pattern and velocity of displacement which occurred in the volcano body, both horizontally and vertically, and also others deformation elements such as; translation, rotation and dilatation. The Mogi modeling was also used to determine the location and volume of the pressure source which caused deformation of volcano body. By comparing seismic activity and the deformation reveal from GPS measurement, before, during and after eruption, it could be understood there is a correlation between the seismicity and its deformation. These studies is hoping that GPS measurement in Papandayan volcano could be one of supported method to determine the volcano activities, at least in Papandayan volcano.

  11. Observation of Eyjafjallajökull volcano ash over Poland

    Zielinski, T.; Petelski, T.; Makuch, P.; Kowalczyk, J.; Rozwadowska, A.; Drozdowska, V.; Markowicz, K.; Malinowski, S.; Kardas, A.; Posyniak, M.; Jagodnicka, A. K.; Stacewicz, T.; Piskozub, J.


    The plume of Eyjafjallajökull volcano ash has been identified over Poland using three instruments (two lidars and a ceilometer) stationed in two locations: Sopot in northern Poland and Warsaw in central-eastern Poland. The observations made it possible to establish the base of the ash layer. However ash concentration could not be determined.

  12. Volcanic Environments Monitoring by Drones Mud Volcano Case Study

    Amici, S.; Turci, M.; Giulietti, F.; Giammanco, S.; Buongiorno, M. F.; La Spina, A.; Spampinato, L.


    Volcanic activity has often affected human life both at large and at small scale. For example, the 2010 Eyjafjallajokull eruption caused severe economic damage at continental scale due to its strong effect on air traffic. At a local scale, ash fall and lava flow emission can cause harm and disruption. Understanding precursory signals to volcanic eruptions is still an open and tricky challenge: seismic tremor and gas emissions, for example, are related to upcoming eruptive activity but the mechanisms are not yet completely understood. Furthermore, information related to gases emission mostly comes from the summit crater area of a volcano, which is usually hard to investigate with required accuracy. Although many regulation problems are still on the discussion table, an increasing interest in the application of cutting-edge technology like unmanned flying systems is growing up. In this sense, INGV (Istituto Nazionale di Geofisica e Vulcanologia) started to investigate the possibility to use unmanned air vehicles for volcanic environment application already in 2004. A flight both in visual- and radio-controlled mode was carried out on Stromboli volcano as feasibility test. In this work we present the preliminary results of a test performed by INGV in collaboration with the University of Bologna (aerospace division) by using a multi-rotor aircraft in a hexacopter configuration. Thermal camera observations and flying tests have been realised over a mud volcano located on its SW flank of Mt. Etna and whose activity proved to be related to early stages of magma accumulation within the volcano.

  13. Search for shallow magma accumulations at Augustine Volcano

    Kienle, J.; Lalla, D.J.; Pearson, C.F.; Barrett, S.A.


    A search was made for shallow magma accumulations beneath Augustine Volcano using primarily three geophysical techniques: (1) temperature and heat flow measurements, (2) active and passive seismic refraction, and (3) three-dimensional modeling of aeromagnetic data. With these studies it was hoped to gain insight into the interval structure of Augustine Volcano, to delineate, if possible, the size and shape of near surface magma bodies and to assess the potential of the volcano as a natural laboratory for hot rock and magma geothermal energy research. Augustine was chosen because it is a very young and very active volcano with several historic eruptions in 1812, 1883, 1935, 1964/64. One of the main targets for the geophysical studies was a summit lava dome of about 0.05 km/sup 3/ volume, extruded in 1963/64 and suspected to still contain considerable residual heat, perhaps be still partially molten years after its intrusion. Five months after the field work in 1975 this dome was exploded in January 1976. One month later, a hot (about 650 to 800/sup 0/C) viscous dome was intruded into the January summit crater.

  14. The first days of the new submarine volcano near Krakatoa

    Umbgrove, J.H.F.


    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 ens

  15. Topography and Volcanology of the Huangtsuishan Volcano Subgroup, Northern Taiwan

    Yu-Ming Lai


    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.

  16. Deep structure and origin of active volcanoes in China

    Dapeng Zhao; Lucy Liu


    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.

  17. Twilight Phenomena Caused by the Eruption of Agung Volcano.

    Volz, F E


    Increase in twilight glow and in the dust stripes in the twilight arch have been observed from several places in the northern hemisphere from the fall of 1963 until now. Measurements of the twilight brightness indicate a considerable increase of dustiness in the stratosphere; this turbidity may be due to drifting ashes from the eruption of Agung volcano on Bali.

  18. Seismic instrumentation plan for the Hawaiian Volcano Observatory

    Thelen, Weston A.


    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.

  19. Interferometric SAR Persistent Scatterer Analysis of Mayon volcano, Albay, Philippines

    Bato, M. P.; Lagmay, A. A.; Paguican, E. R.


    Persistent Scatterer Interferometry (PSInSAR) is a new method of interferometric processing that overcomes the limitations of conventional Synthetic Aperture Radar differential interferometry (DInSAR) and is capable of detecting millimeter scale ground displacements. PSInSAR eliminate anomalies due to atmospheric delays and temporal and geometric decorrelation eminent in tropical regions by exploiting the temporal and spatial characteristics of radar interferometric signatures derived from time-coherent point-wise targets. In this study, PSInSAR conducted in Mayon Volcano, Albay Province, Bicol, Philippines, reveal tectonic deformation passing underneath the volcano. Using 47 combined ERS and ENVISAT ascending and descending imageries, differential movement between the northern horst and graben on which Mayon volcano lies, is as much as 2.5 cm/year in terms of the line-of-sight (LOS) change in the radar signal. The northern horst moves in the northwest direction whereas the graben moves mostly downward. PSInSAR results when coupled with morphological interpretation suggest left-lateral oblique-slip movement of the northern bounding fault of the Oas graben. The PSInSAR results are validated with dGPS measurements. This work presents the functionality of PSInSAR in a humid tropical environment and highlights the probable landslide hazards associated with an oversteepened volcano that may have been further deformed by tectonic activity.

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


    Key word: Mud volcano, clay mineralogy, geochemistry, mud breccias, North Moroccan Atlantic margin. INTRODUCTION .... The geochemical analysis of the metals shows a high Ti ..... smectite evolved into an illite, or because the initial source is not .... Pinheiro LM, Kopf A, Boetius A (2006): Microbial methane turnover at.

  1. Long-term eruptive activity at a submarine arc volcano.

    Embley, Robert W; Chadwick, William W; Baker, Edward T; Butterfield, David A; Resing, Joseph A; de Ronde, Cornel E J; Tunnicliffe, Verena; Lupton, John E; Juniper, S Kim; Rubin, Kenneth H; Stern, Robert J; Lebon, Geoffrey T; Nakamura, Ko-ichi; Merle, Susan G; Hein, James R; Wiens, Douglas A; Tamura, Yoshihiko


    Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes.

