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Sample records for sakurajima volcano japan

  1. Space Radar Image of Sakura-Jima Volcano, Japan

    Science.gov (United States)

    1994-01-01

    The active volcano Sakura-Jima on the island of Kyushu, Japan is shown in the center of this radar image. The volcano occupies the peninsula in the center of Kagoshima Bay, which was formed by the explosion and collapse of an ancient predecessor of today's volcano. The volcano has been in near continuous eruption since 1955. Its explosions of ash and gas are closely monitored by local authorities due to the proximity of the city of Kagoshima across a narrow strait from the volcano's center, shown below and to the left of the central peninsula in this image. City residents have grown accustomed to clearing ash deposits from sidewalks, cars and buildings following Sakura-jima's eruptions. The volcano is one of 15 identified by scientists as potentially hazardous to local populations, as part of the international 'Decade Volcano' program. The image was acquired by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 9, 1994. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. The image is centered at 31.6 degrees North latitude and 130.6 degrees East longitude. North is toward the upper left. The area shown measures 37.5 kilometers by 46.5 kilometers (23.3 miles by 28.8 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band vertically transmitted, vertically received; green is the average of L-band vertically transmitted, vertically received and C-band vertically transmitted, vertically received; blue is C-band vertically transmitted, vertically received.

  2. A model for crustal deformations associated with the 1914 great eruption of Sakurajima volcano, Kagoshima, Japan

    Science.gov (United States)

    Hashimoto, M.; Tada, T.

    1992-05-01

    Sakurajima volcano, which is located on the southern rim of the Aira caldera, Kagoshima, is one of the most active volcanoes in Japan. The 1914 eruption of Sakurajima volcano was accompanied by an intensive fissure eruption and caused significant crustal deformations. The north side of the newly formed fissure craters, which are arranged in the WNW-ESE direction, moved toward the north by about 5 m, and the south side moved toward the south by 3 m. Furthermore, the ground surface around the Aira caldera was concentrically depressed by 80 cm. In order to explain these significant crustal deformations, a model consisting of a tensile fault and a deflation source is presented. By means of the least-squares fitting of the model to leveling data around the Aira caldera, we obtained the parameters of the deflation source as follows: depth 8.8 ± 1.2 km; subsidence just above the source 157 ± 27 cm. The source is located at the center of the Aira caldera. On the other hand, the tensile fault, which corresponds to the fissure craters, is estimated, on the basis of horizontal movements in Sakurajima, to be 7 km long, 1.5 km wide and 0.5 km deep at its upper margin, with an opening of 20 m. This model suggests that magma flowed out of the reservoir beneath the Aira caldera and broke the crust of Sakurajima, thus creating fissure.

  3. Structural evolution beneath Sakurajima Volcano, Japan, revealed through rounds of controlled seismic experiments

    Science.gov (United States)

    Tsutsui, Tomoki; Iguchi, Masato; Tameguri, Takeshi; Nakamichi, Haruhisa

    2016-04-01

    Structural evolution beneath an active volcano is detected as the variation of seismic reflectivity through controlled seismic experiments, which is interpreted as being associated with discharging magma. The target of the present study is Sakurajima Volcano, which is one of the most active volcanoes in Japan. Six rounds of seismic experiments with controlled sources have been conducted annually at the volcano. Two seismic reflection profiles are obtained from the datasets for each successful round of experiments. The experiments reveal clear annual variation in seismic reflectivity at a depth of 6.2 km in the northeastern part of Sakurajima. The reflectivity is maximum in December 2009 upon the first intrusion of magma and decreases gradually until December 2013, which coincides with the inflation and deflation cycle of Sakurajima Volcano. Reflectivity variation occurred in the embedded clear reflector at depth. An evolving sandwiched structure in the intermediate layer is used as the reflector model. Lower-velocity magma embedded in the intermediate layer and its succeeding velocity increment explain the variation range of reflectivity. This is interpreted as a temperature decrease associated with discharging magma at depth. The present study describes a new approach for instantaneously sensing magma properties and for monitoring active volcanoes.

  4. Seismic Reflectivity Evolution Beneath Sakurajima Volcano, Japan, from 2009 through 2014, Revealed with Rounds of Controlled-source Seismic Experiments

    Science.gov (United States)

    Tsutsui, T.; Iguchi, M.; Tameguri, T.; Nakamichi, H.

