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Sample records for sarychev peak volcano

  1. Satellite and ground observations of the June 2009 eruption of Sarychev Peak volcano, Matua Island, Central Kuriles

    Science.gov (United States)

    Rybin, A.; Chibisova, M.; Webley, P.; Steensen, T.; Izbekov, P.; Neal, C.; Realmuto, V.

    2011-01-01

    After 33 years of repose, one of the most active volcanoes of the Kurile island arc-Sarychev Peak on Matua Island in the Central Kuriles-erupted violently on June 11, 2009. The eruption lasted 9 days and stands among the largest of recent historical eruptions in the Kurile Island chain. Satellite monitoring of the eruption, using Moderate Resolution Imaging Spectroradiometer, Meteorological Agency Multifunctional Transport Satellite, and Advanced Very High Resolution Radiometer data, indicated at least 23 separate explosions between 11 and 16 June 2009. Eruptive clouds reached altitudes of generally 8-16 km above sea level (ASL) and in some cases up to 21 km asl. Clouds of volcanic ash and gas stretched to the north and northwest up to 1,500 km and to the southeast for more than 3,000 km. For the first time in recorded history, ash fall occurred on Sakhalin Island and in the northeast sector of the Khabarovsky Region, Russia. Based on satellite image analysis and reconnaissance field studies in the summer of 2009, the eruption produced explosive tephra deposits with an estimated bulk volume of 0. 4 km3. The eruption is considered to have a Volcanic Explosivity Index of 4. Because the volcano is remote, there was minimal risk to people or infrastructure on the ground. Aviation transport, however, was significantly disrupted because of the proximity of air routes to the volcano. ?? 2011 Springer-Verlag.

  2. Stratospheric aerosols from the Sarychev volcano eruption in the 2009 Arctic summer

    Science.gov (United States)

    Jégou, F.; Berthet, G.; Brogniez, C.; Renard, J.-B.; François, P.; Haywood, J. M.; Jones, A.; Bourgeois, Q.; Lurton, T.; Auriol, F.; Godin-Beekmann, S.; Guimbaud, C.; Krysztofiak, G.; Gaubicher, B.; Chartier, M.; Clarisse, L.; Clerbaux, C.; Balois, J. Y.; Verwaerde, C.; Daugeron, D.

    2013-07-01

    Aerosols from the Sarychev volcano eruption (Kuril Islands, northeast of Japan) were observed in the Arctic lower stratosphere a few days after the strongest SO2 injection which occurred on 15 and 16 June 2009. From the observations provided by the Infrared Atmospheric Sounding Interferometer (IASI) an estimated 0.9 Tg of sulphur dioxide was injected into the upper troposphere and lower stratosphere (UTLS). The resultant stratospheric sulphate aerosols were detected from satellites by the Optical Spectrograph and Infrared Imaging System (OSIRIS) limb sounder and by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and from the surface by the Network for the Detection of Atmospheric Composition Changes (NDACC) lidar deployed at OHP (Observatoire de Haute-Provence, France). By the first week of July the aerosol plume had spread out over the entire Arctic region. The Sarychev-induced stratospheric aerosol over the Kiruna region (north of Sweden) was measured by the Stratospheric and Tropospheric Aerosol Counter (STAC) during eight balloon flights planned in August and September 2009. During this balloon campaign the Micro Radiomètre Ballon (MicroRADIBAL) and the Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NOx (SALOMON) remote-sensing instruments also observed these aerosols. Aerosol concentrations returned to near-background levels by spring 2010. The effective radius, the surface area density (SAD), the aerosol extinction, and the total sulphur mass from STAC in situ measurements are enhanced with mean values in the range 0.15-0.21 μm, 5.5-14.7 μm2 cm-3, 5.5-29.5 × 10-4 km-1, and 4.9-12.6 × 10-10 kg[S] kg-1[air], respectively, between 14 km and 18 km. The observed and modelled e-folding time of sulphate aerosols from the Sarychev eruption is around 70-80 days, a value much shorter than the 12-14 months calculated for aerosols from the 1991 eruption of Mt Pinatubo. The OSIRIS stratospheric aerosol optical depth (AOD

  3. Stratospheric aerosols from the Sarychev volcano eruption in the 2009 Arctic summer

    Directory of Open Access Journals (Sweden)

    F. Jégou

    2013-07-01

    Full Text Available Aerosols from the Sarychev volcano eruption (Kuril Islands, northeast of Japan were observed in the Arctic lower stratosphere a few days after the strongest SO2 injection which occurred on 15 and 16 June 2009. From the observations provided by the Infrared Atmospheric Sounding Interferometer (IASI an estimated 0.9 Tg of sulphur dioxide was injected into the upper troposphere and lower stratosphere (UTLS. The resultant stratospheric sulphate aerosols were detected from satellites by the Optical Spectrograph and Infrared Imaging System (OSIRIS limb sounder and by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP and from the surface by the Network for the Detection of Atmospheric Composition Changes (NDACC lidar deployed at OHP (Observatoire de Haute-Provence, France. By the first week of July the aerosol plume had spread out over the entire Arctic region. The Sarychev-induced stratospheric aerosol over the Kiruna region (north of Sweden was measured by the Stratospheric and Tropospheric Aerosol Counter (STAC during eight balloon flights planned in August and September 2009. During this balloon campaign the Micro Radiomètre Ballon (MicroRADIBAL and the Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NOx (SALOMON remote-sensing instruments also observed these aerosols. Aerosol concentrations returned to near-background levels by spring 2010. The effective radius, the surface area density (SAD, the aerosol extinction, and the total sulphur mass from STAC in situ measurements are enhanced with mean values in the range 0.15–0.21 μm, 5.5–14.7 μm2 cm−3, 5.5–29.5 × 10−4 km−1, and 4.9–12.6 × 10−10 kg[S] kg−1[air], respectively, between 14 km and 18 km. The observed and modelled e-folding time of sulphate aerosols from the Sarychev eruption is around 70–80 days, a value much shorter than the 12–14 months calculated for aerosols from the 1991 eruption of Mt Pinatubo. The OSIRIS

  4. Stratospheric aerosols from the Sarychev volcano eruption in the 2009 Arctic summer

    Directory of Open Access Journals (Sweden)

    F. Jégou

    2013-02-01

    Full Text Available Aerosols from the Sarychev volcano eruption (Kuril Islands, northeast of Japan were observed in the Arctic lower stratosphere a few days after the strongest SO2 injection which occurred on 15 and 16 June 2009. From the observations provided by the Infrared Atmospheric Sounding Interferometer (IASI an estimated 0.9 Tg of sulphur dioxide was injected into the Upper Troposphere and Lower Stratosphere (UTLS. The resultant stratospheric sulphate aerosols were detected by the Optical Spectrograph and Infrared Imaging System (OSIRIS limb sounder and by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP satellite instruments. By the first week of July the aerosol plume had spread out over the entire Arctic region. The Sarychev-induced stratospheric aerosol over the Kiruna region (north of Sweden was measured by the Stratospheric and Tropospheric Aerosol Counter (STAC during eight balloon flights planned in August and September 2009. During this balloon campaign the Micro RADIomètre BALlon (MicroRADIBAL and the Spectroscopie d'Absorption Lunaire pour l'Observation des Minoritaires Ozone et NOx (SALOMON remote-sensing instruments also observed these aerosols. Aerosol concentrations returned to near-background levels by spring 2010. The effective radius, the Surface Area Density (SAD, the aerosol extinction, and the total sulphur mass from STAC in situ measurements are enhanced with mean values in the range 0.15–0.21 μm, 5.5–14.7 μm2 cm−3, 5.5–29.5×10−4 km−1, and 4.9–12.6×10−10 kg [S] kg−1 [air], respectively, between 14 km and 18 km. The observed and modelled e-folding time of sulphate aerosols from the Sarychev eruption is around 70–80 days, a value much shorter than the 12–14 months calculated for aerosols from the 1991 eruption of Mt. Pinatubo. The OSIRIS stratospheric Aerosol Optical Depth (AOD at 750 nm is enhanced by a factor of 6 with a

  5. A multi-sensor analysis of the 2009 eruption of Sarychev Peak, Kuril Islands: A case study for hazards to aviation

    Science.gov (United States)

    Williams, D.; Thomas, H. E.; Watson, M. I.

    2010-12-01

    The eruption of Sarychev Peak Volcano (48°N,153°E), Kuril Islands, occurred between June 12 and 18 2009 emplacing large volumes of sulphur dioxide and volcanic ash into the atmosphere and severely disrupting air traffic in the region. The eruption was observed by several satellite-borne sensors, including the Ozone Monitoring Instrument (OMI), the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS). This work uses these three sensors concurrently, as the use of several instruments provides more frequent datasets enabling improvements in accurately locating volcanic clouds and the subsequent validation of dispersion models. The North Pacific region sees a large amount of air traffic and the clouds from Sarychev Peak intersected many major air routes. Volcanic ash poses a threat to the operation of aircraft by abrading the engines which can result in failure, as well as “sand blasting” of the cockpit windows. It is also important to detect and map any sulphur dioxide clouds created, as this can also be hazardous for aircraft. Volcanic aerosol can cause corrosion on the aircraft exterior and sulphur based minerals may be deposited within the engines, blocking cooling holes over time. SO2 can also enter the aircraft cabin through the ventilation system, which can cause respiratory problems for the passengers and crew. In addition, SO2 is often associated with volcanic ash as the two species are frequently collocated. When ash retrievals are limited by high concentrations of water vapour and ice in the atmosphere, the presence of SO2 can be used to infer the location of a potential ash cloud, so that aircraft encounters may be avoided. A collection of images from the three sensors, ranging from June 10 to 24 were acquired to determine the mass and location of the SO2 cloud. This data, along with ash cloud data collected from the two MODIS sensors for dates between June 11 and 20, was then used to create a chronology of

  6. The 1992 eruptions of Crater Peak vent, Mount Spurr Volcano, Alaska

    Science.gov (United States)

    Keith, Terry E.C.

    1995-01-01

    Sulfur dioxide scrubbing by liquid water masked SO2 emissions from shallow magma during the 1992 eruptions of Crater Peak and effectively prevented observation of SO2 emissions from shallow magma both before and after explosive eruptions and seismic crises. Airborne ultraviolet correlation spectrometer (COSPEC) measurements from July 22, 1991, to September 24, 1992, indicate only background to minor ( H2S(aq) + 3H+(aq) + 3HSO4-(aq). Sulfur dioxide hydrolysis also explains the increase in the sulfate content of Crater Peak lake water prior to the first eruption, the strong H2S odor during periods of background to low SO2 emission, the TOMS evidence for significant H2S emissions during the explosive eruptions, and the observed decline of SO2 during periods of volcanic tremor. Abundant, local sources of melt water and a high permeability for the Mount Spurr volcanic edifice are probably the chief factors responsible for masking SO2 emissions by scrubbing, and possibly for quenching shallow intrusions that were ascending. Large SO2 emissions unencumbered by scrubbing were only possible during the three explosive eruptions when magma penetrated through liquid water zones under Crater Peak and reached the surface. Nonexplosive SO2 emissions of as much as 750 t/d were possible, however, for a brief period when dry pathways to the surface existed from September 25 until about October 10, 1992. Airborne infrared spectrometer (MIRAN) measurements of CO2 emissions indicate that in addition to the degassing of magma through dry pathways, degassing through boiling water with the loss of SO2 by scrubbing was also important during that time. The CO2 emission data indicate that magma degassing was taking place, and CO2/SO2 values calculated from MIRAN and COSPEC data are in the range 10 to 100, which supports the hypothesis of SO2 loss by scrubbing. Because of its strong preference for the vapor phase during boiling, CO2 emissions from degassing magma are less likely to be masked

  7. Volcanoes

    Science.gov (United States)

    ... 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 ...

  8. Volcanoes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    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

  9. Analysis of composition and chronology of dome emplacement at Black Peak Volcano, Alaska utilizing aster remote sensing data and field-based studies

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Black Peak volcano is a ~3.5lcin-diameter caldera located on the Alaska Peninsula that formed ~4,600 years ago in an eruption that excavated >101cm 3 of material....

  10. Detection of volcanic sulfate aerosol with Envisat MIPAS shown for the Kasatochi, Sarychev, and Nabro eruptions

    Science.gov (United States)

    Griessbach, Sabine; Hoffmann, Lars; Spang, Reinhold; von Hobe, Marc; Müller, Rolf; Riese, Martin

    2013-04-01

    Stratospheric sulfate aerosol is known to have a strong impact on climate. Transport pathways of sulfur dioxide and sulfate aerosol to the stratosphere are still discussed. It is known that volcanic eruptions can inject significant amounts of sulfur directly into the stratosphere. Most sulfur, however, is injected into the troposphere and only a fraction of it can make its way into the stratosphere. Global and altitude resolved time series of observations are a valuable source of information for sulfur dioxide and sulfate aerosol detection. Here we present a new aerosol detection method for the infrared limb sounder Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and the results for the Kasatochi, Sarychev, and Nabro eruptions. The new detection method utilizes three infrared window regions that are located around 830, 960, and 1224 cm-1. The combination of these three windows allows for a better detection of enhanced aerosol events in the troposphere as well as the discrimination from ice clouds. With this new method the 10 year record of MIPAS measurements was analyzed. The most remarkable sulfate aerosol events follow the Kasatochi, Sarychev, and Nabro eruptions. After these eruptions enhanced aerosol is detected in the upper troposphere and lower stratosphere (UTLS) region. Within one to two months it spreads over most of the northern hemisphere. In the tropics the aerosol reaches altitudes up to around 20 km and in the Arctic up to 15 km. The enhanced aerosol signal can be observed for about 5, 7, and up to 10 month for the Kasatochi, Sarychev, and Nabro eruptions, respectively. During this period the enhanced aerosol detections decrease in number, strength, and observation altitude. After the Nabro eruption on 13 June 2011 volcanic aerosol is detected in the UTLS region two days after the initial eruption. The following days the aerosol moves around the northern edge of the Asian monsoon region, is then transported southwards and later

  11. Temporal and spatial variation of local stress fields before and after the 1992 eruptions of Crater Peak vent, Mount Spurr volcano, Alaska

    Science.gov (United States)

    Roman, D.C.; Moran, S.C.; Power, J.A.; Cashman, K.V.

    2004-01-01

    We searched for changes in local stress-field orientation at Mount Spurr volcano, Alaska, between August 1991 and December 2001. This study focuses on the stress-field orientation beneath Crater Peak vent, the site of three eruptions in 1992, and beneath the summit of Mount Spurr. Local stress tensors were calculated by inverting subsets of 140 fault-plane solutions for earthquakes beneath Crater Peak and 96 fault-plane solutions for earthquakes beneath Mount Spurr. We also calculated an upper-crustal regional stress tensor by inverting fault-plane solutions for 66 intraplate earthquakes located near Mount Spurr during 1991-2001. Prior to the 1992 eruptions, and for 11 months beginning with a posteruption seismic swarm, the axis of maximum compressive stress beneath Crater Peak was subhorizontal and oriented N67-76??E, approximately perpendicular to the regional axis of maximum compressive stress (N43??W). The strong temporal correlation between this horizontal stress-field rotation (change in position of the ??1/ ??3 axes relative to regional stress) and magmatic activity indicates that the rotation was related to magmatic activity, and we suggest that the Crater Peak stress-field rotation resulted from pressurization of a network of dikes. During the entire study period, the stress field beneath the summit of Mount Spurr also differed from the regional stress tensor and was characterized by a vertical axis of maximum compressive stress. We suggest that slip beneath Mount Spurr's summit occurs primarily on a major normal fault in response to a combination of gravitational loading, hydrothermal circulation, and magmatic processes beneath Crater Peak. Online material: Regional and local fault-plane solutions.

  12. A Compilation of Gas Emission-Rate Data from Volcanoes of Cook Inlet (Spurr, Crater Peak, Redoubt, Iliamna, and Augustine) and Alaska Peninsula (Douglas, Fourpeaked, Griggs, Mageik, Martin, Peulik, Ukinrek Maars, and Veniaminof), Alaska, from 1995-2006

    Science.gov (United States)

    Doukas, Michael P.; McGee, Kenneth A.

    2007-01-01

    INTRODUCTION This report presents gas emission rates from data collected during numerous airborne plume-measurement flights at Alaskan volcanoes since 1995. These flights began in about 1990 as means to establish baseline values of volcanic gas emissions during periods of quiescence and to identify anomalous levels of degassing that might signal the beginning of unrest. The primary goal was to make systematic measurements at the major volcanic centers around the Cook Inlet on at least an annual basis, and more frequently during periods of unrest and eruption. A secondary goal was to measure emissions at selected volcanoes on the Alaska Peninsula. While the goals were not necessarily met in all cases due to weather, funding, or the availability of suitable aircraft, a rich dataset of quality measurements is the legacy of this continuing effort. An earlier report (Doukas, 1995) presented data for the period from 1990 through 1994 and the current report provides data through 2006. This report contains all of the available measurements for SO2, CO2, and H2S emission rates in Alaska determined by the U. S. Geological Survey from 1995 through 2006; airborne measurements for H2S began in Alaska in 2001. The results presented here are from Cook Inlet volcanoes at Spurr, Crater Peak, Redoubt, Iliamna, and Augustine and cover periods of unrest at Iliamna (1996) and Spurr (2004-2006) as well as the 2006 eruption of Augustine. Additional sporadic measurements at volcanoes on the Alaska Peninsula (Douglas, Martin, Mageik, Griggs, Veniaminof, Ukinrek Maars, Peulik, and Fourpeaked during its 2006 unrest) are also reported here.

  13. Volcano Preparedness

    Science.gov (United States)

    ... 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 ...

  14. Vanishing Volcano

    Institute of Scientific and Technical Information of China (English)

    杨树仁

    1995-01-01

    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.

  15. Dante's volcano

    Science.gov (United States)

    1994-09-01

    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.

  16. What Are Volcano Hazards?

    Science.gov (United States)

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

  17. Santorini Volcano

    Science.gov (United States)

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

    1999-01-01

    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.

  18. Global Volcano Locations Database

    Data.gov (United States)

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

  19. A Scientific Excursion: Volcanoes.

    Science.gov (United States)

    Olds, Henry, Jr.

    1983-01-01

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

  20. Volcano seismology

    Science.gov (United States)

    Chouet, B.

    2003-01-01

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

  1. Volcanoes: Nature's Caldrons Challenge Geochemists.

    Science.gov (United States)

    Zurer, Pamela S.

    1984-01-01

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

  2. PETROGRAPHIC AND MICRO-TEXTURAL FEATURES OF THE YELLOW PUMICE AT TIANWEN PEAK OF CHANGBAISHAN TIANCHI VOLCANO%长白山天池火山天文峰黄色浮岩的岩相学与显微结构特征

    Institute of Scientific and Technical Information of China (English)

    许建东; 于红梅; 赵波

    2013-01-01

    在长白山天池火口天文峰内壁发育数十m厚的爆炸式喷发堆积物,颜色各异.其中1套规模较大的黄色中弱熔结的粗粒浮岩空降堆积,堆积物碎屑粒径大,气孔大量发育,含有大粒径粗面岩岩块.文中对采于该套黄色堆积物的样品进行了全岩成分和显微结构特征分析,并与“千年大喷发”的空降浮岩进行了对比.研究结果表明:1)黄色浮岩与千年喷发的浮岩一样,属于碱性流纹岩,比千年喷发的灰白色浮岩略偏基性,可能由同一岩浆演化而来;2)黄色浮岩呈泡沫状,由不同大小的气孔、气孔壁和少量斑晶组成,部分较大的圆形气孔沿斑晶周围发育,呈串珠状排列,流动特征明显,黄色浮岩的斑晶类型和气孔结构与千年喷发的灰白色浮岩类似;3)已有扫描电镜和X射线衍射分析结果显示黄色浮岩中的长石参数与其他浮岩明显不同,可能是独立火山喷发事件的产物.上述岩石学证据表明,该套黄色堆积物是火山爆炸式喷发作用形成的浮岩空降堆积.%A series of deposits with tens of meters in thickness and in black,grey and yellow colors,from explosive eruptions in the Holocene,are developed at Tianwen peak,the north summit of Tianchi caldera of Changbaishan volcano.Among the deposits,a relatively large scale unit in yellow color,socalled "yellow pumice" by the previous studies,is characterized by coarse tephra and well-developed pores with large-sized trachyte blocks.In this study,we analyzed the petrographic and micro-textural features of the yellow pumice,as well as the grey pumice which is believed to be produced by the millennium eruption in 946 AD.Our results indicate that:1)the yellow pumice can be classified into alkaline rhyolite as like the grey pumice,but is slightly more basaltic than the grey pumice,suggesting that they all are probably from the identical magma source; 2)remarkably similar as the grey pumice in texture,the yellow

  3. Foci of Volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, I.

    1974-01-01

    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.

  4. Renewed unrest at Mount Spurr Volcano, Alaska

    Science.gov (United States)

    Power, John A.

    2004-01-01

    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.

  5. Volcanoes - Direct Download

    Data.gov (United States)

    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...

  6. Italian active volcanoes

    Institute of Scientific and Technical Information of China (English)

    RobertoSantacroce; RenawCristofolini; LuigiLaVolpe; GiovanniOrsi; MauroRosi

    2003-01-01

    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.

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

    Science.gov (United States)

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

    2015-12-01

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

  8. Volcano shapes, entropies, and eruption probabilities

    Science.gov (United States)

    Gudmundsson, Agust; Mohajeri, Nahid

    2014-05-01

    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

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

    Data.gov (United States)

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

  10. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

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

    2017-08-01

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

  11. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

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

    2017-01-01

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

  12. Volcanoes: Coming Up from Under.

    Science.gov (United States)

    Science and Children, 1980

    1980-01-01

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

  13. Organizational changes at Earthquakes & Volcanoes

    Science.gov (United States)

    Gordon, David W.

    1992-01-01

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

  14. Hawaii's volcanoes revealed

    Science.gov (United States)

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

    2003-01-01

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

  15. Santa Maria Volcano, Guatemala

    Science.gov (United States)

    2002-01-01

    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

  16. Anatomy of a volcano

    NARCIS (Netherlands)

    Wassink, J.

    2011-01-01

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

  17. Catalogue of Icelandic Volcanoes

    Science.gov (United States)

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

    2016-04-01

    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

  18. Catalogue of Icelandic volcanoes

    Science.gov (United States)

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

    2015-04-01

    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

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

    Science.gov (United States)

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

    2001-01-01

    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.

  20. Modeling volcano growth on the Island of Hawaii: deep-water perspectives

    Science.gov (United States)

    Lipman, Peter W.; Calvert, Andrew T.

    2013-01-01

    Recent ocean-bottom geophysical surveys, dredging, and dives, which complement surface data and scientific drilling at the Island of Hawaii, document that evolutionary stages during volcano growth are more diverse than previously described. Based on combining available composition, isotopic age, and geologically constrained volume data for each of the component volcanoes, this overview provides the first integrated models for overall growth of any Hawaiian island. In contrast to prior morphologic models for volcano evolution (preshield, shield, postshield), growth increasingly can be tracked by age and volume (magma supply), defining waxing alkalic, sustained tholeiitic, and waning alkalic stages. Data and estimates for individual volcanoes are used to model changing magma supply during successive compositional stages, to place limits on volcano life spans, and to interpret composite assembly of the island. Volcano volumes vary by an order of magnitude; peak magma supply also varies sizably among edifices but is challenging to quantify because of uncertainty about volcano life spans. Three alternative models are compared: (1) near-constant volcano propagation, (2) near-equal volcano durations, (3) high peak-tholeiite magma supply. These models define inconsistencies with prior geodynamic models, indicate that composite growth at Hawaii peaked ca. 800–400 ka, and demonstrate a lower current rate. Recent age determinations for Kilauea and Kohala define a volcano propagation rate of 8.6 cm/yr that yields plausible inception ages for other volcanoes of the Kea trend. In contrast, a similar propagation rate for the less-constrained Loa trend would require inception of Loihi Seamount in the future and ages that become implausibly large for the older volcanoes. An alternative rate of 10.6 cm/yr for Loa-trend volcanoes is reasonably consistent with ages and volcano spacing, but younger Loa volcanoes are offset from the Kea trend in age-distance plots. Variable magma flux

  1. PeakWorks

    Energy Technology Data Exchange (ETDEWEB)

    2016-11-30

    The PeakWorks software is designed to assist in the quantitative analysis of atom probe tomography (APT) generated mass spectra. Specifically, through an interactive user interface, mass peaks can be identified automatically (defined by a threshold) and/or identified manually. The software then provides a means to assign specific elemental isotopes (including more than one) to each peak. The software also provides a means for the user to choose background subtraction of each peak based on background fitting functions, the choice of which is left to the users discretion. Peak ranging (the mass range over which peaks are integrated) is also automated allowing the user to chose a quantitative range (e.g. full-widthhalf- maximum). The software then integrates all identified peaks, providing a background-subtracted composition, which also includes the deconvolution of peaks (i.e. those peaks that happen to have overlapping isotopic masses). The software is also able to output a 'range file' that can be used in other software packages, such as within IVAS. A range file lists the peak identities, the mass range of each identified peak, and a color code for the peak. The software is also able to generate 'dummy' peak ranges within an outputted range file that can be used within IVAS to provide a means for background subtracted proximity histogram analysis.

  2. Geology of Kilauea volcano

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-08-01

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

  3. 4D volcano gravimetry

    Science.gov (United States)

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

    2008-01-01

    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

  4. Pairing the Volcano

    CERN Document Server

    Ionica, Sorina

    2011-01-01

    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 ...

  5. Space Radar Image of Colombian Volcano

    Science.gov (United States)

    1999-01-01

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

  6. Paniek over Peak Food

    NARCIS (Netherlands)

    Koning, N.B.J.

    2015-01-01

    Het kon niet uitblijven. De groei van de voedselproductie stagneert en na Peak Oil dreigt nu Peak Food. Onzin, vindt Niek Koning, die zogenaamde peak is een van de toppen in een langjarige golfbeweging op de landbouwmarkten. Toch zijn er genoeg redenen om je zorgen te maken over de wereldvoedselvoor

  7. Are Bragg Peaks Gaussian?

    Science.gov (United States)

    Hammouda, Boualem

    2014-01-01

    It is common practice to assume that Bragg scattering peaks have Gaussian shape. The Gaussian shape function is used to perform most instrumental smearing corrections. Using Monte Carlo ray tracing simulation, the resolution of a realistic small-angle neutron scattering (SANS) instrument is generated reliably. Including a single-crystal sample with large d-spacing, Bragg peaks are produced. Bragg peaks contain contributions from the resolution function and from spread in the sample structure. Results show that Bragg peaks are Gaussian in the resolution-limited condition (with negligible sample spread) while this is not the case when spread in the sample structure is non-negligible. When sample spread contributes, the exponentially modified Gaussian function is a better account of the Bragg peak shape. This function is characterized by a non-zero third moment (skewness) which makes Bragg peaks asymmetric for broad neutron wavelength spreads. PMID:26601025

  8. Italian Volcano Supersites

    Science.gov (United States)

    Puglisi, G.

    2011-12-01

    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.

  9. Ruiz Volcano: Preliminary report

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2011-01-01

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

  11. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  12. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

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

    Science.gov (United States)

    Waythomas, Christopher F.; Miller, Thomas P.

    1999-01-01

    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.

  14. Elementary analysis of data from Tianchi Volcano

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

    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.

  15. Mount Rainier active cascade volcano

    Science.gov (United States)

    1994-01-01

    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.

  16. Mount Rainier active cascade volcano

    Science.gov (United States)

    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.

  17. The central peak revisited

    Energy Technology Data Exchange (ETDEWEB)

    Shirane, G.

    1995-10-27

    The central peak in SrTiO{sub 3} was first observed by Riste and his collaborators in 1971. This was one of the key discoveries leading to an understanding of the dynamics of phase transitions. The most recent discovery of two length scales in SrTiO{sub 3} motivated a reinvestigation of the soft phonon and associated central peak by neutron scattering. These recent experiments shed new light on the nature of the central peak. It is now well established to be strongly sample dependent and it originates from defects in bulk crystals.

  18. Soufriere Hills Volcano

    Science.gov (United States)

    2002-01-01

    In this ASTER image of Soufriere Hills Volcano on Montserrat in the Caribbean, continued eruptive activity is evident by the extensive smoke and ash plume streaming towards the west-southwest. Significant eruptive activity began in 1995, forcing the authorities to evacuate more than 7,000 of the island's original population of 11,000. The primary risk now is to the northern part of the island and to the airport. Small rockfalls and pyroclastic flows (ash, rock and hot gases) are common at this time due to continued growth of the dome at the volcano's summit.This image was acquired on October 29, 2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA

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

    Science.gov (United States)

    Yamamoto, M.; Miura, S.

    2014-12-01

    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

  20. Pikes Peak, Colorado

    Science.gov (United States)

    Brunstein, Craig; Quesenberry, Carol; Davis, John; Jackson, Gene; Scott, Glenn R.; D'Erchia, Terry D.; Swibas, Ed; Carter, Lorna; McKinney, Kevin; Cole, Jim

    2006-01-01

    For 200 years, Pikes Peak has been a symbol of America's Western Frontier--a beacon that drew prospectors during the great 1859-60 Gold Rush to the 'Pikes Peak country,' the scenic destination for hundreds of thousands of visitors each year, and an enduring source of pride for cities in the region, the State of Colorado, and the Nation. November 2006 marks the 200th anniversary of the Zebulon M. Pike expedition's first sighting of what has become one of the world's most famous mountains--Pikes Peak. In the decades following that sighting, Pikes Peak became symbolic of America's Western Frontier, embodying the spirit of Native Americans, early explorers, trappers, and traders who traversed the vast uncharted wilderness of the Western Great Plains and the Southern Rocky Mountains. High-quality printed paper copies of this poster are available at no cost from Information Services, U.S. Geological Survey (1-888-ASK-USGS).

  1. Peak Oil, Peak Coal and Climate Change

    Science.gov (United States)

    Murray, J. W.

    2009-05-01

    Research on future climate change is driven by the family of scenarios developed for the IPCC assessment reports. These scenarios create projections of future energy demand using different story lines consisting of government policies, population projections, and economic models. None of these scenarios consider resources to be limiting. In many of these scenarios oil production is still increasing to 2100. Resource limitation (in a geological sense) is a real possibility that needs more serious consideration. The concept of 'Peak Oil' has been discussed since M. King Hubbert proposed in 1956 that US oil production would peak in 1970. His prediction was accurate. This concept is about production rate not reserves. For many oil producing countries (and all OPEC countries) reserves are closely guarded state secrets and appear to be overstated. Claims that the reserves are 'proven' cannot be independently verified. Hubbert's Linearization Model can be used to predict when half the ultimate oil will be produced and what the ultimate total cumulative production (Qt) will be. US oil production can be used as an example. This conceptual model shows that 90% of the ultimate US oil production (Qt = 225 billion barrels) will have occurred by 2011. This approach can then be used to suggest that total global production will be about 2200 billion barrels and that the half way point will be reached by about 2010. This amount is about 5 to 7 times less than assumed by the IPCC scenarios. The decline of Non-OPEC oil production appears to have started in 2004. Of the OPEC countries, only Saudi Arabia may have spare capacity, but even that is uncertain, because of lack of data transparency. The concept of 'Peak Coal' is more controversial, but even the US National Academy Report in 2007 concluded only a small fraction of previously estimated reserves in the US are actually minable reserves and that US reserves should be reassessed using modern methods. British coal production can be

  2. Peak of Achievement

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China’s first inland research station on the highest peak of Antarctic progresses smoothly China will complete the construction of its first inland Antarctic research station at Dome A,the highest polar icecap peak at 4,093 meters above sea level,next year,according to a south pole scientist involved in the project. "The preparatory work for the new sta-

  3. Characteristics of Hawaiian volcanoes

    Science.gov (United States)

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

    2014-01-01

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

  4. Volcanoes in Eruption - Set 1

    Data.gov (United States)

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

  5. Volcanoes in Eruption - Set 2

    Data.gov (United States)

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

  6. USGS Volcano Notification Service (VNS)

    Data.gov (United States)

    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...

  7. HYPOCENTER DISTRIBUTION OF LOW FREQUENCY EVENT AT PAPANDAYAN VOLCANO

    Directory of Open Access Journals (Sweden)

    Muhammad Mifta Hasan

    2016-10-01

    Full Text Available Papandayan volcano is a stratovolcano with irregular cone-shaped has eight craters around the peak. The most active crater in Papandayan is a Mas crater. Distribution of relocated event calculated using Geiger Adaptive Damping Algorithm (GAD shows that the epicenter of the event centered below Mas crater with maximum rms 0.114. While depth of the hypocenter range between 0-2 km and 5-6 km due to activity of steam and gas.

  8. Seismic Hazards at Kilauea and Mauna LOA Volcanoes, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Fred W.

    1994-04-22

    A significant seismic hazard exists in south Hawaii from large tectonic earthquakes that can reach magnitude 8 and intensity XII. This paper quantifies the hazard by estimating the horizontal peak ground acceleration (PGA) in south Hawaii which occurs with a 90% probability of not being exceeded during exposure times from 10 to 250 years. The largest earthquakes occur beneath active, unbuttressed and mobile flanks of volcanoes in their shield building stage.

  9. GLACIERS OF THE KORYAK VOLCANO

    Directory of Open Access Journals (Sweden)

    T. M. Manevich

    2012-01-01

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

  10. Mahukona: The missing Hawaiian volcano

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-11-01

    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.

  11. Climbing in the high volcanoes of central Mexico

    Science.gov (United States)

    Secor, R. J.

    1984-01-01

    A chain of volcanoes extends across central Mexico along the 19th parallel, a line just south of Mexico City. The westernmost of these peaks is Nevado de Colima at 4,636 feet above sea level. A subsidiary summit of Nevado de Colima is Volcan de Colima, locally called Fuego (fire) it still emits sulphurous fumes and an occasional plume of smoke since its disastrous eruption in 1941. Parictuin, now dormant, was born in the fall of 1943 when a cornfield suddenly erupted. Within 18 months, the cone grew more than 1,700 feet. Nevado de Toluca is a 15,433-foot volcanic peak south of the city of Toluca. Just southeast of Mexico City are two high volcanoes that are permanently covered by snow: Iztaccihuatl (17,342 fet) and Popocatepetl (17,887 feet) Further east is the third highest mountain in North America: 18,700-foot Citlateptl, or El Pico de Orizaba. North of these high peaks are two volcanoes, 14, 436-foot La Malinche and Cofre de Perote at 14,048 feet. This range of mountains is known variously as the Cordillera de Anahuac, the Sierra Volcanica Transversal, or the Cordillera Neovolcanica. 

  12. Correlation-Peak Imaging

    Science.gov (United States)

    Ziegler, A.; Metzler, A.; Köckenberger, W.; Izquierdo, M.; Komor, E.; Haase, A.; Décorps, M.; von Kienlin, M.

    1996-08-01

    Identification and quantitation in conventional1H spectroscopic imagingin vivois often hampered by the small chemical-shift range. To improve the spectral resolution of spectroscopic imaging, homonuclear two-dimensional correlation spectroscopy has been combined with phase encoding of the spatial dimensions. From the theoretical description of the coherence-transfer signal in the Fourier-transform domain, a comprehensive acquisition and processing strategy is presented that includes optimization of the width and the position of the acquisition windows, matched filtering of the signal envelope, and graphical presentation of the cross peak of interest. The procedure has been applied to image the spatial distribution of the correlation peaks from specific spin systems in the hypocotyl of castor bean (Ricinus communis) seedlings. Despite the overlap of many resonances, correlation-peak imaging made it possible to observe a number of proton resonances, such as those of sucrose, β-glucose, glutamine/glutamate, lysine, and arginine.

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

    Science.gov (United States)

    Chivarean, Radu

    2017-04-01

    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

  14. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...

  15. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...

  16. Impact Crater with Peak

    Science.gov (United States)

    2002-01-01

    (Released 14 June 2002) The Science This THEMIS visible image shows a classic example of a martian impact crater with a central peak. Central peaks are common in large, fresh craters on both Mars and the Moon. This peak formed during the extremely high-energy impact cratering event. In many martian craters the central peak has been either eroded or buried by later sedimentary processes, so the presence of a peak in this crater indicates that the crater is relatively young and has experienced little degradation. Observations of large craters on the Earth and the Moon, as well as computer modeling of the impact process, show that the central peak contains material brought from deep beneath the surface. The material exposed in these peaks will provide an excellent opportunity to study the composition of the martian interior using THEMIS multi-spectral infrared observations. The ejecta material around the crater can is well preserved, again indicating relatively little modification of this landform since its initial creation. The inner walls of this approximately 18 km diameter crater show complex slumping that likely occurred during the impact event. Since that time there has been some downslope movement of material to form the small chutes and gullies that can be seen on the inner crater wall. Small (50-100 m) mega-ripples composed of mobile material can be seen on the floor of the crater. Much of this material may have come from the walls of the crater itself, or may have been blown into the crater by the wind. The Story When a meteor smacked into the surface of Mars with extremely high energy, pow! Not only did it punch an 11-mile-wide crater in the smoother terrain, it created a central peak in the middle of the crater. This peak forms kind of on the 'rebound.' You can see this same effect if you drop a single drop of milk into a glass of milk. With craters, in the heat and fury of the impact, some of the land material can even liquefy. Central peaks like the one

  17. Mud Volcanoes Formation And Occurrence

    Science.gov (United States)

    Guliyev, I. S.