  2. Understanding the Potential for Volcanoes at Yucca Mountain



    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.

  3. Eruptions of Eyjafjallajökull Volcano, Iceland

    Gudmundsson, Magnús T.; Pedersen, Rikke; Vogfjörd, Kristín; Thorbjarnardóttir, Bergthóra; Jakobsdóttir, Steinunn; Roberts, Matthew J.


    The April 2010 eruption of Eyjafjallajökull volcano (Figure 1), located on Iceland's southern coast, created unprecedented disruptions to European air traffic during 15-20 April, costing the aviation industry an estimated $250 million per day (see the related news item in this issue). This cost brings into focus how volcanoes can affect communities thousands of miles away. Eyjafjallajökull rises to 1666 meters above sea level and hosts agricultural land on its southern slopes, with farms located as close as 7 kilometers from the summit caldera. In the past 1500 years, Eyjafjallajökull has produced four comparatively small eruptions. The eruption previous to 2010 began in December 1821 and lasted for over a year, with intermittent explosive activity spreading a thin layer of tephra (ash and larger ejected clasts) over the surrounding region. In contrast, the explosive 2010 eruption, sourced within the ice-capped summit of the volcano, so far is larger and characterized by magma of a slightly different composition. This may suggest that deep within the volcano, the 1821 magma source is mixing with new melt, or that residual melt from past intrusive events is being pushed out by new magma.

  4. Deep structure and origin of active volcanoes in China

    Dapeng Zhao


    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.

  5. Collaborative Monitoring and Hazard Mitigation at Fuego Volcano, Guatemala

    Lyons, J. J.; Bluth, G. J.; Rose, W. I.; Patrick, M.; Johnson, J. B.; Stix, J.


    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. An Overview of Geodetic Volcano Research in the Canary Islands

    Fernández, José; González, Pablo J.; Camacho, Antonio G.; Prieto, Juan F.; Brú, Guadalupe


    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.

  7. Tsunami wave generation by the eruption of underwater volcano

    Y. Egorov


    Full Text Available Eruption of volcanoes represents one of important origins of tsunami waves and is responsible for most catastrophic tsunami (Krakatau, 1883; Thira, BC. The products of volcano eruption include solids, liquids (lava and gases. The present article presents hydrodynamic model of relatively slow process of eruption, with domination of liquids. The process of underwater eruption of lava causes the disturbance of ocean free surface. The standard formulation of hydrodynamic problem for incompressible fluid in cylindrically symmetric layer of with rigid bottom and free surface with local hydrodynamic source (volcano is used. This problem is solved by constructing Green function using methodology of Sretenskij. The solution is obtained in the form of an integral and depends on the dynamics of eruption. Real data show that some volcanoes can erupt several millions of tons of lava during several dozens of seconds (Bezimjannij, Kamchatka. The long waves are more efficiently generated by larger T: these tsunamis can have smaller initial perturbations of free surface, but the waves are long and can transmit their energy over longer distances.

  8. Ice and water on Newberry Volcano, central Oregon

    Donnelly-Nolan, Julie M.; Jensen, Robert A.; O'Connor, Jim; Madin, Ian P.; Dorsey, Rebecca


    Newberry Volcano in central Oregon is dry over much of its vast area, except for the lakes in the caldera and the single creek that drains them. Despite the lack of obvious glacial striations and well-formed glacial moraines, evidence indicates that Newberry was glaciated. Meter-sized foreign blocks, commonly with smoothed shapes, are found on cinder cones as far as 7 km from the caldera rim. These cones also show evidence of shaping by flowing ice. In addition, multiple dry channels likely cut by glacial meltwater are common features of the eastern and western flanks of the volcano. On the older eastern flank of the volcano, a complex depositional and erosional history is recorded by lava flows, some of which flowed down channels, and interbedded sediments of probable glacial origin. Postglacial lava flows have subsequently filled some of the channels cut into the sediments. The evidence suggests that Newberry Volcano has been subjected to multiple glaciations.

  9. Dense Local Seismic Network at Villarrica Volcano (Southern Chile)

    Mora-Stock, C.; Thorwart, M.; Dzieran, L.; Rabbel, W.


    Villarrica volcano is one of the most active volcanoes in the Southern Andes. It has been presenting constant fumarole activity and seismicity since its last eruption in 1984-85. A local network was installed at Villarrica volcano (Southern Chile) during the first two weeks of March, 2012. In total, 75 DSS-Cube short-period stations (30 3-Component, 45 1-Component) were deployed at and around the volcano area, covering approx. 63 km x 55 km. The average station spacing is 1.5 km for stations inside the perimeter of the volcanic edifice, and 5km outside this perimeter. The network recorded ca. 94 volcano tectonic (VT) events located SSW, SSE and North of the crater, with clear P- and S-wave arrivals. Many others, ca.73 events, could be classified as 'hybrid' events (HB), which present high frequencies at the beginning of the signal, and a sharp and notorious S-wave at the crater stations, but a strong scattering, lower frequency content, and elongated coda on the stations along the volcanic edifice. This strong scattering effect is probably caused by the heterogeneous ash layers on the edifice structure. Few long period events (LP), with main frequencies between 2-4 Hz, were observed. From the tectonic regional events, three sets of events can be distinguished. One coming from the southern end of the focal plane of the Maule earthquake (2010), with S-P wave travel time difference of ca. 30 s or more. Another closer group with S-P wave travel time difference between 10 s and 20 s, and the last group with S-P wave travel time difference of 10 s or less. A cross-correlation analysis to the travel times of the regional events and a teleseismic event from Argentina was applied in order to determine the average velocity structure of the volcano, and obtained an average P-wave velocity of 3.6 km/s for the volcanic edifice inside a radius of 6.5 km, and 4.1 km/s for the surrounding area outside this radius. This model serves as a starting point for local earthquake

  10. Evaluation of volcanic risk management in Merapi and Bromo Volcanoes

    Bachri, S.; Stöetter, J.; Sartohadi, J.; Setiawan, M. A.