    2015-12-01

    Evolution in seismic reflectivity is detected beneath an active volcano, Sakurajima Volcano, from 2009 through 2014 with using controlled seismic experiments . The reflectivity variation is interpreted to associate with discharging magma. Sakurajima Volcano is the target of this study, which is one of the most active volcanoes in Japan. Seven rounds of the seismic experiment with controlled sources have been conducted annually in the volcano. Two seismic reflection profiles tied up are obtained from the datasets under successful reproduction during rounds. Clear annual variation in seismic reflectivity at 6.2km depth is detected in the northeastern part of Sakurajima during the rounds. The reflectivity marked its maximum on December 2009 on the first intrusion of magma and decreased gradually until December 2013, which coincides with inflation and following deflation in Sakurajima Volcano. The active reflector at 6.2km depth occupies a part of embedded clear reflector. A sandwich structure is invoked as the reflector model. Intrusion of fresh and high temperature magma into the intermediate layer of the model and its decline explains the variation range of reflectivity successfully. Our study presents one of new approaches for sensing magma properties instantaneously and for monitoring active volcanoes.

  5. Characterization of fine volcanic ash from explosive eruption from Sakurajima volcano, South Japan

    Science.gov (United States)

    Nanayama, F.; Furukawa, R.; Ishizuka, Y.; Yamamoto, T.; Geshi, N.; Oishi, M.

    2013-12-01

    Explosive volcanic eruptions can affect infrastructure and ecosystem by their dispersion of the volcanic particle. Characterization of volcanic particle expelled by explosive eruption is crucial for evaluating for quantitative hazard assessment by future volcanic eruption. Especially for fine volcanic ash less than 64 micron in diameter, it can disperse vast area from the source volcano and be easily remobilized by surface wind and precipitation after the deposition. As fine volcanic ash is not preserved well at the earth surface and in strata except for enormously large scale volcanic eruption. In order to quantify quantitative characteristics of fine volcanic ash particle, we sampled volcanic ash directly falling from the eruption cloud from Showa crater, the most active vent of Sakurajima volcano, just before landing on ground. We newly adopted high precision digital microscope and particle grain size analyzer to develop hazard evaluation method of fine volcanic ash particle. Field survey was performed 5 sequential days in January, 2013 to take tamper-proof volcanic ash samples directly obtained from the eruption cloud of the Sakurajima volcano using disposable paper dishes and plastic pails. Samples were taken twice a day with time-stamp in 40 localities from 2.5 km to 43 km distant from the volcano. Japan Meteorological Agency reported 16 explosive eruptions of vulcanian style occurred during our survey and we took 140 samples of volcanic ash. Grain size distribution of volcanic ash was measured by particle grain size analyzer (Mophologi G3S) detecting each grain with parameters of particle diameter (0.3 micron - 1 mm), perimeter, length, area, circularity, convexity, solidity, and intensity. Component of volcanic ash was analyzed by CCD optical microscope (VHX-2000) which can take high resolution optical image with magnifying power of 100-2500. We discriminated each volcanic ash particle by color, texture of surface, and internal structure. Grain size

  6. Potential impacts of tephra fallout from a large-scale explosive eruption at Sakurajima volcano, Japan

    Science.gov (United States)

    Biass, S.; Todde, A.; Cioni, R.; Pistolesi, M.; Geshi, N.; Bonadonna, C.

    2017-10-01

    We present an exposure analysis of infrastructure and lifeline to tephra fallout for a future large-scale explosive eruption of Sakurajima volcano. An eruption scenario is identified based on the field characterization of the last subplinian eruption at Sakurajima and a review of reports of the eruptions that occurred in the past six centuries. A scenario-based probabilistic hazard assessment is performed using the Tephra2 model, considering various eruption durations to reflect complex eruptive sequences of all considered reference eruptions. A quantitative exposure analysis of infrastructures and lifelines is presented primarily using open-access data. The post-event impact assessment of Magill et al. (Earth Planets Space 65:677-698, 2013) after the 2011 VEI 2 eruption of Shinmoedake is used to discuss the vulnerability and the resilience of infrastructures during a future large eruption of Sakurajima. Results indicate a main eastward dispersal, with longer eruption durations increasing the probability of tephra accumulation in proximal areas and reducing it in distal areas. The exposure analysis reveals that 2300 km of road network, 18 km2 of urban area, and 306 km2 of agricultural land have a 50% probability of being affected by an accumulation of tephra of 1 kg/m2. A simple qualitative exposure analysis suggests that the municipalities of Kagoshima, Kanoya, and Tarumizu are the most likely to suffer impacts. Finally, the 2011 VEI 2 eruption of Shinmoedake demonstrated that the already implemented mitigation strategies have increased resilience and improved recovery of affected infrastructures. Nevertheless, the extent to which these mitigation actions will perform during the VEI 4 eruption presented here is unclear and our hazard assessment points to possible damages on the Sakurajima peninsula and the neighboring municipality of Tarumizu.