    2007-12-01

    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

  18. Thermal surveillance of volcanoes of the Cascade Range utilizing ERTS DCP systems and imagery

    Science.gov (United States)

    Friedman, J. D. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Successful installation of DCP sets at Mt. Baker volcano and at Mt. St. Helens volcano, Washington, completed the installation phase of experiment SR 251. Aerial IR scanner missions over the Cascade volcanoes were completed with a mission April 29th which provided thermographic IR images of Glacier Peak, Mt. Baker, Mt. St. Helens, Mt. Rainier, and Mt. Adams. Earlier repetitive coverage had obtained IR images depicting thermal anomalies of Lassen Volcanic National Park, Shasta, Crater Lake, and the northern Cascades. The April 29th mission and subsequent ground reconnaissance yielded new information on 48 heretofore unreported pinpoint radiation anomalies, of possible fumarolic origin, on the flanks of Mt. Rainier and several new thermal points on Mt. Baker. Cartographic plots of these anomalies, in conjunction with surface temperature and other data obtained as a result of experiment SR 251 will permit estimation of radiation heat loss during the repose periods of the host volcanoes.

  19. Global Volcano Model

    Science.gov (United States)

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

    2012-04-01

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

  20. Remote Sensing of Active Volcanoes

    Science.gov (United States)

    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.

  1. Mount Rainier: A decade volcano

    Science.gov (United States)

    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.”

  2. Systematic radon survey over active volcanoes

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-01

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

  3. Volcano-Hydrothermal Systems of the Central and Northern Kuril Island Arc - a Review

    Science.gov (United States)

    Kalacheva, E.; Taran, Y.; Voloshina, E.; Ptashinsky, L.

    2015-12-01

    More than 20 active volcanoes with historical eruptions are known on 17 islands composing the Central and Northern part of the Kurilian Arc. Six islands - Paramushir, Shiashkotan, Rasshua, Ushishir, Ketoy and Simushir - are characterized by hydrothermal activity, complementary to the fumarolic activity in their craters. There are several types of volcano-hydrothermal systems on the islands. At Paramushir, Shiashkotan and Ketoy the thermal manifestations are acidic to ultra-acidic water discharges associated with hydrothermal aquifers inside volcano edifices and formed as the result of the absorption of magmatic gases by ground waters. A closest known analogue of such activity is Satsuma-Iwojima volcano-island at the Ryukyu Arc. Another type of hydrothermal activity are wide spread coastal hot springs (Shiashkotan, Rasshua), situated as a rule within tide zones and formed by mixing of the heated seawater with cold groundwater or, in opposite, by mixing of the steam- or conductively heated groundwater with seawater. This type of thermal manifestation is similar to that reported for other volcanic islands of the world (Satsuma Iwojima, Monserrat, Ischia, Socorro). Ushishir volcano-hydrothermal system is formed by the absorption of magmatic gases by seawater. Only Ketoy Island hosts a permanent acidic crater lake. At Ebeko volcano (Paramushir) rapidly disappearing small acidic lakes (formed after phreatic eruptions) have been reported. The main hydrothermal manifestation of Simushir is the Zavaritsky caldera lake with numerous coastal thermal springs and weak steam vents. The last time measured temperatures of fumaroles at the islands are: >500ºC at Pallas Peak (Ketoy), 480ºC at Kuntamintar volcano (Shiashkotan), variable and fast changing temperatures from 120º C to 500ºC at Ebeko volcano (Paramushir), 150ºC in the Rasshua crater, and > 300ºC in the Chirpoy crater (Black Brothers islands). The magmatic and rock-forming solute output by the Kurilian volcano

  4. Alaska volcanoes guidebook for teachers

    Science.gov (United States)

    Adleman, Jennifer N.

    2011-01-01

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

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

    Science.gov (United States)

    Waythomas, Christopher F.; Waitt, Richard B.

    1998-01-01

    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.

  6. Permanent Infrasound Monitoring of Active Volcanoes in Ecuador

    Science.gov (United States)

    Ruiz, M. C.; Yepes, H. A.; Steele, A.; Segovia, M.; Vaca, S.; Cordova, A.; Enriquez, W.; Vaca, M.; Ramos, C.; Arrais, S.; Tapa, I.; Mejia, F.; Macias, C.

    2013-12-01

    Since 2006, infrasound monitoring has become a permanent tool for observing, analyzing and understanding volcanic activity in Ecuador. Within the framework of a cooperative project between the Japanese International Cooperation Agency (JICA) and the Instituto Geofísico to enhance volcano monitoring capabilities within the country, 10 infrasound sensors were deployed in conjunction with broadband seismic stations at Cotopaxi and Tungurahua volcanoes. Each station comprises 1 ACO microphone (model 7144) and an amplifier with a flat response down to 0.1 Hz. At Tungurahua, between July 2006 and July 2013, the network recorded more than 5,500 explosion events with peak-to-peak pressure amplitudes larger than 45 Pa at station Mason (BMAS) which is located ~ 5.5 km from the active crater. This includes 3 explosions with pressure amplitudes larger than 1,000 Pa and which all have exhibited clear shock wave components. Two seismic and infrasound arrays were also installed in 2006 under the Acoustic Surveillance for Hazardous Eruptions (ASHE) project, used in volcano monitoring at Tungurahua, Sangay, and Reventador. This venture was led by the Geological Survey of Canada and the University of Hawaii. Through the SENESCYT-IGEPN project, the Instituto Geofísico is currently installing a regional network of MB2005 microbarometers with the aim to enhance monitoring of active and potentially active volcanoes that include Reventador, Guagua Pichincha, Chimborazo, Antisana, Sangay, and Volcán Chico in the Galapagos Islands. Through the infrasound monitoring station at Volcán Chico it is also possible to extend observations to any activity initiated from Sierra Negra, Fernandina, Cerro Azul, and Alcedo volcanoes. During the past decade, a series of temporary acoustic arrays have also been deployed around Ecuador's most active volcanoes, helping to aid in short term volcanic monitoring and/or used in a series of research projects aimed at better understanding volcanic systems

  7. Mount Rainier, a decade volcano

    Energy Technology Data Exchange (ETDEWEB)

    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)

    1993-04-01

    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.

  8. Observations of two special kinds of tremor at Galeras volcano, Colombia (1989-1991)

    Energy Technology Data Exchange (ETDEWEB)

    Gil Cruz, F. [Observatorio Vulcanologico y Sismologico, Manizales (Colombia)

    1999-06-01

    The paper analyzes two kinds of tremor produced by Galeras volcano in 1988: flute tremor and spasmodic tremor. Spectrum and peak of flute tremor are described. The paper also distinguishes two types of spasmodic tremor on the basis of their spectral characteristics and field observations.

  9. Geyser Peak Cabernet Sauvignon

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>年份:2000产地:美国加州Sonoma County售价:$196 Geyser Peak(盖世峰)成立于1880年,是美国军有的过百岁葡萄酒庄。可惜美国酿制葡萄酒的技术在近三四十年才有突破,历史再悠久也没有太多帮助近二十年Geyser Peak就努力改进,希望迎头赶上其它加州新秀的水平,1989年,他们就聘请了澳洲Penfolds酒庄的酿酒师Daryl Groom,让旗下出品多了一份澳洲式的"霎眼娇"风格。2003年,Geyser Peak更在International Wine & Spirit Competition赢得"最佳美国葡萄酒生产商"大奖。

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

    Data.gov (United States)

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

  11. Volcano Monitoring Using Google Earth

    Science.gov (United States)

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

    2006-12-01

    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.

  12. Modeling eruptions of Karymsky volcano

    OpenAIRE

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

    2001-01-01

    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...

  13. Earthquakes - Volcanoes (Causes and Forecast)

    Science.gov (United States)

    Tsiapas, E.

    2009-04-01

    EARTHQUAKES - VOLCANOES (CAUSES AND FORECAST) ELIAS TSIAPAS RESEARCHER NEA STYRA, EVIA,GREECE TEL.0302224041057 tsiapas@hol.gr 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).

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

    Science.gov (United States)

    Lundgren, Paul

    1997-01-01

    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.

  15. Peak mass and dynamical friction

    CERN Document Server

    Del Popolo, A

    1995-01-01

    We show how the results given by several authors relatively to the mass of a density peak are changed when small scale substructure induced by dynamical friction are taken into account. The peak mass obtained is compared to the result of Peacock \\& Heavens (1990) and to the peak mass when dynamical friction is absent to show how these effects conspire to reduce the mass accreted by the peak.

  16. Peak capacity in unidimensional chromatography.

    Science.gov (United States)

    Neue, Uwe Dieter

    2008-03-14

    The currently existing knowledge about peak capacity in unidimensional separations is reviewed. The majority of the paper is dedicated to reversed-phase gradient chromatography, covering specific techniques as well as the subject of peak compression. Other sections deal with peak capacity in isocratic chromatography, size-exclusion chromatography and ion-exchange chromatography. An important topic is the limitation of the separation power and the meaning of the concept of peak capacity for real applications.

  17. Campgrounds in Hawaii Volcanoes National Park

    Data.gov (United States)

    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...

  18. Horizontal-vertical Spectral Ratio Method in Microtremor to Estimate Engineering Bedrock Thickness at Sedati Mud Volcano

    Science.gov (United States)

    Prabawa Arwananda, Alif; Aryaseta, Bagas; Dezulfakar, Hafidz; Fatahillah, Yosar; Pandu Gya Nur Rochman, Juan

    2017-04-01

    Based on field study, Sedati Mud Volcano located in a line with Gunung Anyar Mud Volcano and occurred by increased pressure in the compression area and rapid loss of gas. The combination of both fast-growing constructions of infrastructures and the presence of the mud volcanoes brings new challenges in Sidoarjo city. The purpose of this scientific research is to determine the sedimentary thickness around Sedati mud volcano. Only a few data show real amplitude spectrum, which represent high contrast impedance. At some point, there are several peaks indicating the presence of contrast impedance between layers. Based on 20 processed data, Sedati Mud Volcano has a 30 - 70m engineering bedrock thickness and natural frequency between 0.5 until 14.4 Hz. The enhancement of natural frequency tends to occur along decrement of layer thickness in the upper basement layer. The result shows the natural frequency parameter and its amplification is slightly variated around Sedati Mud Volcano, as caused by sedimentary lateral depth variation and/or the presence of variation on existing rock. Further analysis indicates a fault inside the area of mud volcano as possible reason behind the occurring mudflow.

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

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuexia; BO Liqun; LU Xingchang

    2001-01-01

    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.

  20. Volcanic hazards at Atitlan volcano, Guatemala

    Science.gov (United States)

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

    2006-01-01

    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.

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

    CERN Document Server

    Grasso, J R

    2003-01-01

    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...

  2. Most recent fall deposits of Ksudach Volcano, Kamchatka, Russia

    Science.gov (United States)

    Bursik, M.; Melekestsev, I. V.; Brajtseva, O. A.

    1993-01-01

    Three of four Plinian eruptions from Ksudach Volcano are among the four largest explosive eruptions in southern Kamchatka during the past 2000 years. The earliest of the eruptions was voluminous and was accompanied by an ignimbrite and the fifth and most recent Cddera collapse event at Ksudach. The isopach pattern is consistent with a column height of 23 km. The three more recent and smaller eruptions were from the Shtyubel' Cone, within the fifth caldera. Using isopach and grain size isopleth patterns, column heights ranged from >10 to 22 kin. Although the oldest eruption may have produced a large acidity peak in the Greenland ice, the three Shtyubel' events may not be related to major acid deposition. Thus it is possible that few if any of the uncorrelated acidity peaks of the past 2000 years in Greenland ice cores result from eruptions in southern Kamchatka.

  3. Newberry Volcano's youngest lava flows

    Science.gov (United States)

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

    2015-01-01

    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.

  4. Glacial cycles and the growth and destruction of Alaska volcanoes

    Science.gov (United States)

    Coombs, M. L.; Calvert, A. T.; Bacon, C. R.

    2014-12-01

    Glaciers have affected profoundly the growth, collapse, preservation, and possibly, eruptive behavior of Quaternary stratovolcanoes in Alaska. Holocene alpine glaciers have acted as effective agents of erosion on volcanoes north of ~55 °N and especially north of 60 °N. Cook Inlet volcanoes are particularly vulnerable as they sit atop rugged intrusive basement as high as 3000 m asl. Holocene glaciers have swept away or covered most of the deposits and dome lavas of frequently active Redoubt (60.5 °N); carved through the flanks of Spurr's active vent, Crater Peak (61.3 °N); and all but obscured the edifice of Hayes (61.6 °N), whose Holocene eruptive history is known almost exclusively though far-traveled tephra and flowage deposits. Relationships between Pleistocene eruptive histories, determined by high-precision Ar-Ar dating of lava flows, and marine oxygen isotope stages (MIS) 2-8 (Bassinot et al., 1994, EPSL, v. 126, p. 91­-108) vary with a volcano's latitude, size, and elevation. At Spurr, 26 ages cluster in interglacial periods. At Redoubt, 28 ages show a more continual eruptive pattern from the end of MIS 8 to the present, with a slight apparent increase in output following MIS 6, and almost no preservation before 220 ka. Veniaminof (56.2 °N) and Emmons (55.5°N), large, broad volcanoes with bases near sea level, had voluminous eruptive episodes during the profound deglaciations after MIS 8 and MIS 6. At Akutan (54.1 °N), many late Pleistocene lavas show evidence for ice contact; ongoing dating will be able to pinpoint ice thicknesses. Furthest south and west, away from thick Pleistocene ice on the Alaska Peninsula and mainland, the Tanaga volcanic cluster (51.9 °N) has a relatively continuous eruptive record for the last 200 k.y. that shows no clear-cut correlation with glacial cycles, except a possible hiatus during MIS 6. Finally, significant edifice collapse features have been temporally linked with deglaciations. A ~10-km3 debris

  5. PEAK SHAVING CONSIDERING STREAMFLOW UNCERTAINTIES

    African Journals Online (AJOL)

    user

    The main thrust of this paper is peak shaving with a Stochastic hydro model. In peak sharing, the amount of ... Fuel cost at a conventional hydro plant is nil. On the other hand, the ... s(k) = spill at the hydro plant in period k. I(k) = loss due to ...

  6. USGS GNSS Applications to Volcano Disaster Response and Hazard Mitigation

    Science.gov (United States)

    Lisowski, M.; McCaffrey, R.

    2015-12-01

    Peak), northern California (Mount Shasta, Medicine Lake, Lassen Peak), and Long Valley. These models take advantage of the data from dense GNSS networks, they provide source parameters for volcanic and tectonic transients, and can be used to discriminate possible short- and long-term volcano- tectonic interactions.

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

    Science.gov (United States)

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

    2008-01-01

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

  8. How to use your peak flow meter

    Science.gov (United States)

    Peak flow meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak flow meter ... If your airways are narrowed and blocked due to asthma, your peak flow values drop. You can ...

  9. Volcanoes

    Science.gov (United States)

    ... 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 ...

  10. Redoubt Volcano: 2009 Eruption Overview

    Science.gov (United States)

    Bull, K. F.

    2009-12-01

    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

  11. Eruptive history of Chimborazo volcano (Ecuador): A large, ice-capped and hazardous compound volcano in the Northern Andes

    Science.gov (United States)

    Samaniego, Pablo; Barba, Diego; Robin, Claude; Fornari, Michel; Bernard, Benjamin

    2012-04-01

    New fieldwork, radiometric and whole-rock chemical data permit the reconstruction of the main eruptive stages of the Chimborazo compound volcano, the highest summit of the Northern Andes. Chimborazo is composed of three successive edifices. The Basal Edifice (CH-I) was active from ~ 120 to 60 ka and resulted in a large, mostly effusive edifice which was built up during two stages of cone-building, terminating with the formation of a dome complex. This edifice was affected by a huge sector collapse around 65-60 ka which produced a major debris avalanche that spread out into the Riobamba basin, covering about 280 km2 with an average thickness of 40 m and a total volume of ~ 10-12 km3. After the emplacement of the Riobamba debris avalanche, eruptive activity resumed at the eastern outlet of the avalanche scar and was responsible for the construction of a less voluminous, Intermediary Edifice (CH-II), whose current remnants are the Politécnica and Martínez peaks. This edifice developed from 60 to 35 ka. Lastly, eruptive activity shifted to the west, leading to the construction of the morphologically well-preserved Young Cone (CH-III) which currently forms the highest summit (Whymper). The average eruptive rate of Chimborazo volcano is 0.5-0.7 km3/ka. However, looking at the three successive edifices individually, we estimate that there has been a progressive decrease in magma output rate from the Basal Edifice (0.7-1.0 km3/ka), through the Intermediary Edifice (0.4-0.7 km3/ka) to the Young Cone (~ 0.1 km3/ka). However, during the main cone-building stages, the peak eruption rates are markedly higher, indicating significant variations in the magma output rate during the lifespan of this arc volcano. During the Holocene, the Chimborazo eruptive activity consisted of small-volume explosive events that occurred at quite regular intervals, between about 8000 and 1000 yr ago. Since the last eruption occurred between the early part of the 5th century and the end of the 7th

  12. Doppler peaks from active perturbations

    CERN Document Server

    Magueijo, J; Coulson, D; Ferreira, P; Magueijo, Joao; Albrecht, Andreas; Coulson, David; Ferreira, Pedro

    1995-01-01

    We examine how the qualitative structure of the Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy depends on the fundamental nature of the perturbations which produced them. The formalism of Hu and Sugiyama is extended to treat models with cosmic defects. We discuss how perturbations can be ``active'' or ``passive'' and ``incoherent'' or ``coherent'', and show how causality and scale invariance play rather different roles in these various cases. We find that the existence of secondary Doppler peaks and the rough placing of the primary peak unambiguously reflect these basic properties.

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

    Science.gov (United States)

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

    2015-12-01

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

  14. Sulfur dioxide emissions from Alaskan volcanoes quantified using an ultraviolet SO_{2} camera

    Science.gov (United States)

    Kern, Christoph; Werner, Cynthia; Kelly, Peter; Brewer, Ian; Ketner, Dane; Paskievitch, John; Power, John

    2016-04-01

    Alaskan volcanoes are difficult targets for direct gas measurements as they are extremely remote and their peaks are mostly covered in ice and snow throughout the year. This makes access extremely difficult. In 2015, we were able to make use of an ultraviolet SO2 camera to quantify the SO2 emissions from Augustine Volcano, Redoubt Volcano, Mount Cleveland and Shishaldin Volcano in the Aleutian Arc. An airborne gas survey performed at Augustine Volcano in April 2015 found that the SO2 emission rate from the summit area was below 10 tonnes per day (t/d). SO2 camera measurements were performed two months later (June 2015) from a snow-free area just 100 meters from the fumarole on the south side of Augustine's summit dome to maximize camera sensitivity. Though the visible appearance of the plume emanating from the fumarole was opaque, the SO2 emissions were only slightly above the 40 ppmṡm detection limit of the SO2 camera. Still, SO2 could be detected and compared to coincident MultiGAS measurements of SO2, CO2 and H2S. At Redoubt Volcano, SO2 camera measurements were conducted on 13 June 2015 from a location 2 km to the north of the final 72x106 m3 dome extruded during the 2009 eruption. Imagery was collected of the plume visibly emanating from the top of the dome. Preliminary evaluation of the imagery and comparison with a coincident, helicopter-based DOAS survey showed that SO2 emission rates had dropped below 100 t/d (down from 180 t/d measured in April 2014). Mount Cleveland and Shishaldin Volcano were visited in August 2015 as part of an NSF-funded ship-based research expedition in the Central Aleutian Arc. At Mount Cleveland, inclement weather prohibited the collection of a lengthy time-series of SO2 camera imagery, but the limited data that was collected shows an emission rate of several hundred t/d. At Shishaldin, several hours of continuous imagery was acquired from a location 5 km east of the summit vent. The time series shows an SO2 emission rate of

  15. Recording Tilt with Broadband Seismic Sensors at Erupting Volcanoes

    Science.gov (United States)

    Young, B. E.; Lees, J. M.; Lyons, J. J.

    2011-12-01

    little or no tilt on the flanks of the volcano, indicating that activity is restricted to the very peak of the cone where degassing takes place. Possibly little or no deformation is observed where slug flow or the accumulation of large bubbles does not occur in the deeper parts of the volcano conduit. The timing and nature of inflation and deflation cycles reported for different volcanoes is variable. Data analyzed by Genco and Ripepe (GRL, 2010) from Stromboli volcano show periods of slow inflation with rapid deflation occurring at eruption onset. Alternatively, Sanderson et al. (JVGR, 2010) found little or no inflation prior to eruptions at Santiaguito, but eruptions were followed by strong deflationary pulses. The peak magnitudes of observed tilt are likewise dissimilar, ranging from 60 nanoradians at Stromboli up to ~2 microradians at Anatahan. The effect of sensor location, the style and geometry of the erupting edifice, and analytical methods are explored and illustrated.

  16. Make peak flow a habit!

    Science.gov (United States)

    ... asthma - peak flow References Durrani SR, Busse WW. Management of asthma in adolescents and adults. In: Adkinson NF Jr, Bochner BS, Burks AW, et al, eds. Middleton's Allergy Principles and Practice . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap ...

  17. Tornillo seismic events at Galeras volcano, Colombia: a summary and new information from broadband three-component measurements

    Directory of Open Access Journals (Sweden)

    M. Hellweg

    1999-06-01

    Full Text Available Long-duration events have been recorded at several active, andesitic volcanoes. Their main characteristics are a single, sharp frequency peak, and an exceptionally long coda. Because their seismograms resemble a screw, these signals are called "tornillos" in Colombia. These events have been recorded during different stages of volcanic activity at various volcanoes worldwide. Tornillos have occurred for example, as a short-term precursor to eruptions at Galeras volcano, Colombia (1992-1993; and at Asama volcano, Japan, (1983. At Tokachi volcano, Japan, they were recorded after an eruption (1989. The Tornillo's dominant frequency appears to be related to the time of occurrence during an eruption cycle. It is independent of epicentral distance, azimuth, travel time, and lapse time, indicating that it is a source characteristic. Damping coefficients for the tornillo's coda range between 0.002 and 0.02. In contrast, damping coefficients for normal long-period events lies between 0.010 and 0.025 and for volcano-tectonic events between 0.010 and 0.040. In March 1996, the Galeras seismic network, which consists of short period, single-component seismometers, was augmented with a broadband, three-component station. This station, installed 1.5 km south of Galeras active cone, recorded a series of six tornillos. Narrowband and broadband tornillo records have similar characteristics in the time and frequency domains.

  18. Volcano Monitoring Using Google Earth

    Science.gov (United States)

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

    2009-12-01

    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.

  19. Lahar hazards at Agua volcano, Guatemala

    Science.gov (United States)

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

    2001-01-01

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

  20. Volcanoes muon imaging using Cherenkov telescopes

    CERN Document Server

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

    2015-01-01

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting 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...

  1. Radial anisotropy ambient noise tomography of volcanoes

    Science.gov (United States)

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

    2016-04-01

    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.

  2. A field guide to Newberry Volcano, Oregon

    Science.gov (United States)

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

    2009-01-01

    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.

  3. Late Pleistocene-Holocene cataclysmic eruptions at Nevado de Toluca and Jocotitlan volcanoes, central Mexico

    Science.gov (United States)

    Macias, J.L.; Garcia, P.A.; Arce, J.L.; Siebe, C.; Espindola, J.M.; Komorowski, J.C.; Scott, K.

    1997-01-01

    This field guide describes a five day trip to examine deposits of Late Pleistocene-Holocene cataclysmic eruptions at Nevado de Toluca and Jocotitlan volcanoes in central Mexico. We will discuss the stratigraphy, petrology, and sedimentological characteristics of these deposits which provide insights into the eruptive history, type of volcanic activity, and transport and emplacement mechanisms of pyroclastic materials. These parameters will allow us to discuss the kinds of hazards and the risk that they pose to populations around these volcanoes. The area to be visited is tectonically complex thus we will also discuss the location of the volcanoes with respect to the tectonic environment. The first four days of the field trip will be dedicated to Nevado de Toluca Volcano (19 degrees 09'N; 99 degrees 45'W) located at 23 km. southwest of the City of Toluca, and is the fourth highest peak in the country, reaching an elevation of 4,680 meters above sea level (m.a.s.l.). Nevado de Toluca is an andesitic-dacitic stratovolcano, composed of a central vent excavated upon the remains of older craters destroyed by former events. Bloomfield and Valastro, (1974, 1977) concluded that the last cycle of activity occurred nearly equal 11,600 yr. ago. For this reason Nevado de Toluca has been considered an extinct volcano. Our studies, however, indicate that Nevado de Toluca has had at least two episodes of cone destruction by sector collapse as well as several explosive episodes including plinian eruptions and dome-destruction events. These eruptions occurred during the Pleistocene but a very young eruption characterized by surge and ash flows occurred ca. 3,300 yr. BP. This new knowledge of the volcano's eruptive history makes the evaluation of its present state of activity and the geological hazards necessary. This is important because the area is densely populated and large cities such as Toluca and Mexico are located in its proximity.

  4. Variations in community exposure to lahar hazards from multiple volcanoes in Washington State (USA)

    Science.gov (United States)

    Diefenbach, Angela K.; Wood, Nathan J.; Ewert, John W.

    2015-01-01

    Understanding how communities are vulnerable to lahar hazards provides critical input for effective design and implementation of volcano hazard preparedness and mitigation strategies. Past vulnerability assessments have focused largely on hazards posed by a single volcano, even though communities and officials in many parts of the world must plan for and contend with hazards associated with multiple volcanoes. To better understand community vulnerability in regions with multiple volcanic threats, we characterize and compare variations in community exposure to lahar hazards associated with five active volcanoes in Washington State, USA—Mount Baker, Glacier Peak, Mount Rainier, Mount Adams and Mount St. Helens—each having the potential to generate catastrophic lahars that could strike communities tens of kilometers downstream. We use geospatial datasets that represent various population indicators (e.g., land cover, residents, employees, tourists) along with mapped lahar-hazard boundaries at each volcano to determine the distributions of populations within communities that occupy lahar-prone areas. We estimate that Washington lahar-hazard zones collectively contain 191,555 residents, 108,719 employees, 433 public venues that attract visitors, and 354 dependent-care facilities that house individuals that will need assistance to evacuate. We find that population exposure varies considerably across the State both in type (e.g., residential, tourist, employee) and distribution of people (e.g., urban to rural). We develop composite lahar-exposure indices to identify communities most at-risk and communities throughout the State who share common issues of vulnerability to lahar-hazards. We find that although lahars are a regional hazard that will impact communities in different ways there are commonalities in community exposure across multiple volcanoes. Results will aid emergency managers, local officials, and the public in educating at-risk populations and developing

  5. Volcano-tectonic earthquakes: A new tool for estimating intrusive volumes and forecasting eruptions

    Science.gov (United States)

    White, Randall A.; McCausland, Wendy

    2016-01-01

    We present data on 136 high-frequency earthquakes and swarms, termed volcano-tectonic (VT) seismicity, which preceded 111 eruptions at 83 volcanoes, plus data on VT swarms that preceded intrusions at 21 other volcanoes. We find that VT seismicity is usually the earliest reported seismic precursor for eruptions at volcanoes that have been dormant for decades or more, and precedes eruptions of all magma types from basaltic to rhyolitic and all explosivities from VEI 0 to ultraplinian VEI 6 at such previously long-dormant volcanoes. Because large eruptions occur most commonly during resumption of activity at long-dormant volcanoes, VT seismicity is an important precursor for the Earth's most dangerous eruptions. VT seismicity precedes all explosive eruptions of VEI ≥ 5 and most if not all VEI 4 eruptions in our data set. Surprisingly we find that the VT seismicity originates at distal locations on tectonic fault structures at distances of one or two to tens of kilometers laterally from the site of the eventual eruption, and rarely if ever starts beneath the eruption site itself. The distal VT swarms generally occur at depths almost equal to the horizontal distance of the swarm from the summit out to about 15 km distance, beyond which hypocenter depths level out. We summarize several important characteristics of this distal VT seismicity including: swarm-like nature, onset days to years prior to the beginning of magmatic eruptions, peaking of activity at the time of the initial eruption whether phreatic or magmatic, and large non-double couple component to focal mechanisms. Most importantly we show that the intruded magma volume can be simply estimated from the cumulative seismic moment of the VT seismicity from:

  6. Digital Data for Volcano Hazards from Mount Rainier, Washington, Revised 1998

    Science.gov (United States)

    Schilling, S.P.; Doelger, S.; Hoblitt, R.P.; Walder, J.S.; Driedger, C.L.; Scott, K.M.; Pringle, P.T.; Vallance, J.W.

    2008-01-01

    Mount Rainier at 4393 meters (14,410 feet) is the highest peak in the Cascade Range; a dormant volcano having glacier ice that exceeds that of any other mountain in the conterminous United States. This tremendous mass of rock and ice, in combination with great topographic relief, poses a variety of geologic hazards, both during inevitable future eruptions and during the intervening periods of repose. The volcano's past behavior is the best guide to possible future hazards. The written history (about A.D. 1820) of Mount Rainier includes one or two small eruptions, several small debris avalanches, and many small lahars (debris flows originating on a volcano). In addition, prehistoric deposits record the types, magnitudes, and frequencies of other events, and areas that were affected. Mount Rainier deposits produced since the latest ice age (approximately during the past 10,000 years) are well preserved. Studies of these deposits indicate we should anticipate potential hazards in the future. Some phenomena only occur during eruptions such as tephra falls, pyroclastic flows and surges, ballistic projectiles, and lava flows while others may occur without eruptive activity such as debris avalanches, lahars, and floods. The five geographic information system (GIS) volcano hazard data layers used to produce the Mount Rainier volcano hazard map in USGS Open-File Report 98-428 (Hoblitt and others, 1998) are included in this data set. Case 1, case 2, and case 3 layers were delineated by scientists at the Cascades Volcano Observatory and depict various lahar innundation zones around the mountain. Two additional layers delineate areas that may be affected by post-lahar sedimentation (postlahar layer) and pyroclastic flows (pyroclastic layer).

  7. Peak Oil and other threatening peaks-Chimeras without substance

    Energy Technology Data Exchange (ETDEWEB)

    Radetzki, Marian, E-mail: marian@radetzki.bi [Lulea University of Technology (Sweden)

    2010-11-15

    The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth.

  8. Peak Oil and other threatening peaks. Chimeras without substance

    Energy Technology Data Exchange (ETDEWEB)

    Radetzki, Marian [Luleaa University of Technology (Sweden)

    2010-11-15

    The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth. (author)

  9. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  10. Thermal surveillance of active volcanoes. [infrared scanner recordings of thermal anomalies of Mt. Baker volcano

    Science.gov (United States)

    Friedman, J. D. (Principal Investigator)

    1974-01-01

    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.

  11. Characteristics of S-wave Envelope Broadening in the Changbaishan Tianchi Volcano

    Institute of Scientific and Technical Information of China (English)

    Fan Xiaoping; Li Qinghe; He Haibing; Yang Congjie; Jin Shumei

    2010-01-01

    High-frequency S-wave seismogram envelopes of microearthquakes broaden with increasing travel distance,a phenomenon known as S-wave envelope broadening.Multiple forward scattering and diffraction for the random inhomogeneities along the seismic ray path are the main causes of S-wave envelope broadening,so the phenomenon of S-wave envelope broadening is used to study the inhomogeneity of the medium.The peak delay time of an S-wave,which is defined as the time lag from the direct S-wave onset to the maximum amplitude arrival of its envelope.is accepted to quantify S-wave envelope broadening.204 small earthquake records in Changbaishan Tianchi volcano were analyzed by the S-wave envelope broadening algorithm.The results show that S-wave envelope broadening in the Changbaishan Tianchi volcano is obvious,and that the peak delay time of S-wave has a positive correlation with the hypocenter distance and frequency of the Swave.The relationships between the S-wave peak delay time and the hypocenter distance for different frequency bands were obtained using the statistics method.The results are beneficial to the understanding of the S-wave envelope broadening phenomena and the quantitative research on the inhomogeneities of the crust medium in the Changbaishan Tianchi volcano region.

  12. Volcanic gas impacts on vegetation at Turrialba Volcano, Costa Rica

    Science.gov (United States)

    Teasdale, R.; Jenkins, M.; Pushnik, J.; Houpis, J. L.; Brown, D. L.

    2010-12-01

    Turrialba volcano is an active composite stratovolcano that is located approximately 40 km east of San Jose, Costa Rica. Seismic activity and degassing have increased since 2005, and gas compositions reflect further increased activity since 2007 peaking in January 2010 with a phreatic eruption. Gas fumes dispersed by trade winds toward the west, northwest, and southwest flanks of Turrialba volcano have caused significant vegetation kill zones, in areas important to local agriculture, including dairy pastures and potato fields, wildlife and human populations. In addition to extensive vegetative degradation is the potential for soil and water contamination and soil erosion. Summit fumarole temperatures have been measured over 200 degrees C and gas emissions are dominated by SO2; gas and vapor plumes reach up to 2 km (fumaroles and gases are measured regularly by OVSICORI-UNA). A recent network of passive air sampling, monitoring of water temperatures of hydrothermal systems, and soil pH measurements coupled with measurement of the physiological status of surrounding plants using gas exchange and fluorescence measurements to: (1) identify physiological correlations between leaf-level gas exchange and chlorophyll fluorescence measurements of plants under long term stress induced by the volcanic gas emissions, and (2) use measurements in tandem with remotely sensed reflectance-derived fluorescence ratio indices to track natural photo inhibition caused by volcanic gas emissions, for use in monitoring plant stress and photosynthetic function. Results may prove helpful in developing potential land management strategies to maintain the biological health of the area.

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

    Science.gov (United States)

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

    2001-01-01

    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

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

    Science.gov (United States)

    Tsiapas, Elias

    2014-05-01

    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

  15. Significance Tests for Periodogram Peaks

    CERN Document Server

    Frescura, F A M; Frank, B S

    2007-01-01

    We discuss methods currently in use for determining the significance of peaks in the periodograms of time series. We discuss some general methods for constructing significance tests, false alarm probability functions, and the role played in these by independent random variables and by empirical and theoretical cumulative distribution functions. We also discuss the concept of "independent frequencies" in periodogram analysis. We propose a practical method for estimating the significance of periodogram peaks, applicable to all time series irrespective of the spacing of the data. This method, based on Monte Carlo simulations, produces significance tests that are tailor-made for any given astronomical time series.

  16. Spreading and collapse of big basaltic volcanoes

    Science.gov (United States)

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

    2016-04-01

    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.

    Science.gov (United States)

    D'Auria, L.

    2009-04-01

    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. Short term precursors of Strombolian explosions at Yasur volcano (Vanuatu)

    Science.gov (United States)

    Battaglia, Jean; Métaxian, Jean-Philippe; Garaebiti, Esline

    2016-03-01

    The seismic wavefield associated with Strombolian activity is usually dominated by explosion quakes (EQs), tremor, and various signals generated by surface phenomena. Looking at the seismicity recorded at Yasur volcano in 2008, we found that beside the transient events which occur simultaneously with surface explosions, the seismicity includes events related to a deeper process. These long period (LP) events form a family of similar events located below the southeastern part of the crater rim at a depth of about 700-1200 m below the summit. They are commonly followed by EQs with a variable delay. The examination of about 20,000 LP-EQ sequences at several stations near the summit shows that interevent delays follow distributions peaked around 11-12 s. This short delay compared to the relatively great source depth of the LPs favors a causal relationship linked to pressure transfer rather than gas slug propagation after nucleation at the LP source.

  19. Hubbert's Peak -- A Physicist's View

    Science.gov (United States)

    McDonald, Richard

    2011-04-01

    Oil, as used in agriculture and transportation, is the lifeblood of modern society. It is finite in quantity and will someday be exhausted. In 1956, Hubbert proposed a theory of resource production and applied it successfully to predict peak U.S. oil production in 1970. Bartlett extended this work in publications and lectures on the finite nature of oil and its production peak and depletion. Both Hubbert and Bartlett place peak world oil production at a similar time, essentially now. Central to these analyses are estimates of total ``oil in place'' obtained from engineering studies of oil reservoirs as this quantity determines the area under the Hubbert's Peak. Knowing the production history and the total oil in place allows us to make estimates of reserves, and therefore future oil availability. We will then examine reserves data for various countries, in particular OPEC countries, and see if these data tell us anything about the future availability of oil. Finally, we will comment on synthetic oil and the possibility of carbon-neutral synthetic oil for a sustainable future.

  20. Crater Peak (Mt. Spurr), Alaska: Eruptions of 1992

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Alaska has a number of active and potentially active volcanoes. More than one-half of the population of Alaska lives within 300 km of an active volcano. In the last...

  1. Discriminate Modelling of Peak and Off-Peak Motorway Capacity

    Directory of Open Access Journals (Sweden)

    Hashim Mohammed Alhassan

    2013-02-01

    Full Text Available Traffic theory is concerned with the movement of discrete objects in real time over a finite network in 2 Dimensions. It is compatible with or dependent on fundamental diagram of traffic. Without question traffic flow is an essential quantitative parameter that is used in planning, designs and roadway improvements.  Road capacity is significant because it is an important indicator of road performance and can point road managers in the right road maintenance and traffic management direction. In this paper four direct empirical capacity measurement methods have been considered. To test the efficacy of each method, data for peak period, off-peak and transition to peak have been used. The headway and the volume methods lack predictive capability and are suitable only for current assessment of flow rates.  The product limit method is weak in its predictive capability in view of the arbitrariness in the selection of the capacity value. It is also an extreme value method; hence not all volume data can be used with this method. The fundamental diagram method has good predictive capability and furnishes capacity values consistent with the standard of the facility. Unlike other methods, it does not rely on bottleneck conditions to deliver the capacity value.  The paper concluded that each method is uniquely suited to prevailing conditions and can be so employed.

  2. Dynamics of strombolian eruptions at Batu Tara volcano (Indonesia)

    Science.gov (United States)

    Scarlato, P.; Del Bello, E.; Gaudin, D.; Taddeucci, J.; Ricci, T.; Cesaroni, C.