    Merapi (Central Java Province) and Bromo (East Java Province) volcanoes have human-environmental systems with unique characteristics, thus causing specific consequences on their risk management. Various efforts have been carried out by many parties (institutional government, scientists, and non-governmental organizations) to reduce the risk in these areas. However, it is likely that most of the actions have been done for temporary and partial purposes, leading to overlapping work and finally to a non-integrated scheme of volcanic risk management. This study, therefore, aims to identify and evaluate actions of risk and disaster reduction in Merapi and Bromo Volcanoes. To achieve this aims, a thorough literature review was carried out to identify earlier studies in both areas. Afterward, the basic concept of risk management cycle, consisting of risk assessment, risk reduction, event management and regeneration, is used to map those earlier studies and already implemented risk management actions in Merapi and Bromo. The results show that risk studies in Merapi have been developed predominantly on physical aspects of volcanic eruptions, i.e. models of lahar flows, hazard maps as well as other geophysical modeling. Furthermore, after the 2006 eruption of Merapi, research such on risk communication, social vulnerability, cultural vulnerability have appeared on the social side of risk management research. Apart from that, disaster risk management activities in the Bromo area were emphasizing on physical process and historical religious aspects. This overview of both study areas provides information on how risk studies have been used for managing the volcano disaster. This result confirms that most of earlier studies emphasize on the risk assessment and only few of them consider the risk reduction phase. Further investigation in this field work in the near future will accomplish the findings and contribute to formulate integrated volcanic risk management cycles for both

  11. WOVOdat Progress 2012: Installable DB template for Volcano Monitoring Database

    Ratdomopurbo, A.; Widiwijayanti, C.; Win, N.-T.-Z.; Chen, L.-D.; Newhall, C.


    WOVOdat is the World Organization of Volcano Observatories' (WOVO) Database of Volcanic Unrest. Volcanoes are frequently restless but only a fraction of unrest leads to eruptions. We aim to compile and make the data of historical volcanic unrest available as a reference tool during volcanic crises, for observatory or other user to compare or look for systematic in many unrest episodes, and also provide educational tools for teachers and students on understanding volcanic processes. Furthermore, we promote the use of relational databases for countries that are still planning to develop their own monitoring database. We are now in the process of populating WOVOdat in collaboration with volcano observatories worldwide. Proprietary data remains at the observatories where the data originally from. Therefore, users who wish to use the data for publication or to obtain detail information about the data should directly contact the observatories. To encourage the use of relational database system in volcano observatories with no monitoring database, WOVOdat project is preparing an installable standalone package. This package is freely downloadable through our website (, ready to install and serve as database system in the local domain to host various types of volcano monitoring data. The WOVOdat project is now hosted at Earth Observatory of Singapore (Nanyang Technological University). In the current stage of data population, our website supports interaction between WOVOdat developers, observatories, and other partners in building the database, e.g. accessing schematic design, information and documentation, and also data submission. As anticipation of various data formats coming from different observatories, we provide an interactive tools for user to convert their data into standard WOVOdat format file before then able to upload and store in the database system. We are also developing various visualization tools that will be integrated in the system to ease

  12. A Preliminary Study of Seismicity at Ceboruco, Volcano, Nayarit, Mexico

    Sanchez, J. J.; Nunez-Cornu, F. J.; Suarez-Plascencia, C.; Trejo-Gomez, E.


    Ceboruco Volcano is located northwestern of Tepic-Zacoalco graben (Jalisco, Mexico). Its volcanic activity can be divided in four eruptive cycles differentiated by their volcano explosivity index (VEI) and chemical variations as well. As a result of andesitic effusive activity, during the first cycle the "paleo-Ceboruco" edifice was constructed. The end of this cycle is defined by a plinian eruption (VEI is estimated between 3 and 4) which occurred some 1020 years ago and formed the external caldera. During the second cycle an andesitic dome extruded in the interior of the caldera. The dome, called Dos Equis, collapsed and formed the internal caldera. The third cycle is represented by andesitic lava flows which partially cover the northern and south-southwestern part of the edifice. The last cycle is represented by historic andesitic lava flows located in the southwestern flank of the volcano. In February 2003 as part of an agreement with Nayarit Civil Defense a seismic station was installed in the SW flank of the volcano. The station is equipped with a Marslite (lennartz) digitizer with a 3DLe 1Hz. seismic sensor. Detection system is based on a STA/LTA recording algorithm. More than 2000 small earthquakes have been attributed to various local sources, and some of this earthquakes are possibly located beneath Ceboruco volcano. A preliminary classification separates high frequency and low frequency seismic events. The sources of high frequency earthquakes appear to be distributed as evidenced from waveforms variety and changing S-P arrivals separations. The low frequency seismic events also show varying signatures and some of them exhibit extended coda, including some monochromatic character.

  13. Geologic Mapping of the Olympus Mons Volcano, Mars

    Bleacher, J. E.; Williams, D. A.; Shean, D.; Greeley, R.


    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).

  14. Monitoring geodynamic activity in the Victoria Land, East Antarctica: Evidence from GNSS measurements

    Zanutta, A.; Negusini, M.; Vittuari, L.; Cianfarra, P.; Salvini, F.; Mancini, F.; Sterzai, P.; Dubbini, M.; Galeandro, A.; Capra, A.


    GNSS networks in Antarctica are a fundamental tool to define actual crustal displacements due to geological and geophysical processes and to constrain the glacial isostatic models (GIA). A large network devoted to the detection and monitoring of crustal deformations in the Northern Victoria Land (Victoria Land Network for DEFormation control - VLNDEF), was monumented during the 1999-2000 and 2000-2001 field campaigns, as part of Italian National Program for Antarctic Research and surveyed periodically during the Southern summer seasons. In this paper, GPS observations of VLNDEF collected over a more than 15-year span, together with various selected POLENET sites and more than 70 IGS stations, were processed with Bernese Software, using a classical double difference approach. A solution was obtained combining NEQs by means of ADDNEQ2/FODITS tools embedded in Bernese Software. All the Antarctic sites were kept free and a subset of 50 IGS stations were used to frame VLNDEF into ITRF2008. New evidence provided by analysis of GPS time series for the VLNDEF network is presented; also displacements along the vertical component are compared with the recently published GIA models. The absolute velocities indicate an overall displacement of the northern Victoria Land region along the south-east direction (Ve = 10.6 mm/yr, Vn = -11.5 mm/yr) and an average uplift rate of Vu = 0.5 mm/yr. Two GIA models have been analyzed: ICE-6G_C-VM5a proposed by Argus et al. (2014), Peltier et al. (2015) and W12A_v1 by Whitehouse et al. (2012a,b). Up rates, predicted over the VLNDEF sites by the mentioned GIA models, have been extracted and compared with those observed. A preliminary comparison with GPS-derived vertical rates shows that the Victoria Land ICE-6G_C-VM5 and W12A_v1 GIA models predict overestimated uplift rates of 0.7 and 0.9 mm/yr weighted mean residuals respectively. The mean horizontal relative motions within the Victoria Land (VL) area are in most cases negligible, while only