  7. Volcanic Lightning in Eruptions of Sakurajima Volcano

    Science.gov (United States)

    Edens, Harald; Thomas, Ronald; Behnke, Sonja; McNutt, Stephen; Smith, Cassandra; Farrell, Alexandra; Van Eaton, Alexa; Cimarelli, Corrado; Cigala, Valeria; Eack, Ken; Aulich, Graydon; Michel, Christopher; Miki, Daisuke; Iguchi, Masato

    2016-04-01

    In May 2015 a field program was undertaken to study volcanic lightning at the Sakurajima volcano in southern Japan. One of the main goals of the study was to gain a better understanding of small electrical discharges in volcanic eruptions, expanding on our earlier studies of volcanic lightning at Augustine and Redoubt volcanoes in Alaska, USA, and Eyjafjallajökull in Iceland. In typical volcanic eruptions, electrical activity occurs at the onset of an eruption as a near-continual production of VHF emissions at or near to the volcanic vent. These emissions can occur at rates of up to tens of thousands of emissions per second, and are referred to as continuous RF. As the ash cloud expands, small-scale lightning flashes of several hundred meters length begin to occur while the continuous RF ceases. Later on during the eruption larger-scale lightning flashes may occur within the ash cloud that are reminiscent of regular atmospheric lightning. Whereas volcanic lightning flashes are readily observed and reasonably well understood, the nature and morphology of the events producing continuous RF are unknown. During the 2015 field program we deployed a comprehensive set of instrumentation, including a 10-station 3-D Lightning Mapping Array (LMA) that operated in 10 μs high time resolution mode, slow and fast ΔE antennas, a VHF flat-plate antenna operating in the 20-80 MHz band, log-RF waveforms within the 60-66 MHz band, an infra-red video camera, a high-sensitivity Watec video camera, two high-speed video cameras, and still cameras. We give an overview of the Sakurajima field program and present preliminary results using correlated LMA, waveforms, photographs and video recordings of volcanic lightning at Sakurajima volcano.

  8. Eruption mass estimation using infrasound waveform inversion and ash and gas measurements: Evaluation at Sakurajima Volcano, Japan

    Science.gov (United States)

    Fee, David; Izbekov, Pavel; Kim, Keehoon; Yokoo, Akihiko; Lopez, Taryn; Prata, Fred; Kazahaya, Ryunosuke; Nakamichi, Haruhisa; Iguchi, Masato

    2017-12-01

    Eruption mass and mass flow rate are critical parameters for determining the aerial extent and hazard of volcanic emissions. Infrasound waveform inversion is a promising technique to quantify volcanic emissions. Although topography may substantially alter the infrasound waveform as it propagates, advances in wave propagation modeling and station coverage permit robust inversion of infrasound data from volcanic explosions. The inversion can estimate eruption mass flow rate and total eruption mass if the flow density is known. However, infrasound-based eruption flow rates and mass estimates have yet to be validated against independent measurements, and numerical modeling has only recently been applied to the inversion technique. Here we present a robust full-waveform acoustic inversion method, and use it to calculate eruption flow rates and masses from 49 explosions from Sakurajima Volcano, Japan. Six infrasound stations deployed from 12-20 February 2015 recorded the explosions. We compute numerical Green's functions using 3-D Finite Difference Time Domain modeling and a high-resolution digital elevation model. The inversion, assuming a simple acoustic monopole source, provides realistic eruption masses and excellent fit to the data for the majority of the explosions. The inversion results are compared to independent eruption masses derived from ground-based ash collection and volcanic gas measurements. Assuming realistic flow densities, our infrasound-derived eruption masses for ash-rich eruptions compare favorably to the ground-based estimates, with agreement ranging from within a factor of two to one order of magnitude. Uncertainties in the time-dependent flow density and acoustic propagation likely contribute to the mismatch between the methods. Our results suggest that realistic and accurate infrasound-based eruption mass and mass flow rate estimates can be computed using the method employed here. If accurate volcanic flow parameters are known, application of

  9. Simulation of pre-eruptive magma migration and accumulation based on hydrokinetic modeling of magma plumbing system beneath Sakurajima Volcano (Japan)

    Science.gov (United States)

    Minami, S.; Iguchi, M.; Mikada, H.; Goto, T.; Takekawa, J.