    2015-12-01

    In September 2014, high-speed imaging and acoustic data were acquired during 3 days of almost continuous recording (04-06/09/2015) at Batu Tara Volcano, in the small isolated island of Pulau Komba, in the Flores Sea (about 50 km N of Lembata). This volcano is very similar to the Italian Stromboli Volcano in both eruptive style and edifice morphology. The field experiment aimed at investigating degassing and explosive dynamics using a combination of GPS synchronized devices deployed in direct view of the active vent: i) a high-speed visible camera acquiring images at 500 frames per second (fps),ii) a thermal infrared (FLIR) camera acquiring at 50-200 fps, iii) a visible time lapse camera (GO-PRO) acquiring at 0.2-0.5 Hz (2 - 5 s interval), iv) two broadband microphones (Freq. range of kHz to 0.1 Hz) sampled at 10 kHz. Explosions can be discriminated in type according to their visual, thermal and acoustic features.Some explosions are characterized by a first sudden radial ejection of large spatter and bombs (main pulse), eventually followed by other similar events (secondary pulses), with very little amount of ash involved. In these eruptions, infrasonic waveforms are characterized by a first, high amplitude transient, with a first positive peak pressure followed by rapid dampening, typical of a Strombolian eruption.Other explosions are characterized by the sustained ejection of a dense jet of ash, with abundant decimeter to meter sized spatter and hot blocks.These eruptions are not accompanied by a maximum peak pressure at the eruption onset. Spectrograms show a high frequency component propagating for the entire duration of the signal.These two distinct types are sometimes overlapping and eruptions show a high amplitude transient followed by a high frequency coda. These different evolutions suggest that there are at least two repeatable explosion dynamics occurring in the conduit, with comparable gas overpressure, source depth and amount of gas involved

  3. Seismic unrest at Katla Volcano- southern Iceland

    Science.gov (United States)

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

    2014-05-01

    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

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

    Science.gov (United States)

    Thompson, Susan A.; Thompson, Keith S.

    1996-01-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

  6. USGS U.S. Volcanoes with Elevated Status

    Data.gov (United States)

    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...

  7. Longitudinal peak detected Schottky spectrum

    CERN Document Server

    Shaposhnikova, E

    2009-01-01

    The "peak detected Schottky" spectrum is a diagnostic used since the late seventies for beam observation in the SPS and now already applied to the LHC. This tool was always believed, however without proof, to give a good picture of the particle distribution in synchrotron frequencies similar to the longitudinal Schottky spectrum of unbunched beam for revolution frequencies.In this paper an analysis of this measurement technique is presented both in a general form and for the particular realisation in the SPS. In addition the limitations of the present experimental set-up are discussed together with possible improvements. The analysis shows that for an optimised experimental set-up the spectrum of the peak detected signal is very close to the synchrotron frequency distribution inside the bunch - much closer than that given by the traditional longitudinal bunched-beam Schottky spectrum.

  8. The Cenozoic Volcanoes in Northeast China

    Institute of Scientific and Technical Information of China (English)

    LIU Jiaqi; HAN Jingtai; GUO Zhengfu

    2002-01-01

    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.

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

    Science.gov (United States)

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

    2000-01-01

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

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

    Science.gov (United States)

    Dayton, Rebecca; Edwards, Carrie; Sisler, Michelle

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

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

    Science.gov (United States)

    Russo, Joseph; Mattox, Stephen; Kildau, Nicole

    2010-01-01

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

  12. Volcanoes muon imaging using Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-21

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

  13. Applications of geophysical methods to volcano monitoring

    Science.gov (United States)

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

    2006-01-01

    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

  14. Volcanoes muon imaging using Cherenkov telescopes

    Science.gov (United States)

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

    2016-01-01

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

  15. Drivers of peak sales for pharmaceutical brands

    NARCIS (Netherlands)

    Fischer, Marc; Leeflang, Peter S. H.; Verhoef, Peter C.

    2010-01-01

    Peak sales are an important metric in the pharmaceutical industry. Specifically, managers are focused on the height-of-peak-sales and the time required achieving peak sales. We analyze how order of entry and quality affect the level of peak sales and the time-to-peak-sales of pharmaceutical brands.

  16. The origin of the Hawaiian Volcano Observatory

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-15

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

  17. The Geothermal System of the Arjuno-Welirang Volcano (East Java, Indonesia)

    Science.gov (United States)

    Inguaggiato, S.; Mazzini, A.; Vita, F.

    2015-12-01

    Arjuno-Welirang is a twin strato-volcano system located in the East of Java (Indonesia). It features two main peaks: Arjuno (3339 masl) and Welirang (3156 masl). The last recorded eruptive activity took place in August 1950 from the flanks of Kawah Plupuh and in October 1950 by the NW part of the Gunung Welirang. This strato-volcano is characterized by a solfataric area, with high T-vent fumarole at least up to 220°C, located mainly in the Welirang crater zone where sulphur deposits are abundant. In addition, several hot springs vent from the flanks of the volcano, indicating the presence of a large hydrothermal system During July 2015 we carried out a geochemical field campaign on the Arjuno-Welirang volcano-hydrothermal system area sampling water and dissolved gases from the thermal and cold springs located on the flanks of the volcano and from two high-T fumaroles located on the summit area of Welirang. Hydrothermal springs reveal temperatures up to 53°C and pH between 6.2 and 8.2. The hydrothermal springs show a volatile content (mainly CO2 and He) that is several order of magnitude higher than the Air Saturated Waters values (ASW) indicating a strong gas/water interaction processes between waters of meteoric origin and deep volatiles of volcanic origin. The hydrothermal springs have dissolved helium isotopic values with clear magmatic signature (R/Ra around 7) that is remarkably close to the helium isotope values from the fumaroles (R/Ra= 7.30).

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

    Science.gov (United States)

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

    2014-01-01

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

  19. Muons reveal the interior of volcanoes

    CERN Multimedia

    Francesco Poppi

    2010-01-01

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

  20. The reawakening of Alaska's Augustine volcano

    Science.gov (United States)

    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.

    2006-01-01

    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).

  1. Volcano hazards at Fuego and Acatenango, Guatemala

    Science.gov (United States)

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

    2001-01-01

    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.

  2. New volcanoes discovered in southeast Australia

    Science.gov (United States)

    Wendel, JoAnna

    2014-07-01

    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.

  3. Carbonate assimilation at Merapi volcano, Java Indonesia

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  4. Degassing and differentiation in subglacial volcanoes, Iceland

    Science.gov (United States)

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

    1991-01-01

    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.

  5. The coalescence and organization of lahars at Semeru volcano, Indonesia

    Science.gov (United States)

    Doyle, E. E.; Cronin, S. J.; Cole, S. E.; Thouret, J.-C.

    2010-10-01

    We present multi-parameter geophysical measurements of rainfall-induced lahars at Semeru Volcano, East Java, using two observation sites 510 m apart, 11.5 km from the summit. Our study site in the Curah Lengkong channel is composed of a 30-m wide box-valley, with a base of gravel and lava bedrock, representing an ideal geometry for high density measurements of active lahars. Instrumentation included pore-pressure sensors (stage), a broad-band seismograph (arrival times, vibrational energy, and turbulence), video footage, and direct bucket sampling. A total of 8 rainfall-induced lahars were recorded, with durations of 1-3 h, heights 0.5-2 m, and peak velocities 3-6 m/s. Flow types ranged from dilute to dense hyperconcentrated flows. These recorded flows were commonly composed of partly coalesced, discrete and unsteady gravity current packets, represented by multiple peaks within each lahar. These packets most likely originate from multiple lahar sources, and can be traced between instrument sites. Those with the highest concentrations and greatest wetted areas were often located mid-lahar at our measured reach, accelerating towards the flow front. As these lahars travel downstream, the individual packets thus coalesce and the flow develops a more organised structure. Observations of different degrees of coalescence between these discrete flow packets illustrate that a single mature debris flow may have formed from multiple dynamically independent lahars, each with different origins.

  6. Hazard maps of Colima volcano, Mexico

    Science.gov (United States)

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

    2011-12-01

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

  7. The Soufriere Hills Volcano, Montserrat, is "log logistic"

    Science.gov (United States)

    Connor, C.; Sparks, S.; Mason, R.; Bonadonna, C.; Young, S.; Lejeune, A.

    2002-12-01

    The Soufriere Hills Volcano, Montserrat, experienced a remarkable episode of activity in September-October, 1997. During this period, 75 vulcanian explosions generated plumes that commonly rose between 5 to 15 km a.s.l. accompanied by pyroclastic flows. Repose intervals between vulcanian explosions varied from 2.77 to 33.7 hrs, with a median repose interval of 9.0 hr and mean of 9.6 hr. During the eruption, this narrow range of repose intervals was used in a practical way to provide qualitative forecasts of volcanic hazard. We analyzed repose intervals for these 75 vulcanian explosions and discovered they fit a log logistic distribution with > 99% confidence. This comparatively simple, two parameter model accounts for departures from a classical material failure model (Weibull distribution) at long repose intervals, and serves as the basis for improved hazard forecasts. The crucial differences between Weibull, and log logistic probability models for volcano repose interval are illustrated by comparing their hazard functions. For Weibull distributions the hazard increases indefinitely: the volcano must erupt explosively eventually and as time increases the probability of an eruption in the next time interval becomes much greater. In contrast the log logistic hazard function goes through a simple maximum. We note that largest magnitude eruptions in the time series, deduced from column height estimates and seismic explosion amplitudes, correlate with the peak in the log logistic hazard function. The excellent model fit is explained in terms of two competing processes operating in the upper conduit on different time scales. Gas bubble pressure increases with time due to exsolution and due to rheological stiffening of magma of magma following an abrupt decompression caused by a previous explosion. Once bubble gas pressure exceeds the tensile strength of the magma an explosion occurs - a material failure model that should follow a Weibull distribution. However, this

  8. Neurofeedback training for peak performance

    Directory of Open Access Journals (Sweden)

    Marek Graczyk

    2014-11-01

    Full Text Available [b]aim[/b]. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs. [b]case study[/b]. The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. [b]conclusion[/b]. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  9. Peak Detection Using Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Omar Daoud

    2014-07-01

    Full Text Available A new work based-wavelet transform is designed to o vercome one of the main drawbacks that found in the present new technologies. Orthogonal Frequency Divi sion Multiplexing (OFDMis proposed in the literature to enhance the multimedia resolution. Ho wever, the high peak power (PAPR values will obstr uct such achievements. Therefore, a new proposition is found in this work, making use of the wavelet transforms methods, and it is divided into three ma in stages; de-noising stage, thresholding stage and then the replacement stage. In order to check the system stages validity; a mat hematical model has been built and its checked afte r using a MATLAB simulation. A simulated bit error ra te (BER achievement will be compared with our previously published work, where an enhancement fro m 8×10 -1 to be 5×10 -1 is achieved. Moreover, these results will be compared to the work found in the l iterature, where we have accomplished around 27% PAPR extra reduction. As a result, the BER performance has been improved for the same bandwidth occupancy. Moreover and due to the de-noise stage, the verification rate ha s been improved to reach 81%. This is in addition t o the noise immunity enhancement.

  10. Common processes at unique volcanoes – a volcanological conundrum

    Directory of Open Access Journals (Sweden)

    Katharine eCashman

    2014-11-01

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

  11. Instrumental lahar monitoring at Merapi Volcano, Central Java, Indonesia

    Science.gov (United States)

    Lavigne, F.; Thouret, J.-C.; Voight, B.; Young, K.; LaHusen, R.; Marso, J.; Suwa, H.; Sumaryono, A.; Sayudi, D.S.; Dejean, M.

    2000-01-01

    More than 50 volcanic debris flows or lahars were generated around Mt Merapi during the first rainy season following the nuees ardentes of 22 November 1994. The rainfalls that triggered the lahars were analyzed, using such instruments as weather radar and telemetered rain gauges. Lahar dynamics were also monitored, using new non-contact detection instrumentation installed on the slopes of the volcano. These devices include real-time seismic amplitude measurement (RSAM), seismic spectral amplitude measurement (SSAM) and acoustic flow monitoring (AFM) systems. Calibration of the various systems was accomplished by field measurements of flow velocities and discharge, contemporaneously with instrumental monitoring. The 1994–1995 lahars were relatively short events, their duration in the Boyong river commonly ranging between 30 min and 1 h 30 min. The great majority (90%) of the lahars was recognized at Kaliurang village between 13:00 and 17:30 h, due to the predominance of afternoon rainfalls. The observed mean velocity of lahar fronts ranged between 1.1 and 3.4 m/s, whereas the peak velocity of the flows varied from 11 to 15 m/s, under the Gardu Pandang viewpoint location at Kaliurang, to 8–10 m/s at a section 500 m downstream from this site. River slopes vary from 28 to 22 m/km at the two sites. Peak discharges recorded in various events ranged from 33 to 360 m3/s, with the maximum value of peak discharge 360 m3/s, on 20 May 1995. To improve the lahar warning system along Boyong river, some instrumental thresholds were proposed: large and potentially hazardous lahars may be detected by RSAM units exceeding 400, SSAM units exceeding 80 on the highest frequency band, or AFM values greater than 1500 mV on the low-gain, broad-band setting.

  12. Emplacement of Holocene silicic lava flows and domes at Newberry, South Sister, and Medicine Lake volcanoes, California and Oregon

    Science.gov (United States)

    Fink, Jonathan H.; Anderson, Steven W.

    2017-07-19

    This field guide for the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly 2017 focuses on Holocene glassy silicic lava flows and domes on three volcanoes in the Cascade Range in Oregon and California: Newberry, South Sister, and Medicine Lake volcanoes. Although obsidian-rich lava flows have been of interest to geologists, archaeologists, pumice miners, and rock hounds for more than a century, many of their emplacement characteristics had not been scientifically observed until two very recent eruptions in Chile. Even with the new observations, several eruptive processes discussed in this field trip guide can only be inferred from their final products. This makes for lively debates at outcrops, just as there have been in the literature for the past 30 years.Of the three volcanoes discussed in this field guide, one (South Sister) lies along the main axis defined by major peaks of the Cascade Range, whereas the other two lie in extensional tectonic settings east of the axis. These two tectonic environments influence volcano morphology and the magmatic and volcanic processes that form silicic lava flows and domes. The geomorphic and textural features of glass-rich extrusions provide many clues about their emplacement and the magma bodies that fed them.The scope of this field guide does not include a full geologic history or comprehensive explanation of hazards associated with a particular volcano or volcanic field. The geochemistry, petrology, tectonics, and eruption history of Newberry, South Sister, and Medicine Lake volcanic centers have been extensively studied and are discussed on other field excursions. Instead, we seek to explore the structural, textural, and geochemical evolution of well-preserved individual lava flows—the goal is to understand the geologic processes, rather than the development, of a specific volcano.

  13. A sight "fearfully grand": eruptions of Lassen Peak, California, 1914 to 1917

    Science.gov (United States)

    Clynne, Michael A.; Christiansen, Robert L.; Stauffer, Peter H.; Hendley, James W.; Bleick, Heather A.

    2014-01-01

    On May 22, 1915, a large explosive eruption at the summit of Lassen Peak, California, the southernmost active volcano in the Cascade Range, devastated nearby areas and rained volcanic ash as far away as 280 miles to the east. This explosion was the most powerful in a series of eruptions during 1914–17 that were the last to occur in the Cascade Range before the 1980 eruption of Mount St. Helens, Washington. A century after the Lassen eruptions, work by U.S. Geological Survey (USGS) scientists in cooperation with the National Park Service is shedding new light on these events.

  14. Darwin's triggering mechanism of volcano eruptions

    Science.gov (United States)

    Galiev, Shamil

    2010-05-01

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

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

    Science.gov (United States)

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

    2005-12-01

    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

  16. Facility Location with Double-peaked Preferences

    DEFF Research Database (Denmark)

    Filos-Ratsikas, Aris; Li, Minming; Zhang, Jie

    2015-01-01

    We study the problem of locating a single facility on a real line based on the reports of self-interested agents, when agents have double-peaked preferences, with the peaks being on opposite sides of their locations. We observe that double-peaked preferences capture real-life scenarios and thus...... complement the well-studied notion of single-peaked preferences. We mainly focus on the case where peaks are equidistant from the agents’ locations and discuss how our results extend to more general settings. We show that most of the results for single-peaked preferences do not directly apply to this setting...

  17. Effect of gas emissions from Tianchi volcano (NE China) on environment and its potential volcanic hazards

    Institute of Scientific and Technical Information of China (English)

    GUO; Zhengfu; LIU; Jiaqi; HAN; Jingtai; HE; Huaiyu; DAI; Guoliang; YOU; Haitao

    2006-01-01

    The Tianchi volcano in the Changbai Mountains is located on the boundary between China and North Korea. There are many times of eruptions of the Tianchi volcano during the Holocene. One of its large eruptions occurred around 1000 years ago dated by 14C method and historical records. Composition of products of the largest Tianchi volcanic eruption studied is characterized by comenditic Plinian fallout and unwelded ignimbrite, which are mainly distributed in China and North Korea. Caldera is about 4.4 km long and 3.4 km wide, which had filled with water (e.g. Tianchi Lake). The Tianchi volcanic cone is about 2700 m high above sea level. The Tianchi Lake is located on the summit of the volcanic cone, that is also highest peak of the Changbai Mountains in northeastern China. This study analyzed Cl, F, S and H2O concentrations of melt inclusions in the phenocryst minerals (anorthoclase and quartz) and co-existing matrix glasses using the electron microprobe and estimated environmental effect of Tianchi volcanic gases. The authors proposed a new method to evaluate future eruption of active volcano and estimate potential volcanic hazards based on contents of volatile emissions. Using this method, we made a perspective of future volcanic hazard in this region.

  18. Experimental Elucidation of the Oxygen Reduction Volcano in Base on a Pt Alloy Single Crystal

    DEFF Research Database (Denmark)

    Jensen, Kim Degn; Tymoczko, Jakub; Bandarenka, Aliaksandr S.;

    2016-01-01

    and base.[1,2] In our earlier studies, we mapped out the experimental Sabatier volcano for the oxygen reduction reaction in 0.1 M HClO4 using the Cu/Pt(111) near-surface alloy system, see Figure 1 for near-surface alloy schematic.[3,4] In this study, as those of [3,4], we found that by changing...... the subsurface coverage of Cu we could tune the surface binding of the key reaction intermediate, OH; we thus monitored the OH binding energy shift through the observable shifts in the base voltammograms in both acidic and alkaline media. Further, we elucidate the experimental oxygen reduction volcano in 0.1 M...... to Pt(111). However, all surfaces show a ~4 fold improvement in activity in 0.1 M KOH, relative to the same surface in 0.1 M HClO4. At the peak of the volcano the surface exhibits an exceptionally high specific activity of 90 mA/cm2 at 0.9 V with respect to the reversible hydrogen electrode. Thus, our...

  19. Voluminous submarine lava flows from Hawaiian volcanoes

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-05-01

    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.

  20. Vulcan's fury: Man against the volcano

    Science.gov (United States)

    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.

  1. Decision Analysis Tools for Volcano Observatories

    Science.gov (United States)

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

    2005-12-01

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

  2. On the morphometry of terrestrial shield volcanoes

    Science.gov (United States)

    Grosse, Pablo; Kervyn, Matthieu

    2016-04-01

    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

  3. Buried caldera of mauna kea volcano, hawaii.

    Science.gov (United States)

    Porter, S C

    1972-03-31

    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.

  4. Publications of the Volcano Hazards Program 2014

    Science.gov (United States)

    Nathenson, Manuel

    2016-04-08

    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.

  5. Monitoring active volcanoes: The geochemical approach

    Directory of Open Access Journals (Sweden)

    Takeshi Ohba

    2011-06-01

    Full Text Available

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

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

  6. Geothermal Exploration of Newberry Volcano, Oregon

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

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

  7. Seismic and infrasound monitoring at Cotopaxi volcano

    Science.gov (United States)

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

    2012-04-01

    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).

  8. Detecting Blackholes and Volcanoes in Directed Networks

    CERN Document Server

    Li, Zhongmou; Liu, Yanchi

    2010-01-01

    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...

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

    Science.gov (United States)

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

    2006-01-27

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

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

    Science.gov (United States)

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

    2013-12-01

    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.

  11. July 1973 ground survey of active Central American volcanoes

    Science.gov (United States)

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

    1973-01-01

    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.

  12. The critical role of volcano monitoring in risk reduction

    Directory of Open Access Journals (Sweden)

    R. I. Tilling

    2008-01-01

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

  13. Geologic map of Medicine Lake volcano, northern California

    Science.gov (United States)

    Donnelly-Nolan, Julie M.

    2011-01-01

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

  14. The petrology, geochronology and geochemistry of Hauhungatahi volcano, S.W. Taupo Volcanic Zone

    Science.gov (United States)

    Cameron, Errol; Gamble, John; Price, Richard; Smith, Ian; McIntosh, William; Gardner, Mairi

    2010-02-01

    Hauhungatahi volcano is an eroded andesitic edifice 10 km west of Ruapehu volcano constructed on an upfaulted block of Mesozoic marine sediments. Hauhungatahi andesites are distinctively clinopyroxene-phyric with high ratios of clinopyroxene:plagioclase. This contrasts with the plagioclase-phyric dominated assemblages in the stratovolcanoes such as Ruapehu and Tongariro. Hauhungatahi andesites show high MgO (> 8.0% wt), Sr (> 400 ppm), Ni (> 100 ppm) and Cr (> 400 ppm) and low Si, Rb, Ba and Zr relative to andesites from Ruapehu volcano, with fractionated LREE (Ce/Sm) n ~ 2 and flat HREE (Dy/Yb) n ~ 1. Sr-isotope ratios are lower at equivalent Nd isotope ratios than Ruapehu andesites of the (oldest) Te Herenga Formation. 40Ar/ 39Ar step-heating experiments of groundmass concentrates of 4 samples have yielded ages between 881 ± 83 ka and 961 ± 59 ka, with a weighted mean age of 933 ± 46 ka, indicating that Hauhungatahi is significantly older than Ruapehu Volcano where volcanism commenced ~ 250-300 ka. Hauhungatahi is therefore similar in age to the older andesitic edifices that are marginal to the TVZ (eg Titiraupenga, Pureora and Rolles Peak). We suggest that these high-Mg andesites hold clues to the early conditioning of the lithosphere beneath TVZ, prior to the establishment of the large andesite stratovolcanoes that presently dominate the skyline at the southern end of TVZ. The relatively low abundance of plagioclase in the phenocryst assemblages hints at high P H 2O and possible involvement of amphibole in the source.

  15. 27 CFR 9.140 - Atlas Peak.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Atlas Peak. 9.140 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.140 Atlas Peak. (a) Name. The name of the viticultural area described in this section is “Atlas Peak.”...

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

    Directory of Open Access Journals (Sweden)

    Sri Hidayati

    2014-07-01

    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.

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

    Science.gov (United States)

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

    2010-05-01

    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

  18. Measurements of slope distances and vertical angles at Mount Baker and Mount Rainier, Washington, Mount Hood and Crater Lake, Oregon, and Mount Shasta and Lassen Peak, California, 1980-1984

    Science.gov (United States)

    Chadwick, W.W.

    1985-01-01

    Personnel of the U.S.Geological Survey's Cascades Volcano Observatory established trilateration networks at Mount Baker, Mount Rainier, Mount Hood, Crater Lake, Mount Shasta, and Lassen Peak in 1980-1984. These networks are capable of detecting changes in slope distance of several centimeters or more. The networks were established to provide baseline information on potentially active volcanoes and were designed along guidelines found useful at Mount St. Helens. Periodic reoccupation of the networks is planned as part of the overall monitoring program of Cascades volcanoes. Methodology, slope distance and vertical angle data, maps of the networks, and benchmark descriptions are presented in this report. Written benchmark descriptions are augmented by photographs, which we have found by experience to very useful in relocating the marks. All repeat measurements at the six volcanoes are probably within measurement error.

  19. Volcanic tremor associated with eruptive activity at Bromo volcano

    Directory of Open Access Journals (Sweden)

    E. Gottschämmer

    1999-06-01

    Full Text Available Three broadband stations were deployed on Bromo volcano, Indonesia, from September to December 1995. The analysis of the seismograms shows that the signals produced by the volcanic sources cover the frequency range from at least 25 Hz down to periods of several minutes and underlines, therefore, the importance of broadband recordings. Frequency analysis reveals that the signal can be divided into four domains. In the traditional frequency range of volcanic tremor (1-10 Hz sharp transitions between two distinct values of the tremor amplitude can be observed. Additional tremor signal including frequencies from 10 to 20 Hz could be found during late November and early December. Throughout the whole experiment signals with periods of some hundred seconds were observed which are interpreted as ground tilts. For these long-period signals a particle motion analysis was performed in order to estimate the source location. Depth and radius can be estimated when the source is modeled as a sudden pressure change in a sphere. The fourth frequency range lies between 0.1 and 1 Hz and is dominated by two spectral peaks which are due to marine microseism. The phase velocity and the direction of wave propagation of these signals could be determined using the tripartite-method.

  20. On the trail of double peak hydrographs

    Science.gov (United States)

    Martínez-Carreras, Núria; Hissler, Christophe; Gourdol, Laurent; Klaus, Julian; Juilleret, Jérôme; François Iffly, Jean; McDonnell, Jeffrey J.; Pfister, Laurent

    2016-04-01

    A double peak hydrograph features two peaks as a response to a unique rainfall pulse. The first peak occurs at the same time or shortly after the precipitation has started and it corresponds to a fast catchment response to precipitation. The delayed peak normally starts during the recession of the first peak, when the precipitation has already ceased. Double peak hydrographs may occur for various reasons. They can occur (i) in large catchments when lag times in tributary responses are large, (ii) in urban catchments where the first peak is often caused by direct surface runoff on impervious land cover, and the delayed peak to slower subsurface flow, and (iii) in non-urban catchments, where the first and the delayed discharge peaks are explained by different runoff mechanisms (e.g. overland flow, subsurface flow and/or deep groundwater flow) that have different response times. Here we focus on the third case, as a formal description of the different hydrological mechanisms explaining these complex hydrological dynamics across catchments with diverse physiographic characteristics is still needed. Based on a review of studies documenting double peak events we have established a formal classification of catchments presenting double peak events based on their regolith structure (geological substratum and/or its weathered products). We describe the different hydrological mechanisms that trigger these complex hydrological dynamics across each catchment type. We then use hydrometric time series of precipitation, runoff, soil moisture and groundwater levels collected in the Weierbach (0.46 km2) headwater catchment (Luxembourg) to better understand double peak hydrograph generation. Specifically, we aim to find out (1) if the generation of a double peak hydrograph is a threshold process, (2) if the hysteretic relationships between storage and discharge are consistent during single and double peak hydrographs, and (3) if different functional landscape units (the hillslopes

  1. A compilation of sulfur dioxide and carbon dioxide emission-rate data from Cook Inlet volcanoes (Redoubt, Spurr, Iliamna, and Augustine), Alaska during the period from 1990 to 1994

    Science.gov (United States)

    Doukas, Michael P.

    1995-01-01

    Airborne sulfur dioxide (SO2) gas sampling of the Cook Inlet volcanoes (Mt. Spurr, Redoubt, Iliamna, and Augustine) began in 1986 when several measurements were carried out at Augustine volcano during the eruption of 1986 (Rose and others, 1988). More systematic monitoring for SO2 began in March 1990 and for carbon dioxide (CO2) began in June, 1990 at Redoubt Volcano (Brantley, 1990 and Casadevall and others, 1994) and continues to the present. This report contains all of the available daily SO2 and CO2 emission rates determined by the U.S. Geological Survey (USGS) from March 1990 through July 1994. Intermittent measurements (four to six month intervals) at Augustine and Iliamna began in 1990 and continues to the present. Intermittent measurements began at Mt. Spurr volcano in 1991, and were continued at more regular intervals from June, 1992 through the 1992 eruption at the Crater Peak vent to the present.

  2. P-wave scattering and the distribution of heterogeneity around Etna volcano

    Directory of Open Access Journals (Sweden)

    Toni Zieger

    2016-09-01

    Full Text Available Volcanoes and fault zones are areas of increased heterogeneity in the Earth crust that leads to strong scattering of seismic waves. For the understanding of the volcanic structure and the role of attenuation and scattering processes it is important to investigate the distribution of heterogeneity. We used the signals of air-gun shots to investigate the distribution of heterogeneity around Mount Etna. We devise a new methodology that is based on the coda energy ratio which we define as the ratio between the energy of the direct P-wave and the energy in a later coda window. This is based on the basic assumption that scattering caused by heterogeneity removes energy from the direct P-waves. We show that measurements of the energy ratio are stable with respect to changes of the details of the time windows definitions. As an independent proxy of the scattering strength along the ray path we measure the peak delay time of the direct P-wave. The peak delay time is well correlated with the coda energy ratio. We project the observation in the directions of the incident rays at the stations. Most notably is an area with increased wave scattering in the volcano and east of it. The strong heterogeneity found supports earlier observations and confirms the possibility to use P-wave sources for the determination of scattering properties. We interpret the extension of the highly heterogeneous zone towards the east as a potential signature of inelastic deformation processes induced by the eastward sliding of flank of the volcano.

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

    Science.gov (United States)

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

    2014-01-01

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

    Science.gov (United States)

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

    2015-04-01

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

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

    Science.gov (United States)

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

    2015-04-01

    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

  6. Imaging magma plumbing beneath Askja volcano, Iceland

    Science.gov (United States)

    Greenfield, Tim; White, Robert S.

    2015-04-01

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

  7. Lahar Hazard Modeling at Tungurahua Volcano, Ecuador

    Science.gov (United States)

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

    2003-04-01

    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

  8. 36 CFR 7.25 - Hawaii Volcanoes National Park.

    Science.gov (United States)

    2010-07-01

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

  9. A Probabilistic Approach for Real-Time Volcano Surveillance

    Science.gov (United States)

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

    2016-12-01

    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.

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

    Science.gov (United States)

    Schipper, Stacia; Mattox, Stephen

    2010-01-01

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

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

    Science.gov (United States)

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

  12. Monte Carlo Volcano Seismic Moment Tensors

    Science.gov (United States)

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

    2015-12-01

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

  13. VALVE: Volcano Analysis and Visualization Environment

    Science.gov (United States)

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

    2002-12-01

    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

  14. Copahue volcano and its regional magmatic setting

    Science.gov (United States)

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

    2016-01-01

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

  15. Mechanical coupling between earthquakes, volcanos and landslides

    Science.gov (United States)

    Feigl, K. L.; Retina Team

    2003-04-01

    "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

  16. Delayed earthquake-volcano interactions at Campi Flegrei Caledra, Italy

    Science.gov (United States)

    Lupi, Matteo; Frehner, Marcel; Saenger, Erik H.; Tisato, Nicola; Weis, Philipp; Geiger, Sebastian; Chiodini, Giovanni; Driesner, Thomas

    2015-04-01

    The Campi Flegrei Caldera near Naples, Italy, is arguably one of the world's prime examples of volcanic hazard in a heavily populated area. Over the last centuries the ground of the caldera went through cyclical phases of inflation and deflation. The inflation phase consists of rapid vertical ground movements associated with the emission of volcanic gases marked by a strong magmatic component. Such deformations are suggested to be caused by pulses of CO2-rich fluids injected into the caldera's shallow hydrothermal system or by the intrusion of magmatic bodies at shallow depths. We show that since 1945 the uplift crises occurring at the Campi Flegrei Caldera are caused by large regional earthquakes. Our results point out that maximum uplift rates in the caldera take place about three years after the occurrence of large earthquakes that imposed a log10(PGA[cm s-2]) greater than 0.18. These observations are supported by forward seismic simulations and with a semi-quantitative statistical analysis of ground surface displacements and Peak Ground Accelerations (PGA). Our proposed geomechanical model integrates and simplifies previous empirical concepts of upwelling fluids that pressurize the region beneath the Campi Flegrei causing ground surface uplift. Numerical simulations indicate that passing seismic body waves impose high dynamic strains at the upper boundary of the deep magma reservoir as well as at the brittle/ductile transition at about 3 km depth. Such dynamic strains induce short-lived brittle failure in nominally ductile regions causing the release of magmatic fluids. The approximately 3-years time lag between the earthquake and maximum surface uplift reflects the time during which the lithostatically pressured fluids ascend through hot, nominally ductile lithologies without expanding. After passing the brittle/ductile transition at ~3 km depth the H2O-CO2 mixture can expand and phase-separate, pressurizing the subsurface. This leads to a rapid ground uplift

  17. Geology of El Chichon volcano, Chiapas, Mexico

    Science.gov (United States)

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

    1984-01-01

    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

    Science.gov (United States)

    Allen, Carlton C.; Oehler, Dorothy Z.

    2010-01-01

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

  19. Galactic Super-volcano in Action

    Science.gov (United States)

    2010-08-01

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

  20. Volcano morphometry and volume scaling on Venus

    Science.gov (United States)

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

    1994-03-01

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

  1. Volcano deformation and subdaily GPS products

    Science.gov (United States)

    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

    Science.gov (United States)

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

    2001-01-01

    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

    Science.gov (United States)

    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

    2010-01-01

    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. Hydrologic hazards in the lower Drift River basin associated with the 1989-1990 eruptions of Redoubt Volcano, Alaska

    Science.gov (United States)

    Dorava, J.M.; Meyer, D.F.

    1994-01-01

    The eruptions of Redoubt Volcano between December 14, 1989 and April 26, 1990 triggered flows of snow, ice, water, sediment, and debris that traveled down the Drift River as far as its mouth, about 40 km downstream. A major explosive eruption and dome collapse on January 2, 1990 produced the largest flow. The peak discharge of this flow at a location 22 km downstream from the volcano was estimated to be between 12,000 and 60,000 m3 per second. The estimated peak discharge of this event is more than 100 times larger than the 100-year meteorologically generated flood estimated for the Drift River. Pyroclastic flows and hot meltwater scoured the surface of Drift Glacier on the north flank of the volcano and were transformed into multipulsed, multiphased debris flows. Several other significant flows were generated by eruptions during this period: the two largest of these occurred on December 15, 1989 and February 15, 1990. Subsequent channel changes threatened the Drift River Oil Terminal built on an alluvial fan near the mouth of the Drift River. ?? 1994.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Riad Hosein

    2014-10-01

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

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

    Science.gov (United States)

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

    2016-12-01

    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. The geomorphic structure of the runoff peak

    Directory of Open Access Journals (Sweden)

    R. Rigon

    2011-06-01

    Full Text Available This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  9. Highest volcanoes on terrestrial planets and dwarf-planets adorn the deepest depressions of their respective bodies

    Science.gov (United States)

    Kochemasov, G. G.

    2015-10-01

    Four highest volcanoes of the inner solar system tower above four largest and deepest hemispheric depressions of the Earth, Moon, Mars, and Vesta. Of course, this is not a mere coincidence; behind of this fundamental fact stays an equally fundamental planetary regulation. The wave planetology based on elliptical keplerian orbits of cosmic bodies evoking their wave warping shows that the fundamental wave 1 inevitably produces hemispheric tectonic dichotomy. One hemisphere rises, the opposite falls. The uprising half increases its planetary radius and space and thus is intensively cut by numerous faults and rifts. The antipodean subsiding half decreases its radius and space and thus is intensively compacted and affected by folds and faults. Forming extra material finds its way out in form of volcanic ridges and volcanoes. The strongest compaction caused by the wave 1 subsidence produces most voluminous eruptions. That is why the relation exists between the largest and deepest hemispheric basins and the highest basic volcanoes having mantle roots [1-4]. On the Earth's Pacific Ocean floor stay the Hawaiian volcanoes; on the lunar Procellarum Ocean occurs Crater Copernicus (erroneously taken as an impact feature); Martian Vastitas Borealis is adorned with Olympus Mons; Vestan Reasilvia Basin (obviously tectonic not impact feature) has the central mountain -the highest volcanic peak in the Solar system (Fig. 1-4). A regular row of increasing heights of these largest volcanoes extends in the outward direction. A study of the dwarf-planet Ceres only begins(DAWN project). Already the first distant images of this globe about 950 km in diameter have shown that it is, as was predicted [5], tectonically two-faced or dichotomous body (Fig. 5, 6). It seems that on its relatively even subsided hemisphere there are some elevated locations often bright white in color (Fig. 6). They could represent prominent "edifices" covered with frozen ices -degassing traces [6].

  10. [A peak recognition algorithm designed for chromatographic peaks of transformer oil].

    Science.gov (United States)

    Ou, Linjun; Cao, Jian

    2014-09-01

    In the field of the chromatographic peak identification of the transformer oil, the traditional first-order derivative requires slope threshold to achieve peak identification. In terms of its shortcomings of low automation and easy distortion, the first-order derivative method was improved by applying the moving average iterative method and the normalized analysis techniques to identify the peaks. Accurate identification of the chromatographic peaks was realized through using multiple iterations of the moving average of signal curves and square wave curves to determine the optimal value of the normalized peak identification parameters, combined with the absolute peak retention times and peak window. The experimental results show that this algorithm can accurately identify the peaks and is not sensitive to the noise, the chromatographic peak width or the peak shape changes. It has strong adaptability to meet the on-site requirements of online monitoring devices of dissolved gases in transformer oil.