  15. Volcanic Stratigraphy and Potential Hazards of the Chihsingshan Volcano Subgroup in the Tatun Volcano Group, Northern Taiwan

    Yu-Wei Tsai


    Full Text Available The Chihsingshan Volcano Subgroup (CVSG is one of the most important landforms located within the Tatun Volcano Group in northern Taiwan. Based on a Digital Terrain Model, contour maps and field investigations, the CVSG can be divided into four types of volcanic landforms: (1 a strato- or composite volcano, Chihsingshan; (2 domes, the Shamaoshan and a hidden unit; (3 lava cones, the Baiyunshan and the Hsiaotsaoshan; and (4 a scoria cone, the Chikushan. Meanwhile, many small craters are distributed linearly along two northeast trending normal-fault systems. The occurrences are predominantly lava flows with subsidiary fall deposits, pyroclastic flows, and lahars in which at least twenty layers of lava flow in the CVSG can be recognized. Among them, 16 layers in the Chihsingshan volcano, named as C1 - C16, two in the Baiyunshan, B1 - B2, and two in the Hsiaotsaoshan, H1 - H2. Our study suggests that the potential volcanic hazards include lava and pyroclastic flows and simultaneous or subsequent lahars, if the Chihsingshan erupts in a similar manner as in the past. A volcanic hazard zonation map can be constructed for the purpose of mitigation assuming the future eruptive center and eruptive volume.

  16. Using the Landsat Thematic Mapper to detect and monitor active volcanoes - An example from Lascar volcano, northern Chile

    Francis, P. W.; Rothery, D. A.


    The Landsat Thematic Mapper (TM) offers a means of detecting and monitoring thermal features of active volcanoes. Using the TM, a prominent thermal anomaly has been discovered on Lascar volcano, northern Chile. Data from two short-wavelength infrared channels of the TM show that material within a 300-m-diameter pit crater was at a temperature of at least 380 C on two dates in 1985. The thermal anomaly closely resembles in size and radiant temperature the anomaly over the active lava lake at Erta'ale in Ethiopia. An eruption took place at Lascar on Sept. 16, 1986. TM data acquired on Oct. 27, 1986, revealed significant changes within the crater area. Lascar is in a much more active state than any other volcano in the central Andes, and for this reason it merits further careful monitoring. Studies show that the TM is capable of confidently identifying thermal anomalies less than 100 m in size, at temperatures of above 150 C, and thus it offers a valuable means of monitoring the conditions of active or potentially active volcanoes, particularly those in remote regions.

  17. Colonization and demographic structure of Deschampsia antarctica and Colobanthus quitensis along an altitudinal gradient on Livingston Island, South Shetland Islands, Antarctica

    María Luisa Vera


    Full Text Available The colonization capacity and demographic structure of populations of Deschampsia antarctica and Colobanthus quitensis were studied in different microhabitats between 10 and 147 m a.s.l. on Livingston Island, South Shetland Islands, near the Spanish Antarctic base Juan Carlos I, in February 2002. At the highest site (147 m a.s.l., mean temperatures were about 1°C lower than at sea level. Both species are less common in inland areas and at the highest altitudes only occur at restricted sites that are frequently snow-free in the early austral summer. The diameters of the largest plants (C. quitensis cushions 7–8 cm; D. antarctica tufts 10–11 cm in the populations growing at the highest altitudes (110 and 147 m a.s.l. suggest that these populations were established about 24–28 years ago. The largest diameter plants (Deschampsia 20 cm; Colobanthus 18 cm were found at the lowest altitudes on deep soil. The presence of numerous seedlings and young individuals on the periphery of populations established several years ago or at recently colonized sites suggests an active process of expansion. There were more emerged seedlings of C. quitensis than of D. antarctica, but the density of established individuals was higher for D. antarctica, suggesting these species have different demographic strategies.

  18. A New Statistical Model for Eruption Forecasting at Open Conduit Volcanoes: an Application to Mt Etna and Kilauea Volcanoes

    Passarelli, Luigi; Sanso, Bruno; Laura, Sandri; Marzocchi, Warner


    One of the main goals in volcanology is to forecast volcanic eruptions. A trenchant forecast should be made before the onset of a volcanic eruption, using the data available at that time, with the aim of mitigating the volcanic risk associated to the volcanic event. In other words, models implemented with forecast purposes have to take into account the possibility to provide "forward" forecasts and should avoid the idea of a merely "retrospective" fitting of the data available. In this perspective, the main idea of the present model is to forecast the next volcanic eruption after the end of the last one, using only the data available at that time. We focus our attention on volcanoes with open conduit regime and high eruption frequency. We assume a generalization of the classical time predictable model to describe the eruptive behavior of open conduit volcanoes and we use a Bayesian hierarchical model to make probabilistic forecast. We apply the model to Kilauea volcano eruptive data and Mt. Etna volcano flank eruption data. The aims of this model are: 1) to test whether or not the Kilauea and Mt Etna volcanoes follow a time predictable behavior; 2) to discuss the volcanological implications of the time predictable model parameters inferred; 3) to compare the forecast capabilities of this model with other models present in literature. The results obtained using the MCMC sampling algorithm show that both volcanoes follow a time predictable behavior. The numerical values of the time predictable model parameters inferred suggest that the amount of the erupted volume could change the dynamics of the magma chamber refilling process during the repose period. The probability gain of this model compared with other models already present in literature is appreciably greater than zero. This means that our model performs better forecast than previous models and it could be used in a probabilistic volcanic hazard assessment scheme. In this perspective, the probability of

  19. Preliminary hyperspectral volcano observations using Airborne Radiative Spectral Scanner (ARTS)

    Jitsufuchi, T.


    Airborne-imaging spectral systems can often efficiently identify volcanic phenomena that are difficult to detect by satellite imagery. Since 1990, the National Research Institute for Earth Science and Disaster Prevention (NIED) has been developing our original airborne-imaging spectral systems for volcano observations. In 2006, we developed a new airborne hyperspectral sensor, the Airborne Radiative Transfer Spectral Scanner (ARTS), for hyperspectral volcano observations. ARTS is a push-broom imaging spectrometer covering wavelengths from 380 to 1100nm (VNIR; 288 bands), 950 to 2450nm (SWIR; 101 bands), and 8000 to 11500nm (LWIR; 32 bands) and has precise position and attitude measurement systems (GPS/IMU) to achieve direct geo-correction of the acquired image. The ARTS specifications were planned to provide hyperspectral images to support developing algorithms for remotely sensing the geothermal distribution, ash- fall areas, and content of volcanic gas columns. ARTS will also be useful for operational volcanic observations to assess volcanic activity and to mitigate volcanic disasters.Before beginning the operational use of ARTS, it is important to validate its in-flight performance. Therefore, we have been conducting validation on the B200 platform. In this study, we present the results of two experiment observations, the overflight of ARTS instrument at the NIED building site on April 5, 2007, and the volcano observations flight over active volcano (Sakurajima volcano) just after its eruption on April 8, 2008. At the NIED building site, we validated the radiometric fidelity of all bands and the accuracy of geo-corrections. At the Sakurajima volcano, we tried to demonstrate the functions of ARTS, especially those for volcano observation. At the NIED building site, the validation results indicate that the geo-correction accuracy is typically less than a two-pixel difference (RMS), and that there was good agreement between the predicted radiance at the sensor and