    2012-12-01

    We numerically simulated a transient magma accumulating process in the magma plumbing system beneath an active Showa crater of Sakurajima Volcano (Japan). Our objective is to find dominant geophysical parameters in the accumulating process before eruption. Geodetic observations showed that a periodic inflation and deflation event had lasted 30 hours before an explosive eruption. Our model consists of shallower gas and deeper magma reservoirs connected by a volcanic conduit as inferred from the past geophysical observations. A pressure difference between the two reservoirs forces the magma to move from the deeper up to the shallower reservoir. We assumed a constant rate of magma supply to the deeper reservoir as an input to the magma plumbing system. In a cylindrical volcanic conduit, a viscous multiphase magma flow is demonstrated by 1-dimentional transient flow simulations with the effects of the relative motion of gas in magma, the exsolution of volatiles in melt, the crystallization of microlites in groundmass, the change in height of magma head, etc. As a result, we found that the radius of the volcanic conduit, the magma supply rate and the compressibility of the deeper reservoir are key parameters to reproduce the observed volumetric variations before the eruption. These three parameters are estimated about 13 m, 3.5 m3/s and 10 GPa, respectively by means of a least squares method. Finally, the inflation and deflation event observed before the eruption are well reproduced. We would like to propose our numerical model as one of quantitative simulation methods that could be applied to the future eruptive events not only at Sakurajima Volcano but for the other volcanoes. Some of parameters of the magma plumbing system need to be fixed as in this study should be discussed in terms of the sensitivity in the analysis at the time of the application.

  10. Multiple-pressure-source model for ground inflation during the period of high explosivity at Sakurajima volcano, Japan - Combination analysis of continuous GNSS, tilt and strain data -

    Science.gov (United States)

    Hotta, Kohei; Iguchi, Masato; Ohkura, Takahiro; Yamamoto, Keigo

    2016-01-01

    We herein propose a three-pressure-source model for ground inflation with highly eruptive activity at the Showa crater of Sakurajima volcano, Japan. We applied a model of stacked spherical sources to continuous combined geodetic data from a global navigation satellite system, tilt and strainmeters. The data were recorded during ground inflation throughout an eruptive episode that began in October 2011 and ended in March 2012. Using a genetic algorithm, we obtained the locations and volumes of three sources. A pressure source analysis of ground inflation during the period from October 2011 to March 2012 revealed inflation sources to be located at a depth of 9.6 km beneath Aira caldera (A-source) and 3.3 km beneath Kita-dake (K-source), and a shallow deflation source is located at a depth of 0.7 km beneath Minami-dake (M-source). The A-source corresponds to the main magma reservoir at a depth of 10 km beneath the Aira caldera inferred by previous geophysical studies. The K-source is a-reservoir of Sakurajima volcano, where magma intrudes from the main magma reservoir beneath the Aira caldera during the first stage of eruptive activity. The M-source is the uppermost part of a conduit from the K-source to the summit and the Showa crater. Magma injection into the A-source started in mid-November 2011, instantly triggering the migration of increased volumes of magma from the A-source to the K-source. Approximately one month later, in mid-December 2011, an increased volume of magma started migrating from the K-source to the M-source and finally erupted at the surface. The accumulation rate for the A-source is comparable to the magma supply rate for the past 100 years (0.8 to 1.6 × 107 m3). The three-pressure-source model was applied to inflation events before the 2011 event in order to reconstruct the magma migration process. Applying our source model to earlier activity phases, we found that injected magma from the A-source remained at the K-source and a small amount of

  11. Observations of electrical discharges during eruptions of Sakurajima volcano

    Science.gov (United States)

    Edens, H. E.; Thomas, R. J.; Behnke, S. A.; McNutt, S. R.; Smith, C. M.; Farrell, A. K.; Van Eaton, A. R.; Cimarelli, C.; Cigala, V.; Michel, C. W.; Miki, D.; Iguchi, M.