  11. Plume Tracker: Interactive mapping of volcanic sulfur dioxide emissions with high-performance radiative transfer modeling

    Science.gov (United States)

    Realmuto, Vincent J.; Berk, Alexander

    2016-11-01

    We describe the development of Plume Tracker, an interactive toolkit for the analysis of multispectral thermal infrared observations of volcanic plumes and clouds. Plume Tracker is the successor to MAP_SO2, and together these flexible and comprehensive tools have enabled investigators to map sulfur dioxide (SO2) emissions from a number of volcanoes with TIR data from a variety of airborne and satellite instruments. Our objective for the development of Plume Tracker was to improve the computational performance of the retrieval procedures while retaining the accuracy of the retrievals. We have achieved a 300 × improvement in the benchmark performance of the retrieval procedures through the introduction of innovative data binning and signal reconstruction strategies, and improved the accuracy of the retrievals with a new method for evaluating the misfit between model and observed radiance spectra. We evaluated the accuracy of Plume Tracker retrievals with case studies based on MODIS and AIRS data acquired over Sarychev Peak Volcano, and ASTER data acquired over Kilauea and Turrialba Volcanoes. In the Sarychev Peak study, the AIRS-based estimate of total SO2 mass was 40% lower than the MODIS-based estimate. This result was consistent with a 45% reduction in the AIRS-based estimate of plume area relative to the corresponding MODIS-based estimate. In addition, we found that our AIRS-based estimate agreed with an independent estimate, based on a competing retrieval technique, within a margin of ± 20%. In the Kilauea study, the ASTER-based concentration estimates from 21 May 2012 were within ± 50% of concurrent ground-level concentration measurements. In the Turrialba study, the ASTER-based concentration estimates on 21 January 2012 were in exact agreement with SO2 concentrations measured at plume altitude on 1 February 2012.

  12. Headless Debris Flows From Mount Spurr Volcano, Alaska

    Science.gov (United States)

    McGimsey, R. G.; Neal, C. A.; Waythomas, C. F.; Wessels, R.; Coombs, M. L.; Wallace, K. L.

    2004-12-01

    Sometime between June 20 and July 15, 2004-and contemporaneous with an increase of seismicity beneath the volcano, and elevated gas emissions-a sudden release of impounded water from the summit area of Mt. Spurr volcano produced about a dozen separate debris flow lobes emanating from crevasses and bergschrunds in the surface ice several hundred meters down the east-southeast flank from the summit. These debris flows were first observed by AVO staff on a July 15 overflight and appeared to represent a single flooding event; subsequent snow cover and limited accessibility have prevented direct investigation of these deposits. Observed from the air, they are dark, elongate lobate deposits, up to several hundred meters long and tens of meters wide, draping the steep (up to ~45 degree) slopes and cascading over and into crevasses. A water-rich phase from the flows continued down slope of the termini of several lobate deposits, eroding linear rills into the snow and ice down slope. We infer that the dark material composing these flows is likely remobilized coarse lapilli from the June 1992 tephra fall produced by an eruption of Crater Peak, a satellite vent of Mt. Spurr located 3.5 km to the south. Between 1 and 2 meters of basaltic andesite tephra fell directly on the Spurr summit during the 1992 eruption. The exact mechanism for sudden release of water-laden remobilized tephra flows from the summit basin is not clear. However, observations in early August, 2004, of an 80 m x 110-m-wide pit in the summit area snow and ice suggest the possibility of a partial roof collapse of a summit meltwater basin, likely associated with subglacial melting due to recent heat flux. Such a collapse could have led to the hydraulic surge of meltwater, and rapid mixing with tephra to produce slurries. These slurries traveled down slope beneath the ice surface to emerge through existing crevasses and other easy points of exit on the steep inclines. Mount Spurr is an ice- and snow covered

  13. The volcanoes and clouds of Venus

    Science.gov (United States)

    Prinn, R. G.

    1985-03-01

    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.

  14. Volcano-ice interactions on Mars

    Science.gov (United States)

    Allen, C. C.

    1979-01-01

    Central volcanic eruptions beneath terrestrial glaciers have built steep-sided, flat-topped mountains composed of pillow lava, glassy tuff, capping flows, and cones of basalt. Subglacial fissure eruptions produced ridges of similar 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.

  15. Monitoring Santorini volcano (Greece) breathing from space

    Science.gov (United States)

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

    2013-04-01

    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.

  16. Space Radar Image of Karisoke & Virunga Volcanoes

    Science.gov (United States)

    1994-01-01

    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

  17. Terrestrial Real-Time Volcano Monitoring

    Science.gov (United States)

    Franke, M.

    2013-12-01

    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

  18. Igneous Petrogenesis of Tequila Volcano, Western Mexico

    Science.gov (United States)

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

    2011-12-01

    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

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

    Science.gov (United States)

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

    1974-01-01

    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.

  20. Do dark matter halos explain lensing peaks?

    Science.gov (United States)

    Zorrilla Matilla, José Manuel; Haiman, Zoltán; Hsu, Daniel; Gupta, Arushi; Petri, Andrea

    2016-10-01

    We have investigated a recently proposed halo-based model, Camelus, for predicting weak-lensing peak counts, and compared its results over a collection of 162 cosmologies with those from N-body simulations. While counts from both models agree for peaks with S /N >1 (where S /N is the ratio of the peak height to the r.m.s. shape noise), we find ≈50 % fewer counts for peaks near S /N =0 and significantly higher counts in the negative S /N tail. Adding shape noise reduces the differences to within 20% for all cosmologies. We also found larger covariances that are more sensitive to cosmological parameters. As a result, credibility regions in the {Ωm,σ8} are ≈30 % larger. Even though the credible contours are commensurate, each model draws its predictive power from different types of peaks. Low peaks, especially those with 2 important cosmological information in N-body data, as shown in previous studies, but Camelus constrains cosmology almost exclusively from high significance peaks (S /N >3 ). Our results confirm the importance of using a cosmology-dependent covariance with at least a 14% improvement in parameter constraints. We identified the covariance estimation as the main driver behind differences in inference, and suggest possible ways to make Camelus even more useful as a highly accurate peak count emulator.

  1. Electrocapillary instability of magnetic fluid peak

    CERN Document Server

    Mkrtchyan, Levon; Dikansky, Yuri

    2013-01-01

    The paper presents an experimental study of the capillary electrostatic instability occurring under effect of a constant electric field on a magnetic fluid individual peak. The peaks under study occur at disintegration of a magnetic fluid layer applied on a flat electrode surface under effect of a perpendicular magnetic field. The electrocapillary instability shows itself as an emission of charged drops jets from the peak point in direction of the opposing electrode. The charged drops emission repeats periodically and results in the peak shape pulsations. It is shown that a magnetic field affects the electrocapillary instability occurrence regularities and can stimulate its development. The critical electric and magnetic field strengths at which the instability occurs have been measured; their dependence on the peak size is shown. The hysteresis in the system has been studied; it consists in that the charged drops emission stops at a lesser electric (or magnetic) field strength than that of the initial occurr...

  2. The enormous Chillos Valley Lahar: An ash-flow-generated debris flow from Cotopaxi Volcano, Ecuador

    Science.gov (United States)

    Mothes, P.A.; Hall, M.L.; Janda, R.J.

    1998-01-01

    The Chillos Valley Lahar (CVL), the largest Holocene debris flow in area and volume as yet recognized in the northern Andes, formed on Cotopaxi volcano's north and northeast slopes and descended river systems that took it 326 km north-northwest to the Pacific Ocean and 130+ km east into the Amazon basin. In the Chillos Valley, 40 km downstream from the volcano, depths of 80-160 m and valley cross sections up to 337000m2 are observed, implying peak flow discharges of 2.6-6.0 million m3/s. The overall volume of the CVL is estimated to be ???3.8 km3. The CVL was generated approximately 4500 years BP by a rhyolitic ash flow that followed a small sector collapse on the north and northeast sides of Cotopaxi, which melted part of the volcano's icecap and transformed rapidly into the debris flow. The ash flow and resulting CVL have identical components, except for foreign fragments picked up along the flow path. Juvenile materials, including vitric ash, crystals, and pumice, comprise 80-90% of the lahar's deposit, whereas rhyolitic, dacitic, and andesitic lithics make up the remainder. The sand-size fraction and the 2- to 10-mm fraction together dominate the deposit, constituting ???63 and ???15 wt.% of the matrix, respectively, whereas the silt-size fraction averages less than ???10 wt.% and the clay-size fraction less than 0.5 wt.%. Along the 326-km runout, these particle-size fractions vary little, as does the sorting coefficient (average = 2.6). There is no tendency toward grading or improved sorting. Limited bulking is recognized. The CVL was an enormous non-cohesive debris flow, notable for its ash-flow origin and immense volume and peak discharge which gave it characteristics and a behavior akin to large cohesive mudflows. Significantly, then, ash-flow-generated debris flows can also achieve large volumes and cover great areas; thus, they can conceivably affect large populated regions far from their source. Especially dangerous, therefore, are snowclad volcanoes

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

    Science.gov (United States)

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

    2016-05-01

    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.

  4. Acoustic scattering from mud volcanoes and carbonate mounds.

    Science.gov (United States)

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

    2006-12-01

    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.

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

    Science.gov (United States)

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

    2012-12-01

    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

  6. Volcano instability induced by strike-slip faulting

    Science.gov (United States)

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

    2000-09-01

    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.

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

    Science.gov (United States)

    Dzurisin, D.

    2015-12-01

    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!

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Science.gov (United States)

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

    2008-12-01

    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

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

    Science.gov (United States)

    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.

    2012-04-01

    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.

  11. The Origin of Weak Lensing Convergence Peaks

    CERN Document Server

    Liu, Jia

    2016-01-01

    Weak lensing convergence peaks are a promising tool to probe nonlinear structure evolution at late times, providing additional cosmological information beyond second-order statistics. Previous theoretical and observational studies have shown that the cosmological constraints on $\\Omega_m$ and $\\sigma_8$ are improved by a factor of up to ~ 2 when peak counts and second-order statistics are combined, compared to using the latter alone. We study the origin of lensing peaks using observational data from the 154 deg$^2$ Canada-France-Hawaii Telescope Lensing Survey. We found that while high peaks (with height $\\kappa$ >3.5 $\\sigma_\\kappa$, where $\\sigma_\\kappa$ is the r.m.s. of the convergence $\\kappa$) are typically due to one single massive halo of ~$10^{15}M_\\odot$, low peaks ($\\kappa$ ~ their virial radii), compared with ~0.25 virial radii for halos linked with high peaks, hinting that low peaks are more immune to baryonic processes whose impact is confined to the inner regions of the dark matter halos. Our fi...

  12. Muon imaging of volcanoes with Cherenkov telescopes

    Science.gov (United States)

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

    2017-04-01

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

  13. Large-N in Volcano Settings: Volcanosri

    Science.gov (United States)

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

    2014-12-01

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

  14. Degassing Processes at Persistently Active Explosive Volcanoes

    Science.gov (United States)

    Smekens, Jean-Francois

    Among volcanic gases, sulfur dioxide (SO2) is by far the most commonly measured. More than a monitoring proxy for volcanic degassing, SO 2 has the potential to alter climate patterns. Persistently active explosive volcanoes are characterized by short explosive bursts, which often occur at periodic intervals numerous times per day, spanning years to decades. SO 2 emissions at those volcanoes are poorly constrained, in large part because the current satellite monitoring techniques are unable to detect or quantify plumes of low concentration in the troposphere. Eruption plumes also often show high concentrations of ash and/or aerosols, which further inhibit the detection methods. In this work I focus on quantifying volcanic gas emissions at persistently active explosive volcanoes and their variations over short timescales (minutes to hours), in order to document their contribution to natural SO2 flux as well as investigate the physical processes that control their behavior. In order to make these measurements, I first develop and assemble a UV ground-based instrument, and validate it against an independently measured source of SO2 at a coal-burning power plant in Arizona. I establish a measurement protocol and demonstrate that the instrument measures SO 2 fluxes with 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

  15. Isotopic evolution of Mauna Loa volcano

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-04-01

    In an effort to understand the temporal helium isotopic variations in Mauna Loa volcano, we have measured helium, strontium and lead isotopes in a suite of Mauna Loa lavas that span most of the subaerial eruptive history of the volcano. The lavas range in age from historical flows to Ninole basalt which are thought to be several hundred thousand years old. Most of the samples younger than 30 ka in age (Kau Basalt) are radiocarbon-dated flows, while the samples older than 30 ka are stratigraphically controlled (Kahuku and Ninole Basalt). The data reveal a striking change in the geochemistry of the lavas approximately 10 ka before present. The lavas older than 10 ka are characterized by high {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).

  16. Multibeam Bathymetry of Haleakala Volcano, Maui

    Science.gov (United States)

    Eakins, B. W.; Robinson, J.

    2002-12-01

    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

  17. ANCIENT VOLCANOES AND TECTONIC STRUCTURES OF A RELIEF OF MARS

    Directory of Open Access Journals (Sweden)

    S. G. Pugacheva

    2014-01-01

    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.

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

    Science.gov (United States)

    Diker, Caner; Ulusoy, Inan

    2014-05-01

    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

  19. Progresses in geology and hazards analysis of Tianchi Volcano

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

    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.

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

    Science.gov (United States)

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

    2015-01-01

    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.

  1. Peak load arrangements : Assessment of Nordel guidelines

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Two Nordic countries, Sweden and Finland, have legislation that empowers the TSO to acquire designated peak load resources to mitigate the risk for shortage situations during the winter. In Denmark, the system operator procures resources to maintain a satisfactory level of security of supply. In Norway the TSO has set up a Regulation Power Option Market (RKOM) to secure a satisfactory level of operational reserves at all times, also in winter with high load demand. Only the arrangements in Finland and Sweden fall under the heading of Peak Load Arrangements defined in Nordel Guidelines. NordREG has been invited by the Electricity Market Group (EMG) to evaluate Nordel's proposal for 'Guidelines for transitional Peak Load Arrangements'. The EMG has also financed a study made by EC Group to support NordREG in the evaluation of the proposal. The study has been taken into account in NordREG's evaluation. In parallel to the EMG task, the Swedish regulator, the Energy Markets Inspectorate, has been given the task by the Swedish government to investigate a long term solution of the peak load issue. The Swedish and Finnish TSOs have together with Nord Pool Spot worked on finding a harmonized solution for activation of the peak load reserves in the market. An agreement accepted by the relevant authorities was reached in early January 2009, and the arrangement has been implemented since 19th January 2009. NordREG views that the proposed Nordel guidelines have served as a starting point for the presently agreed procedure. However, NordREG does not see any need to further develop the Nordel guidelines for peak load arrangements. NordREG agrees with Nordel that the market should be designed to solve peak load problems through proper incentives to market players. NordREG presumes that the relevant authorities in each country will take decisions on the need for any peak load arrangement to ensure security of supply. NordREG proposes that such decisions should be

  2. Estimated pressure source and vertical deformation in Tatun volcano group, Taiwan, detected by precise leveling in June 2006-August 2007

    Science.gov (United States)

    Murase, M.; Ishikawa, K.; Lin, C.; Lin, J.; Pu, H.; Kimata, F.; Miyajima, R.; Nakamichi, H.; Suzuki, A.

    2007-12-01

    Tatun volcano group including more than 20 volcanoes is located in the 15 km northeastward from Taipei, Taiwan. Although Chihsing-shan, the highest peak of the Tatun volcano group, has no record of volcano eruption in history, it has a hydrothermal activity characterized by some strenuous fumarolic activities and hot springs. Seismological network installed in 2003 detects a micro-seismic activity such as the volcano-tectonic earthquakes, tremors, monochromatic events and long-period earthquakes in and around Chihsing-shan (Lin et al., 2005; Konstantinou et al., 2007). Since those volcano-seismic swarm occur just around some fumaroles, it strongly suggests that the micro- seismic activity and the hydrothermal activity are closely related. It is generally accepted that the swarm activity around volcano is often accompanied by vertical deformation (Hill et al.,2003; Oris et al.,1999; Kimata et al., 2004). The relationship between the micro-seismic activity and hydrothermal activity is an important consideration and can be investigated by using precise leveling data. In this study, therefore, we established 10km leveling route from south part to north part of the Chihsing-shan volcano to detect the vertical deformation and the leveling surveys were conducted in June 2006, March 2007 and August 2007. We detected the deformation with the maximum subsidence of 5 mm in the east part of the Chihsing-shan volcano for 9 months from June 2006 to March 2007. The result of the observation between March-August 2007 is similar to the preceding observation and the total subsidence of 10mm was detected for 14 months from June 2006 to August 2007. It suggested same mechanism is continued throughout the year and it also shows the high accuracy of our observation. Since seismic activity was low in the period of our precise leveling, we believe that volcanic fluid was not supplied to the shallow portion around the volcano in this period. The distribution of the leveling route is not

  3. Space Radar Image of Kilauea Volcano, Hawaii

    Science.gov (United States)

    1994-01-01

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

  4. Antarctic volcanoes: A remote but significant hazard

    Science.gov (United States)

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

    2017-04-01

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

  5. Shallow velocity imaging of an active volcano

    Science.gov (United States)

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

    2014-12-01

    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.

  6. Geomechanical rock properties of a basaltic volcano

    Directory of Open Access Journals (Sweden)

    Lauren N Schaefer

    2015-06-01

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

  7. Submarine volcanoes along the Aegean volcanic arc

    Science.gov (United States)

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

    2013-06-01

    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.

  8. Embedded multiparametric system for volcano monitoring

    Science.gov (United States)

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

    2014-05-01

    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.

  9. Newberry Volcano EGS Demonstration - Phase I Results

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2011-10-23

    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

  10. Bayesian peak picking for NMR spectra.

    Science.gov (United States)

    Cheng, Yichen; Gao, Xin; Liang, Faming

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein-DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  11. Osteoporosis: Peak Bone Mass in Women

    Science.gov (United States)

    ... not supported by your browser. Home Osteoporosis Women Osteoporosis: Peak Bone Mass in Women Publication available in: ... drug products. NIH Pub. No. 15-7891 NIH Osteoporosis and Related Bone Diseases ~ National Resource Center 2 ...

  12. Bayesian Peak Picking for NMR Spectra

    KAUST Repository

    Cheng, Yichen

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  13. Amplification of postwildfire peak flow by debris

    Science.gov (United States)

    Kean, J. W.; McGuire, L. A.; Rengers, F. K.; Smith, J. B.; Staley, D. M.

    2016-08-01

    In burned steeplands, the peak depth and discharge of postwildfire runoff can substantially increase from the addition of debris. Yet methods to estimate the increase over water flow are lacking. We quantified the potential amplification of peak stage and discharge using video observations of postwildfire runoff, compiled data on postwildfire peak flow (Qp), and a physically based model. Comparison of flood and debris flow data with similar distributions in drainage area (A) and rainfall intensity (I) showed that the median runoff coefficient (C = Qp/AI) of debris flows is 50 times greater than that of floods. The striking increase in Qp can be explained using a fully predictive model that describes the additional flow resistance caused by the emergence of coarse-grained surge fronts. The model provides estimates of the amplification of peak depth, discharge, and shear stress needed for assessing postwildfire hazards and constraining models of bedrock incision.

  14. Peak Vegetation Growth 2000 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2000 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  15. Peak Vegetation Growth 2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2004 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  16. Peak Vegetation Growth 1999 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1999 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  17. Peak Vegetation Growth 1993 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1993 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  18. Peak Vegetation Growth 1994 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1994 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  19. Peak Vegetation Growth 1995 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1995 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  20. Peak Vegetation Growth 1998 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1998 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  1. Peak Vegetation Growth 2001 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2001 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  2. Peak Vegetation Growth 2003 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2003 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  3. Peak Vegetation Growth 1997 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1997 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  4. Peak Vegetation Growth 1990 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1990 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  5. Peak Vegetation Growth 1996 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1996 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  6. Peak Vegetation Growth 2005 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2005 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  7. Tectonics, Climate and Earth's highest peaks

    Science.gov (United States)

    Robl, Jörg; Prasicek, Günther; Hergarten, Stefan

    2016-04-01

    Prominent peaks characterized by high relief and steep slopes are among the most spectacular morphological features on Earth. In collisional orogens they result from the interplay of tectonically driven crustal thickening and climatically induced destruction of overthickened crust by erosional surface processes. The glacial buzz-saw hypothesis proposes a superior status of climate in limiting mountain relief and peak altitude due to glacial erosion. It implies that peak altitude declines with duration of glacial occupation, i.e., towards high latitudes. This is in strong contrast with high peaks existing in high latitude mountain ranges (e.g. Mt. St. Elias range) and the idea of peak uplift due to isostatic compensation of spatially variable erosional unloading an over-thickened orogenic crust. In this study we investigate landscape dissection, crustal thickness and vertical strain rates in tectonically active mountain ranges to evaluate the influence of erosion on (latitudinal) variations in peak altitude. We analyze the spatial distribution of serval thousand prominent peaks on Earth extracted from the global ETOPO1 digital elevation model with a novel numerical tool. We compare this dataset to crustal thickness, thickening rate (vertical strain rate) and mean elevation. We use the ratios of mean elevation to peak elevation (landscape dissection) and peak elevation to crustal thickness (long-term impact of erosion on crustal thickness) as indicators for the influence of erosional surface processes on peak uplift and the vertical strain rate as a proxy for the mechanical state of the orogen. Our analysis reveals that crustal thickness and peak elevation correlate well in orogens that have reached a mechanically limited state (vertical strain rate near zero) where plate convergence is already balanced by lateral extrusion and gravitational collapse and plateaus are formed. On the Tibetan Plateau crustal thickness serves to predict peak elevation up to an altitude

  8. Cosmic Microwave Background Acoustic Peak Locations

    CERN Document Server

    Pan, Zhen; Mulroe, Brigid; Narimani, Ali

    2016-01-01

    The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and twelve extrema in the cross (TE) power spectrum. The relative locations of these extrema give a striking, and beautiful, demonstration of what we expect from acoustic oscillations in the plasma; e.g., that EE peaks fall half way between TT peaks. We expect this because the temperature map is predominantly sourced by temperature variations in the last scattering surface, while the polarization map is predominantly sourced by gradients in the velocity field, and the harmonic oscillations have temperature and velocity 90 degrees out of phase. However, there are large differences in expectations for extrema locations from simple analytic models vs. numerical calculations. Here we quantitatively explore the origin of these differences in gravitational potential tr...

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

    Energy Technology Data Exchange (ETDEWEB)

    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: ltelesca@imaa.cnr.it

    2005-03-01

    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.

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

    Science.gov (United States)

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

    2014-01-01

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

  11. Do dark matter halos explain lensing peaks?

    CERN Document Server

    Matilla, José Manuel Zorrilla; Hsu, Daniel; Gupta, Arushi; Petri, Andrea

    2016-01-01

    We have investigated a recently proposed halo-based model, Camelus, for predicting weak-lensing peak counts, and compared its results over a collection of 162 cosmologies with those from N-body simulations. While counts from both models agree for peaks with $\\mathcal{S/N}>1$ (where $\\mathcal{S/N}$ is the ratio of the peak height to the r.m.s. shape noise), we find $\\approx 50\\%$ fewer counts for peaks near $\\mathcal{S/N}=0$ and significantly higher counts in the negative $\\mathcal{S/N}$ tail. Adding shape noise reduces the differences to within $20\\%$ for all cosmologies. We also found larger covariances that are more sensitive to cosmological parameters. As a result, credibility regions in the $\\{\\Omega_m, \\sigma_8\\}$ are $\\approx 30\\%$ larger. Even though the credible contours are commensurate, each model draws its predictive power from different types of peaks. Low peaks, especially those with $23)$. Our results confirm the importance of using a cosmology-dependent covariance with at least a 14\\% improveme...

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

    Science.gov (United States)

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

    2016-08-01

    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.

  13. Distribution of acidic groundwater around quaternary volcanoes in Japan

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-06-01

    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)

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

    Data.gov (United States)

    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...

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

    Science.gov (United States)

    Duffield, Wendell A.

    2003-01-01

    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.

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

    Science.gov (United States)

    Driedger, Carolyn L.; Scott, William E.

    2008-01-01

    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.

  17. Sulfur dioxide contributions to the atmosphere by volcanoes.

    Science.gov (United States)

    Stoiber, R E; Jepsen, A

    1973-11-01

    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.

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

    Science.gov (United States)

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

    2017-07-01

    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.

  19. Geomorphometric comparative analysis of Latin-American volcanoes

    Science.gov (United States)

    Camiz, Sergio; Poscolieri, Maurizio; Roverato, Matteo

    2017-07-01

    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.

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

    Science.gov (United States)

    Lagmay, Alfredo Mahar Francisco A.

    2006-06-01

    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.

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

    Science.gov (United States)

    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.

    2010-05-01

    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

  2. The preliminary results: Seismic ambient noise Rayleigh wave tomography around Merapi volcano, central Java, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Trichandi, Rahmantara, E-mail: rachmantara.tri@gmail.com [Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, 40132, Bandung (Indonesia); Yudistira, Tedi; Nugraha, Andri Dian [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Zulhan, Zulfakriza [Earth Science Graduate Program, Faculty of Earth Science and Technology, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Saygin, Erdinc [Research School of Earth Sciences, The Australian National University, Canberra ACT 0200 (Australia)

    2015-04-24

    Ambient noise tomography is relatively a new method for imaging the shallow structure of the Earth subsurface. We presents the application of this method to produce a Rayleigh wave group velocity maps around the Merapi Volcano, Central Java. Rayleigh waves group velocity maps were reconstructed from the cross-correlation of ambient noise recorded by the DOMERAPI array which consists 43 broadband seismometers. In the processing stage, we first filtered the observation data to separatethe noise from the signal that dominated by the strong volcanic activities. Next, we cross-correlate the filtered data and stack to obtain the Green’s function for all possible station pairs. Then we carefully picked the peak of each Green’s function to estimate the dispersion trend and appliedMultiple Filter Technique to obtain the dispersion curve. Inter-station group velocity curvesare inverted to produceRayleigh wave group velocity maps for periods 1 to 10 s. The resulted Rayleigh group velocity maps show the interesting features around the Merapi Volcano which generally agree with the previous studies. Merapi-Lawu Anomaly (MLA) is emerged as a relatively low anomaly in our group velocity maps.

  3. The preliminary results: Seismic ambient noise Rayleigh wave tomography around Merapi volcano, central Java, Indonesia

    Science.gov (United States)

    Trichandi, Rahmantara; Yudistira, Tedi; Nugraha, Andri Dian; Zulhan, Zulfakriza; Saygin, Erdinc

    2015-04-01

    Ambient noise tomography is relatively a new method for imaging the shallow structure of the Earth subsurface. We presents the application of this method to produce a Rayleigh wave group velocity maps around the Merapi Volcano, Central Java. Rayleigh waves group velocity maps were reconstructed from the cross-correlation of ambient noise recorded by the DOMERAPI array which consists 43 broadband seismometers. In the processing stage, we first filtered the observation data to separatethe noise from the signal that dominated by the strong volcanic activities. Next, we cross-correlate the filtered data and stack to obtain the Green's function for all possible station pairs. Then we carefully picked the peak of each Green's function to estimate the dispersion trend and appliedMultiple Filter Technique to obtain the dispersion curve. Inter-station group velocity curvesare inverted to produceRayleigh wave group velocity maps for periods 1 to 10 s. The resulted Rayleigh group velocity maps show the interesting features around the Merapi Volcano which generally agree with the previous studies. Merapi-Lawu Anomaly (MLA) is emerged as a relatively low anomaly in our group velocity maps.

  4. Monitoring Monitoring Evolving Activity at Popocatepetl Volcano, Mexico, 2000-2001

    Science.gov (United States)

    Martin-DelPozzo, A.; Aceves, F.; Bonifaz, R.; Humberto, S.

    2001-12-01

    After 6 years of small eruptions, activity at Mexico's 5,452m high Popocatepetl Volcano in central Mexico, peaked in the December 2000-January 2001 eruptions. Precursors included an important increase in seismicity as well as in magmatic components of spring water and small scale deformation which resulted in growth of a new crater dome from January 16 on. Evacuation of the towns nearest the volcano over Christmas was decided because of the possibility of pyroclastic flows. During the previous years, crater dome growth, contraction and explosive clearing has dominated the activity. The January 22 eruption produced an eruption column approximately 17km high with associated pyroclastic flows. Ejecta was composed of both basic and evolved scoria and pumice and dome lithics. A large proportion of the juvenile material was intermediate between these 2 endmenbers (59-63percent SiO2 and 3.5 to 5.5 MgO) consistent with a small basic pulse entering a more evolved larger batch of magma. The January eruption left a large pit which has been partially infilled by another crater dome this August 2001.

  5. Experimental Elucidation of the Oxygen Reduction Volcano in Base on a Pt Alloy Single Crystal

    DEFF Research Database (Denmark)

    Jensen, Kim Degn; Tymoczko, Jakub; Bandarenka, Aliaksandr S.

    2016-01-01

    to Pt(111). However, all surfaces show a ~4 fold improvement in activity in 0.1 M KOH, relative to the same surface in 0.1 M HClO4. At the peak of the volcano the surface exhibits an exceptionally high specific activity of 90 mA/cm2 at 0.9 V with respect to the reversible hydrogen electrode. Thus, our......It is of fundamental importance to understand the factors controlling trends in activity for electrocatalytic reactions as a function of pH. In the case of the oxygen reduction reaction, numerous reports suggest significant divergences between noble metals surface catalytic performances in acid...... and base.[1,2] In our earlier studies, we mapped out the experimental Sabatier volcano for the oxygen reduction reaction in 0.1 M HClO4 using the Cu/Pt(111) near-surface alloy system, see Figure 1 for near-surface alloy schematic.[3,4] In this study, as those of [3,4], we found that by changing...

  6. Tidal Triggering and Statistical Patterns of Microseismicity at Axial Volcano on the Juan de Fuca Ridge

    Science.gov (United States)

    Bohnenstiehl, D. R.; Dziak, R. P.; Caplan-Auerbach, J.; Haxel, J. H.; Mann, M. E.; Pennington, C.; Weis, J.; Womack, N.; Levy, S.

    2015-12-01

    Tidal stress changes are known to modulate the timing of microearthquakes within many mid-ocean ridge volcanic systems. At Axial Volcano, located on the Juan de Fuca Ridge, earthquakes occur preferentially when volumetric extension peaks near times of low ocean tide. Autonomous ocean-bottom hydrophone (OBH, 2007-2011) and cabled ocean bottom seismometer (OBS, Nov. 2014-) data are used to quantify the strength of tidal triggering in time periods before the April 2011 and April 2015 eruptions at Axial Volcano. The mean percent excess at times of low ocean-tide is ~14% (16% std) in the four years prior to the 2011 eruption and ~18% (17% std) in the five months prior to the 2015 eruption. The sensitivity of earthquakes to tidal stress does not evolve systematically prior to either eruption; however, this pattern is disturbed by much larger stress changes associated with the onset of dike intrusion. Following dike injection and eruption, seismicity rates drop sharply. As seismicity rates continue to rise in the months following the 2015 eruption, real-time data available from the cabled OBS network will be used quantify temporal patterns in microearthquake activity as dike induced stresses are relaxed and the magma chamber inflates.

  7. Internal stress field at Mount Vesuvius: A model for background seismicity at a central volcano

    Science.gov (United States)

    de Natale, Giuseppe; Petrazzuoli, Stefano M.; Troise, Claudia; Pingue, Folco; Capuano, Paolo

    2000-07-01

    We propose a model to explain the background seismicity occurring at Somma-Vesuvius in its present, mostly quiescent period. A finite element procedure has been used to simulate the stress field due to gravitational body forces in an axisymmetric volcano characterized by a central high-rigidity anomaly. Results emphasize the important effect of axial high-rigidity, which concentrates at its borders stresses resulting from the gravitational load of the volcanic edifice, as well as external (regional) stresses. The joint effect of the gravitational loading and of the presence of the anomaly produces stresses very close to or above the critical rupture threshold. The observed spatial concentrations of seismicity and moment release correlate well with peaks of computed maximum shear stress. Seismicity is then interpreted as due to small stress perturbations concentrated around the high-rigidity core and added to a system already close, to the failure threshold. This model can explain the widely observed occurrence of background seismicity at central volcanoes worldwide.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

    Rashidov, Tofig

    2014-05-01

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

  10. 2006-2008 Eruptions and Volcano Hazards Of Soputan Volcano, North Sulawesi, Indonesia

    Science.gov (United States)

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

    2010-12-01

    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

  11. Felsic maar-diatreme volcanoes: a review

    Science.gov (United States)

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

    2017-02-01

    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

  12. The PEAK experience in South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    The PEAK Institute was developed to provide a linkage for formal (schoolteachers) and nonformal educators (extension agents) with agricultural scientists of Clemson University`s South Carolina Agricultural Experiment Station System. The goal of the Institute was to enable teams of educators and researchers to develop and provide PEAK science and math learning experiences related to relevant agricultural and environmental issues of local communities for both classroom and 4-H Club experiences. The Peak Institute was conducted through a twenty day residential Institute held in June for middle school and high school teachers who were teamed with an Extension agent from their community. These educators participated in hands-on, minds-on sessions conducted by agricultural researchers and Clemson University Cooperative Extension specialists. Participants were given the opportunity to see frontier science being conducted by scientists from a variety of agricultural laboratories.

  13. Spatial Analysis of Volcanoes at Convergent Margins on Earth

    Science.gov (United States)

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

    2009-12-01

    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

  14. The 2009 eruption of Redoubt Volcano, Alaska

    Science.gov (United States)

    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.

    2012-01-01

    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

  15. Volcano surveillance by ACR silver fox

    Science.gov (United States)

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

    2005-01-01

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

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

    Science.gov (United States)

    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

  17. Complex behavior and source model of the tremor at Arenal volcano, Costa Rica

    Science.gov (United States)

    Lesage, Philippe; Mora, Mauricio M.; Alvarado, Guillermo E.; Pacheco, Javier; Métaxian, Jean-Philippe

    2006-09-01

    Typical records of volcanic tremor and explosion quakes at Arenal volcano are analyzed with a high-resolution time-frequency method. The main characteristics of these seismic signals are: (1) numerous regularly spaced spectral peaks including both odd and even overtones; (2) frequency gliding in the range [0.9-2] Hz of the fundamental peak; (3) frequency jumps with either positive or negative increments; (4) tremor episodes with two simultaneous systems of spectral peaks affected by independent frequency gliding; (5) progressive transitions between spasmodic tremor and harmonic tremor; (6) lack of clear and systematic relationship between the occurrence of explosions and tremor. Some examples of alternation between two states of oscillation characterized by different fundamental frequencies are also observed. Some tremor and explosion codas are characterized by acoustic and seismic waves with identical spectral content and frequency gliding, which suggests a common excitation process. We propose a source model for the tremor at Arenal in which intermittent gas flow through fractures produces repetitive pressure pulses. The repeating period of the pulses is stabilized by a feedback mechanism associated with standing or traveling waves in the magmatic conduit. The pressure pulses generate acoustic waves in the atmosphere and act as excitation of the interface waves in the conduit. When the repeating period of the pulses is stable enough, they produce regularly spaced spectral peaks by the Dirac comb effect and hence harmonic tremor. When the period stability is lost, because of failures in the feedback mechanism, the tremor becomes spasmodic. The proposed source model of tremor is similar to the sound emission process of a clarinet. Fractures in the solid or viscous layer capping the lava pool in the crater act as the clarinet reed, and the conduit filled with low velocity bubbly magma is equivalent to the pipe of the musical instrument. The frequency gliding is

  18. Seismic scattering and absorption mapping of debris flows, feeding paths, and tectonic units at Mount St. Helens volcano

    Science.gov (United States)

    De Siena, L.; Calvet, M.; Watson, K. J.; Jonkers, A. R. T.; Thomas, C.

    2016-05-01

    Frequency-dependent peak-delay times and coda quality factors have been used jointly to separate seismic absorption from scattering quantitatively in Earth media at regional and continental scale; to this end, we measure and map these two quantities at Mount St. Helens volcano. The results show that we can locate and characterize volcanic and geological structures using their unique contribution to seismic attenuation. At 3 Hz a single high-scattering and high-absorption anomaly outlines the debris flows that followed the 1980 explosive eruption, as deduced by comparison with remote sensing imagery. The flows overlay a NNW-SSE interface, separating rocks of significant varying properties down to 2-4 km, and coinciding with the St. Helens Seismic Zone. High-scattering and high-absorption anomalies corresponding to known locations of magma emplacement follow this signature under the volcano, showing the important interconnections between its feeding systems and the regional tectonic boundaries. With frequency increasing from 6 to 18 Hz the NNW-SSE tectonic/feeding trends rotate around an axis centered on the volcano in the direction of the regional-scale magmatic arc (SW-NE). While the aseismic high-scattering region WSW of the volcano shows no evidence of high absorption, the regions of highest-scattering and absorption are consistently located at all frequencies under either the eastern or the south-eastern flank of the volcanic edifice. From the comparison with the available geological and geophysical information we infer that these anomalies mark both the location and the trend of the main feeding systems at depths greater than 4 km.

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

    Science.gov (United States)

    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.

    2012-12-01

    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.

  20. Some Phenomenological Aspects of the Peak Experience

    Science.gov (United States)

    Rosenblatt, Howard S.; Bartlett, Iris

    1976-01-01

    This article relates the psychological dynamics of "peak experiences" to two concepts, intentionality and paradoxical intention, within the philosophical orientation of phenomenology. A review of early philosophical theories of self (Kant and Hume) is presented and compared with the experiential emphasis found in the phenomenology of Husserl.…

  1. Some Phenomenological Aspects of the Peak Experience

    Science.gov (United States)

    Rosenblatt, Howard S.; Bartlett, Iris

    1976-01-01

    This article relates the psychological dynamics of "peak experiences" to two concepts, intentionality and paradoxical intention, within the philosophical orientation of phenomenology. A review of early philosophical theories of self (Kant and Hume) is presented and compared with the experiential emphasis found in the phenomenology of Husserl.…

  2. Real estate price peaks: a comparative overview

    CERN Document Server

    Röhner, B M

    2006-01-01

    First, we emphasize that the real estate price peaks which are currently under way in many industrialized countries (one important exception is Japan) share many of the characteristics of previous historical price peaks. In particular, we show that: (i) In the present episode real price increases are, at least for now, of the same order of magnitude as in previous episodes, typically of the order of 80 percent to 100 percent. (ii) Historically, price peaks turned out to be symmetrical with respect to the peak; soft landing, i.e. an upgoing phase followed by a plateau, has rarely (if ever) been observed. (iii) The inflated demand is mainly boosted by investors and high-income buyers. (iv) In the present as well as in previous episodes, the main engines in the upgoing phase have been the hot markets which developed in major cities such as London, Los Angeles, New York, Paris, San Francisco or Sydney. In our conclusion, we propose a prediction for real estate prices in the West of the United States over the peri...