  20. Hydrochemical fluxes from Baransky volcano, Iturup, Kuril Islands

    Chelnokov, George; Zharkov, Rafael; Bragin, Ivan; Kharitonova, Natalia


    The Sernaya River and its tributary the Kipyashaya River are the only rivers that drain all thermal waters coming down the Baransky volcano (Iturup, the Kuril Islands). Hydrological parameters and a chemical composition relating to these rivers and all inflow streams coming from the volcano were measured from August to October 2013. The main aims of this investigation were to develop a data baseline for the catchment of the Sernaya River in order to monitor the Baransky volcano, to estimate total discharge of solute elements and finally to identify thermal groundwater inflow. Since the Kipyashaya River and the Sernaya River receive all water streams coming along the south-west and south flanks of the Baransky volcano within approximately 10 kilometers we can suggest that the whole thermal discharge runs into the Kipyashaya River. Thus a frequent sampling of the rivers presents the best way to monitor the volcano as they comprise a mix of all thermal waters from the Baransky volcano. The Sernaia River, at the end of its course along the flanks of the Baransky volcano, has a total flux of 12 m³/s ± 1%. Multiplication of the discharge by the concentration in main ions of the river at this point yields an aggregate flux of ~130 tons/day ± 10%. This flux performs the dissolution flux as a result of rocks dissolution beneath the active crater and in the aquifer of the Kipyashaya River. Cl total discharge was estimated at ~33 tons/day ± 10%, SO4 ~67 tons/day ± 10%, and total cation discharge ~28 tons/day ± 10%. The Kipyashaya River brings in to the Sernaya River 15 tons/day ± 10% of Cl, ~30 tons/day ± 10% of SO4, and ~3,5 tons/day ± 10% cations average. Several thermal springs with low water discharge are located on the right waterside of the Sernaya River 100 m up and down from the Kipyashaya River influx. These thermal springs with Cl discharge ~ 5g/s have significant concentrations of Ca due to water-rock interaction with basement rocks. The way of sampling

  1. Thermal surveillance of active volcanoes. [infrared scanner recordings of thermal anomalies of Mt. Baker volcano

    Friedman, J. D. (Principal Investigator)


    The author has identified the following significant results. By the end of 1973, aerial infrared scanner traverses for thermal anomaly recordings of all Cascade Range volcanoes were essentially completed. Amplitude level slices of the Mount Baker anomalies were completed and compiled at a scale of 1:24,000, thus producing, for the first time, an accurate map of the distribution and intensity of thermal activity on Mount Baker. The major thermal activity is concentrated within the crater south of the main summit and although it is characterized by intensive solfataric activity and warm ground, it is largely subglacial, causing the development of sizable glacier perforation features. The outgoing radiative flux from the east breach anomalies is sufficient to account for the volume of ice melted to form the glacier perforations. DCP station 6251 has been monitoring a thermally anomalous area on the north slope of Mount Baker. The present thermal activity of Mount Baker accounts for continuing hydrothermal alteration in the crater south of the main summit and recurrent debris avalanches from Sherman Peak on its south rim. The infrared anomalies mapped as part of the experiment SR 251 are considered the basic evidence of the subglacial heating which was the probable triggering mechanism of an avalanche down Boulder Glacier on August 20-21, 1973.

  2. Surface ozone characterization at Larsemann Hills and Maitri, Antarctica.

    Ali, Kaushar; Trivedi, D K; Sahu, S K


    Data are analyzed in terms of daily average ozone, its diurnal variation and its relation with meteorological parameters like dry bulb temperature (T), wet bulb temperature (Tw), atmospheric pressure and wind speed based on measurement of these parameters at two Indian Antarctic stations (Larsemann Hills, and Maitri) during 28th Indian Scientific Expedition of Antarctica (ISEA) organized during Antarctic summer of the year 2008-09. The work has been carried out to investigate summer time ozone level and its day-to-day and diurnal variability at these coastal locations and to highlight possible mechanism of ozone production and destruction. The result of the analysis indicates that daily average ozone concentration at Larsemann Hills varied from ~13 and ~20ppb with overall average value of ~16ppb and at Maitri, it varied from ~16 and ~21ppb with overall average value of ~18ppb. Photochemistry is found to partially contribute occasionally to the surface layer ozone at both the stations. Lower concentration of ozone at Maitri during beginning of the observational days may be due to destruction of ozone through activated halogens, whereas higher ozone on latter days may be due to photochemistry and advective transport from east to south-east areas. Ozone concentration during blizzard episodes at both the stations is reduced due to slow photochemical production of ozone, its photochemical removal and removal through deposition of ozone molecules on precipitation particles. Diurnal variation of ozone at Larsemann Hills and Maitri has been found to be absent.

  3. GIS representation of coal-bearing areas in Antarctica

    Merrill, Matthew D.


    Understanding the distribution of coal-bearing geologic units in Antarctica provides information that can be used in sedimentary, geomorphological, paleontological, and climatological studies. This report is a digital compilation of information on Antarctica’s coal-bearing geologic units found in the literature. It is intended to be used in small-scale spatial geographic information system (GIS) investigations and as a visual aid in the discussion of Antarctica’s coal resources or in other coal-based geologic investigations. Instead of using spatially insignificant point markers to represent large coal-bearing areas, this dataset uses polygons to represent actual coal-bearing lithologic units. Specific locations of coal deposits confirmed from the literature are provided in the attribution for the coal-bearing unit polygons. Coal-sample-location data were used to confirm some reported coal-bearing geology. The age and extent of the coal deposits indicated in the literature were checked against geologic maps ranging from local scale at 1:50,000 to Antarctic continental scale at 1:5,000,000; if satisfactory, the map boundaries were used to generate the polygons for the coal-bearing localities.