    2015-12-01

    In May 2015 a field program was undertaken to study volcanic lightning at the Sakurajima volcano in southern Japan. One of the main goals of the study was to gain a better understanding of small electrical discharges in volcanic eruptions. Prior studies of volcanic lightning have shown that there are several types of electrical discharges that can occur in volcanic eruption clouds. One of these is referred to as continuous RF, which manifests itself as a continual production of VHF emissions that typically last several seconds to a minute during the initial, active phase of an eruption. Its nature and origins are not well understood. Another type of discharge are small, discrete lightning flashes, which start occurring later on within the eruption cloud and are similar to atmospheric lightning. During the 2015 field program we studied the characteristics of continuous RF and discrete flashes during volcanic eruptions of Sakurajima volcano using a comprehensive set of instrumentation. This included a 10-station 3-D Lightning Mapping Array (LMA) that operated in 10 μs high time resolution mode, slow and fast ΔE antennas, a VHF flat-plate antenna operating in the 20-80 MHz band, log-RF waveforms within the 60-66 MHz band, an infra-red video camera, a high-sensitivity Watec video camera, two high-speed video cameras, and still cameras. We present correlated LMA, waveform, photographs and video recordings of continuous RF and discrete volcanic lightning flashes. We discuss the nature of continuous RF and its possible origins, and how it compares to VHF emissions from regular, discrete flashes. We also discuss the polarity of leaders of discrete flashes and the general time evolution of the charge structure in eruption clouds.

  12. The size distribution of 210Po in the atmosphere around Mt. Sakurajima in Kagoshima prefecture, Japan

    International Nuclear Information System (INIS)

    Ashikawa, N.; Matsuoka, N.; Takashima, Y.; Syojo, N.; Imamura, H.; Fujisaki, M.

    1998-01-01

    The concentration and size distribution of 210 Po in particulate matters in the atmosphere were measured around the active volcano, Mt. Sakurajima in Kagoshima prefecture, Japan. The samples were collected eight times at four sampling points for the period from June 1994 to January 1996. The highest concentration of 210 Po was 2940 μBq/m 3 at Akamizu located 2 km away from the crater of Mt. Sakurajima. The 210 Po concentrations decreased with the increase of distance form Mt. Sakurajima. The size distribution curves of 210 Po in the particulate matters showed that 210 Po is usually condensed to fine particles smaller than 2 μm in diameter. In addition, it was suggested that the 210 Po concentration in particulate matters collected at Akamizu was affected by the wind direction over Mt. Sakurajima. (author)

  13. The 1914 Taisho eruption of Sakurajima volcano: stratigraphy and dynamics of the largest explosive event in Japan during the twentieth century

    Science.gov (United States)

    Todde, A.; Cioni, R.; Pistolesi, M.; Geshi, N.; Bonadonna, C.

    2017-10-01

    The 1914 Taisho eruption of Sakurijima volcano was Japan's highest intensity and magnitude eruption of the twentieth century. After a 35-year period of quiescence, the volcano suddenly rewoke a few days before the eruption, when earthquakes began to be felt on Sakurajima Island. The eruption began on January 12, 1914, from two fissures located on opposite sides of the volcano, and was characterized by a complex time evolution and changes in eruptive styles. The eruption began with a subPlinian explosive phase in which two convective columns rose from the two fissures. Both plumes were sustained for at least 2 days. This resulted in deposition of a widely dispersed tephra sequence. After this phase, the eruption evolved to a final, waning phase, shifting toward effusive activity that lasted until April 1914. During the first weeks, effusive activity was also accompanied by ash emission. The complex sequence of events, characterized by contemporaneous explosive and effusive activity, is typical of several recently observed mid-intensity eruptions, such as during the 2011 eruption of Cordón Caulle, Chile. The stratigraphic sequence of the eruptive deposits from the Taisho eruption comprises alternating coarse-to-fine lapilli beds with ash beds dispersed toward the ESE and SE. These deposits can be subdivided into three lapilli-bearing units (Units T1, T2 and T3, which correspond to the subPlinian phase) and one ash-bearing unit (Unit T4, which corresponds to the final ash venting, accompanying the first day/weeks of lava flow activity). Grain size analyses from each unit reveal a marked polymodal distribution generally described by the sum of two or three Gaussian subpopulations. Both the modes and the relative amounts of the coarse subpopulations vary with distance from vent, with those of the fine subpopulation remaining nearly constant. Within the vertical sequence, component analysis shows a progressive increase in lithic fragments, suggesting that conduit

  14. Mechanism of explosive eruption revealed by geophysical observations at the Sakurajima, Suwanosejima and Semeru volcanoes

    Science.gov (United States)

    Iguchi, Masato; Yakiwara, Hiroshi; Tameguri, Takeshi; Hendrasto, Muhamad; Hirabayashi, Jun-ichi