  3. SUBMARINE VOLCANO CHARACTERISTICS IN SABANG WATERS

    Directory of Open Access Journals (Sweden)

    Hananto Kurnio

    2017-07-01

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

  4. Research drilling in young silicic volcanoes

    Energy Technology Data Exchange (ETDEWEB)

    Eichelberger, J.C.

    1989-06-30

    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.

  5. Deep Stimulation at Newberry Volcano EGS Demonstration

    Science.gov (United States)

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

    2014-12-01

    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.

  6. Newberry Volcano EGS Demonstration Stimulation Modeling

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-23

    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.

  7. Analysis of gas jetting and fumarole acoustics at Aso Volcano, Japan

    Science.gov (United States)

    McKee, Kathleen; Fee, David; Yokoo, Akihiko; Matoza, Robin S.; Kim, Keehoon

    2017-06-01

    The gas-thrust region of a large volcanic eruption column is predominately a momentum-driven, fluid flow process that perturbs the atmosphere and produces sound akin to noise from jet and rocket engines, termed ;jet noise;. We aim to enhance understanding of large-scale volcanic jets by studying an accessible, less hazardous fumarolic jet. We characterize the acoustic signature of 2.5-meter wide vigorously jetting fumarole at Aso Volcano, Japan using a 5-element infrasound array located on the nearby crater. The fumarole opened on 13 July 2015 on the southwest flank of the partially collapsed pyroclastic cone within Aso Volcano's Naka-dake crater and had persistent gas jetting, which produced significant audible jet noise. The array was 220 m from the fumarole and 57.6° from the vertical jet axis, a recording angle not typically feasible in volcanic environments. Array processing is performed to distinguish fumarolic jet noise from wind. Highly correlated periods are characterized by sustained, low-amplitude signal with a 7-10 Hz spectral peak. Finite difference time domain method numerical modeling suggests the influence of topography near the vent and along the propagation path significantly affects the spectral content, complicating comparisons with laboratory jet noise. The fumarolic jet has a low estimated Mach number (0.3 to 0.4) and measured temperature of 260 °C. The Strouhal number for infrasound from volcanic jet flows and geysers is not known; thus we assume a peak Strouhal number of 0.19 based on pure-air laboratory jet experiments. This assumption leads to an estimated exit velocity of the fumarole of 79 to 132 m/s. Using published gas composition data from 2003 to 2009, the fumarolic vent area estimated from thermal infrared images, and estimated jet velocity, we estimate total volatile flux at 160-270 kg/s (14,000-23,000 t/d).

  8. Analysis of gas jetting and fumarole acoustics at Aso Volcano, Japan

    Energy Technology Data Exchange (ETDEWEB)

    McKee, Kathleen; Fee, David; Yokoo, Akihiko; Matoza, Robin S.; Kim, Keehoon

    2017-06-01

    The gas-thrust region of a large volcanic eruption column is predominately a momentum-driven, fluid flow process that perturbs the atmosphere and produces sound akin to noise from jet and rocket engines, termed “jet noise”. We aim to enhance understanding of large-scale volcanic jets by studying an accessible, less hazardous fumarolic jet. We characterize the acoustic signature of ~ 2.5-meter wide vigorously jetting fumarole at Aso Volcano, Japan using a 5-element infrasound array located on the nearby crater. The fumarole opened on 13 July 2015 on the southwest flank of the partially collapsed pyroclastic cone within Aso Volcano's Naka-dake crater and had persistent gas jetting, which produced significant audible jet noise. The array was ~ 220 m from the fumarole and 57.6° from the vertical jet axis, a recording angle not typically feasible in volcanic environments. Array processing is performed to distinguish fumarolic jet noise from wind. Highly correlated periods are characterized by sustained, low-amplitude signal with a 7–10 Hz spectral peak. Finite difference time domain method numerical modeling suggests the influence of topography near the vent and along the propagation path significantly affects the spectral content, complicating comparisons with laboratory jet noise. The fumarolic jet has a low estimated Mach number (0.3 to 0.4) and measured temperature of ~ 260 °C. The Strouhal number for infrasound from volcanic jet flows and geysers is not known; thus we assume a peak Strouhal number of 0.19 based on pure-air laboratory jet experiments. This assumption leads to an estimated exit velocity of the fumarole of ~ 79 to 132 m/s. Using published gas composition data from 2003 to 2009, the fumarolic vent area estimated from thermal infrared images, and estimated jet velocity, we estimate total volatile flux at ~ 160–270 kg/s (14,000–23,000 t/d).

  9. Spanish Peaks, Sangre de Cristo Range, Colorado

    Science.gov (United States)

    2002-01-01

    The Spanish Peaks, on the eastern flank of the Sangre de Cristo range, abruptly rise 7,000 feet above the western Great Plains. Settlers, treasure hunters, trappers, gold and silver miners have long sighted on these prominent landmarks along the Taos branch of the Santa Fe trail. Well before the westward migration, the mountains figured in the legends and history of the Ute, Apache, Comanche, and earlier tribes. 'Las Cumbres Espanolas' are also mentioned in chronicles of exploration by Spaniards including Ulibarri in 1706 and later by de Anza, who eventually founded San Francisco (California). This exceptional view (STS108-720-32), captured by the crew of Space Shuttle mission STS108, portrays the Spanish Peaks in the context of the southern Rocky Mountains. Uplift of the Sangre de Cristo began about 75 million years ago and produced the long north-trending ridges of faulted and folded rock to the west of the paired peaks. After uplift had ceased (26 to 22 million years ago), the large masses of igneous rock (granite, granodiorite, syenodiorite) that form the Peaks were emplaced (Penn, 1995-2001). East and West Spanish Peaks are 'stocks'-bodies of molten rock that intruded sedimentary layers, cooled and solidified, and were later exposed by erosion. East Peak (E), at 12,708 ft is almost circular and is about 5 1/2 miles long by 3 miles wide, while West Peak (W), at 13,623 ft is roughly 2 3/4 miles long by 1 3/4 miles wide. Great dikes-long stone walls-radiate outward from the mountains like spokes of a wheel, a prominent one forms a broad arc northeast of East Spanish Peak. As the molten rock rose, it forced its way into vertical cracks and joints in the sedimentary strata; the less resistant material was then eroded away, leaving walls of hard rock from 1 foot to 100 feet wide, up to 100 feet high, and as long as 14 miles. Dikes trending almost east-west are also common in the region. For more information visit: Sangres.com: The Spanish Peaks (accessed January 16

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

    Science.gov (United States)

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

    2013-12-01

    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

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

    Science.gov (United States)

    Thomas, D. M.; Bevens, D.

    2015-12-01

    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.

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

    Science.gov (United States)

    Unglert, Katharina; Jellinek, A. Mark

    2016-04-01

    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.

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

    Science.gov (United States)

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

    2016-12-01

    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.

  14. Predicting VO2peak from Submaximal- and Peak Exercise Models: The HUNT 3 Fitness Study, Norway.

    Directory of Open Access Journals (Sweden)

    Henrik Loe

    Full Text Available Peak oxygen uptake (VO2peak is seldom assessed in health care settings although being inversely linked to cardiovascular risk and all-cause mortality. The aim of this study was to develop VO2peak prediction models for men and women based on directly measured VO2peak from a large healthy population.VO2peak prediction models based on submaximal- and peak performance treadmill work were derived from multiple regression analysis. 4637 healthy men and women aged 20-90 years were included. Data splitting was used to generate validation and cross-validation samples.The accuracy for the peak performance models were 10.5% (SEE = 4.63 mL⋅kg(-1⋅min(-1 and 11.5% (SEE = 4.11 mL⋅kg(-1⋅min(-1 for men and women, respectively, with 75% and 72% of the variance explained. For the submaximal performance models accuracy were 14.1% (SEE = 6.24 mL⋅kg(-1⋅min(-1 and 14.4% (SEE = 5.17 mL⋅kg(-1⋅min(-1 for men and women, respectively, with 55% and 56% of the variance explained. The validation and cross-validation samples displayed SEE and variance explained in agreement with the total sample. Cross-classification between measured and predicted VO2peak accurately classified 91% of the participants within the correct or nearest quintile of measured VO2peak.Judicious use of the exercise prediction models presented in this study offers valuable information in providing a fairly accurate assessment of VO2peak, which may be beneficial for risk stratification in health care settings.

  15. Effect of gear ratio on peak power and time to peak power in BMX cyclists.

    Science.gov (United States)

    Rylands, Lee P; Roberts, Simon J; Hurst, Howard T

    2017-03-01

    The aim of this study was to ascertain if gear ratio selection would have an effect on peak power and time to peak power production in elite Bicycle Motocross (BMX) cyclists. Eight male elite BMX riders volunteered for the study. Each rider performed three, 10-s maximal sprints on an Olympic standard indoor BMX track. The riders' bicycles were fitted with a portable SRM power meter. Each rider performed the three sprints using gear ratios of 41/16, 43/16 and 45/16 tooth. The results from the 41/16 and 45/16 gear ratios were compared to the current standard 43/16 gear ratio. Statistically, significant differences were found between the gear ratios for peak power (F(2,14) = 6.448; p = .010) and peak torque (F(2,14) = 4.777; p = .026), but no significant difference was found for time to peak power (F(2,14) = 0.200; p = .821). When comparing gear ratios, the results showed a 45/16 gear ratio elicited the highest peak power,1658 ± 221 W, compared to 1436 ± 129 W and 1380 ± 56 W, for the 43/16 and 41/16 ratios, respectively. The time to peak power showed a 41/16 tooth gear ratio attained peak power in -0.01 s and a 45/16 in 0.22 s compared to the 43/16. The findings of this study suggest that gear ratio choice has a significant effect on peak power production, though time to peak power output is not significantly affected. Therefore, selecting a higher gear ratio results in riders attaining higher power outputs without reducing their start time.

  16. The Doppler peaks from a generic defect

    CERN Document Server

    Magueijo, J

    1996-01-01

    We investigate which of the exotic Doppler peak features found for textures and cosmic strings are generic novelties pertaining to defects. We find that the ``out of phase'' texture signature is an accident. Generic defects, when they generate a secondary peak structure similar to inflation, apply to it an additive shift. It is not necessary for this shift to be ``out of phase''. We also show which factors are responsible for the absence of secondary oscillations found for cosmic strings. Within this general analysis we finally consider the conditions under which topological defects and inflation can be confused. It is argued that only \\Omega=1 inflation and a defect with a horizon size coherence length have a chance to be confused. Any other inflationary or defect model always differ distinctly. (To appear in the proceedings of the XXXIth Moriond meeting, ``Microwave Background Anisotropies'')

  17. Solar Cycle 24: is the peak coming?

    CERN Document Server

    Sello, Stefano

    2012-01-01

    Solar cycle activity forecasting, mainly its magnitude and timing, is an essential issue for numerous scientific and technological applications: in fact, during an active solar period, many strong eruptions occur on the Sun with increasing frequency, such as flares, coronal mass ejections, high velocity solar wind photons and particles, which can severely affect the Earth's ionosphere and the geomagnetic field, with impacts on the low atmosphere. Thus it is very important to develop reliable solar cycle prediction methods for the incoming solar activity. The current solar cycle 24 appeared unusual from many points of view: an unusually extended minimum period, and a global low activity compared to those of the previous three or four cycles. Currently, there are many different evidences that the peak in the northern hemisphere already occurred at 2011.6 but not yet in the southern hemisphere. In this brief note we update the peak prediction and its timing, based on the most recent observations.

  18. Peak oil, food systems, and public health.

    Science.gov (United States)

    Neff, Roni A; Parker, Cindy L; Kirschenmann, Frederick L; Tinch, Jennifer; Lawrence, Robert S

    2011-09-01

    Peak oil is the phenomenon whereby global oil supplies will peak, then decline, with extraction growing increasingly costly. Today's globalized industrial food system depends on oil for fueling farm machinery, producing pesticides, and transporting goods. Biofuels production links oil prices to food prices. We examined food system vulnerability to rising oil prices and the public health consequences. In the short term, high food prices harm food security and equity. Over time, high prices will force the entire food system to adapt. Strong preparation and advance investment may mitigate the extent of dislocation and hunger. Certain social and policy changes could smooth adaptation; public health has an essential role in promoting a proactive, smart, and equitable transition that increases resilience and enables adequate food for all.

  19. Excursion set peaks: the role of shear

    CERN Document Server

    Castorina, Emanuele; Hahn, Oliver; Sheth, Ravi K

    2016-01-01

    Recent analytical work on the modelling of dark halo abundances and clustering has demonstrated the advantages of combining the excursion set approach with peaks theory. We extend these ideas and introduce a model of excursion set peaks that incorporates the role of initial tidal effects or shear in determining the gravitational collapse of dark haloes. The model -- in which the critical density threshold for collapse depends on the tidal influences acting on protohaloes -- is well motivated from ellipsoidal collapse arguments and is also simple enough to be analytically tractable. We show that the predictions of this model are in very good agreement with measurements of the halo mass function and traditional scale dependent halo bias in N-body simulations across a wide range of masses and redshift. The presence of shear in the collapse threshold means that halo bias is naturally predicted to be nonlocal, and that protohalo densities at fixed mass are naturally predicted to have Lognormal-like distributions. ...

  20. Reducing Peak Power in Automated Weapon Laying

    Science.gov (United States)

    2016-02-01

    The values used are determined based on a number of factors including available power, maximum motor speed , maximum safe slewing speeds , peak...METHODS, ASSUMPTIONS, AND PROCEDURES Conventions and Variable Definitions Before describing the formulas to solve the aforementioned problems, it is...These two formulas are set equal to each other in equation 9 and then solved for t2 in equation 10. Note that the negative value of α2 results in a

  1. Hanford Site peak gust wind speeds

    Energy Technology Data Exchange (ETDEWEB)

    Ramsdell, J.V.

    1998-09-29

    Peak gust wind data collected at the Hanford Site since 1945 are analyzed to estimate maximum wind speeds for use in structural design. The results are compared with design wind speeds proposed for the Hanford Site. These comparisons indicate that design wind speeds contained in a January 1998 advisory changing DOE-STD-1020-94 are excessive for the Hanford Site and that the design wind speeds in effect prior to the changes are still appropriate for the Hanford Site.

  2. Hunting remnants of maar-diatreme-volcanoes

    Science.gov (United States)

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

    2010-05-01

    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

  3. Dynamics of degassing at Kilauea Volcano, Hawaii

    Science.gov (United States)

    Vergniolle, Sylvie; Jaupart, Claude

    1990-03-01

    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

  4. Acid fluids from Copahue Volcano, Argentina, and their environmental effects

    Science.gov (United States)

    Varekamp, J. C.; Kading, T.

    2010-12-01

    The acid hydrothermal system of Copahue volcano (province of Neuquen, Argentina) consists of a crater lake, acid hot springs (both with pH values of <1 to 2) and a severely acidified fluvial-lake system, with the voluminous Lake Caviahue (0.5 km3; pH 2.2 - 3). Annual measurements of river water fluxes and water compositions and vertical lake water profiles provide a 12 year record of geochemical evolution of the system. Copahue erupted in 2000, and the hydrothermal dissolved element fluxes peaked at that time. Since 2001, the K and Al fluxes have decreased notably as a result of alunite saturation within the hydrothermal system, whereas over the last few years redissolution of that alunite has led to increases in K and Al discharges. The fluxes of Mg and Fe have remained high over time, while the overall system has become more dilute since 2000. Once the distal downstream system reached pH values of 2.9-3.2, the mineral Schwertmannite started to precipitate through a bacterially mediated pathway. The precipitation front gradually moved upstream with ongoing dilution, and reached the exit of Lake Caviahue in 2009. The lake bottom waters were already saturated with the mineral at that time, and if this trend continues, the currently clear blue lake may turn into a bright yellow-brown mass of Schwertmannite over the next few years. Schwertmannite is common in acid mine drainage fluids but has not often been described from volcanic environments. It strongly adsorbs oxyanions (or structurally incorporates them) and the precipitates contain up to 6000 ppm P, 1100 ppm V and 1000 ppm As. The Schwertmannite appears to convert to goethite-like minerals over time, although the exact stoichiometry has been difficult to constrain (variable mixtures of FeOOH and Fe8O8(OH)6SO4 nH2O). The oxyanions appear to remain in the mineral mix during aging. If Lake Caviahue becomes a focus of Schwertmannite deposition, the precipitates will scavenge As, P and V from the watercolumn and

  5. METing SUSY on the Z peak

    Energy Technology Data Exchange (ETDEWEB)

    Barenboim, G.; Bernabeu, J.; Vives, O. [Universitat de Valencia, Departament de Fisica Teorica, Burjassot (Spain); Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain); Mitsou, V.A.; Romero, E. [Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain)

    2016-02-15

    Recently the ATLAS experiment announced a 3 σ excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E{sub T}{sup miss} > 225 GeV and HT > 600 GeV, to be compared with 10.6 ± 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m{sub g} or similar 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out. (orig.)

  6. Basaltic cannibalism at Thrihnukagigur volcano, Iceland

    Science.gov (United States)

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

    2014-12-01

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

  7. Dynamics of degassing at Kilauea Volcano, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-03-10

    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.

  8. Digging into Augustine Volcano's Silicic Past

    Science.gov (United States)

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

    2014-12-01

    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.

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

    Science.gov (United States)

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

    2014-01-01

    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.

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

    Science.gov (United States)

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

    2016-04-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Bruno Massa

    2016-11-01

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

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

    Science.gov (United States)

    Dzurisin, D.

    1980-01-01

    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

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

    Science.gov (United States)

    Kerlow, Isaac

    2017-04-01

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

  14. The Unexpected Awakening of Chaitén Volcano, Chile

    Science.gov (United States)

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

    2009-01-01

    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.

  15. Linking petrology and seismology at an active volcano.

    Science.gov (United States)

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

    2012-05-25

    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.

  16. The Unexpected Awakening of Chaitén Volcano, Chile

    Science.gov (United States)

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

    2009-06-01

    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.

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2016-11-01

    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.

  19. Will peak oil accelerate carbon dioxide emissions?

    Science.gov (United States)

    Caldeira, K.; Davis, S. J.; Cao, L.

    2008-12-01

    The relative scarcity of oil suggests that oil production is peaking and will decline thereafter. Some have suggested that this represents an opportunity to reduce carbon dioxide emissions. However, in the absence of constraints on carbon dioxide emission, "peak oil" may drive a shift towards increased reliance on coal as a primary energy source. Because coal per unit energy, in the absence of carbon capture and disposal, releases more carbon dioxide to the atmosphere than oil, "peak oil" may lead to an acceleration of carbon dioxide emissions. We will never run out of oil. As oil becomes increasingly scarce, prices will rise and therefore consumption will diminish. As prices rise, other primary energy sources will become increasingly competitive with oil. The developed world uses oil primarily as a source of transportation fuels. The developing world uses oil primarily for heat and power, but the trend is towards increasing reliance on oil for transportation. Liquid fuels, including petroleum derivatives such as gasoline and diesel fuel, are attractive as transportation fuels because of their relative abundance of energy per unit mass and volume. Such considerations are especially important for the air transport industry. Today, there is little that can compete with petroleum-derived transportation fuels. Future CO2 emissions from the transportation sector largely depend on what replaces oil as a source of fuel. Some have suggested that biomass-derived ethanol, hydrogen, or electricity could play this role. Each of these potential substitutes has its own drawbacks (e.g., low power density per unit area in the case of biomass, low power density per unit volume in the case of hydrogen, and low power density per unit mass in the case of battery storage). Thus, it is entirely likely that liquefaction of coal could become the primary means by which transportation fuels are produced. Since the burning of coal produces more CO2 per unit energy than does the burning of

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

    Science.gov (United States)

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

    2015-04-01

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

  1. Effect of Rainfall on Traffic Stream Characteristics during Peak and Non-Peak Periods

    Directory of Open Access Journals (Sweden)

    Hashim Mohammed Alhassan

    2012-01-01

    Full Text Available This paper examined the effect of rainfall on traffic stream behaviour during  peak and non-peak periods on a basic highway section. Data on this section which is located on the J5 was collected for four months during which 99 rainfall events occurred. The traffic consisted of 75.80% cars, 10.23% motorcycles, 3.51% trucks and 10.46%  of other vehicles. Traffic was observed for both rain and no-rain conditions and the data was analysed to see the effect of the rain. The results showed decreases in the speed as the rain intensity increased. Similarly, the traffic flow rates decreased as the rain intensity increased. This trend was observed for both peak and non-peak periods and for both directions. It is concluded that the effect of rain during peak period could have more serious consequences on the traffic flow than during non-peak periods because of the higher flow rates and the constrained nature of the flow. Consequently, capacity degradations up to 30% during peak periods would require resources to be employed to manage the traffic.

  2. Interactive Volcano Studies and Education Using Virtual Globes

    Science.gov (United States)

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

    2006-12-01

    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.

  3. Schoolyard Volcanoes: A Unit in Volcanology and Hazards

    Science.gov (United States)

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

    2014-12-01

    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

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

    Science.gov (United States)

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

    2007-12-01

    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.

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

    Science.gov (United States)

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

    2016-12-01

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

  6. Output rate of magma from active central volcanoes

    Science.gov (United States)

    Wadge, G.

    1980-01-01

    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.

  7. OMI Observations of Bromine Monoxide Emissions from Volcanoes

    Science.gov (United States)

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

    2016-12-01

    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.

  8. Experimental simulation and morphological quantification of volcano growth

    Science.gov (United States)

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

    2016-04-01

    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

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

    Science.gov (United States)

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

    1989-01-01

    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.

  10. Analysis of active volcanoes from the Earth Observing System

    Science.gov (United States)

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

    1991-01-01

    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.

  11. Eyjafjallajökull Volcano Eruption – A Brief Approach

    Directory of Open Access Journals (Sweden)

    OROIAN I.

    2010-08-01

    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.

  12. Tracking Pyroclastic Flows at Soufrière Hills Volcano

    Science.gov (United States)

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

    2009-07-01

    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.

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

    Science.gov (United States)

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

    2016-04-01

    Tenerife (2,034 km2), the largest of the Canary Islands, is the only island that has developed a central volcanic complex (Teide-Pico Viejo stratovolcanoes), characterized by the eruption of differentiated magmas. This central volcanic complex has been built in the intersection of the three major volcanic rift-zones of Tenerife, where most of the historical volcanic activity has taken place. The existence of a volcanic-hydrothermal system beneath Teide volcano is suggested by the occurrence of a weak fumarolic system, steamy ground and high rates of diffuse CO2 degassing all around the summit cone of Teide (Pérez et al., 2013). Diffuse emission studies of non-reactive and/or highly mobile gases such as helium have recently provided promising results to detect changes in the magmatic gas component at surface related to volcanic unrest episodes (Padrón et al., 2013). The geochemical properties of He minimize the interaction of this noble gas on its movement toward the earth's surface, and its isotopic composition is not affected by subsequent chemical reactions. It is highly mobile, chemically inert, physically stable, non-biogenic, sparingly soluble in water under ambient conditions, almost non-adsorbable, and highly diffusive with a diffusion coefficient ˜10 times that of CO2. As part of the geochemical monitoring program for the volcanic surveillance of Teide volcano, yearly surveys of diffuse He emission through the surface of the summit cone of Teide volcano have been performed since 2006. Soil He emission rate was measured yearly at ˜130 sampling sites selected in the surface environment of the summit cone of Teide volcano (Tenerife, Canary Islands), covering an area of ˜0.5 km2, assuming that He emission is governed by convection and diffusion. The distribution of the sampling sites was carefully chosen to homogeneously cover the target area, allowing the computation of the total He emission by sequential Gaussian simulation (sGs). Nine surveys have been

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

    Directory of Open Access Journals (Sweden)

    S. Rontogianni

    2012-07-01

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

  15. Overview of the precursors and dynamics of the 2012-13 basaltic fissure eruption of Tolbachik Volcano, Kamchatka, Russia

    Science.gov (United States)

    Belousov, Alexander; Belousova, Marina; Edwards, Benjamin; Volynets, Anna; Melnikov, Dmitry

    2015-12-01

    We present a broad overview of the 2012-13 flank fissure eruption of Plosky Tolbachik Volcano in the central Kamchatka Peninsula. The eruption lasted more than nine months and produced approximately 0.55 km3 DRE (volume recalculated to a density of 2.8 g/cm3) of basaltic trachyandesite magma. The 2012-13 eruption of Tolbachik is one of the most voluminous historical eruptions of mafic magma at subduction related volcanoes globally, and it is the second largest at Kamchatka. The eruption was preceded by five months of elevated seismicity and ground inflation, both of which peaked a day before the eruption commenced on 27 November 2012. The batch of high-Al magma ascended from depths of 5-10 km; its apical part contained 54-55 wt.% SiO2, and the main body 52-53 wt.% SiO2. The eruption started by the opening of a 6 km-long radial fissure on the southwestern slope of the volcano that fed multi-vent phreatomagmatic and magmatic explosive activity, as well as intensive effusion of lava with an initial discharge of > 440 m3/s. After 10 days the eruption continued only at the lower part of the fissure, where explosive and effusive activity of Hawaiian-Strombolian type occurred from a lava pond in the crater of the main growing scoria cone. The discharge rate for the nine month long, effusion-dominated eruption gradually declined from 140 to 18 m3/s and formed a compound lava field with a total area of ~ 36 km2; the effusive activity evolved from high-discharge channel-fed 'a'a lavas to dominantly low-discharge tube-fed pahoehoe lavas. On 23 August, the effusion of lava ceased and the intra-crater lava pond drained. Weak Strombolian-type explosions continued for several more days on the crater bottom until the end of the eruption around 5 September 2013. Based on a broad array of new data collected during this eruption, we develop a model for the magma storage and transport system of Plosky Tolbachik that links the storage zones of the two main genetically related magma

  16. Electromechanical Peak Devices of Distributed Power Generation

    Directory of Open Access Journals (Sweden)

    S. V. Konstantinova

    2011-01-01

    Full Text Available The power world crises (1973, 1979 have demonstrated that mankind entered the expensive energy epoch. More and more attitude is given to power saving problem by including renewable power sources in energy balance of the countries. The paper analyzes a power system inBelarusand a typical chart of the active load is cited in the paper. Equalization of load chart is considered as one of measures directed on provision of higher operational efficiency of power system and power saving.  This purpose can be obtained while including electromechanical peak devices of the distributed generation in the energy balance.

  17. LARAMIE PEAK WILDERNESS STUDY AREA, WYOMING.

    Science.gov (United States)

    Segerstrom, Kenneth; Weisner, R.C.

    1984-01-01

    On the basis of a mineral survey, most of the Laramie Peak Wilderness study area in Wyoming was concluded to have little promise for the occurrence of mineral or energy resources. Only three small areas in the northern part, one extending outside the study area to Esterbrook, were found to have probable mineral-resource potential for copper and lead. The geologic setting precludes the presence of fossil-fuel resources in the study area. There are no surface indications that geothermal energy could be developed within or near the study area.

  18. Forecasting peaks of seasonal influenza epidemics.

    Science.gov (United States)

    Nsoesie, Elaine; Mararthe, Madhav; Brownstein, John

    2013-06-21

    We present a framework for near real-time forecast of influenza epidemics using a simulation optimization approach. The method combines an individual-based model and a simple root finding optimization method for parameter estimation and forecasting. In this study, retrospective forecasts were generated for seasonal influenza epidemics using web-based estimates of influenza activity from Google Flu Trends for 2004-2005, 2007-2008 and 2012-2013 flu seasons. In some cases, the peak could be forecasted 5-6 weeks ahead. This study adds to existing resources for influenza forecasting and the proposed method can be used in conjunction with other approaches in an ensemble framework.

  19. Peak oil, economic growth, and wildlife conservation

    CERN Document Server

    Gates, J Edward; Czech, Brian

    2014-01-01

    The proposed book focuses on one of the most important issues affecting humankind in this century - Peak Oil or the declining availability of abundant, cheap energy-and its effects on our industrialized economy and wildlife conservation. Energy will be one of the defining issues of the 21st Century directly affecting wildlife conservation wherever energy extraction is a primary economic activity and indirectly through deepening economic recessions. Since cheap, abundant energy has been at the core of our industrial society, and has resulted in the technological advancements we enjoy today, the

  20. Particle creation by peak electric field

    CERN Document Server

    Adorno, T C; Gitman, D M

    2016-01-01

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially-increasing and another exponentially-decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered.

  1. Particle creation by peak electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Gavrilov, S.P. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Herzen State Pedagogical University of Russia, Department of General and Experimental Physics, St. Petersburg (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); P. N. Lebedev Physical Institute, Moscow (Russian Federation); University of Sao Paulo, Institute of Physics, CP 66318, Sao Paulo, SP (Brazil)

    2016-08-15

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially increasing and another exponentially decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered. (orig.)

  2. ACTIVITY AND Vp/Vs RATIO OF VOLCANO-TECTONIC SEISMIC SWARM ZONES AT NEVADO DEL RUIZ VOLCANO, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Londoño B. John Makario

    2010-06-01

    Full Text Available An analysis of the seismic activity for volcano-tectonic earthquake (VT swarms zones at Nevado del Ruiz Volcano (NRV was carried out for the interval 1985- 2002, which is the most seismic active period at NRV until now (2010. The swarm-like seismicity of NRV was frequently concentrated in very well defined clusters around the volcano. The seismic swarm zone located at the active crater was the most active during the entire time. The seismic swarm zone located to the west of the volcano suggested some relationship with the volcanic crises. It was active before and after the two eruptions occurred in November 1985 and September 1989. It is believed that this seismic activity may be used as a monitoring tool of volcanic activity. For each seismic swarm zone the Vp/Vs ratio was also calculated by grouping of earthquakes and stations. It was found that each seismic swarm zone had a distinct Vp/Vs ratio with respect to the others, except for the crater and west swarm zones, which had the same value. The average Vp/Vs ratios for the seismic swarm zones located at the active crater and to the west of the volcano are about 6-7% lower than that for the north swarm zone, and about 3% lower than that for the south swarm zone. We suggest that the reduction of the Vp/Vs ratio is due to degassing phenomena inside the central and western earthquake swarm zones, or due to the presence of microcracks inside the volcano. This supposition is in agreement with other studies of geophysics, geochemistry and drilling surveys carried out at NRV.

  3. Beyond the Peak - Tactile Temporal Discrimination Does Not Correlate with Individual Peak Frequencies in Somatosensory Cortex.

    Science.gov (United States)

    Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

    2017-01-01

    The human sensory systems constantly receive input from different stimuli. Whether these stimuli are integrated into a coherent percept or segregated and perceived as separate events, is critically determined by the temporal distance of the stimuli. This temporal distance has prompted the concept of temporal integration windows or perceptual cycles. Although this concept has gained considerable support, the neuronal correlates are still discussed. Studies suggested that neuronal oscillations might provide a neuronal basis for such perceptual cycles, i.e., the cycle lengths of alpha oscillations in visual cortex and beta oscillations in somatosensory cortex might determine the length of perceptual cycles. Specifically, recent studies reported that the peak frequency (the frequency with the highest spectral power) of alpha oscillations in visual cortex correlates with subjects' ability to discriminate two visual stimuli. In the present study, we investigated whether peak frequencies in somatosensory cortex might serve as the correlate of perceptual cycles in tactile discrimination. Despite several different approaches, we were unable to find a significant correlation between individual peak frequencies in the alpha- and beta-band and individual discrimination abilities. In addition, analysis of Bayes factor provided evidence that peak frequencies and discrimination thresholds are unrelated. The results suggest that perceptual cycles in the somatosensory domain are not necessarily to be found in the peak frequency, but in other frequencies. We argue that studies based solely on analysis of peak frequencies might thus miss relevant information.

  4. PeakVizor: Visual Analytics of Peaks in Video Clickstreams from Massive Open Online Courses.

    Science.gov (United States)

    Chen, Qing; Chen, Yuanzhe; Liu, Dongyu; Shi, Conglei; Wu, Yingcai; Qu, Huamin

    2016-10-01

    Massive open online courses (MOOCs) aim to facilitate open-access and massive-participation education. These courses have attracted millions of learners recently. At present, most MOOC platforms record the web log data of learner interactions with course videos. Such large amounts of multivariate data pose a new challenge in terms of analyzing online learning behaviors. Previous studies have mainly focused on the aggregate behaviors of learners from a summative view; however, few attempts have been made to conduct a detailed analysis of such behaviors. To determine complex learning patterns in MOOC video interactions, this paper introduces a comprehensive visualization system called PeakVizor. This system enables course instructors and education experts to analyze the "peaks" or the video segments that generate numerous clickstreams. The system features three views at different levels: the overview with glyphs to display valuable statistics regarding the peaks detected; the flow view to present spatio-temporal information regarding the peaks; and the correlation view to show the correlation between different learner groups and the peaks. Case studies and interviews conducted with domain experts have demonstrated the usefulness and effectiveness of PeakVizor, and new findings about learning behaviors in MOOC platforms have been reported.

  5. TOMO-ETNA Experiment -Etna volcano, Sicily, investigated with active and passive seismic methods

    Science.gov (United States)

    Luehr, Birger-G.; Ibanez, Jesus M.; Díaz-Moreno, Alejandro; Prudencio, Janire; Patane, Domenico; Zieger, Toni; Cocina, Ornella; Zuccarello, Luciano; Koulakov, Ivan; Roessler, Dirk; Dahm, Torsten

    2017-04-01

    arrival to any part later in the seismic wave train. As an independent proxy of the scattering strength along the ray path, we measure the peak delay time of a direct P-wave, which is well correlated with the coda energy ratio. As a result the distribution of heterogeneities around Etna could be visualized as the projection of the observation in directions of incident rays at the stations. Increased seismic scattering could be detected in the volcano and east of it. The strong heterogeneous zone towards the east coast of Sicily supports earlier observations, and is interpreted as a potential signature of the eastward sliding volcano flank. Beside the investigation of P-wave scattering the new seismic tomography software PARTOS (Passive Active Ray Tomography Software) has been developed based on a joint inversion of active and passive seismic sources. With PARTOS real data inversion has been carried out using three different subsets: i) active data; ii) passive data; and iii) joint dataset, permitting to obtain a new tomographic approach of that region.

  6. Eruptive history and petrology of Mount Drum volcano, Wrangell Mountains, Alaska

    Science.gov (United States)

    Richter, D.H.; Moll-Stalcup, E. J.; Miller, T.P.; Lanphere, M.A.; Dalrymple, G.B.; Smith, R.L.

    1994-01-01

    Mount Drum is one of the youngest volcanoes in the subduction-related Wrangell volcanic field (80x200 km) of southcentral Alaska. It lies at the northwest end of a series of large, andesite-dominated shield volcanoes that show a northwesterly progression of age from 26 Ma near the Alaska-Yukon border to about 0.2 Ma at Mount Drum. The volcano was constructed between 750 and 250 ka during at least two cycles of cone building and ring-dome emplacement and was partially destroyed by violent explosive activity probably after 250 ka. Cone lavas range from basaltic andesite to dacite in composition; ring-domes are dacite to rhyolite. The last constructional activity occured in the vicinity of Snider Peak, on the south flank of the volcano, where extensive dacite flows and a dacite dome erupted at about 250 ka. The climactic explosive eruption, that destroyed the top and a part of the south flank of the volcano, produced more than 7 km3 of proximal hot and cold avalanche deposits and distal mudflows. The Mount Drum rocks have medium-K, calc-alkaline affinities and are generally plagioclase phyric. Silica contents range from 55.8 to 74.0 wt%, with a compositional gap between 66.8 and 72.8 wt%. All the rocks are enriched in alkali elements and depleted in Ta relative to the LREE, typical of volcanic arc rocks, but have higher MgO contents at a given SiO2, than typical orogenic medium-K andesites. Strontium-isotope ratios vary from 0.70292 to 0.70353. The compositional range of Mount Drum lavas is best explained by a combination of diverse parental magmas, magma mixing, and fractionation. The small, but significant, range in 87Sr/86Sr ratios in the basaltic andesites and the wide range of incompatible-element ratios exhibited by the basaltic andesites and andesites suggests the presence of compositionally diverse parent magmas. The lavas show abundant petrographic evidence of magma mixing, such as bimodal phenocryst size, resorbed phenocrysts, reaction rims, and

  7. Rockfalls and Avalanches from Little Tahoma Peak on Mount Rainier, Washington

    Science.gov (United States)

    Crandell, Dwight Raymond; Fahnestock, Robert K.

    1965-01-01

    In December 1963 rockfalls from Little Tahoma Peak on the east side of Mount Rainier volcano fell onto Emmons Glacier and formed avalanches of rock debris that traveled about 4 miles down the glacier and the White River valley. In this distance, the rock debris descended as much as 6,200 feet in altitude. Minor lithologic differences and crosscutting relations indicate that the rockfalls caused at least seven separate avalanches, having an estimated total volume of 14 million cubic yards. The initial rockfall may have been caused by a small steam explosion near the base of Little Tahoma Peak. During movement, some of the avalanches were deflected from one side of the valley to the other. Calculations based on the height to which the avalanches rose on the valley walls suggest that their velocity reached at least 80 or 90 miles per hour. The unusually long distance some of the avalanches were transported is attributed to a cushion of trapped and compressed air at their base, which buoyed them up amid reduced friction.