  4. Eocene paleosols of King George Island, Maritime Antarctica

    Spinola, Diogo; Portes, Raquel; Schaefer, Carlos; Kühn, Peter


    Red layers between lava flows on King George Island, Maritime Antarctica, were formed during the Eocene, which was one of the warmest periods on Earth in the Cenozoic. Our hypothesis is that these red layers are paleosols formed in periods of little or no volcanic activity. Therefore, our main objective was to identify the main pedogenic properties and features to distinguish these from diagenetic features formed after the lava emplacement. Additionally, we compared our results with volcanic soils formed under different climates to find the best present analogue. The macromorphological features indicate a pedogenic origin, because of the occurrence of well-defined horizons based on colour and structure. Micromorphological analyses showed that most important pedogenic features are the presence of biological channels, plant residues, anisotropic b-fabric, neoformed and illuvial clay and distinct soil microstructure. Although the paleosols are not strongly weathered, the geochemical data also support the pedogenic origin despite of diagenetic features as the partial induration of the profiles and zeolites filling nearly all voids in the horizons in contact with the overlying lava flow, indicating circulation of hydrothermal fluids. The macromorphological and micromorphological features of these paleosols are similar to the soils formed under seasonal climates. Thus, these paleosol features do not correspond to the other proxies (e.g. sediment, plant fossils), which indicate a wet, non-seasonal climate, as in Valdivian Forest, Chile, during the Eocene in King George Island

  5. Observations of OH and HO2 radicals in coastal Antarctica

    S. J.-B. Bauguitte


    Full Text Available OH and HO2 radical concentrations have been measured in the boundary layer of coastal Antarctica for a six-week period during the austral summer of 2005. The measurements were performed at the British Antarctic Survey's Halley Research Station (75° 35' S, 26° 19' W, using the technique of on-resonance laser-induced fluorescence to detect OH, with HO2 measured following chemical conversion through addition of NO. The mean radical levels were 3.9×105 molecule cm−3 for OH, and 0.76 ppt for HO2 (ppt denotes parts per trillion, by volume. Typical maximum (local noontime levels were 7.9×105 molecule cm−3 and 1.50 ppt for OH and HO2 respectively. The main sources of HOx were photolysis of O3 and HCHO, with potentially important but uncertain contributions from HONO and higher aldehydes. Of the measured OH sinks, reaction with CO and CH4 dominated, however comparison of the observed OH concentrations with those calculated via the steady state approximation indicated that additional co-reactants were likely to have been present. Elevated levels of NOx resulting from snowpack photochemistry contributed to HOx cycling and enhanced levels of OH, however the halogen oxides IO and BrO dominated the CH3O2 – HO2 – OH conversion in this environment, with associated ozone destruction.

  6. Triassic leech cocoon from Antarctica contains fossil bell animal

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.; Moestrup, Øjvind; Taylor, Edith L.


    Our understanding of the evolution of life on Earth is limited by the imperfection of the fossil record. One reason for this imperfect record is that organisms without hard parts, such as bones, shells, and wood, have a very low potential to enter the fossil record. Occasionally, however, exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica. The microfossil consists of a helically contractile stalk that attaches to a main body with a peristomial feeding apparatus and a large C-shaped macronucleus. It agrees in every aspect with the living bell animals, such as Vorticella. Vorticellids and similar peritrichs are vital constituents of aquatic ecosystems worldwide, but so far have lacked any fossil record. This discovery offers a glimpse of ancient soft-bodied protozoan biotas, and also highlights the potential of clitellate cocoons as microscopic "conservation traps" comparable to amber.

  7. Biomimetic affinity purification of Candida antarctica lipase B.

    Yao, Hongyan; Zhang, Tian; Xue, Hongwei; Tang, Kexuan; Li, Rongxiu


    Candida antarctica lipase B (CalB) is one of the most widely used biocatalysts in organic synthesis. The traditional method for purification of CalB is a multi-step, high cost and low recovery procedure. Biomimetic affinity purification had high efficiency purification. We selected 298 ligand columns from a 700-member library of synthetic ligands to screen Pichia pastoris protein extract. Of the 298, three columns (named as A9-14, A9-10, and A11-33) had one-step purification effect, and A9-14 of these affinity ligands, had both high purification and recovery. The one-step recovery of CalB reached 73% and the purification reached 91% upon purification. The active groups of A9-14 were cyclohexylamine and propenylamine. Furthermore, both A9-14 and A9-10 had the same R1 active group of cyclohexylamine which might act the main binding role for CalB. The synthetic ligand A9-14 had a binding capacity of 0.4 mg/mL and had no negative effects on its hydrolytic activity. Unlike a natural affinity ligand, this synthetic ligand is highly stable to resist 1M NaOH, and thus has great potential for industrial scale production of CalB.

  8. Radiocarbon analyses along the EDML ice core in Antarctica

    Wal, R.S.W. van de; Veen, C. van der [Utrecht Univ. (Netherlands). Inst. for Marine and Atmospheric research; Meijer, H.A.J.; De Rooij, M. [Univ. of Groningen (Netherlands). Center for Isotope Research


    Samples, 17 in total, from the EDML core drilled at Kohnen station Antarctica are analysed for {sup 14}CO and {sup 14}CO{sub 2} with a dry-extraction technique in combination with accelerator mass spectrometry. Results of the in situ produced {sup 14}CO fraction show a very low concentration of in situ produced {sup 14}CO. Despite these low levels in carbon monoxide, a significant in situ production is observed in the carbon dioxide fraction. For the first time we found background values for the ice samples which are equal to line blanks. The data set is used to test a model for the production of {sup 14}C in the ice matrix, in combination with a degassing as {sup 14}CO{sub 2} and possibly as {sup 14}CO into the air bubbles. Application of the model, for which no independent validation is yet possible, offers the opportunity to use radiocarbon analysis as dating technique for the air bubbles in the ice. Assigning an arbitrary error of 25% to the calculation of the in situ production leads to age estimates, after correction for the in situ production, which are in agreement with age estimates based on a volcanic layer match of EDML to the Dome C timescale in combination with a correction for firn diffusion.

  9. Vapor transport and sublimation on Mullins Glacier, Antarctica

    Lamp, J. L.; Marchant, D. R.


    We utilize an environmental chamber capable of recreating the extreme polar conditions of the McMurdo Dry Valleys (MDV) of Antarctica to investigate the sublimation rate of the Mullins Valley debris-covered glacier (hereafter Mullins Glacier), reportedly one of the oldest debris-covered alpine glaciers in the world. We measure ice loss via sublimation beneath sediment thicknesses ranging from 0 to 69 mm; from this, we determine an effective diffusivity for Fickian vapor transport through Mullins till of (5.2 ± 0.3) ×10-6 m2s-1 at -10 °C. We use this value, coupled with micrometeorological data from Mullins Valley (atmospheric temperature, relative humidity, and soil temperature) to model the sublimation rate of buried glacier ice near the terminus of Mullins Glacier, where the overlying till thickness approaches 70 cm. We find that the ice-lowering rate during the modeled year (2011) was 0.066 mm under 70 cm of till, a value which is in line with previous estimates for exceedingly slow rates of ice sublimation. These results provide further evidence supporting the probable antiquity of Mullins Glacier ice and overall landscape stability in upland regions of the MDV.