    2008-11-01

    A common sequence of phenomena associated with volcanic explosions is extracted based on seismic and ground deformation observations at 3 active volcanoes in Japan and Indonesia. Macroscopic inflation-related ground deformations are detected prior to individual explosions, while deflations are observed during eruptions. Precursory inflation occurs 5 min to several hours before eruption at the Sakurajima volcano, but just 1-2 min at Suwanosejima and 3-30 min at the Semeru volcano. The sequence commences with minor contraction, which is detected by extensometers 1.5 min before eruption at Sakurajima, as a dilatant first motion of the explosion earthquakes 0.2-0.3 s before surface explosions at Suwanosejima, and as downward tilt 4-5 s prior to eruption at the Semeru volcano. The sequence is detected for explosive eruptions with > 0.1 μrad tilt change at Sakurajima, 90% at Suwanosejima and 75% at Semeru volcanoes. It is inferred that the minor contraction is caused by a volume and pressure decrease due to the release of gas from a pocket at the top of the conduit as the gas pressure exceeds the strength of the confining plug. The subsequent violent expansion may be triggered by sudden outgassing of the water-saturated magma induced by the decrease in confining pressure.

  15. Source Mechanisms of Volcanic Explosion Revealed by Geophysical Observations at Sakurajima, Suwanosejima and Semeru volcanoes

    Science.gov (United States)

    Iguchi, M.; Tameguri, T.; Yakiwara, H.

    2006-12-01

    Source mechanisms of volcanic explosions were investigated from seismic, ground deformation and visual observation data at Sakurajima and Suwanosejima in Japan, and Semeru, East Java, Indonesia. More than 7800 Vulcanian explosions have been repeated at the summit crater of Sakurajima since 1955. In the active period of eruptivity, Strombolian eruptions occurred in the time interval of 3-5 minutes at the summit crater of Suwanosejima. Similarly, explosive eruptions have been repeated in the time interval of 5-50 minutes at Semeru volcano. We installed broadband seismometers and tiltmeters at the volcanoes. The observations indicate two common features of explosive eruptions. At these volcanoes, inflation tilt or upward displacement is detected prior to the explosive eruptions and the inflation tilt or upward displacement turns deflation tilt or downward displacement when explosive eruption occurs at the craters. The inflation precursors appear 5 minutes to several hours, 50-100 seconds and 5 minutes before occurrence of explosions at Sakurajima, Suwanosejima and Semeru volcanoes, respectively. This indicates that volcanic explosions are macroscopically processes of increase in volume and decrease in volume due to ejection of magma. To see more detailed waveforms of explosion earthquakes, the first motions of explosion earthquakes precede the beginning of eruptions at the surface of the craters. This indicates that explosion earthquakes are not initiated by removal of lid of the conduits and that the lid is removed, triggered by the beginning of explosive eruptions. The first motions of explosion earthquakes are generated 1-2 s prior to the surface explosions. Expansion processes proceed at Sakurajima and Semeru volcanoes, and the explosion earthquakes are initiated by contraction process at Suwanosejima.

  16. Pressure Source Model for Ground Inflation during the Periods of High Explosivity at Sakurajima Volcano in Japan - Combination Analysis of GPS, Tilt, and Strain Data -

    Science.gov (United States)

    Hotta, K.; Iguchi, M.; Ohkura, T.; Yamamoto, K.

    2014-12-01

    During frequent vulcanian activity at the Minami-dake crater at Sakurajima during the period of 1974 - 1992, ground subsidence was observed and its pattern was modeled by two deflation sources: located in Aira caldera at a depth of about 10 km, about 6 km north from Minami-dake, and beneath Minami-dake at a depth of about 3 km [Eto, 1989]. Eruptive activities at Showa crater, about 500 m east of Minami-dake, since 2006 increased, accompanying ground inflation in October 2009 - May 2010 (2009 event) in contrast to the Minami-dake period. Similar inflation occurred in October 2011 - March 2012 (2011 event). In this study, we analyzed GPS, tilt and strain data synthetically to obtain pressure sources around Sakurajima during the periods of high explosivity with ground inflation. We applied 3-pressure-source model to the deformation of 2009 and 2011 events. Main inflation source is located beneath Aira caldera at a depth of 9.6 km, similar to previous study. In Sakurajima, inflation pressure source is located beneath Kita-dake 1 km north of Minami-dake at a depth of 3.3 km (K-source), and deflation source is located beneath Minami-dake at a depth of 0.7 km (M-source). We estimated temporal change of volume of K- and M-sources fixing inflation rate of Aira source for 2011 event. Inflation rate of K-source increased in November 2011 and kept at a constant rate until January 2012. Deflation rate of M-source increased at the same time as inflation rate of K-source increased, and kept at a constant rate until March 2012. Amount of volume increase of K-source is nearly 20 times larger than that of volume decrease of M-source. Magma was thought to migrate from Aira source to K-source in November 2011 and continued until January 2012. Due to higher eruptive volume from Showa crater than migration of magma from K-source, M-source deflated slightly from late November 2011 to March 2012.