  8. Characterization of seismic events during the 2009 eruption of Redoubt Volcano, Alaska

    Science.gov (United States)

    Ketner, Dane; Power, John

    2013-06-01

    Seismic events were automatically detected and characterized throughout the 2009 eruption of Redoubt Volcano, Alaska on a single short period station located 3 km from the volcanic crater. A total of 126,789 individual events were identified from continuous recording of seismic data from January 1 to June 30 (average 29 events per hour) using a short-term average/long-term average detection algorithm. Nine metrics were computed for this suite of events including event duration, inter-event time, event rate, peak amplitude, peak-to-peak amplitude, root-mean-square (RMS) amplitude, peak frequency, center frequency, and frequency index. Eight swarms were identified with event rates exceeding 100 events per hour. The first two occurred in late January and are attributed to high amplitude spasmodic tremor. Five additional swarms were manually repicked including swarms on February 26-27, March 20-23, March 27, March 29, and April 2-4. Three of these swarms immediately preceded major explosions including March 20-23, March 27, and April 2-4. A final swarm on May 2-9 was re-picked using a correlation detection scheme. We identified 146 event families that occurred within this suite of selected events using a cross correlation technique. Seven explosions were each immediately preceded by one or more event families. Events from the dominant family during each of these periods was additionally re-picked using correlation detection. The procession of event metrics and occurrence of event families formed a complex distribution throughout the eruption. A single-station approach was used to gain a fine-scale view of variations in seismic behavior at Redoubt with a focus on potential indicators of impending explosions. These techniques may serve an important role in future real-time eruption monitoring efforts.

  9. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...

  10. Equivalence Principle and the Baryon Acoustic Peak

    CERN Document Server

    Baldauf, Tobias; Simonović, Marko; Zaldarriaga, Matias

    2015-01-01

    We study the dominant effect of a long wavelength density perturbation $\\delta(\\lambda_L)$ on short distance physics. In the non-relativistic limit, the result is a uniform acceleration, fixed by the equivalence principle, and typically has no effect on statistical averages due to translational invariance. This same reasoning has been formalized to obtain a "consistency condition" on the cosmological correlation functions. In the presence of a feature, such as the acoustic peak at $l_{\\rm BAO}$, this naive expectation breaks down for $\\lambda_Lpeak, and is calculable to all orders in the long modes. This can be used to improve the result of perturbative calculations - a technique known as "infra-red resummation"- and is explicitly applied to the one-loop calculation of power spectrum. Finally, the success of BAO reconstruction schemes is argue...

  11. Microwave peak absorption frequency of liquid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms,and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent),the material will intensively absorb microwave energy. This is also known as resonant absorption,and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work,dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model,the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time,the expression of microwave peak absorption frequency as a func-tion of the material physical structure,rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene,and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material,but also provide a possible guide for the experiment of microwave-assisted extraction.

  12. Microwave peak absorption frequency of liquid

    Institute of Scientific and Technical Information of China (English)

    HAN GuangZe; CHEN MingDong

    2008-01-01

    Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms, and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent), the material will intensively absorb microwave energy. This is also known as resonant absorption, and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work, dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model, the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time, the expression of microwave peak absorption frequency as a func-tion of the material physical structure, rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene, and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material, but also provide a possible guide for the experiment of microwave-assisted extraction.

  13. Method and apparatus for current-output peak detection

    Energy Technology Data Exchange (ETDEWEB)

    De Geronimo, Gianluigi

    2017-01-24

    A method and apparatus for a current-output peak detector. A current-output peak detector circuit is disclosed and works in two phases. The peak detector circuit includes switches to switch the peak detector circuit from the first phase to the second phase upon detection of the peak voltage of an input voltage signal. The peak detector generates a current output with a high degree of accuracy in the second phase.

  14. , Recorded at Ladron Peak, Central New Mexico

    Science.gov (United States)

    Ricketts, J. W.; Kelley, S.; Read, A. S.; Karlstrom, K. E.

    2010-12-01

    Ladron Peak, situated on the western flank of the Rio Grande rift ~30 miles NW of Socorro, NM, is composed of Precambrian granitic and metamorphic assemblages that have been faulted and uplifted during the late Tertiary formation of the rift. The area is bounded on three sides by normal faults, including the anomalously low-angle (~26°) Jeter fault to the east, which places Precambrian rocks in the footwall against Paleozoic and Mesozoic fault slivers, and mainly Cenozoic Santa Fe Group basin fill in the hanging wall. New apatite fission track (AFT) thermochronological data collected at 22 locations along the NE and SE margins of Ladron Peak give a range of ages from 10.9 ± 1.9 to 20.4 ± 8.6 Ma. Samples within the footwall include granitic and metasedimentary rocks that have mean track lengths of 13.1 to 14.1 μm; one quartzite sample has a mean track length of 12.5 μm, suggesting time in the partial annealing zone. Within the hanging wall block, new AFT ages from the Permian Bursum and Abo Formations give cooling ages of 23.1 ± 3.3 Ma. and 59.9 ± 12.4 Ma., respectively. The Bursum Formation sample, with a track length of 13.7 μm, cooled below the 110°C isotherm during the Miocene, while the Abo Formation sample, with a track length of 11.2 μm, was only partially reset prior to rift-related deformation. Mylonitized granitic and metamorphic rocks in the immediate footwall preserve dip-slip lineations that are parallel to slip on the Jeter fault. This suggests that strain associated with exhumation was recorded by both brittle and ductile deformation. Although this type of deformation is common within metamorphic core complexes in highly extended terranes, ductile normal faulting has not been recognized within the Rio Grande rift in New Mexico, though there is some suggestion of ductile deformation around Blanca Peak in the San Luis Valley in Colorado. These observations imply one or both of the following: (1) Ductile deformation at Ladron Peak was

  15. Time dependent deformation of Kilauea Volcano, Hawaii

    Science.gov (United States)

    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

  16. Geodetic constraints on volcanic plume height at Grímsvötn volcano, Iceland

    Science.gov (United States)

    Hreinsdóttir, Sigrún; Sigmundsson, Freysteinn; Roberts, Matthew; Björnsson, Halldór; Grapenthin, Ronni; Arason, Pórdur; Árnadóttir, Thóra; Hólmjárn, Jósef; Geirsson, Halldór; Bennett, Richard; Gudmundsson, Magnús; Oddsson, Björn; Ófeigsson, Benedikt; Villemin, Thierry; Jónsson, Torsteinn; Sturkell, Erik; Höskuldsson, Ármann; Larsen, Gudrún; Thordarson, Thor; Óladóttir, Bergrún

    2014-05-01

    In 2011 a VEI 4 explosive eruption took place at Grímsvötn volcano, Iceland. Grímsvötn is a subglacial basaltic volcano beneath the Vatnajökull ice cap. It is Iceland's most frequently erupting volcano, with recent eruptions in 1983, 1998, 2004, and 2011. The volcano has a low seismic velocity anomaly down to about 3 km depth, interpreted as a magma chamber. A continuous GPS station and a tiltmeter are located on a nunatak, Mount Grímsfjall, which protrudes from the ice at the southern rim of the caldera. The 21-28 May 2011 eruption was Grímsvötn's largest since 1873, resulting in airspace closure in northern Europe and the cancellation of about 900 passenger flights. The eruption was preceded by gradual inflation following the 2004 eruption and progressive increase in seismicity. Kinematic 1 Hz solutions were derived for the position of the GPS station in the hours immediately before and during the 2011 eruption. The onset of deformation preceded the eruption by one hour and reached maximum of 0.57 m within 48 hours. Throughout the eruption the GPS station moved consistently in direction N38.4+/-0.5W, opposite to the direction of movements during the 2004-2011 inter eruptive phase. The deformation characteristics suggest that the signal was mostly due to pressure change in a source at 1.7 +/- 0.2 km depth. We use the geodetic measurements to infer co-eruptive pressure change in the magma chamber using the Mogi model. The rate of pressure drop is then used to estimate the magma flow rate from the chamber. Numerous studies have shown that plume height in explosive eruptions can be related to magma discharge. Using an empirical relationship between the volcanic plume height and magma flow rate (Mastin et al., 2009) we estimate the evolution of the plume height from the geodetic data. Two weather radars monitored the height of the volcanic plume during the eruption. A strong initial plume with peaks at 20-25 km was followed by a declining, pulsating activity

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

    Energy Technology Data Exchange (ETDEWEB)

    G.A> Valentine; F.V. Perry

    2006-06-06

    The distribution and characteristics of individual basaltic volcanoes in the waning Southwestern Nevada Volcanic Field provide insight into the changing physical nature of magmatism and the controls on volcano location. During Pliocene-Pleistocene times the volumes of individual volcanoes have decreased by more than one order of magnitude, as have fissure lengths and inferred lava effusion rates. Eruptions evolved from Hawaiian-style eruptions with extensive lavas to eruptions characterized by small pulses of lava and Strombolian to violent Strombolian mechanisms. These trends indicate progressively decreasing partial melting and length scales, or magmatic footprints, of mantle source zones for individual volcanoes. The location of each volcano is determined by the location of its magmatic footprint at depth, and only by shallow structural and topographic features that are within that footprint. The locations of future volcanoes in a waning system are less likely to be determined by large-scale topography or structures than were older, larger volume volcanoes.

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

    Directory of Open Access Journals (Sweden)

    Dina A. Sarsito

    2006-11-01

    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.

  19. Observation of Eyjafjallajökull volcano ash over Poland

    Science.gov (United States)

    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.

    2010-05-01

    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.

  20. Volcanic Environments Monitoring by Drones Mud Volcano Case Study

    Science.gov (United States)

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

    2013-08-01

    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.

  1. Search for shallow magma accumulations at Augustine Volcano

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-05-01

    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.

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

    NARCIS (Netherlands)

    Umbgrove, J.H.F.

    1926-01-01

    The geological history of the Krakatoa volcano, especially the eruption of 1883, is amply described in the great work “Krakatau” by R. D. M. Verheer (1885), the Report of the Krakatoa Committee (Royal Soc. London 1888) and in the publications of B. G. Escher (Handel. 1e Nederl. Indisch Natuurwet ens

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

    Directory of Open Access Journals (Sweden)

    Yu-Ming Lai

    2010-01-01

    Full Text Available Combining the shaded relief topography model and the slope map from the Digital Terrain Model (DTM images, toporaphical map, field occurrences and petrography, the volcanic sequences of the Huangtsuishan Volcano Subgroup (HVS can be constructed. Two types of volcanic centers can be identified in this area. One is the Tachienhou volcanic dome, which may be located in the center of an older caldera. The other is the Huangtsui composite volcano, which is composed of interbedding lava flows and pyroclastic deposits with a volcanic crater named the Huangtsui pond at the summit. Eight lava plateaus radiated from Mts. Huangtsui and Tachienhou to the north and the east can be distinguished based on the DTM images. The volcanic deposits are comprised of four lithofacies, the lava flows, pyroclastic breccias, tuffs and lahars on the base of field occurrences. At least thirteen layers of lava flow, named the H1 to H13 can be recognized in the HVS and can be reconstructed and categorized into four stages. An old and large volcano erupted lava flows to form the products of stages one and two, then collapsed to form a caldera with a dome for the third stage. The latest stage of lava flow was poured out from the Huangtsui volcano, which formed a crater at the summit.

  4. Deep structure and origin of active volcanoes in China

    Institute of Scientific and Technical Information of China (English)

    Dapeng Zhao; Lucy Liu

    2010-01-01

    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. Twilight Phenomena Caused by the Eruption of Agung Volcano.

    Science.gov (United States)

    Volz, F E

    1964-05-29

    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.

  6. Seismic instrumentation plan for the Hawaiian Volcano Observatory

    Science.gov (United States)

    Thelen, Weston A.

    2014-01-01

    The seismic network operated by the U.S. Geological Survey’s Hawaiian Volcano Observatory (HVO) is the main source of authoritative data for reporting earthquakes in the State of Hawaii, including those that occur on the State’s six active volcanoes (Kīlauea, Mauna Loa, Hualālai, Mauna Kea, Haleakalā, Lō‘ihi). Of these volcanoes, Kīlauea and Mauna Loa are considered “very high threat” in a report on the rationale for a National Volcanic Early Warning System (NVEWS) (Ewert and others, 2005). This seismic instrumentation plan assesses the current state of HVO’s seismic network with respect to the State’s active volcanoes and calculates the number of stations that are needed to upgrade the current network to provide a seismic early warning capability for forecasting volcanic activity. Further, the report provides proposed priorities for upgrading the seismic network and a cost assessment for both the installation costs and maintenance costs of the improved network that are required to fully realize the potential of the early warning system.

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

    Science.gov (United States)

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

    2011-12-01

    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.

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

    African Journals Online (AJOL)

    AJL

    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.

  9. Long-term eruptive activity at a submarine arc volcano.

    Science.gov (United States)

    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

    2006-05-25

    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.

  10. Understanding the Potential for Volcanoes at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2002-08-01

    By studying the rocks and geologic features of an area, experts can assess whether it is vulnerable to future volcanic eruptions. Scientists have performed extensive studies at and near Yucca Mountain to determine whether future volcanoes could possibly affect the proposed repository for nuclear waste.

  11. Eruptions of Eyjafjallajökull Volcano, Iceland

    Science.gov (United States)

    Gudmundsson, Magnús T.; Pedersen, Rikke; Vogfjörd, Kristín; Thorbjarnardóttir, Bergthóra; Jakobsdóttir, Steinunn; Roberts, Matthew J.

    2010-05-01

    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.

  12. Deep structure and origin of active volcanoes in China

    Directory of Open Access Journals (Sweden)

    Dapeng Zhao

    2010-10-01

    Full Text Available We synthesize significant recent results on the deep structure and origin of the active volcanoes in mainland China. Magmatism in the western Pacific arc and back-arc areas is caused by dehydration of the subducting slab and by corner flow in the mantle wedge, whereas the intraplate magmatism in China has different origins. The active volcanoes in Northeast China (such as the Changbai and Wudalianchi are caused by hot upwelling in the big mantle wedge (BMW above the stagnant slab in the mantle transition zone and deep slab dehydration as well. The Tengchong volcano in Southwest China is caused by a similar process in the BMW above the subducting Burma microplate (or Indian plate. The Hainan volcano in southernmost China is a hotspot fed by a lower-mantle plume which may be associated with the Pacific and Philippine Sea slabs’ deep subduction in the east and the Indian slab’s deep subduction in the west down to the lower mantle. The stagnant slab finally collapses down to the bottom of the mantle, which can trigger the upwelling of hot mantle materials from the lower mantle to the shallow mantle beneath the subducting slabs and may cause the slab–plume interactions.

  13. Collaborative Monitoring and Hazard Mitigation at Fuego Volcano, Guatemala

    Science.gov (United States)

    Lyons, J. J.; Bluth, G. J.; Rose, W. I.; Patrick, M.; Johnson, J. B.; Stix, J.

    2007-05-01

    A portable, digital sensor network has been installed to closely monitor changing activity at Fuego volcano, which takes advantage of an international collaborative effort among Guatemala, U.S. and Canadian universities, and the Peace Corps. The goal of this effort is to improve the understanding shallow internal processes, and consequently to more effectively mitigate volcanic hazards. Fuego volcano has had more than 60 historical eruptions and nearly-continuous activity make it an ideal laboratory to study volcanic processes. Close monitoring is needed to identify base-line activity, and rapidly identify and disseminate changes in the activity which might threaten nearby communities. The sensor network is comprised of a miniature DOAS ultraviolet spectrometer fitted with a system for automated plume scans, a digital video camera, and two seismo-acoustic stations and portable dataloggers. These sensors are on loan from scientists who visited Fuego during short field seasons and donated use of their sensors to a resident Peace Corps Masters International student from Michigan Technological University for extended data collection. The sensor network is based around the local volcano observatory maintained by Instituto National de Sismologia, Vulcanologia, Metrologia e Hidrologia (INSIVUMEH). INSIVUMEH provides local support and historical knowledge of Fuego activity as well as a secure location for storage of scientific equipment, data processing, and charging of the batteries that power the sensors. The complete sensor network came online in mid-February 2007 and here we present preliminary results from concurrent gas, seismic, and acoustic monitoring of activity from Fuego volcano.

  14. An Overview of Geodetic Volcano Research in the Canary Islands

    Science.gov (United States)

    Fernández, José; González, Pablo J.; Camacho, Antonio G.; Prieto, Juan F.; Brú, Guadalupe

    2015-11-01

    The Canary Islands are mostly characterized by diffuse and scattered volcanism affecting a large area, with only one active stratovolcano, the Teide-Pico Viejo complex (Tenerife). More than 2 million people live and work in the 7,447 km2 of the archipelago, resulting in an average population density three times greater than the rest of Spain. This fact, together with the growth of exposure during the past 40 years, increases volcanic risk with respect previous eruptions, as witnessed during the recent 2011-2012 El Hierro submarine eruption. Therefore, in addition to purely scientific reasons there are economic and population-security reasons for developing and maintaining an efficient volcano monitoring system. In this scenario geodetic monitoring represents an important part of the monitoring system. We describe volcano geodetic monitoring research carried out in the Canary Islands and the results obtained. We consider for each epoch the two main existing constraints: the level of volcanic activity in the archipelago, and the limitations of the techniques available at the time. Theoretical and observational aspects are considered, as well as the implications for operational volcano surveillance. Current challenges of and future perspectives in geodetic volcano monitoring in the Canaries are also presented.

  15. Tsunami wave generation by the eruption of underwater volcano

    Directory of Open Access Journals (Sweden)

    Y. Egorov

    2007-01-01

    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.

  16. Ice and water on Newberry Volcano, central Oregon

    Science.gov (United States)

    Donnelly-Nolan, Julie M.; Jensen, Robert A.; O'Connor, Jim; Madin, Ian P.; Dorsey, Rebecca

    2009-01-01

    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.

  17. Peak Wind Tool for General Forecasting

    Science.gov (United States)

    Barrett, Joe H., III

    2010-01-01

    The expected peak wind speed of the day is an important forecast element in the 45th Weather Squadron's (45 WS) daily 24-Hour and Weekly Planning Forecasts. The forecasts are used for ground and space launch operations at the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45 WS also issues wind advisories for KSC/CCAFS when they expect wind gusts to meet or exceed 25 kt, 35 kt and 50 kt thresholds at any level from the surface to 300 ft. The 45 WS forecasters have indicated peak wind speeds are challenging to forecast, particularly in the cool season months of October - April. In Phase I of this task, the Applied Meteorology Unit (AMU) developed a tool to help the 45 WS forecast non-convective winds at KSC/CCAFS for the 24-hour period of 0800 to 0800 local time. The tool was delivered as a Microsoft Excel graphical user interface (GUI). The GUI displayed the forecast of peak wind speed, 5-minute average wind speed at the time of the peak wind, timing of the peak wind and probability the peak speed would meet or exceed 25 kt, 35 kt and 50 kt. For the current task (Phase II ), the 45 WS requested additional observations be used for the creation of the forecast equations by expanding the period of record (POR). Additional parameters were evaluated as predictors, including wind speeds between 500 ft and 3000 ft, static stability classification, Bulk Richardson Number, mixing depth, vertical wind shear, temperature inversion strength and depth and wind direction. Using a verification data set, the AMU compared the performance of the Phase I and II prediction methods. Just as in Phase I, the tool was delivered as a Microsoft Excel GUI. The 45 WS requested the tool also be available in the Meteorological Interactive Data Display System (MIDDS). The AMU first expanded the POR by two years by adding tower observations, surface observations and CCAFS (XMR) soundings for the cool season months of March 2007 to April 2009. The POR was expanded

  18. Dense Local Seismic Network at Villarrica Volcano (Southern Chile)

    Science.gov (United States)

    Mora-Stock, C.; Thorwart, M.; Dzieran, L.; Rabbel, W.

    2013-12-01

    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

  19. Late Pleistocene Holocene stratigraphy and radiocarbon dating of La Malinche volcano, Central Mexico

    Science.gov (United States)

    Castro-Govea, Renato; Siebe, Claus

    2007-04-01

    Previous studies of La Malinche identified and radiocarbon dated several volcanic layers, the youngest of which yielded an age of ca. 7.5 ka. An additional ash fallout layer that crops out at high altitudes was considered the most recent deposit, with an estimated age of 6 ka. In the present work 38 new radiocarbon ages are presented. From these, several date the young ash fallout layer and lie around 3.1 ka. With the aid of these dates a new and comprehensive stratigraphy documenting the Late Pleistocene-Holocene eruptive history of La Malinche is presented. The stratigraphy indicates two main stages of volcanic activity: Pre-Malinche and Malinche. The first undoubtedly comprises the major part of the eruptive history, but its deposits are largely covered by the products of the latter stage, on which this study is focused. The Malinche stage was subdivided into three eruptive periods. Period 1 started with the emplacement of the Huamantla Pumice more than 45 ka ago. This deposit consists of a thick pumice fallout overlain by pyroclastic flow deposits. Subsequently, several episodes of construction and collapse of summit domes occurred. The oldest dome was dated at ca. 45 ka. Period 2 started 21.5 ka ago with the Malinche Pumice I, a widespread pumice fallout covering the entire slopes of the volcano. Pyroclastic flows and lahars related to this eruption were channeled along deep barrancas and reached considerable distances. Deposits produced by partial sector collapse and dated at ca. 20.9 ka, and a pumice-and-ash flow deposit dated at 15.9 ka were also generated during this period. The last period started with the eruption of the Malinche Pumice II, a distinctive fallout deposit overlain by ash flow deposits on the NE slope of the volcano. The age of this pumice layer is estimated between 12 and 9 ka. Formation of block-and-ash flows, lahars and pumice-and-ash flows followed during this period, and peaked in a most intensive episode that was dated at 7.5 ka

  20. Transporting and Deposition Dynamics in the Plinian Column of Tianchi Volcano, Changbaishan

    Institute of Scientific and Technical Information of China (English)

    Wei Haiquan; Liu Ruoxin; Song Shengrong; Yang Qingfu

    2000-01-01

    The huge comendite ignimbrite- forming eruption of Tianchi Volcano maintained a stable plinian column during its earlier stage of eruption, and succeeded a collapsing of the column producing pumiceous ignimbrite deposits. It is estimated that the column height (Hb) varied from 20km to 10km in its eruption period, with a maximum height of 25km in the eruption peak. Its umbrella cloud spread into the stratosphere with a top height of 35km (Ht). The dense lithics whose diameter exceeded 8cm followed a ballistics trajectory in a 3km - high gas thrust region, while the smaller lithics and pumices entered the convection region in the column. The initial magma temperature was 780℃. The comendite magma had an exit velocity of 300m/s, volatile content of about 1wt% and lithics of 8.5wt%. From a 400m - wide vent the magma was expelled out with a mass eruption rate of 108.36kg/s, corresponding to a volume rate of 104.95m3/s. Over 1. 3436 × 1019J of energy had been released from Tianchi Volcano, of which the kinetic proportion was about 8 %. The plume had a temperature of -50℃ at the base focus of the cloud and a upward speed of 215m/s. The cloud spread out at a gradually downspeed with the increasement of distance from its center. For example, at a distance of 25km from its center the spreading velocity is about 250m/s, and is about 60m/s at distance of 100km. The main part of the plinian column, that is the convection region, once occurred in the height between 3 to 25km, and its maximum width was about 13km in radius.

  1. Determination and uncertainty of moment tensors for microearthquakes at Okmok Volcano, Alaska

    Science.gov (United States)

    Pesicek, J.D.; Sileny, J.; Prejean, S.G.; Thurber, C.H.

    2012-01-01

    Efforts to determine general moment tensors (MTs) for microearthquakes in volcanic areas are often hampered by small seismic networks, which can lead to poorly constrained hypocentres and inadequate modelling of seismic velocity heterogeneity. In addition, noisy seismic signals can make it difficult to identify phase arrivals correctly for small magnitude events. However, small volcanic earthquakes can have source mechanisms that deviate from brittle double-couple shear failure due to magmatic and/or hydrothermal processes. Thus, determining reliable MTs in such conditions is a challenging but potentially rewarding pursuit. We pursued such a goal at Okmok Volcano, Alaska, which erupted recently in 1997 and in 2008. The Alaska Volcano Observatory operates a seismic network of 12 stations at Okmok and routinely catalogues recorded seismicity. Using these data, we have determined general MTs for seven microearthquakes recorded between 2004 and 2007 by inverting peak amplitude measurements of P and S phases. We computed Green's functions using precisely relocated hypocentres and a 3-D velocity model. We thoroughly assessed the quality of the solutions by computing formal uncertainty estimates, conducting a variety of synthetic and sensitivity tests, and by comparing the MTs to solutions obtained using alternative methods. The results show that MTs are sensitive to station distribution and errors in the data, velocity model and hypocentral parameters. Although each of the seven MTs contains a significant non-shear component, we judge several of the solutions to be unreliable. However, several reliable MTs are obtained for a group of previously identified repeating events, and are interpreted as compensated linear-vector dipole events.

  2. Volcanic Source Mechanisms from the Low Frequency End of Broadband Recordings: Examples from Fuego Volcano

    Science.gov (United States)

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

    2014-12-01

    With the proliferation of broadband recordings from volcanoes, it has become clear that conduit processes produce seismic signals with an extensive range of frequencies. Near the low corner of broadband instruments, the affects of ground rotation can be significant; rotation dominates at periods below the corner. Unraveling the relative influence of translation and rotation on recordings of very-long-period (12 - 120 s) and ultra-long-period (120-600 s) events is an important challenge, because including tilt in inversion of VLP and ULP signals associated with small eruptions can provide constraints on the dynamics of conduit processes. At Fuego volcano in Guatemala, we recorded hundreds of small-scale explosions in field campaigns since 2008 using temporary arrays of seismometers, tiltmeters and microbarometers. Explosions are frequently preceded by 5 to 20 minutes of tilt, indicative of pressurization of the upper conduit. The onset of explosive eruptions, which last from many tens of seconds to more than two minutes, include VLPs with peak periods from less than 30 to nearly 50 seconds. The events are dominated by ash emission that suggests a vulcanian-style downward migration of the magma fragmentation front. Joint inversions of the seismic and tilt signals using synthetic tilt and displacement Green functions provides a more complete view of the eruption process at Fuego. Inversions without tilt point to a source centroid 200 m west of and 300 m below the vent. When lower frequencies are included in the inversion, the source centroid shallows and moves east to a position directly below the vent. We interpret this to reflect a process where the vent seals and pressurizes, producing the ULP signal. The VLP signal results from a rapid change in the deformation of the upper few hundred meters of the conduit due to the ejection of magma during the explosion.

  3. Peak Electric Load Relief in Northern Manhattan

    Directory of Open Access Journals (Sweden)

    Hildegaard D. Link

    2014-08-01

    Full Text Available The aphorism “Think globally, act locally,” attributed to René Dubos, reflects the vision that the solution to global environmental problems must begin with efforts within our communities. PlaNYC 2030, the New York City sustainability plan, is the starting point for this study. Results include (a a case study based on the City College of New York (CCNY energy audit, in which we model the impacts of green roofs on campus energy demand and (b a case study of energy use at the neighborhood scale. We find that reducing the urban heat island effect can reduce building cooling requirements, peak electricity loads stress on the local electricity grid and improve urban livability.

  4. Tim Peake and Britain's road to space

    CERN Document Server

    Seedhouse, Erik

    2017-01-01

    This book puts the reader in the flight suit of Britain’s first male astronaut, Tim Peake. It chronicles his life, along with the Principia mission and the down-to-the-last-bolt descriptions of life aboard the ISS, by way of the hurdles placed by the British government and the rigors of training at Russia’s Star City military base. In addition, this book discusses the learning curves required in astronaut and mission training and the complexity of the technologies required to launch an astronaut and keep them alive for months on end. This book underscores the fact that technology and training, unlike space, do not exist in a vacuum; complex technical systems, like the ISS, interact with the variables of human personality, and the cultural background of the astronauts. .

  5. Postglacial volcanic deposits at Glacier Peak, Washington, and potential hazards from future eruptions; a preliminary report

    Science.gov (United States)

    Beget, J.E.

    1982-01-01

    Eruptions and other geologic events at Glacier Peak volcano in northern Washington have repeatedly affected areas near the volcano as well as areas far downwind and downstream. This report describes the evidence of this activity preserved in deposits on the west and east flanks of the volcano. On the west side of Glacier Peak the oldest postglacial deposit is a large, clayey mudflow which traveled at least 35 km down the White Chuck River valley sometime after 14,000 years ago. Subsequent large explosive eruptions produced lahars and at least 10 pyroclastic-flow deposits, including a semiwelded vitric tuff in the White Chuck River valley. These deposits, known collectively as the White Chuck assemblage, form a valley fill which is locally preserved as far as 100 km downstream from the volcano in the Stillaguamish River valley. At least some of the assemblage is about 11,670-11,500 radiocarbon years old. A small clayey lahar, containing reworked blocks of the vitric tuff, subsequently traveled at least 15 km down the White Chuck River. This lahar is overlain by lake sediments containing charred wood which is about 5,500 years old. A 150-m-thick assemblage of pyroclastic-flow deposits and lahars, called the Kennedy Creek assemblage, is in part about 5,500-5,100 radiocarbon years old. Lithic lahars from this assemblage extend at least 100 km downstream in the Skagit River drainage. The younger lahar assemblages, each containing at least three lahars and reaching at least 18 km downstream from Glacier Peak in the White Chuck River valley, are about 2,800 and 1,800 years old, respectively. These are postdated by a lahar containing abundant oxyhornblende dacite, which extends at least 30 km to the Sauk River. A still younger lahar assemblage that contains at least five lahars, and that also extends at least 30 km to the Sauk River, is older than a mature forest growing on its surface. At least one lahar and a flood deposit form a low terrace at the confluence of the

  6. Evaluation of volcanic risk management in Merapi and Bromo Volcanoes

    Science.gov (United States)

    Bachri, S.; Stöetter, J.; Sartohadi, J.; Setiawan, M. A.

    2012-04-01

    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

  7. WOVOdat Progress 2012: Installable DB template for Volcano Monitoring Database

    Science.gov (United States)

    Ratdomopurbo, A.; Widiwijayanti, C.; Win, N.-T.-Z.; Chen, L.-D.; Newhall, C.

    2012-04-01

    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 (www.wovodat.org), 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

  8. A Preliminary Study of Seismicity at Ceboruco, Volcano, Nayarit, Mexico

    Science.gov (United States)

    Sanchez, J. J.; Nunez-Cornu, F. J.; Suarez-Plascencia, C.; Trejo-Gomez, E.

    2007-12-01

    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.

  9. Geologic Mapping of the Olympus Mons Volcano, Mars

    Science.gov (United States)

    Bleacher, J. E.; Williams, D. A.; Shean, D.; Greeley, R.

    2012-01-01

    We are in the third year of a three-year Mars Data Analysis Program project to map the morphology of the Olympus Mons volcano, Mars, using ArcGIS by ESRI. The final product of this project is to be a 1:1,000,000-scale geologic map. The scientific questions upon which this mapping project is based include understanding the volcanic development and modification by structural, aeolian, and possibly glacial processes. The project s scientific objectives are based upon preliminary mapping by Bleacher et al. [1] along a approx.80-km-wide north-south swath of the volcano corresponding to High Resolution Stereo Camera (HRSC) image h0037. The preliminary project, which covered approx.20% of the volcano s surface, resulted in several significant findings, including: 1) channel-fed lava flow surfaces are areally more abundant than tube-fed surfaces by a ratio of 5:1, 2) channel-fed flows consistently embay tube-fed flows, 3) lava fans appear to be linked to tube-fed flows, 4) no volcanic vents were identified within the map region, and 5) a Hummocky unit surrounds the summit and is likely a combination of non-channelized flows, dust, ash, and/or frozen volatiles. These results led to the suggestion that the volcano had experienced a transition from long-lived tube-forming eruptions to more sporadic and shorter-lived, channel-forming eruptions, as seen at Hawaiian volcanoes between the tholeiitic shield building phase (Kilauea to Mauna Loa) and alkalic capping phase (Hualalai and Mauna Kea).

  10. Volcanic Stratigraphy and Potential Hazards of the Chihsingshan Volcano Subgroup in the Tatun Volcano Group, Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Yu-Wei Tsai

    2010-01-01

    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.

  11. Using the Landsat Thematic Mapper to detect and monitor active volcanoes - An example from Lascar volcano, northern Chile

    Science.gov (United States)

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

    1987-01-01

    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.

  12. A New Statistical Model for Eruption Forecasting at Open Conduit Volcanoes: an Application to Mt Etna and Kilauea Volcanoes

    Science.gov (United States)

    Passarelli, Luigi; Sanso, Bruno; Laura, Sandri; Marzocchi, Warner

    2010-05-01

    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

  13. Peak, multi-peak and broadband absorption in graphene-based one-dimensional photonic crystal

    Science.gov (United States)

    Miloua, R.; Kebbab, Z.; Chiker, F.; Khadraoui, M.; Sahraoui, K.; Bouzidi, A.; Medles, M.; Mathieu, C.; Benramdane, N.

    2014-11-01

    We theoretically investigate the possibility of enhancing light absorption in graphene-based one dimensional photonic crystal. We demonstrate that it is possible to achieve total light absorption at technologically important wavelengths using one-dimensional graphene-based photonic crystals. By means of the transfer matrix method, we investigate the effect of refractive indices and layer numbers on the optical response of the structure. We found that it is possible to achieve one peak, multi-peak or broadband, and complete optical absorption. As a result, the proposed photonic structures enable myriad potential applications such as photodetection, shielding and optical sensing.

  14. Norwegian hydropower a valuable peak power source

    Energy Technology Data Exchange (ETDEWEB)

    Brekke, Hermod

    2010-07-01

    given on a possible increase of the Norwegian hydropower peak power production to meet the growing the European demand for peak power caused by the growing non stationary production from wind mills and ocean energy from waves and sea current. Also building of reversible pump turbine power plants will be discussed even if approximately 10% power will be consumed by loss in the pumping phase compared to direct use of the water from reservoirs. (Author)

  15. Preliminary hyperspectral volcano observations using Airborne Radiative Spectral Scanner (ARTS)

    Science.gov (United States)

    Jitsufuchi, T.

    2008-12-01

    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

  16. Hydrochemical fluxes from Baransky volcano, Iturup, Kuril Islands

    Science.gov (United States)

    Chelnokov, George; Zharkov, Rafael; Bragin, Ivan; Kharitonova, Natalia

    2014-05-01

    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

  17. Revealing the Eruptive History of Volcanoes from Massive Cross-Correlation of Seismic Signal at Global Scale

    Science.gov (United States)

    Dupont, A.; Gaillard, P.; Grenouille, A.; Bui-Quang, P.; Guilhem, A.; Bobrov, D.; Kitov, I. O.; Rozhkov, M.

    2015-12-01

    We propose here a massive cross-correlation technique applied to seismic events located around volcanoes and recorded at teleseismic distance. Multichannel cross-correlations are performed between 2002 to 2012 using seismic templates occurring at the time of moderate to large volcanic eruptions. The volcanic periods are reported from the Global Volcanism Program database while the waveform data are obtained from the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The temporal distribution of new seismic events, built from the association of teleseismic detections reveals acceleration patterns, which are highly correlated to the past eruptive activities. These newly detected events are relocated using Bayesian approach and leads to preliminary interpretation of the volcanic plumbing system. Two examples are presented. First, the large 2008 eruption (Volcanic Explosivity Index, VEI4) of Kasatochi (Aleutian Islands, 52.10°N/175.31°W) is used to demonstrate that only few seismic templates (~3) help to reveal the time scale of the eruption. Results are compared to hydroacoustic signal, which is highly correlated to the distribution of new seismic events prior and during eruption. We also show that after the peaked seismic activity (i.e., ~ 100 seismic events in 1 hour) the infrasound signal starts and signs the volcanic plume activity. The second case example reveals with success seven past volcanic eruptions of lower magnitude (VEI1 to VEI2) of the Karangetang volcano (Siau Island in Indonesia, 2.46°N/125.24°E). We show the potential of this method to detect volcanic eruptions in isolated areas. This is of special interest especially when there is no volcano observatory to monitor the volcanic activity, or when the last eruptive period is unknown.

  18. Peak-valley-peak pattern of histone modifications delineates active regulatory elements and their directionality

    DEFF Research Database (Denmark)

    Pundhir, Sachin; Bagger, Frederik Otzen; Lauridsen, Felicia Kathrine Bratt

    2016-01-01

    Formation of nucleosome free region (NFR) accompanied by specific histone modifications at flanking nucleosomes is an important prerequisite for enhancer and promoter activity. Due to this process, active regulatory elements often exhibit a distinct shape of histone signal in the form of a peak...

  19. Peak phosphorus - peak food? The need to close the phosphorus cycle.

    Science.gov (United States)

    Rhodes, Christopher J

    2013-01-01

    The peak in the world production of phosphorus has been predicted to occur in 2033, based on world reserves of rock phosphate (URR) reckoned at around 24,000 million tonnes (Mt), with around 18,000 Mt remaining. This figure was reckoned-up to 71,000 Mt, by the USGS, in 2012, but a production maximum during the present century is still highly probable. There are complex issues over what the demand will be for phosphorus in the future, as measured against a rising population (from 7 billion to over 9 billion in 2050), and a greater per capita demand for fertiliser to grow more grain, in part to feed animals and meet a rising demand for meat by a human species that is not merely more populous but more affluent. As a counterweight to this, we may expect that greater efficiencies in the use of phosphorus - including recycling from farms and of human and animal waste - will reduce the per capita demand for phosphate rock. The unseen game changer is peak oil, since phosphate is mined and recovered using machinery powered by liquid fuels refined from crude oil. Hence, peak oil and peak phosphorus might appear as conjoined twins. There is no unequivocal case that we can afford to ignore the likelihood of a supply-demand gap for phosphorus occurring sometime this century, and it would be perilous to do so.