  10. Mass balance of the Lambert Glacier basin, East Antarctica


    Since it is the largest glacier system in Antarctica, the Lambert Glacier basin plays an important role in the mass balance of the overall Antarctic ice sheet. The observed data and shallow core studies from the inland traverse investigations in recent years show that there are noticeable differences in the distribution and variability of the snow accumulation rate between east and west sides. On the east side, the accumulation is higher on the average and has increased in the past decades, while on the west side it is contrary. The ice movement measurement and the ice flux calculation indicate that the ice velocity and the flux are larger in east than in west, meaning that the major part of mass supply for the glacier is from the east side. The mass budget estimate with the latest data gives that the integrated accumulation over the upstream area of the investigation traverse route is larger than the outflow ice flux by 13%, suggesting that the glacier basin is in a positive mass balance state and the ice thickness will increase if the present climate is keeping.

  11. Detection of integron integrase genes on King George Island, Antarctica

    Vernica Antelo; Hctor Romero; Silvia Batista


    The presence and diversity of class 1 integrase gene (intI) sequences were evaluated by PCR using previously designed primers. Two clone libraries were constructed from DNA in sediment and microbial mat samples collected on Fildes Peninsula, King George Island, Antarctica.The libraries constructed from samples collected at Halfthree Point (HP) and Norma Cove (NC) contained 62 and 36 partial intI sequences, respectively. These sequences clustered into 10 different groups with <95% amino acid identity. Alignment of the deduced amino acid sequences with those from recognized integron-encoded integrases demonstrated the presence of highly conserved motifs characteristic of intI integrases. The HP library contained 42 nucleotide sequences identical to the class 1 intI gene found in a collection of trimethoprim-resistant (Tmpr) Antarctic Enterobacter sp. isolates, previously collected in the same area. These integrons, located on plasmids, had a genetic organization similar to that of pKOX105 from Klebsiella oxytoca. The 20 remaining HP and NC library sequences were similar to integrase sequences previously determined in a metagenomic analysis of environmental samples. We have demonstrated the presence of integron integrase genes in Antarctic sediment samples. About half these genes were very similar to the class 1 integrons found in human-associated microbiota, suggesting that they originated from human-dominated ecosystems. The remaining integrase genes were probably associated with endemic bacteria.

  12. Ambient noise correlation on the Amery Ice Shelf, East Antarctica

    Zhan, Zhongwen; Tsai, Victor C.; Jackson, Jennifer M.; Helmberger, Don


    The structure of ice shelves is important for modelling the dynamics of ice flux from the continents to the oceans. While other, more traditional techniques provide many constraints, passive imaging with seismic noise is a complementary tool for studying and monitoring ice shelves. As a proof of concept, here we study noise cross-correlations and autocorrelations on the Amery Ice Shelf, East Antarctica. We find that the noise field on the ice shelf is dominated by energy trapped in a low-velocity waveguide caused by the water layer below the ice. Within this interpretation, we explain spectral ratios of the noise cross-correlations as P-wave resonances in the water layer, and obtain an independent estimate of the water-column thickness, consistent with other measurements. For stations with noise dominated by elastic waves, noise autocorrelations also provide similar results. High-frequency noise correlations also require a 50-m firn layer near the surface with P-wave velocity as low as 1 km s-1. Our study may also provide insight for future planetary missions that involve seismic exploration of icy satellites such as Titan and Europa.

  13. The New Very Broadband Seismic Station TROLL, Antarctica

    Kvaerna, Tormod; Schweitzer, Johannes; Pirli, Myrto; Roth, Michael


    Troll is the name of the Norwegian permanent research station in Dronning Maud Land, Antarctica. The research base is located inside the continent, at an elevation of about 1300 m and at a distance of about 230 km from the shelf ice border. In the first week of February 2012, a new very broadband seismic station was installed at TROLL. Contrary to many other seismic stations inside the Antarctic continent, the new seismic sensor could be installed on bedrock (migmatite), on a hill at about 300 m distance from the main buildings of the Troll research base. A bedrock installation has the advantage that seismic signals are not disturbed by multiples due to the thick Antarctic ice sheet. The equipment consists of a Streckeisen STS-2.5 broadband sensor and a Quanterra Q330HR 26 bit digitizer. All data are transferred in real time via a satellite link to NORSAR for analysis and further distribution. During the first year, the new seismic station and corresponding data transmission has been running very stably. Initial analysis of the station's event detection capability shows that the performance is comparable to, and sometimes better than, the best performing three-component stations of the International Monitoring System (IMS). We will present examples of diurnal and seasonal variations in the background noise level of the station, the observed global, regional and local seismicity, and the very exciting monitoring capabilities of icebergs drifting along the coast of Dronning Maud Land.

  14. A preliminary study of airborne microbial biodiversity over Peninsular Antarctica.

    Hughes, K A; McCartney, H A; Lachlan-Cope, T A; Pearce, D A


    This study used PCR-based molecular biological identification techniques to examine the biodiversity of air sampled over Rothera Point (Antarctic Peninsula). 16S rDNA fragments of 132 clones were sequenced and identified to reveal a range of microorganisms, including cyanobacteria, actinomycetes, diatom plastids and other uncultivated bacterial groups. Matches for microorganisms that would be considered evidence of human contamination were not found. The closest matches for many of the sequences were from Antarctic clones already in the databases or from other cold environments. Whilst the majority of the sequences are likely to be of local origin, back trajectory calculations showed that the sampled air may have travelled over the Antarctic Peninsula immediately prior to reaching the sample site. As a result, a proportion of the detected biota may be of non-local origin. Conventional identification methods based on propagule morphology or culture are often inadequate due to poor preservation of characteristic features or loss of viability during airbome transfer. The application of molecular biological techniques in describing airbome microbial biodiversity represents a major step forward in the study of airborne biota over Antarctica and in the distribution of microorganisms and propagules in the natural environment.

  15. Indicator Species Population Monitoring in Antarctica with Uav

    Zmarz, A.; Korczak-Abshire, M.; Storvold, R.; Rodzewicz, M.; Kędzierska, I.