  17. High-definition and low-noise muography of the Sakurajima volcano with gaseous tracking detectors.

    Science.gov (United States)

    Oláh, László; Tanaka, Hiroyuki K M; Ohminato, Takao; Varga, Dezső

    2018-02-16

    Muography is a novel method to highly resolve the internal structure of active volcanoes by taking advantage of the cosmic muon's strong penetration power. In this paper, we present the first high-definition image in the vicinity of craters of an erupting volcano called Sakurajima, Kyushu, Japan. The muography observation system based on the technique of multi-wire proportional chamber (mMOS) has been operated reliably during the data taking period of 157 days. The mMOS measured precisely the flux of muons up to the thickness of 5,000 meter-water-equivalent. It was shown that high-definition density maps around the Craters A, B and Showa could be determined with a precision of less than 7.5 × 7.5 m 2 which earlier had not yet been achieved. The observed density distribution suggests that the fall back deposits filled the magma pathway and increased their density underneath Craters A and B.

  18. The 2006-2012 deformation at Sakurajima stratovolcano (Japan) detected via spaceborne multisensor SAR Interferometry

    Science.gov (United States)

    Pepe, Susi; Trippanera, Daniele; Casu, Francesco; Tizzani, Pietro; Nobile, Adriano; Aoki, Yosuke; Zoffoli, Simona; Acocella, Valerio; Sansosti, Eugenio

    2013-04-01

    We analyze the evolution of the ground deformation at Sakurajima active stratovolcano located in the Aira caldera (Kagoshima prefecture Japan). This caldera, extending over more than 20 km, has been formed as a consequence of a huge eruption, occurred 22,000 years ago, that caused a magma chamber collapse. The Sakurajima volcano is an andesitic cone formed by more recent activity within the caldera, beginning about 13,000 years ago. Its first historical recorded eruption occurred in 963 AD. Most eruptions are Strombolian and Vulcanian and affect only the summit area. The larger explosive (plinian) eruptions occurred in 1471-1476, 1779-1782 and 1914, each producing 1 - 2 km3 of lava and pyroclastic materials. Explosive eruptions of Vulcanian type, with ash emissions, have occurred intermittently from 1955 to 2002. From 2009 to December 2012, a strong and continuous period of volcanic activity has been recorded mainly at the Showa Crater producing plumes that reached altitudes of 1.8-3.5 km. In order to analyze the active deformation processes of the volcano complex and its surrounding areas, we performed SAR Interferometry (InSAR) techniques by using COSMOSkyMed (X-band) and ALOS (L-band) data. The joint data analysis allowed us to increase the spatial coverage of InSAR measurements., we processed 19 descending and 25 ascending orbit SAR images acquired by ALOS satellite from 2008 to 2011 and 2006 to 2011, respectively; we computed 57 descending and 71 ascending interferograms which were subsequently inverted via SBAS-InSAR algorithm to obtain mean velocity maps and deformation time series. The X-band dataset consists of 20 images acquired only on descending orbits between 2011 and 2012; from this dataset we computed 44 interferograms. The preliminary analysis of the mean deformation velocity reveals the presence of a consistent uplift signal in the North region of the Sakurajima Island that extends also to the North sector of Kagoshima bay. The corresponding

  19. Orographic effects on the transport and deposition of volcanic ash: A case study of Mount Sakurajima, Japan

    Science.gov (United States)

    Poulidis, Alexandros P.; Takemi, Tetsuya; Iguchi, Masato; Renfrew, Ian A.