  20. Analysis of the Peak Resistance Frequency Method.

    Science.gov (United States)

    Wang, Boshuo; Weiland, James D

    2016-10-01

    This study analyzes the peak resistance frequency (PRF) method described by Mercanzini et al., a method that can easily extract the tissue resistance from impedance spectroscopy for many neural engineering applications but has no analytical description thus far. Mathematical analyses and computer simulations were used to explore underlying principles, accuracy, and limitations of the PRF method. The mathematical analyses demonstrated that the PRF method has an inherent but correctable deviation dependent on the idealness of the electrode-tissue interface, which is validated by simulations. Further simulations show that both frequency sampling and noise affect the accuracy of the PRF method, and in general, it performs less accurately than least squares methods. However, the PRF method achieves simplicity and reduced measurement and computation time at the expense of accuracy. From the qualitative results, the PRF method can work with reasonable precision and simplicity, although its limitation and the idealness of the electrode-tissue interface involved should be taken into consideration. This paper provides a mathematical foundation for the PRF method and its practical implementation.

  1. Z-peaked excess in goldstini scenarios

    CERN Document Server

    Liew, Seng Pei; Mawatari, Kentarou; Sakurai, Kazuki; Vereecken, Matthias

    2015-01-01

    We study a possible explanation of a 3.0 $\\sigma$ excess recently reported by the ATLAS Collaboration in events with Z-peaked same-flavour opposite-sign lepton pair, jets and large missing transverse momentum in the context of gauge-mediated SUSY breaking with more than one hidden sector, the so-called goldstini scenario. In a certain parameter space, the gluino two-body decay chain $\\tilde g\\to g\\tilde\\chi^0_{1,2}\\to gZ\\tilde G'$ becomes dominant, where $\\tilde\\chi^0_{1,2}$ and $\\tilde G'$ are the Higgsino-like neutralino and the massive pseudo-goldstino, respectively, and gluino pair production can contribute to the signal. We find that a mass spectrum such as $m_{\\tilde g}\\sim 900$ GeV, $m_{\\tilde\\chi^0_{1,2}}\\sim 700$ GeV and $m_{\\tilde G'}\\sim 600$ GeV demonstrates the rate and the distributions of the excess, without conflicting with the stringent constraints from jets plus missing energy analyses and with the CMS constraint on the identical final state.

  2. Z-peaked excess in goldstini scenarios

    Directory of Open Access Journals (Sweden)

    Seng Pei Liew

    2015-11-01

    Full Text Available We study a possible explanation of a 3.0 σ excess recently reported by the ATLAS Collaboration in events with Z-peaked same-flavour opposite-sign lepton pair, jets and large missing transverse momentum in the context of gauge-mediated SUSY breaking with more than one hidden sector, the so-called goldstini scenario. In a certain parameter space, the gluino two-body decay chain g˜→gχ˜1,20→gZG˜′ becomes dominant, where χ˜1,20 and G˜′ are the Higgsino-like neutralino and the massive pseudo-goldstino, respectively, and gluino pair production can contribute to the signal. We find that a mass spectrum such as mg˜∼1000 GeV, mχ˜1,20∼800 GeV and mG˜′∼600 GeV demonstrates the rate and the distributions of the excess, without conflicting with the stringent constraints from jets plus missing energy analyses and with the CMS constraint on the identical final state.

  3. Asymmetry parameter of peaked Fano line shapes

    Science.gov (United States)

    Meierott, S.; Hotz, T.; Néel, N.; Kröger, J.

    2016-10-01

    The spectroscopic line shape of electronic and vibrational excitations is ubiquitously described by a Fano profile. In the case of nearly symmetric and peaked Fano line shapes, the fit of the conventional Fano function to experimental data leads to difficulties in unambiguously extracting the asymmetry parameter, which may vary over orders of magnitude without degrading the quality of the fit. Moreover, the extracted asymmetry parameter depends on initially guessed values. Using the spectroscopic signature of the single-Co Kondo effect on Au(110) the ambiguity of the extracted asymmetry parameter is traced to the highly symmetric resonance profile combined with the inevitable scattering of experimental data. An improved parameterization of the conventional Fano function is suggested that enables the nonlinear optimization in a reduced parameter space. In addition, the presence of a global minimum in the sum of squared residuals and thus the independence of start parameters may conveniently be identified in a two-dimensional plot. An angular representation of the asymmetry parameter is suggested in order to reliably determine uncertainty margins via linear error propagation.

  4. The velocity structure of crust and upper mantle in the Wudalianchi volcano area inferred from the receiver function

    Institute of Scientific and Technical Information of China (English)

    贺传松; 王椿镛; 吴建平

    2003-01-01

    The Wudalianchi volcano is a modern volcano erupted since the Holocene. Its frequent occurrence of the small earthquake is considered to be indicator of active dormancy volcano. The S wave velocity structure is inferred from the receiver function for the crust and upper mantle of the Wudalianchi volcano area. The results show that the low velocity structure of S wave is widely distributed underneath the volcano area and part of the low-velocity-zone located at shallow depth in the Wudalianchi volcano area. The low velocity structure is related to the seismicity. The Moho interface is not clear underneath the volcano area, which may be regard to be an necessary condition for the lava upwelling. Therefore, we infer that the Wudalianchi volcano has the deep structural condition for the volcano activity and may be alive again.

  5. A Study On The Final Phase Of The Bardarbunga Volcano Of 2015 Using Vlf Wave Of Nrk Signal Of Iceland Received At Kiel Longwave Monitor

    Directory of Open Access Journals (Sweden)

    Govinda Sharma

    2015-08-01

    Full Text Available Seismo-ionospheric changes often affect the VLF waves resulting in possible changes in the terminator times and often lead to night time fluctuations. The Bardarbunga volcano which started on 2014 ended on the last days of February of 2015. In this paper we present the results of the VLF analysis of the first three months of 2015 using a signal of 37.50 KHz where an analysis on the sunset terminator time D-layer dissipation time daytime fluctuation and night time fluctuation of the VLF amplitude was done. We contrasted the values of these parameters for the first two months of 2015 where the volcano was active with third month of 2015 when the volcano had completely subsided. The Sunset terminator time and the daytime fluctuations in the VLF amplitude for the first two months showed no major anomalies. The anomaly in the D-layer disappearance time and night time fluctuation count reached its peak values for the volcanically active months.

  6. Volcanoes and carcinoma of the thyroid: a possible association.

    Science.gov (United States)

    Kung, T M; Ng, W L; Gibson, J B

    1981-01-01

    Environmental factors contributing to incidences of thyroid carcinoma are re-evaluated and emphasized in this study. Thyroid cancers appear to occur independent of endemic goiter, based on epidemiologic and histologic evidence. While environmental factors appear to be important, the specific etiologic agent has not yet been identified or suggested. The number of thyroid cancer incidences available from cancer registries are analyzed in an attempt to identify a specific environmental carcinogenic agent. The presence of active volcanoes that produce abundant lava is found to be the common denominator of Iceland and Hawaii, where the incidence of thyroid cancer is outstandingly high. Comparison with other areas with active volcanoes is made. The presence of a carcinogenic agent in the lava is postulated and its possible mode of action on humans through fish products is hypothesized.

  7. The Mediterranean Supersite Volcanoes (MED-SUV) Project: an overview

    Science.gov (United States)

    Puglisi, Giuseppe

    2014-05-01

    The EC FP7 MEDiterranean SUpersite Volcanoes (MED-SUV) EC-FP7 Project, which started on June 2013, aims to improve the capacity of the scientific institutions, end users and SME forming the project consortium to assess the volcanic hazards at Italian Supersites, i.e. Mt. Etna and Campi Flegrei/Vesuvius. The Project activities will focus on the optimisation and integration of ground and space monitoring systems, the breakthrough in understanding of volcanic processes, and on the increase of the effectiveness of the coordination between the scientific and end-user communities in the hazard management. The overall goal of the project is to apply the rationale of the Supersites GEO initiative to Mt. Etna and Campi Flegrei/Vesuvius, considered as cluster of Supersites. For the purpose MED-SUV will integrate long-term observations of ground-based multidisciplinary data available for these volcanoes, i.e. geophysical, geochemical, and volcanological datasets, with Earth Observation (EO) data. Merging of different parameters over a long period will provide better understanding of the volcanic processes. In particular, given the variety of styles and intensities of the volcanic activity observed at these volcanoes, and which make them sort of archetypes for 'closed conduit ' and 'open conduit' volcanic systems, the combination of different data will allow discrimination between peculiar volcano behaviours associated with pre-, syn- and post-eruptive phases. Indeed, recognition of specific volcano patterns will allow broadening of the spectrum of knowledge of geo-hazards, as well as better parameterisation and modelling of the eruptive phenomena and of the processes occurring in the volcano supply system; thus improving the capability of carrying out volcano surveillance activities. Important impacts on the European industrial sector, arising from a partnership integrating the scientific community and SMEs to implement together new observation/monitoring sensors/systems, are

  8. Kilometer-scale Kaiser effect identified in Krafla volcano, Iceland

    Science.gov (United States)

    Heimisson, Elías Rafn; Einarsson, Páll; Sigmundsson, Freysteinn; Brandsdóttir, Bryndís.

    2015-10-01

    The Krafla rifting episode in 1975-1984, consisted of around 20 inflation-deflation events within the Krafla caldera, where magma accumulated during inflation periods and was intruded into the transecting fissure swarm during brief periods of deflation. We reanalyze geodetic and seismic data from the rifting episode and perform a time-dependent inversion of a leveling time series for a spherical point source in an elastic half-space. Using the volume change as a proxy for stress shows that during inflation periods the seismicity rate remains low until the maximum inflation of previous cycles is exceeded thus exhibiting the Kaiser effect. Our observations demonstrate that this phenomenon, commonly observed in small-scale experiments, is also produced in kilometer-scale volcanic deformation. This behavior sheds new light on the relationship between deformation and seismicity of a deforming volcano. As a consequence of the Kaiser effect, a volcano may inflate rapidly without significant changes in seismicity rate.

  9. Geomagnetism, volcanoes, global climate change, and predictability. A progress report

    Directory of Open Access Journals (Sweden)

    G. P. Gregori

    1994-06-01

    Full Text Available A model is investigated, by which the encounters of the solar system with dense interstellar clouds ought to trigger either geomagnetic field reversals or excursions, that produce extra electric currents within the Earth dynamo, that cause extra Joule's heating, that supplies volcanoes and endogenous processes. Volcanoes increase the Earth degassing into the atmosphere, hence the concentration of the minor atmospheric constituents, including the greenhouse gases, hence they affect climate temperature, glacier melting, sea level and global change. This investigation implies both theoretical studies and observational data handling on different time scales, including present day phenomena, instrumental data series, historical records, proxy data, and geological and palaeontological evidences. The state of the art is briefly outlined, mentioning some already completed achievements, investigations in progress, and future perspectives.

  10. Geochemical characterization of the Nirano Mud Volcano Field

    Science.gov (United States)

    Sciarra, Alessandra; Cantucci, Barbara; Ricci, Tullio; Conventi, Marzia

    2016-04-01

    Mud volcanoes, among fluid venting structures, are the most important phenomena related to natural seepage from the Earth's surface. The occurrence of mud volcanoes is controlled by several factors, such as tectonic activity and continuous hydrocarbon accumulation in a reservoir. Mud volcanoes in Italy occur along the external compressive margin of the Apennine chain. These mud volcanoes are usually small and unspectacular, when compared to other world examples. They rarely exhibit the periodic explosions, which is often related to important seismic activity. The Nirano Mud Volcano Field (NMVF) is located in the western sector of the Modena Apennine margin (Italy), which belongs to the Northern Apennines. The NMVF occurs over the crest of a thrust anticline associated with the main Pede-Apennine thrust and represents a good example of an onshore relationship between a mud volcano caldera structure and active thrust deformation, even if the fluid pathways are still not well understood at depth. The mud volcanoes are distributed along an area of about 10 ha, inside of the wider Natural Reserve, and are situated at the bottom of a wide sub-circular depression. The NMVF is currently formed by four main vents composed of a number of individual active cones (or gryphons) defining structural alignments trending ENE-WSW. A geochemical soil gas survey of 230 CO2 and CH4 fluxes and 150 CO2, CH4, Rn, He, H2 concentration measurements has been carried out inside the NMVF. Moreover, the fluid emissions from 4 active cones located in different sectors of NMVF have been sampled for chemical and isotopical analysis of water and free gas. The distribution of pathfinder elements as 222Rn, He e H2 has been studied in order to identify potential faults and/or fractures related to preferential migration pathways and the possible interactions between reservoir and surface. Soil gas data highlight two zones characterized by higher values, localized in the WSW and ENE of the NMVF area. In

  11. Volcano plots in hydrogen electrocatalysis - uses and abuses.

    Science.gov (United States)

    Quaino, Paola; Juarez, Fernanda; Santos, Elizabeth; Schmickler, Wolfgang

    2014-01-01

    Sabatier's principle suggests, that for hydrogen evolution a plot of the rate constant versus the hydrogen adsorption energy should result in a volcano, and several such plots have been presented in the literature. A thorough examination of the data shows, that there is no volcano once the oxide-covered metals are left out. We examine the factors that govern the reaction rate in the light of our own theory and conclude, that Sabatier's principle is only one of several factors that determine the rate. With the exception of nickel and cobalt, the reaction rate does not decrease for highly exothermic hydrogen adsorption as predicted, because the reaction passes through more suitable intermediate states. The case of nickel is given special attention; since it is a 3d metal, its orbitals are compact and the overlap with hydrogen is too low to make it a good catalyst.

  12. Volcanic tremor and plume height hysteresis from Pavlof Volcano, Alaska.

    Science.gov (United States)

    Fee, David; Haney, Matthew M; Matoza, Robin S; Eaton, Alexa R; Cervelli, Peter; Schneider, David J; Iezzi, Alexandra M

    2017-01-06

    The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation of more than 100 flights in North America. The eruption generated strong tremor that was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting that flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes that are detectable in geophysical data. We propose that the time-varying relationship at Pavlof arose from changes in the tremor source related to volcanic vent erosion. This relationship may improve estimates of volcanic emissions and characterization of eruption size and intensity.

  13. In Brief: Underwater volcano gets real-time monitoring

    Science.gov (United States)

    Zielinski, Sarah

    2007-05-01

    A real-time underwater earthquake monitoring system was installed on the top of Kick'em Jenny, an underwater volcano located off the north coast of Grenada, on 6 May. The Real Time Offshore Seismic Station (RTOSS) consists of an ocean-bottom seismometer connected by a stretchy hose to a buoy on the ocean surface. The buoy is powered by solar panels and transmits seismic data by high-frequency radio to an observatory in Sauteurs, Grenada. The RTOSS research team, led by scientists from the Woods Hole Oceanographic Institution, is coordinating with the Grenadian National Disaster Management Agency and the Seismic Unit of the University of the West Indies to incorporate the RTOSS data into existing regional monitoring. Kick'em Jenny, the only `live' submarine volcano in the West Indies, last erupted in 2001.

  14. Determining dyke-propagation paths at Santorini volcano, Greece

    Science.gov (United States)

    Drymoni, Kyriaki; Browning, John; Lecoeur, Nora; Gudmundsson, Agust

    2016-04-01

    The volcanic Island of Santorini constitutes a complex of collapse calderas which has experienced a range of explosive and effusive volcanic eruptions and is still active. Numerous stratigraphic horizons which constitute the upper part of the volcano have widely different mechanical properties, resulting in local stresses that may act as dyke-traps, preventing the dykes from reaching the surface to erupt. Several caldera collapses (<3.6 ka) have exposed part of the stratigraphy and a dyke swarm (composed of at least 63 dykes, many arrested and some feeders) within a section of the northern caldera wall, allowing detailed examination. This ongoing study will (1) document the petrological and structural characteristics of feeder and non-feeder (arrested) dykes and estimate their frequency; (2) determine the physiochemical and mechanical conditions that control dyke arrest/dyke penetration at contacts between layers; (3) explore the fluid and mechanical conditions of the associated magma chamber(s) that must be satisfied for chamber rupture and dyke injection to occur; (4) make numerical and probabilistic models as to the likely dyke paths in heterogeneous and anisotropic crustal segments/volcanoes (such as Santorini), including the likelihood of injected dykes reaching the surface during an unrest period in a volcano of a given type; (5) compare the data collected from Santorini with existing data on dykes worldwide, particularly those on dykes in Tenerife and Iceland. The principal aim of the study is to provide models that, during an unrest period in Santorini and other similar volcanoes, allow us to forecast (a) the condition for magma-chamber rupture and dyke injection, and (b) the likely path of the resulting dyke. The latter includes assessment of the likelihood as to dyke arrest versus dyke propagation to the surface, the latter resulting in an eruption. For dyke-fed eruptions, the study will also provide methods for forecasting the likely volumetric flow

  15. Database for volcanic processes and geology of Augustine Volcano, Alaska

    Science.gov (United States)

    McIntire, Jacqueline; Ramsey, David W.; Thoms, Evan; Waitt, Richard B.; Beget, James E.

    2012-01-01

    Augustine Island (volcano) in lower Cook Inlet, Alaska, has erupted repeatedly in late-Holocene and historical times. Eruptions typically beget high-energy volcanic processes. Most notable are bouldery debris avalanches containing immense angular clasts shed from summit domes. Coarse deposits of these avalanches form much of Augustine's lower flanks. This geologic map at 1:25,000 scale depicts these deposits, these processes.

  16. Ring and Volcano Structures Formed by a Metal Dipyrromethene Complex

    Energy Technology Data Exchange (ETDEWEB)

    Son, Seung Bae; Hahn, Jae Ryang [Chonbuk National Univ., Jeonju (Korea, Republic of); Miao, Qing; Shin, Jiyoung; Dolphin, David [Univ. of British Columbia, Columbia (Canada)

    2014-06-15

    Dichloromethane liquid droplets containing a cobalt dipyrromethene trimer deposited on a graphite surface were found to form coffee ring, toroid ring, or volcano dot structures due to the redistribution of the solute during solvent evaporation. The shapes and size distributions of the ring structures depended on the drying temperature. The shape differences were attributed to the fact that the solvent evaporation rate controlled the self-assembly process that yielded the coffee stain and pinhole structures.

  17. Hawaiian Volcano Observatory seismic data, January to March 2009

    Science.gov (United States)

    Nakata, Jennifer S.; Okubo, Paul G.

    2010-01-01

    This U.S. Geological Survey (USGS), Hawaiian Volcano Observatory (HVO) summary presents seismic data gathered during January–March 2009. The seismic summary offers earthquake hypocenters without interpretation as a source of preliminary data and is complete in that most data for events of M≥1.5 are included. All latitude and longitude references in this report are stated in Old Hawaiian Datum.

  18. Thermal mapping of Hawaiian volcanoes with ASTER satellite data

    Science.gov (United States)

    Patrick, Matthew R.; Witzke, Coral-Nadine

    2011-01-01

    Thermal mapping of volcanoes is important to determine baseline thermal behavior in order to judge future thermal activity that may precede an eruption. We used cloud-free kinetic temperature images from the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) sensor obtained between 2000 and 2010 to produce thermal maps for all five subaerial volcanoes in Hawai‘i that have had eruptions in the Holocene (Kīlauea, Mauna Loa, Hualālai, Mauna Kea, and Haleakalā). We stacked the images to provide time-averaged thermal maps, as well as to analyze temperature trends through time. Thermal areas are conspicuous at the summits and rift zones of Kīlauea and Mauna Loa, and the summit calderas of these volcanoes contain obvious arcuate, concentric linear thermal areas that probably result from channeling of rising gas along buried, historical intracaldera scarps. The only significant change in thermal activity noted in the study period is the opening of the Halema‘uma‘u vent at Kīlauea's summit in 2008. Several small thermal anomalies are coincident with pit craters on Hualālai. We suspect that these simply result from the sheltered nature of the depression, but closer inspection is warranted to determine if genuine thermal activity exists in the craters. Thermal areas were not detected on Haleakalā or Mauna Kea. The main limitation of the study is the large pixel size (90 m) of the ASTER images, which reduces our ability to detect subtle changes or to identify small, low-temperature thermal activity. This study, therefore, is meant to characterize the broad, large-scale thermal features on these volcanoes. Future work should study these thermal areas with thermal cameras and thermocouples, which have a greater ability to detect small, low-temperature thermal features.

  19. Digital photogrammetry and GIS-based analysis of the bio-geomorphological evolution of Sakurajima Volcano, diachronic analysis from 1947 to 2006

    Science.gov (United States)

    Gomez, Christopher

    2014-06-01

    The Sakurajima Volcano is one of the most active volcanoes in the world with regular activity dominated by vulcanian eruptions since 1955. Located in Kagoshima Prefecture - Kyushu Island, Japan - the Sakurajima Volcano is a stratovolcano with two main vents at the summit, the Kitadake and the Minamidake, and a third smaller central vent, the Nakadake. The two firsts peak at 1117 and 1060 m dominate the slopes mainly composed of lava-flow deposits, secondary volcaniclastic material and recent ejectas from the Vulcanian eruptions. Although the volcano has been very closely monitored by Japanese Universities (mostly Kyoto University and Kagoshima University) and governmental agencies, there has been very little geomorphological investigation of the structure of the volcano. Using the digital photogammetric method SfM-MVS (Structure from Motion and Multiple-view Stereophotogrammetry) applied to historical aerial photographs, the present contribution aims to provide an analysis of the volcanic structure and the recent bio-geomorphological evolution for the period 1947-2006. First, the results have proved that SfM-MVS is a method that can be successfully applied to aerial photographs for diachronic reconstruction of geomorphological landscape evolution. This method is especially important in active volcanic areas, as the geomorphology can change very rapidly within the historical period. Secondly, the results have shown that during the last ~ 60 years, the summit area of the Sakurajima has greatly evolved: the morpholology of the Minamidake crater has changed due to its regular explosive activity; the upper slopes have been covered in ejecta, modifying their elevation and their smoothness. The lower slopes have seen the apparition of lahar deposition areas, while valleys, upslope, have widened due to the lahar activity and the upward progression of the deposits. The 3D derived from SfM-MVS has also shown how the lahar deposits are using the topographic low, created on

  20. Monitoring Active Volcanos Using Aerial Images and the Orthoview Tool

    Directory of Open Access Journals (Sweden)

    Maria Marsella

    2014-12-01

    Full Text Available In volcanic areas, where it can be difficult to perform direct surveys, digital photogrammetry techniques are rarely adopted for routine volcano monitoring. Nevertheless, they have remarkable potentialities for observing active volcanic features (e.g., fissures, lava flows and the connected deformation processes. The ability to obtain accurate quantitative data of definite accuracy in short time spans makes digital photogrammetry a suitable method for controlling the evolution of rapidly changing large-area volcanic phenomena. The systematic acquisition of airborne photogrammetric datasets can be adopted for implementing a more effective procedure aimed at long-term volcano monitoring and hazard assessment. In addition, during the volcanic crisis, the frequent acquisition of oblique digital images from helicopter allows for quasi-real-time monitoring to support mitigation actions by civil protection. These images are commonly used to update existing maps through a photo-interpretation approach that provide data of unknown accuracy. This work presents a scientific tool (Orthoview that implements a straightforward photogrammetric approach to generate digital orthophotos from single-view oblique images provided that at least four Ground Control Points (GCP and current Digital Elevation Models (DEM are available. The influence of the view geometry, of sparse and not-signalized GCP and DEM inaccuracies is analyzed for evaluating the performance of the developed tool in comparison with other remote sensing techniques. Results obtained with datasets from Etna and Stromboli volcanoes demonstrate that 2D features measured on the produced orthophotos can reach sub-meter-level accuracy.

  1. Electrical conductivity of intermediate magmas from Uturuncu Volcano (Bolivia)

    Science.gov (United States)

    Laumonier, Mickael; Gaillard, Fabrice; Sifre, David

    2015-04-01

    Magmas erupted at Uturuncu volcano (South Bolivia) comes from the Altiplano-Puna Magma Body (APMB, Chile-Bolivia), a crustal massive body of 80 km long by 10 km thick located at ~ 35 km depth named. Recent magneto telluric surveys reveal a resistivity lower than 1 ohm.m due to the presence of melt which could result in the reactivation of the volcano. In order to better constrain the resistivity profiles and thus the conditions of magma storage of the APMB, we have performed in situ electrical measurements on natural dacites and andesites from Uturuncu with a 4-wire set up in a piston cylinder and internally heated pressure vessel. The range of temperature (500 to 1300°C), pressure (0.3 to 2 Gpa), and the various water contents covers the respective ranges occurring at natural conditions. The results show that the conductivity increases with the temperature and the water content but slightly decreases with the pressure. Then a model was built from these results so as to help in (i) interpreting the electrical signature of natural magmas, (ii) constraining their conditions (chemical composition, temperature, pressure, water content, melt fraction) from the source to the storage location and (iii) providing information on the interior structure of a volcano and its reservoir.

  2. Anatomy of the Colima volcano magmatic system, Mexico

    Science.gov (United States)

    Spica, Zack; Perton, Mathieu; Legrand, Denis

    2017-02-01

    Colima volcano is one of the most active volcanoes in continental north America. It is located within the Colima graben on the western part of the Colima rift zone. Although extensively studied, the internal structure and deep magmatic system remains unknown. This research gives new clues to understand how and where magmas are produced and stored at depth. Using ambient seismic noise, we jointly invert for Rayleigh and Love wave dispersion curves for both phase and group velocity, which is applied for the first time in a volcanic environment. We invert for both the shear wave velocity and radial anisotropy. The 3D high resolution shear wave velocity model shows a deep, large and well-delineated elliptic-shape magmatic reservoir below the Colima volcano complex at a depth of about 15 km. On the other hand, the radial anisotropy model shows a significant negative feature (i.e., VSV >VSH) revealed from ≥35 km depth until the top of the magma reservoir at about 12 km depth. The latter suggests the presence of numerous vertical fractures where fluids, rooting from a well-known mantle window, can easily migrate upward and then accumulate in the magma reservoir. Furthermore, the convergence of both a low velocity zone and a negative anisotropy suggests that the magma is mainly stored in conduits or inter-fingered dykes as opposed to horizontally stratified magma reservoir.

  3. Peeking Beneath the Caldera: Communicating Subsurface Knowledge of Newberry Volcano

    Science.gov (United States)

    Mark-Moser, M.; Rose, K.; Schultz, J.; Cameron, E.

    2016-12-01

    "Imaging the Subsurface: Enhanced Geothermal Systems and Exploring Beneath Newberry Volcano" is an interactive website that presents a three-dimensional subsurface model of Newberry Volcano developed at National Energy Technology Laboratory (NETL). Created using the Story Maps application by ArcGIS Online, this format's dynamic capabilities provide the user the opportunity for multimedia engagement with the datasets and information used to build the subsurface model. This website allows for an interactive experience that the user dictates, including interactive maps, instructive videos and video capture of the subsurface model, and linked information throughout the text. This Story Map offers a general background on the technology of enhanced geothermal systems and the geologic and development history of Newberry Volcano before presenting NETL's modeling efforts that support the installation of enhanced geothermal systems. The model is driven by multiple geologic and geophysical datasets to compare and contrast results which allow for the targeting of potential EGS sites and the reduction of subsurface uncertainty. This Story Map aims to communicate to a broad audience, and provides a platform to effectively introduce the model to researchers and stakeholders.

  4. Volcano collapse along the Aleutian Ridge (western Aleutian Arc

    Directory of Open Access Journals (Sweden)

    C. Montanaro

    2011-03-01

    Full Text Available The Aleutian Ridge, in the western part of the Aleutian Arc, consists of a chain of volcanic islands perched atop the crest of a submarine ridge with most of the active Quaternary stratocones or caldera-like volcanoes being located on the northern margins of the Aleutian Islands. Integrated analysis of marine and terrestrial data resulted in the identification and characterization of 17 extensive submarine debris avalanche deposits from 11 volcanoes. Two morphological types of deposits are recognizable, elongate and lobate, with primary controls on the size and distribution of the volcanic debris being the volume and nature of material involved, proportion of fine grained material, depth of emplacement and the paleo-bathymetry. Volume calculations show the amount of material deposited in debris avalanches is as much as three times larger than the amount of material initially involved in the collapse, suggesting the incorporation of large amounts of submarine material during transport. The orientation of the collapse events is influenced by regional fault systems underling the volcanoes. The western Aleutian Arc has a significant tsunamigenic potential and communities within the Aleutian Islands and surrounding areas of the North Pacific as well as shipping and fishing fleets that cross the North Pacific may be at risk during future eruptions in this area.

  5. El Misti Volcano and the City of Arequipa, Peru

    Science.gov (United States)

    2002-01-01

    This three-dimensional perspective view was created from an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model combined with a simulated natural color ASTER image, acquired July 13, 2001. It shows El Misti volcano towering 5822 meters high above the second city of Peru, Arequipa, with a population of more than one million. Geologic studies indicate that El Misti has had five minor eruptions this century, and a major eruption in the 15th century when residents were forced to flee the city. Despite the obvious hazard, civil defense authorities see it as a remote danger, and city planners are not avoiding development on the volcano side of the city. This view shows human development extending up the flanks of the volcano along gullies which would form natural channels for flows of lava, superheated ash and gas, or melted ice, snow, and mud from the summit snowfield in the event of an eruption. Image by Mike Abrams, NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

  6. Seismic event classification and precursor identification at Fuego Volcano, Guatemala

    Science.gov (United States)

    Brill, K. A.; Waite, G. P.; Rodriguez, K.

    2013-12-01

    Understanding the nature and origins of seismic signals generated by volcanic activity can greatly aid in hazard mitigation efforts. Systematic identification and detailed cataloging of explosive events provide a first step for this understanding, and can be even more valuable when the events span longer time periods. Beyond simply being a more useful monitoring tool, the detailed classification of events can illuminate the processes behind different conduit flow phenomena such as rheological sealing or piston-style chugging. Fuego volcano, Guatemala, is a basaltic-andesite stratovolcano that has been continually active since 1999. Activity is characterized by small-scale explosive eruptions and intermittent lava flows. In this study, we categorize different events recorded with a 10 station temporary seismic array at Fuego volcano in Guatemala in January 2012 that included infrasound and tilt sensors. Waveform analysis, along with visual and thermal characteristics captured by cameras allow us to identify precursory activity in different bandwidths that precedes some of the event types. We investigate the physical mechanisms behind these precursors to explain why some event types exhibit them while others may not, and how these mechanisms influence our conceptual models of explosion dynamics at Fuego. Finally, we compare events recorded in 2012 with other studies conducted at Fuego volcano in previous years to identify changes in the signal characteristics and their potential influences on activity styles observed during different field campaigns to highlight the importance of longitudinal studies at persistently active volcanic systems.

  7. Forecasting magma-chamber rupture at Santorini volcano, Greece

    Science.gov (United States)

    Browning, John; Drymoni, Kyriaki; Gudmundsson, Agust

    2015-10-01

    How much magma needs to be added to a shallow magma chamber to cause rupture, dyke injection, and a potential eruption? Models that yield reliable answers to this question are needed in order to facilitate eruption forecasting. Development of a long-lived shallow magma chamber requires periodic influx of magmas from a parental body at depth. This redistribution process does not necessarily cause an eruption but produces a net volume change that can be measured geodetically by inversion techniques. Using continuum-mechanics and fracture-mechanics principles, we calculate the amount of magma contained at shallow depth beneath Santorini volcano, Greece. We demonstrate through structural analysis of dykes exposed within the Santorini caldera, previously published data on the volume of recent eruptions, and geodetic measurements of the 2011-2012 unrest period, that the measured 0.02% increase in volume of Santorini’s shallow magma chamber was associated with magmatic excess pressure increase of around 1.1 MPa. This excess pressure was high enough to bring the chamber roof close to rupture and dyke injection. For volcanoes with known typical extrusion and intrusion (dyke) volumes, the new methodology presented here makes it possible to forecast the conditions for magma-chamber failure and dyke injection at any geodetically well-monitored volcano.

  8. Design of Deformation Monitoring System for Volcano Mitigation

    Science.gov (United States)

    Islamy, M. R. F.; Salam, R. A.; Munir, M. M.; Irsyam, M.; Khairurrijal

    2016-08-01

    Indonesia has many active volcanoes that are potentially disastrous. It needs good mitigation systems to prevent victims and to reduce casualties from potential disaster caused by volcanoes eruption. Therefore, the system to monitor the deformation of volcano was built. This system employed telemetry with the combination of Radio Frequency (RF) communications of XBEE and General Packet Radio Service (GPRS) communication of SIM900. There are two types of modules in this system, first is the coordinator as a parent and second is the node as a child. Each node was connected to coordinator forming a Wireless Sensor Network (WSN) with a star topology and it has an inclinometer based sensor, a Global Positioning System (GPS), and an XBEE module. The coordinator collects data to each node, one a time, to prevent collision data between nodes, save data to SD Card and transmit data to web server via GPRS. Inclinometer was calibrated with self-built in calibrator and tested in high temperature environment to check the durability. The GPS was tested by displaying its position in web server via Google Map Application Protocol Interface (API v.3). It was shown that the coordinator can receive and transmit data from every node to web server very well and the system works well in a high temperature environment.

  9. Volcano hazards assessment for the Lassen region, northern California

    Science.gov (United States)

    Clynne, Michael A.; Robinson, Joel E.; Nathenson, Manuel; Muffler, L.J. Patrick

    2012-01-01

    The Lassen region of the southernmost Cascade Range is an active volcanic area. At least 70 eruptions have occurred in the past 100,000 years, including 3 in the past 1,000 years, most recently in 1915. The record of past eruptions and the present state of the underlying magmatic and hydrothermal systems make it clear that future eruptions within the Lassen Volcanic Center are very likely. Although the annual probability of an eruption is small, the consequences of some types of eruptions could be severe. Compared to those of a typical Cascade composite volcano, eruptive vents at Lassen Volcanic Center and the surrounding area are widely dispersed, extending in a zone about 50 km wide from the southern boundary of Lassen Volcanic National Park north to the Pit River. This report presents a discussion of volcanic and other geologic hazards in the Lassen area and delineates hazards zones for different types of volcanic activity. Owing to its presence in a national park with significant visitorship, its explosive behavior, and its proximity to regional infrastructure, the Lassen Volcanic Center has been designated a "high threat volcano" in the U.S. Geological Survey National Volcano Early Warning System assessment. Volcanic eruptions are typically preceded by seismic activity and ground deformation, and the Lassen area has a network of seismometers and Global Positioning System stations in place to monitor for early warning of volcanic activity.

  10. Volcano-related materials in concretes: a comprehensive review.

    Science.gov (United States)

    Cai, Gaochuang; Noguchi, Takafumi; Degée, Hervé; Zhao, Jun; Kitagaki, Ryoma

    2016-04-01

    Massive volcano-related materials (VRMs) erupted from volcanoes bring the impacts to natural environment and humanity health worldwide, which include generally volcanic ash (VA), volcanic pumice (VP), volcanic tuff (VT), etc. Considering the pozzolanic activities and mechanical characters of these materials, civil engineers propose to use them in low carbon/cement and environment-friendly concrete industries as supplementary cementitious materials (SCMs) or artificial/natural aggregates. The utilization of VRMs in concretes has attracted increasing and pressing attentions from research community. Through a literature review, this paper presents comprehensively the properties of VRMs and VRM concretes (VRMCs), including the physical and chemical properties of raw VRMs and VRMCs, and the fresh, microstructural and mechanical properties of VRMCs. Besides, considering environmental impacts and the development of long-term properties, the durability and stability properties of VRMCs also are summarized in this paper. The former focuses on the resistance properties of VRMCs when subjected to aggressive environmental impacts such as chloride, sulfate, seawater, and freezing-thawing. The latter mainly includes the fatigue, creep, heat-insulating, and expansion properties of VRMCs. This study will be helpful to promote the sustainability in concrete industries, protect natural environment, and reduce the impacts of volcano disaster. Based on this review, some main conclusions are discussed and important recommendations regarding future research on the application of VRMs in concrete industries are provided.

  11. Tephra hazard assessment at Concepción Volcano, Nicaragua

    Science.gov (United States)

    Scaini, C.; Folch, A.; Navarro, M.

    2012-03-01

    Concepción volcano in Ometepe Island, Nicaragua, is a highly active volcano with a rich historical record of explosive eruptions. Tephra fallout from Concepción jeopardizes the surrounding populations, whereas volcanic ash clouds threat aerial navigation at a regional level. The assessment of these hazards is important for territorial planning and adoption of mitigation measures. Here we compute probabilistic hazard maps for Concepción volcano considering three different eruptive scenarios based on past reference events. Previous geological analysis is used to quantify the eruption parameters of the reference events. We account for uncertainties in the definition of the scenarios trough probability density functions. A representative meteorological dataset is created for each scenario by running the WRF-ARW mesoscale meteorological model over a typical meteorological year, defined in terms of wind speed and direction at a given atmospheric height. Tephra transport and deposition under different eruption and wind conditions is modelled using the FALL3D dispersion model. For each scenario, simulations are combined to build probabilistic hazard maps for critical values of tephra load and for threshold values of airborne ash concentration at relevant flight levels. Results are useful to identify the expected impacts for each eruption type and aim at improving the assessment and management of risk in the region.

  12. Geology and geothermal potential of the tecuamburro volcano area, Guatemala

    Science.gov (United States)

    Duffield, W.A.; Heiken, G.H.; Wohletz, K.H.; Maassen, L.W.; Dengo, G.; McKee, E.H.; Castaneda, O.