    A program to monitor bird and pinniped species in the vicinity of Arctowski Station, King George Island, South Shetlands, Antarctica, has been conducted over the past 38 years. Annual monitoring of these indicator species includes estimations of breeding population sizes of three Pygoscelis penguin species: Adélie, gentoo and chinstrap. Six penguin colonies situated on the western shores of two bays: Admiralty and King George are investigated. To study changes in penguin populations Unmanned Aerial Vehicles were used for the first time in the 2014/15 austral summer season. During photogrammetric flights the high-resolution images of eight penguin breeding colonies were taken. Obtained high resolution images were used for estimation of breeding population size and compared with the results of measurements taken at the same time from the ground. During this Antarctic expedition eight successful photogrammetry missions (total distance 1500 km) were performed. Images were taken with digital SLR Canon 700D, Nikon D5300, Nikon D5100 with a 35mm objective lens. Flights altitude at 350 - 400 AGL, allowed images to be taken with a resolution GSD (ground sample distance) less than 5 cm. The Image J software analysis method was tested to provide automatic population estimates from obtained images. The use of UAV for monitoring of indicator species, enabled data acquisition from areas inaccessible by ground methods.


    A. Zmarz


    Full Text Available A program to monitor bird and pinniped species in the vicinity of Arctowski Station, King George Island, South Shetlands, Antarctica, has been conducted over the past 38 years. Annual monitoring of these indicator species includes estimations of breeding population sizes of three Pygoscelis penguin species: Adélie, gentoo and chinstrap. Six penguin colonies situated on the western shores of two bays: Admiralty and King George are investigated. To study changes in penguin populations Unmanned Aerial Vehicles were used for the first time in the 2014/15 austral summer season. During photogrammetric flights the high-resolution images of eight penguin breeding colonies were taken. Obtained high resolution images were used for estimation of breeding population size and compared with the results of measurements taken at the same time from the ground. During this Antarctic expedition eight successful photogrammetry missions (total distance 1500 km were performed. Images were taken with digital SLR Canon 700D, Nikon D5300, Nikon D5100 with a 35mm objective lens. Flights altitude at 350 – 400 AGL, allowed images to be taken with a resolution GSD (ground sample distance less than 5 cm. The Image J software analysis method was tested to provide automatic population estimates from obtained images. The use of UAV for monitoring of indicator species, enabled data acquisition from areas inaccessible by ground methods.

  17. Note On The Ross Sea Shelf Water Downflow Processes (antarctica)

    Bergamasco, A.; Defendi, V.; Spezie, G.; Budillon, G.; Carniel, S.

    In the framework of the CLIMA Project of the Italian National Program for Research in Antarctica, three different experimental data sets were acquired along the continental shelf break; two of them (in 1997 and 2001) close to Cape Adare, the 1998 one in the middle of the Ross Sea (i.e. 75 S, 177 W). The investigations were chosen in order to explore the downslope flow of the bottom waters produced in the Ross Sea, namely the High Salinity Shelf Water (HSSW, the densest water mass of the southern ocean coming from its formation site in the polynya region in Terra Nova bay), and the Ice Shelf Water (ISW, originated below the Ross Ice Shelf and outflowing northward). Both bottom waters spill over the shelf edge and mix with the Circumpolar Deep Water (CDW) contributing to the formation of the Antarctic Bottom Waters (AABW). Interpreting temperature, salinity and density maps in terms of cascading processes, both HSSW and ISW overflows are evidenced during, respectively, 1997 and 1998. During the 2001 acquisition there is no presence of HSSW along the shelf break, nevertheless distribution captures the evidence of a downslope flow process.

  18. Summer fast ice evolution off Zhongshan Station, Antarctica

    Lei Ruibo; Li Zhijun; Zhang Zhanhai; Cheng Yanfeng; Dou Yinke


    Based on the field data acquired in the program of fast ice observationoff Zhongshan Station,Prydz Bay,East Antarctica during the austral summer 2005/2006,physical properties evolution of fast ice during the ice ablation seasonis analyzed in detail.Results show that the annual maximum ice thickness in 2005 occurred in later November,and then ice started to melt,and the ablation duration was 62 days; sea water under the ice became warmer synchronously; corresponding to the warming sea ice temperature,a "relative cold mid layer" appeared in sea ice; the fast ice marginal line recoiled back to the shore observably,and the recoil distance was 20.9 km from 18 December 2005 through 14 January 2006.In addition,based on the data of sea ice thickness survey along the investigation course of MV Xuelong on December 18 of 2005,the ice thickness distribution paten in the marginal ice zone have been described: sea ice thickness increased,but the diversity of floe ice thickness decreased from open water to fast icezone distinctly.

  19. Meteorological data for the astronomical site at Dome A, Antarctica

    Hu, Yi; Ashley, Michael C B; Bonner, Collin S; Hu, Keliang; Liu, Qiang; Li, Yuansheng; Ma, Bin; Wang, Lifan; Wen, Haikun


    We present an analysis of the meteorological data collected at Dome A, Antarctica by the Kunlun Automated Weather Station, including temperatures and wind speeds at eight elevations above the snow surface between 0m and 14.5m. The average temperatures at 2m and 14.5m are $-54^{\\circ}$C and $-46^{\\circ}$C, respectively. We find that a strong temperature inversion existed at all heights for more than 70% of the time, and the temperature inversion typically lasts longer than 25 hours, indicating an extremely stable atmosphere. The temperature gradient is larger at lower elevations than higher elevations. The average wind speed was 1.5m/s at 4m elevation. We find that the temperature inversion is stronger when the wind speed is lower and the temperature gradient decreases sharply at a specific wind speed for each elevation. The strong temperature inversion and low wind speed results in a shallow and stable boundary layer with weak atmospheric turbulence above it, suggesting that Dome A should be an excellent site...

  20. Connected subglacial lake drainage beneath Thwaites Glacier, West Antarctica

    Smith, Benjamin E.; Gourmelen, Noel; Huth, Alexander; Joughin, Ian


    We present conventional and swath altimetry data from CryoSat-2, revealing a system of subglacial lakes that drained between June 2013 and January 2014 under the central part of Thwaites Glacier, West Antarctica (TWG). Much of the drainage happened in less than 6 months, with an apparent connection between three lakes spanning more than 130 km. Hydro-potential analysis of the glacier bed shows a large number of small closed basins that should trap water produced by subglacial melt, although the observed large-scale motion of water suggests that water can sometimes locally move against the apparent potential gradient, at least during lake-drainage events. This shows that there are important limitations in the ability of hydro-potential maps to predict subglacial water flow. An interpretation based on a map of the melt rate suggests that lake drainages of this type should take place every 20-80 years, depending on the connectivity of the water flow at the bed. Although we observed an acceleration in the downstream part of TWG immediately before the start of the lake drainage, there is no clear connection between the drainage and any speed change of the glacier.