    1992-01-01

    Tecuamburro, an andesitic stratovolcano in southeastern Guatemala, is within the chain of active volcanoes of Central America. Though Tecuamburro has no record of historic eruptions, radiocarbon ages indicate that eruption of this and three other adjacent volcanoes occurred within the past 38,300 years. The youngest eruption produced a dacite dome. Moreover, powerful steam explosions formed a 250 m wide crater about 2900 years ago near the base of this dome. The phreatic crater contains a pH-3 thermal lake. Fumaroles are common along the lake shore, and several other fumaroles are located nearby. Neutral-chloride hot springs are at lower elevations a few kilometers away. All thermal manifestations are within an area of about 400 km2 roughly centered on Tecuamburro Volcano. Thermal implications of the volume, age, and composition of the post-38.3 ka volcanic rocks suggest that magma, or recently solidified hot plutons, or both are in the crust beneath these lavas. Chemical geothermometry carried out by other workers suggests that a hydrothermal-convection system is centered over this crustal heat source. Maximum temperatures of about 300??C are calculated for samples collected in the area of youngest volcanism, whereas samples from outlying thermal manifestations yield calculated temperatures <- 165??C. An 808 m deep drill hole completed in 1990 to partly test the geothermal model developed from surface studies attained a maximum temperature of almost 240??C. Thus, the possibility of a commercial-grade hydrothermal resource in the area seems high. ?? 1992.

  13. Building a flood hazard map due to magma effusion into the caldera lake of the Baekdusan Volcano

    Science.gov (United States)

    Lee, K.; Kim, S.; Yun, S.; Yu, S.; Kim, I.

    2013-12-01

    Many volcanic craters and calderas are filled with large amounts of water that can pose significant flood hazards to downstream communities due to their high elevation and the potential for catastrophic releases of water. Recent reports pointed out the Baekdusan volcano that is located between the border of China and North Korea as a potential active volcano. Since Millennium Eruption around 1000 AD, smaller eruptions have occurred at roughly 100-year intervals, with the last one in 1903. The volcano is showing signs of waking from a century-long slumber recently and the volcanic ash may spread up to the northeastern of Japan. The development of various forecasting techniques to prevent and minimize economic and social damage is in urgent need. Floods from lake-filled calderas may be particularly large and high. Volcanic flood may cause significant hydrologic hazards for this reason. This study focuses on constructing a flood hazard map triggered by the uplift of lake bottom due to magma effusion in the Baekdusan volcano. A physically-based uplift model was developed to compute the amount of water and time to peak flow. The ordinary differential equation was numerically solved using the finite difference method and Newton-Raphson iteration method was used to solve nonlinear equation. The magma effusion rate into the caldera lake is followed by the past record from other volcanic activities. As a result, the hydrograph serves as an upper boundary condition when hydrodynamic model (Flo-2D) runs to simulate channel routing downstream. The final goal of the study stresses the potential flood hazard represented by the huge volume of water in the caldera lake, the unique geography, and the limited control capability. he study will contribute to build a geohazard map for the decision-makers and practitioners. Keywords: Effusion rate, Volcanic flood, Caldera lake, Uplift, Flood hazard map Acknowledgement This research was supported by a grant [NEMA-BAEKDUSAN-2012-1-2] from

  14. Analytical results for non-Hermitian parity–time-symmetric and Hermitian asymmetric volcano potentials

    Indian Academy of Sciences (India)

    XIE QIONGTAO; YAN LINA; WANG LINMAO; FU JUN

    2016-05-01

    We investigate both the non-Hermitian parity–time-(PT-)symmetric and Hermitianasymmetric volcano potentials, and present the analytical solution in terms of the confluent Heun function. Under certain special conditions, the confluent Heun function can be terminated as a polynomial, thereby leading to certain exact analytical results. It is found that the non-Hermitian PTsymmetric volcano potentials support the normalizable and non-normalizable reflectionless stateswith real energies. The Hermitian asymmetric volcano potentials allow normalizable reflectionless states with complex energies.

  15. Investigation of a fossil geothermal system, Hamblin-Cleopatra Volcano, Clark County, Nevada. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Barker, D.S.

    1986-07-28

    The Hamblin-Cleopatra volcano, selected for study because erosion and fault displacement have exposed the entire volcanic succession, the intrusive core, a radial dike systems, and sedimentary and volcanic rocks that predate and postdate the volcano, was investigated to estimate the proportions of igneous materials forming lava flows, pyroclastic deposits, intrusive bodies, and reworked debris. Chemical changes in the magma throughout the active period of the volcano were documented. The geothermal system active within the pile after activity ceased was reconstructed. (ACR)

  16. Volcano monitoring using GPS: Developing data analysis strategies based on the June 2007 Kīlauea Volcano intrusion and eruption

    Science.gov (United States)

    Larson, Kristine M.; Poland, Michael; Miklius, Asta

    2010-01-01

    The global positioning system (GPS) is one of the most common techniques, and the current state of the art, used to monitor volcano deformation. In addition to slow (several centimeters per year) displacement rates, GPS can be used to study eruptions and intrusions that result in much larger (tens of centimeters over hours-days) displacements. It is challenging to resolve precise positions using GPS at subdaily time intervals because of error sources such as multipath and atmospheric refraction. In this paper, the impact of errors due to multipath and atmospheric refraction at subdaily periods is examined using data from the GPS network on Kīlauea Volcano, Hawai'i. Methods for filtering position estimates to enhance precision are both simulated and tested on data collected during the June 2007 intrusion and eruption. Comparisons with tiltmeter records show that GPS instruments can precisely recover the timing of the activity.

  17. 2014 volcanic activity in Alaska: Summary of events and response of the Alaska Volcano Observatory

    Science.gov (United States)

    Cameron, Cheryl E.; Dixon, James P.; Neal, Christina A.; Waythomas, Christopher F.; Schaefer, Janet R.; McGimsey, Robert G.

    2017-09-07

    The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest or suspected unrest, and seismic events at 18 volcanic centers in Alaska during 2014. The most notable volcanic activity consisted of intermittent ash eruptions from long-active Cleveland and Shishaldin Volcanoes in the Aleutian Islands, and two eruptive episodes at Pavlof Volcano on the Alaska Peninsula. Semisopochnoi and Akutan volcanoes had seismic swarms, both likely the result of magmatic intrusion. The AVO also installed seismometers and infrasound instruments at Mount Cleveland during 2014.

  18. The Pulse of the Volcano: Discovery of Episodic Activity at Prometheus on Io

    Science.gov (United States)

    Davies, A. G.

    2003-01-01

    The temporal behaviour of thermal output from a volcano yields valuable clues to the processes taking place at and beneath the surface. Galileo Near Infrared Mapping Spectrometer (NIMS) data show that the ionian volcanoes Prometheus and Amirani have significant thermal emission in excess of nonvolcanic background emission in every geometrically appropriate NIMS observation. The 5 micron brightness of these volcanoes shows considerable variation from orbit to orbit. Prometheus in particular exhibits an episodicity that yields valuable constraints to the mechanisms of magma supply and eruption. This work is part of an on-going study to chart and quantify the thermal emission of Io's volcanoes, determine mass eruption rates, and note eruption style.

  19. Vhub: a knowledge management system to facilitate online collaborative volcano modeling and research

    National Research Council Canada - National Science Library

    Palma, Jose L; Courtland, Leah; Charbonnier, Sylvain; Tortini, Riccardo; Valentine, Greg A

    2014-01-01

    ... ) is a community cyberinfrastructure platform designed for collaboration in volcanology research, education, outreach, and discovery that complements existing volcano databases and other cyberinfrastructure projects...

  20. Update of the volcanic risk map of Colima volcano, Mexico

    Science.gov (United States)

    Suarez-Plascencia, C.; Nuñez Cornu, F. J.; Marquez-Azua, B.

    2010-12-01

    The Colima volcano, located in western Mexico (19° 30.696 N, 103° 37.026 W) began its current eruptive process in February 10, 1999. This event was the basis for the development of two volcanic hazard maps: one for ballistics (rock fall) lahars, and another one for ash fall. During the period of 2003 to 2008 this volcano has had an intense effusive-explosive activity, similar to the one that took place during the period of 1890 through 1900. Intense pre-Plinian eruption in January 20, 1913, generated little economic losses in the lower parts of the volcano thanks to the low population density and low socio-economic activities at the time The current volcanic activity has triggered ballistic projections, pyroclastic and ash flows, and lahars, all have exceeded the maps limits established in 1999. Vulnerable elements within these areas have gradually changed due to the expansion of the agricultural frontier on the east and southeast sides of the Colima volcano. On the slopes of the northwest side, new blue agave Tequilana weber and avocado orchard crops have emerged along with important production of greenhouse tomato, alfalfa and fruit (citrus) crops that will eventually be processed and dried for exportation to the United States and Europe. Also, in addition to the above, large expanses of corn and sugar cane have been planted on the slopes of the volcano since the nineteenth century. The increased agricultural activity has had a direct impact in the reduction of the available forest land area. Coinciding with this increased activity, the 0.8% growth population during the period of 2000 - 2005, - due to the construction of the Guadalajara-Colima highway-, also increased this impact. The growth in vulnerability changed the level of risk with respect to the one identified in the year 1999 (Suarez, 2000), thus motivating us to perform an update to the risk map at 1:25,000 using vector models of the INEGI, SPOT images of different dates, and fieldwork done in order

  1. Volcanic structure and composition of Old Shiveluch volcano, Kamchatka

    Science.gov (United States)

    Gorbach, Natalia; Portnyagin, Maxim; Tembrel, Igor

    2013-08-01

    This paper reports results of a new comprehensive geological mapping of the Late Pleistocene Old Shiveluch volcano. The mapping results and geochemical data on major and trace element composition of the volcanic rocks are used to characterize spatial distribution, eruptive sequence and volumetric relationships between different rock types of the volcano. Old Shiveluch volcano had been constructed during two main stages: initial explosive and subsequent effusive ones. Pyroclastic deposits of the initial stage are represented by agglomerate and psephytic tuffs with very few lava flows and form at least 60% of volume of the Old Shiveluch edifice. The deposits of the second stage are dominantly lava flows erupted from four vents: Central, Western, Baidarny and Southern, reconstructed from the field relationships of their lava flows. About 75% of the Old Shiveluch edifice, both pyroclastic deposits and lava, are composed of magnesian andesites (SiO2 = 57.3-63.8 wt.%, Mg# = 0.53-0.57). The most abundant andesitic lavas were coevally erupted from the Central and Western vents in the central part of the edifice. Less voluminous high-Al basaltic andesites (SiO2 = 53.5-55.7 wt.%, Mg# = 0.52-0.56) were produced by the Western, Baidarny and Southern vents situated in the south-western sector. Small volume high-Mg basaltic andesites (SiO2 = 53.9-55.0 wt.%, Mg# = 0.59-0.64) occur in the upper part of the pyroclastic deposits. Andesites of Old and Young Shiveluch Volcanoes have similar compositions, whereas Old Shiveluch basaltic andesites are compositionally distinctive from those of the Young Shiveluch by having lower Mg#, SiO2, Cr and Ni, and higher Al2O3, FeOT, CaO, TiO2, and V contents at given MgO. Geochemical modeling suggests that the compositions of the intermediate Old Shiveluch magmas can be reasonably explained by simple fractional crystallization of olivine, clinopyroxene, plagioclase and magnetite (± hornblende) from water-bearing (~ 3 wt.% H2O) high-Mg# basaltic

  2. Structural evolution of deep-water submarine intraplate volcanoes / Azores

    Science.gov (United States)

    Stakemann, Josefine; Huebscher, Christian; Beier, Christoph; Hildenbrand, Anthony; Nomikou, Paraskevi; Terrinha, Pedro; Weiß, Benedikt

    2017-04-01

    We present multibeam and high-resolution reflection seismic data which elucidate the architecture of three submarine intraplate volcanoes located in the southern Azores Archipelago. Data have been collected during RV Meteor cruise M113 in 2015. Four GI-Guns served as the seismic source. The digital streamer comprised 144 channels distributed over a length of 600 m. The three cones are situated in a depth down to 2300 m with heights varying between 200 m and 243 m, an average diameter of 1360 m and an average slope angle of ca. 22°. All three circular cones are surrounded by a circular channel. These features, previously named "fried eggs" were previously interpreted as impact crater (Dias et al., 2009). A comparison with nearby submarine volcanoes close to São Miguel island (Weiß et al., 2015), however, strongly suggests a volcanic origin. The seismic data indicate that the volcanic cones formed on top of a ca. 100 m thick pelagic succession covering the igneous basement. Magma ascent deformed the volcanic basement, displaced the pelagic sediments and a first eruption phase formed a small, seismically transparent volcanic cone. Further eruptions created a volcanic cone with rather transparent reflections within the inferior region changing to strong reflection amplitudes with a chaotic pattern in the superior area. Compared to the igneous basement internal reflection amplitudes are mainly weak. The seismic transparency and slope angle exclude the presence of effusive rocks, since lavas usually create strong impedance contrasts. A comparison of the seismic characteristics with those from submarine Kolumbo volcano (Hübscher et al., 2015) suggests volcaniclastic lithologies from explosive eruptions. The circular channel around the volcanic cone shows the characteristics of a moat channel created by bottom currents. References: Dias, F.C., Lourenco, N., Lobo, A., Santos de Campos, A., Pinto de Abreu, M., 2009. "Fried Egg": An Oceanic Impact Crater in the Mid

  3. Local Short Period Seismic Network at Villarrica Volcano

    Science.gov (United States)

    Mora-Stock, Cindy; Thorwart, Martin; Dzieran, Laura; Rabbel, Wolfgang

    2014-05-01

    Since its last eruption in 1984-85, the Villarrica volcano has been presenting both seismic and fumarolic activity, accompanied by an open vent and a refulgent lava lake. To study its activity, a local seismic network of 75 DSS-Cubes short-period stations was deployed at and around the volcano. During the first two weeks of March, 2012, 30 3-Component and 45 1-Component stations were installed in a 63 km x 55 km area, with spacing between stations of 1.5 km for stations inside the perimeter of the volcanic edifice, and 5 km outside this perimeter. In total, approximately 94 volcano tectonic (VT) events with clear P- and S- wave arrivals were located to the SSW, SSE and North of the Crater at an average depth of 3 km below sea level. At least 73 events classified as "hybrids" (HB) were observed, predominantly about 2 km above sea level near or at the conduit. They present emergent higher frequencies at the beginning of the signal, and sharp S-wave at the crater stations, but a strong scattering, lower frequency content, and elongated coda on the stations along the volcanic edifice, probably due to ash layers and heterogeneities at the edifice. A few long period events (LP) with frequencies between 2-4 Hz were observed during the two weeks. Three set of groups can be distinguished for the regional tectonic events: aftershocks on the southern end of the rupture of the Maule 2010 event, with S-P wave travel time difference of ca. 30 s or more; a second group with S-P travel time difference between 10 s and 20s; and the much closer group with S-P wave difference of 10 s or less. To determine the average velocity structure of the volcano, a cross-correlation analysis of the waves from a M6.1 event in Argentina and other regional events was performed. The model used was a cylindric model of 6.5 km radius inside the volcanic edifice, which gave a P-wave velocity of 3.6 km/s, and a region outside this radius with a velocity of 4.1 km. The network was divided into five zones

  4. The heartbeat of the volcano: The discovery of episodic activity at Prometheus on Io

    Science.gov (United States)

    Davies, A.G.; Wilson, L.; Matson, D.; Leone, G.; Keszthelyi, L.; Jaeger, W.

    2006-01-01

    The temporal signature of thermal emission from a volcano is a valuable clue to the processes taking place both at and beneath the surface. The Galileo Near Infrared Mapping Spectrometer (NIMS) observed the volcano Prometheus, on the jovian moon Io, on multiple occasions between 1996 and 2002. The 5 micron (??m) brightness of this volcano shows considerable variation from orbit to orbit. Prometheus exhibits increases in thermal emission that indicate episodic (though non-periodic) effusive activity in a manner akin to the current Pu'u 'O'o-Kupaianaha (afterwards referred to as the Pu'u 'O'o) eruption of Kilauea, Hawai'i. The volume of material erupted during one Prometheus eruption episode (defined as the interval from minimum thermal emission to peak and back to minimum) from 6 November 1996 to 7 May 1997 is estimated to be ???0.8 km3, with a peak instantaneous volumetric flux (effusion rate) of ???140 m3 s-1, and an averaged volumetric flux (eruption rate) of ???49 m3 s-1. These quantities are used to model subsurface structure, magma storage and magma supply mechanisms, and likely magma chamber depth. Prometheus appears to be supplied by magma from a relatively shallow magma chamber, with a roof at a minimum depth of ???2-3 km and a maximum depth of ???14 km. This is a much shallower depth range than sources of supply proposed for explosive, possibly ultramafic, eruptions at Pillan and Tvashtar. As Prometheus-type effusive activity is widespread on Io, shallow magma chambers containing magma of basaltic or near-basaltic composition and density may be common. This analysis strengthens the analogy between Prometheus and Pu'u 'O'o, at least in terms of eruption style. Even though the style of eruption appears to be similar (effusive emplacement of thin, insulated, compound pahoehoe flows) the scale of activity at Prometheus greatly exceeds current activity at Pu'u 'O'o in terms of volume erupted, area covered, and magma flux. Whereas the estimated magma chamber at

  5. The use of digital outcrops to study monogenetic volcanoes: Case study at Croscat volcano (Garrotxa Volcanic Zone, Spain)

    Science.gov (United States)

    Geyer, Adelina; García-Sellés, David; Pedrazzi, Dario; Barde-Cabusson, Stéphanie; Martí, Joan; Muñoz, Josep Anton

    2014-05-01

    During the last years, it has been demonstrated that the study of outcrops with difficult or completely restricted access can be carried out by means of digital representations of the outcrop surface. Furthermore, the study of digital outcrops may facilitate visualization of the features of interest over the entire outcrop, as long as the digital outcrop can be analysed while navigating 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 permits the creation of detailed 3-D terrain models of larger coverage and accuracy than conventional methods and with almost complete safety of the operators. Here we show digital outcrops may be useful to perform the description of the internal structure of exposed volcanic edifices. A further advantageous application is the estimate of erosion rates and patterns that may be helpful in terms of hazard assessment or preservation of volcanic landscapes. We use as an example of application the Croscat volcano, a monogenetic edifice of the La Garrotxa volcanic field (Spain), which quarrying jobs have exposed the internal part of the volcano leading to a perfect view of its interior but making difficult the access to the upper parts. The Croscat volcano is additionally one of the most emblematic symbols of the La Garrotxa Volcanic Zone Natural Park being its preservation a main target of the park administration.

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

    Directory of Open Access Journals (Sweden)

    Luis Miguel Peci

    2014-01-01

    Full Text Available This paper describes the development of a multi-parameter system for monitoring volcanic activity. The system permits the remote access and the connection of several modules in a network. An embedded ARMTM processor has been used, allowing a great flexibility in hardware configuration. The use of a complete Linux solution (DebianTM as Operating System permits a quick, easy application development to control sensors and communications. This provides all the capabilities required and great stability with relatively low energy consumption. The cost of the components and applications development is low since they are widely used in different fields. Sensors and commercial modules have been combined with other self-developed modules. The Modular Volcano Monitoring System (MVMS described has been deployed on the active Deception Island (Antarctica volcano, within the Spanish Antarctic Program, and has proved successful for monitoring the volcano, with proven reliability and efficient operation under extreme conditions. In another context, i.e., the recent volcanic activity on El Hierro Island (Canary Islands in 2011, this technology has been used for the seismic equipment and GPS systems deployed, thus showing its efficiency in the monitoring of a volcanic crisis.

  7. Seismicity study of volcano-tectonic in and around Tangkuban Parahu active volcano in West Java region, Indonesia

    Science.gov (United States)

    Ry, Rexha V.; Priyono, A.; Nugraha, A. D.; Basuki, A.

    2016-05-01

    Tangkuban Parahu is one of the active volcano in Indonesia located about 15 km northern part of Bandung city. The objective of this study is to investigate the seismic activity in the time periods of January 2013 to December 2013. First, we identified seismic events induced by volcano-tectonic activities. These micro-earthquake events were identified as having difference of P-wave and S-wave arrival times less than three seconds. Then, we constrained its location of hypocenter to locate the source of the activities. Hypocenter determination was performed using adaptive simulated annealing method. Using these results, seismic tomographic inversions were conducted to image the three-dimensional velocity structure of Vp, Vs, and the Vp/Vs ratio. In this study, 278 micro-earthquake events have been identified and located. Distribution of hypocenters around Tangkuban Parahu volcano forms an alignment structure and may be related to the stress induced by magma below, also movement of shallow magma below Domas Crater. Our preliminary tomographic inversion results indicate the presences of low Vp, high Vs, and low Vp/Vs ratio that associate to accumulated young volcanic eruption products and hot material zones.

  8. Mechanism of the 1996-97 non-eruptive volcano-tectonic earthquake swarm at Iliamna Volcano, Alaska

    Science.gov (United States)

    Roman, D.C.; Power, J.A.

    2011-01-01

    A significant number of volcano-tectonic(VT) earthquake swarms, some of which are accompanied by ground deformation and/or volcanic gas emissions, do not culminate in an eruption.These swarms are often thought to represent stalled intrusions of magma into the mid- or shallow-level crust.Real-time assessment of the likelihood that a VTswarm will culminate in an eruption is one of the key challenges of volcano monitoring, and retrospective analysis of non-eruptive swarms provides an important framework for future assessments. Here we explore models for a non-eruptive VT earthquake swarm located beneath Iliamna Volcano, Alaska, in May 1996-June 1997 through calculation and inversion of fault-plane solutions for swarm and background periods, and through Coulomb stress modeling of faulting types and hypocenter locations observed during the swarm. Through a comparison of models of deep and shallow intrusions to swarm observations,we aim to test the hypothesis that the 1996-97 swarm represented a shallow intrusion, or "failed" eruption.Observations of the 1996-97 swarm are found to be consistent with several scenarios including both shallow and deep intrusion, most likely involving a relatively small volume of intruded magma and/or a low degree of magma pressurization corresponding to a relatively low likelihood of eruption. ?? 2011 Springer-Verlag.

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

    Science.gov (United States)

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

    2014-01-02

    This paper describes the development of a multi-parameter system for monitoring volcanic activity. The system permits the remote access and the connection of several modules in a network. An embedded ARM™ processor has been used, allowing a great flexibility in hardware configuration. The use of a complete Linux solution (Debian™) as Operating System permits a quick, easy application development to control sensors and communications. This provides all the capabilities required and great stability with relatively low energy consumption. The cost of the components and applications development is low since they are widely used in different fields. Sensors and commercial modules have been combined with other self-developed modules. The Modular Volcano Monitoring System (MVMS) described has been deployed on the active Deception Island (Antarctica) volcano, within the Spanish Antarctic Program, and has proved successful for monitoring the volcano, with proven reliability and efficient operation under extreme conditions. In another context, i.e., the recent volcanic activity on El Hierro Island (Canary Islands) in 2011, this technology has been used for the seismic equipment and GPS systems deployed, thus showing its efficiency in the monitoring of a volcanic crisis.

  10. ASSESSING PEAK AEROBIC CAPACITY IN DUTCH LAW ENFORCEMENT OFFICERS

    NARCIS (Netherlands)

    Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

    2015-01-01

    Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report norm

  11. Peak-power-point monitor for solar panel

    Science.gov (United States)

    Schloss, A. I.

    1972-01-01

    Attempt was made to determine solar cell panel peak power capability without disrupting power flow from panel. Separate solar cell strings were switched from panel circuits, and increasingly larger loads were added rapidly until peak power points were transversed. String wattage output was recorded and all stored string measurements summed together indicate peak power point in panel.

  12. Active Volcano Monitoring using a Space-based Hyperspectral Imager

    Science.gov (United States)

    Cipar, J. J.; Dunn, R.; Cooley, T.

    2010-12-01

    Active volcanoes occur on every continent, often in close proximity to heavily populated areas. While ground-based studies are essential for scientific research and disaster mitigation, remote sensing from space can provide rapid and continuous monitoring of active and potentially active volcanoes [Ramsey and Flynn, 2004]. In this paper, we report on hyperspectral measurements of Kilauea volcano, Hawaii. Hyperspectral images obtained by the US Air Force TacSat-3/ARTEMIS sensor [Lockwood et al, 2006] are used to obtain estimates of the surface temperatures for the volcano. ARTEMIS measures surface-reflected light in the visible, near-infrared, and short-wave infrared bands (VNIR-SWIR). The SWIR bands are known to be sensitive to thermal radiation [Green, 1996]. For example, images from the NASA Hyperion hyperspectral sensor have shown the extent of wildfires and active volcanoes [Young, 2009]. We employ the methodology described by Dennison et al, (2006) to obtain an estimate of the temperature of the active region of Kilauea. Both day and night-time images were used in the analysis. To improve the estimate, we aggregated neighboring pixels. The active rim of the lava lake is clearly discernable in the temperature image, with a measured temperature exceeding 1100o C. The temperature decreases markedly on the exterior of the summit crater. While a long-wave infrared (LWIR) sensor would be ideal for volcano monitoring, we have shown that the thermal state of an active volcano can be monitored using the SWIR channels of a reflective hyperspectral imager. References: Dennison, Philip E., Kraivut Charoensiri, Dar A. Roberts, Seth H. Peterson, and Robert O. Green (2006). Wildfire temperature and land cover modeling using hyperspectral data, Remote Sens. Environ., vol. 100, pp. 212-222. Green, R. O. (1996). Estimation of biomass fire temperature and areal extent from calibrated AVIRIS spectra, in Summaries of the 6th Annual JPL Airborne Earth Science Workshop, Pasadena, CA

  13. Automatic readout for nuclear emulsions in muon radiography of volcanoes

    Science.gov (United States)

    Aleksandrov, A.; Bozza, C.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Kose, U.; Lauria, A.; Medinaceli, E.; Miyamoto, S.; Montesi, C.; Pupilli, F.; Rescigno, R.; Russo, A.; Sirignano, C.; Stellacci, S. M.; Strolin, P.; Tioukov, V.

    2012-04-01

    Nuclear emulsions are an effective choice in many scenarios of volcano radiography by cosmic-ray muons. They are cheap and emulsion-based detectors require no on-site power supply. Nuclear emulsion films provide sub-micrometric tracking precision and intrinsic angular accuracy better than 1 mrad. Imaging the inner structure of a volcano requires that the cosmic-ray absorption map be measured on wide angular range. High-absorption directions can be probed by allowing for large statistics, which implies a large overall flux, i.e. wide surface for the detector. A total area of the order of a few m2 is nowadays typical, thanks to the automatic readout tools originally developed for high-energy physics experiments such as CHORUS, PEANUT, OPERA. The European Scanning System is now being used to read out nuclear emulsion films exposed to cosmic rays on the side of volcanoes. The structure of the system is described in detail with respect to both hardware and software. Its present scanning speed of 20 cm2/h/side/microscope is suitable to fulfil the needs of the current exposures of nuclear emulsion films for muon radiograph, but it is worth to notice that applications in volcano imaging are among the driving forces pushing to increase the performances of the system. Preliminary results for the Unzen volcano of a joint effort by research groups in Italy and Japan show that the current system is already able to provide signal/background ratio in the range 100÷10000:1, depending on the quality cuts set in the off-line data analysis. The size of the smallest detectable structures in that experimental setup is constrained by the available statistics in the region of highest absorption to about 50 mrad, or 22 m under the top of the mountain. Another exposure is currently taking data at the Stromboli volcano. Readout of the exposed films is expected to begin in March 2012, and preliminary results will be available soon after. An effort by several universities and INFN has

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

    Science.gov (United States)

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

    2016-05-23

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

  15. Plume composition and volatile flux from Nyamulagira volcano

    Science.gov (United States)

    Calabrese, Sergio; Bobrowski, Nicole; Giuffrida, Giovanni Bruno; Scaglione, Sarah; Liotta, Marcello; Brusca, Lorenzo; D'Alessandro, Walter; Arellano, Santiago; Yalire, Matiew; Galle, Bo; Tedesco, Dario

    2015-04-01

    Nyamulagira, in the Virunga volcanic province (VVP), Democratic Republic of Congo, is one of the most active volcanoes in Africa. The volcano is located about 25 km north-northwest of Lake Kivu in the Western Branch of the East African Rift System (EARS). The activity is characterized by frequent eruptions (on average, one eruption every 2-4 years) which occur both from the summit crater and from the flanks (31 flank eruptions over the last 110 years). Due to the peculiar low viscosity of its lava and its location in the floor of the rift, Nyamulagira morphology is characterized by a wide lava field that covers over 1100 km2 and contains more than 100 flank cones. Indeed, Nyamulagira is a SiO2- undersaturated and alkali-rich basaltic shield volcano with a 3058 m high summit caldera with an extension of about 2 km in diameter. In November 2014 a field expedition was carried out at Nyamulagira volcano and we report here the first assessment of the plume composition and volatile flux from Nyamulagira volcano. Helicopter flights and field observations allowed us to recognize the presence of lava fountains inside an about 350-meter wide pit crater. The lava fountains originated from an extended area of about 20 to 40 m2, in the northeast sector of the central caldera. A second smaller source, close to the previous described one, was clearly visible with vigorous spattering activity. There was no evidence of a lave lake but the persistence of intense activity and the geometry of the bottom of the caldera might evolve in a new lava lake. Using a variety of in situ and remote sensing techniques, we determined the bulk plume concentrations of major volatiles, halogens and trace elements. We deployed a portable MultiGAS station at the rim of Nyamulagira crater, measuring (at 0.5 Hz for about 3 hours) the concentrations of major volcanogenic gas species in the plume (H2O, CO2, SO2, H2S). Simultaneously, scanning differential optical absorption spectroscopy instruments were

  16. Kamchatka and North Kurile Volcano Explosive Eruptions in 2015 and Danger to Aviation

    Science.gov (United States)

    Girina, Olga; Melnikov, Dmitry; Manevich, Alexander; Demyanchuk, Yury; Nuzhdaev, Anton; Petrova, Elena

    2016-04-01

    There are 36 active volcanoes in the Kamchatka and North Kurile, and several of them are continuously active. In 2015, four of the Kamchatkan volcanoes (Sheveluch, Klyuchevskoy, Karymsky and Zhupanovsky) and two volcanoes of North Kurile (Alaid and Chikurachki) had strong and moderate explosive eruptions. Moderate gas-steam activity was observing of Bezymianny, Kizimen, Avachinsky, Koryaksky, Gorely, Mutnovsky and other volcanoes. Strong explosive eruptions of volcanoes are the most dangerous for aircraft because they can produce in a few hours or days to the atmosphere and the stratosphere till several cubic kilometers of volcanic ash and aerosols. Ash plumes and the clouds, depending on the power of the eruption, the strength and wind speed, can travel thousands of kilometers from the volcano for several days, remaining hazardous to aircraft, as the melting temperature of small particles of ash below the operating temperature of jet engines. The eruptive activity of Sheveluch volcano began since 1980 (growth of the lava dome) and is continuing at present. Strong explosive events of the volcano occurred in 2015: on 07, 12, and 15 January, 01, 17, and 28 February, 04, 08, 16, 21-22, and 26 March, 07 and 12 April: ash plumes rose up to 7-12 km a.s.l. and extended more 900 km to the different directions of the volcano. Ashfalls occurred at Ust'-Kamchatsk on 16 March, and Klyuchi on 30 October. Strong and moderate hot avalanches from the lava dome were observing more often in the second half of the year. Aviation color code of Sheveluch was Orange during the year. Activity of the volcano was dangerous to international and local aviation. Explosive-effusive eruption of Klyuchevskoy volcano lasted from 01 January till 24 March. Strombolian explosive volcanic activity began from 01 January, and on 08-09 January a lava flow was detected at the Apakhonchich chute on the southeastern flank of the volcano. Vulcanian activity of the volcano began from 10 January. Ashfalls

  17. Revised tephra volumes for Cascade Range volcanoes

    Science.gov (United States)

    Nathenson, Manuel

    2017-07-01

    Isopach maps from tephra eruptions from Mount St. Helens were reported in Carey et al. (1995) and for tephra eruptions from Glacier Peak in Gardner et al. (1998). For exponential thinning, the isopach data only define a single slope on a log thickness versus square root of area plot. Carey et al. (1995) proposed a model that was used to estimate a second slope, and volumes were presented in both studies using this model. A study by Sulpizio (2005) for estimating the second slope and square root of area where the lines intersect involves a systematic analysis of many eruptions to provide correlation equations. The purpose of this paper is to recalculate the volumes of Cascades eruptions and compare results from the two methods. In order to gain some perspective on the methods for estimating the second slope, we use data for thickness versus distance beyond the last isopach that are available for some of the larger eruptions in the Cascades. The thickness versus square root of area method is extended to thickness versus distance by developing an approximate relation between the two assuming elliptical isopachs with the source at one of the foci. Based on the comparisons made between the Carey et al. (1995) and Sulpizio (2005) methods, it is felt that the later method provides a better estimate of the second slope. For Mount St. Helens, the estimates of total volume using the Sulpizio (2005) method are generally smaller than those using the Carey et al. (1995) method. For the volume estimates of Carey et al. (1995), the volume of the May 18, 1980, eruption of Mount St. Helens is smaller than six of the eight previous eruptions. With the new volumes using the Sulpizio (2005) method, the 1980 eruption is smaller in volume than the upper end of the range for only three of the layers (Wn, Ye, and Yn) and is the same size as layer We. Thus the 1980 eruption becomes representative of the mid-range of volumes rather than being in the lower range.

  18. Revised tephra volumes for Cascade Range volcanoes

    Science.gov (United States)

    Nathenson, Manuel

    2017-01-01

    Isopach maps from tephra eruptions from Mount St. Helens were reported in Carey et al. (1995) and for tephra eruptions from Glacier Peak in Gardner et al. (1998). For exponential thinning, the isopach data only define a single slope on a log thickness versus square root of area plot. Carey et al. (1995) proposed a model that was used to estimate a second slope, and volumes were presented in both studies using this model. A study by Sulpizio (2005) for estimating the second slope and square root of area where the lines intersect involves a systematic analysis of many eruptions to provide correlation equations. The purpose of this paper is to recalculate the volumes of Cascades eruptions and compare results from the two methods. In order to gain some perspective on the methods for estimating the second slope, we use data for thickness versus distance beyond the last isopach that are available for some of the larger eruptions in the Cascades. The thickness versus square root of area method is extended to thickness versus distance by developing an approximate relation between the two assuming elliptical isopachs with the source at one of the foci. Based on the comparisons made between the Carey et al. (1995) and Sulpizio (2005) methods, it is felt that the later method provides a better estimate of the second slope. For Mount St. Helens, the estimates of total volume using the Sulpizio (2005) method are generally smaller than those using the Carey et al. (1995) method. For the volume estimates of Carey et al. (1995), the volume of the May 18, 1980, eruption of Mount St. Helens is smaller than six of the eight previous eruptions. With the new volumes using the Sulpizio (2005) method, the 1980 eruption is smaller in volume than the upper end of the range for only three of the layers (Wn, Ye, and Yn) and is the same size as layer We. Thus the 1980 eruption becomes representative of the mid-range of volumes rather than being in the lower range.

  19. Economic and safety analysis of unconventional peak regulation on power unit of peak shifting start-stop

    Science.gov (United States)

    Cao, X.; Zhao, J. F.; Duan, X. Q.; Jin, Y. A.

    2017-01-01

    Tthe capacity difference of peak regulation between the power gird and the actual demand has become a serious problem considering the growth in the difference between electricity supply and demand. Therefore, peak regulation of power grid needs to be deeply studied. Unconventional peak regulation on unit of peak shifting start-stop is a way that can broaden the range of power regulation, as well as benefit safe operation of the power grid. However, it requires frequent and fast unit start-stop, complex operation, and more staff labor. By carrying out unconventional thermal power unit load test, the start-stop mode of peak auxiliary equipment is studied in this paper, indicating that it has a positive effect on safety and economic of load-peaking operation. The best working conditions of the peak units is found by analysing consumption cost, safety specifications, and life lost of the start-stop peak regulation mode.

  20. Volcano Deformation and Eruption Forecasting using Data Assimilation: Case of Grimsvötn volcano in Iceland

    Science.gov (United States)

    Bato, Mary Grace; Pinel, Virginie; Yan, Yajing

    2016-04-01

    The recent advances in Interferometric Synthetic Aperture Radar (InSAR) imaging and the increasing number of continuous Global Positioning System (GPS) networks recorded on volcanoes provide continuous and spatially extensive evolution of surface displacements during inter-eruptive periods. For basaltic volcanoes, these measurements combined with simple dynamical models (Lengliné et al. 2008 [1], Pinel et al, 2010 [2], Reverso et al, 2014 [3]) can be exploited to characterise and constrain parameters of one or several magmatic reservoirs using inversion methods. On the other hand, data assimilation-a time-stepping process that best combines models and observations, sometimes a priori information based on error statistics to predict the state of a dynamical system-has gained popularity in various fields of geoscience (e.g. ocean-weather forecasting, geomagnetism and natural resources exploration). In this work, we aim to first test the applicability and benefit of data assimilation, in particular the Ensemble Kalman Filter [4], in the field of volcanology. We predict the temporal behaviors of the overpressures and deformations by applying the two-magma chamber model of Reverso et. al., 2014 [3] and by using synthetic deformation data in order to establish our forecasting strategy. GPS time-series data of the recent eruptions at Grimsvötn volcano is used for the real case applicability of the method. [1] Lengliné, O., D Marsan, J Got, V. Pinel, V. Ferrazzini, P. Obuko, Seismicity and deformation induced by magma accumulation at three basaltic volcanoes, J. Geophys. Res., 113, B12305, 2008. [2] V. Pinel, C. Jaupart and F. Albino, On the relationship between cycles of eruptive activity and volcanic edifice growth, J. Volc. Geotherm. Res, 194, 150-164, 2010 [3] T. Reverso, J. Vandemeulebrouck, F. Jouanne, V. Pinel, T. Villemin, E. Sturkell, A two-magma chamber as a source of deformation at Grimsvötn volcano, Iceland, JGR, 2014 [4] Evensen, G., The Ensemble Kalman