    2017-09-01

    Volcanic ash is a major atmospheric hazard that has a significant impact on local populations and international aviation. The topography surrounding a volcano affects the transport and deposition of volcanic ash, but these effects have not been studied in depth. Here we investigate orographic impacts on ash transport and deposition in the context of the Sakurajima volcano in Japan, using the chemistry-resolving version of the Weather Research and Forecasting model. Sakurajima is an ideal location for such a study because of the surrounding mountainous topography, frequent eruptions, and comprehensive observing network. At Sakurajima, numerical experiments reveal that across the 2-8ϕ grain size range, the deposition of "medium-sized" ash (3-5ϕ) is most readily affected by orographic flows. The direct effects of resolving fine-scale orographic phenomena are counteracting: mountain-induced atmospheric gravity waves can keep ash afloat, while enhanced downslope winds in the lee of mountains (up to 50% stronger) can force the ash downward. Gravity waves and downslope winds were seen to have an effect along the dispersal path, in the vicinity of both the volcano and other mountains. Depending on the atmospheric conditions, resolving these orographic effects means that ash can be transported higher than the initial injection height (especially for ash finer than 2ϕ), shortly after the eruption (within 20 min) and close to the vent (within the first 10 km), effectively modifying the input plume height used in an ash dispersal model—an effect that should be taken into account when initializing simulations.

  20. Statistical analysis of dispersal and deposition patterns of volcanic emissions from Mt. Sakurajima, Japan

    Science.gov (United States)

    Poulidis, Alexandros P.; Takemi, Tetsuya; Shimizu, Atsushi; Iguchi, Masato; Jenkins, Susanna F.

    2018-04-01

    With the eruption of Eyjafjallajökull (Iceland) in 2010, interest in the transport of volcanic ash after moderate to major eruptions has increased with regards to both the physical and the emergency hazard management aspects. However, there remain significant gaps in the understanding of the long-term behaviour of emissions from volcanoes with long periods of activity. Mt. Sakurajima (Japan) provides us with a rare opportunity to study such activity, due to its eruptive behaviour and dense observation network. In the 6-year period from 2009 to 2015, the volcano was erupting at an almost constant rate introducing approximately 500 kt of ash per month to the atmosphere. The long-term characteristics of the transport and deposition of ash and SO2 in the area surrounding the volcano are studied here using daily surface observations of suspended particulate matter (SPM) and SO2 and monthly ashfall values. Results reveal different dispersal patterns for SO2 and volcanic ash, suggesting volcanic emissions' separation in the long-term. Peak SO2 concentrations at different locations on the volcano vary up to 2 orders of magnitude and decrease steeply with distance. Airborne volcanic ash increases SPM concentrations uniformly across the area surrounding the volcano, with distance from the vent having a secondary effect. During the period studied here, the influence of volcanic emissions was identifiable both in SO2 and SPM concentrations which were, at times, over the recommended exposure limits defined by the Japanese government, European Union and the World Health Organisation. Depositional patterns of volcanic ash exhibit elements of seasonality, consistent with previous studies. Climatological and topographic effects are suspected to impact the deposition of volcanic ash away from the vent: for sampling stations located close to complex topographical elements, sharp changes in the deposition patterns were observed, with ash deposits for neighbouring stations as close as

  1. 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

  2. Volcano interactions and coupling: insights from Japan and the Galapagos

    Science.gov (United States)

    Brothelande, E.; Amelung, F.; Wdowinski, S.; Zhang, Y.

    2017-12-01

    For the purposes of eruption forecast, it is relevant to characterize if and how adjacent volcanoes interact. More and more cases of interactions are suspected, but little is still known about the mechanisms at stake and the consequences of a deforming or an erupting neighboring edifice. In this study, we use geodetic data (GPS and INSAR) to characterize the mutual effects of deformation/eruption of adjacent volcanoes in two different contexts. We study the case of Aira caldera (Kyushu island, southern Japan), associated to the permanently erupting Sakurajima volcano on its border. The caldera exhibits a steady inflation pattern, which changes during the eruption of Shinmoedake (Kirishima volcanoes), located 25 kms apart. Similarly, on Isabela Island (Galapagos), Sierra Negra exhibits a steady inflation pattern during 2008 that appears to be affected by the activity of Cerro Azul, the neighbor volcano located 30 kms apart. We first characterize the change in the deformation pattern in both cases. In order to understand how pressure changes in a magmatic source under a volcanic edifice may influence deformation patterns observed on neighboring volcanoes, we then investigate two possible mechanisms using finite element modeling: stress transfer between superficial magmatic sources, and connection of plumbing systems through a deeper reservoir. We finally explore the consequences of these short-distance volcanic interactions in terms of deformation interpretation, and eruption delaying or triggering.

  3. Variations in Seismic Anisotropy with time on Volcanoes in Kyushu Island, Southern Japan

    Science.gov (United States)

    Savage, M. K.; Ohkura, T.; Umakoshi, K.; Shimizu, H.; Kohno, Y.; Iguchi, M.; Wessel, A.; Mori, J.

    2008-12-01

    Using a newly developed automatic processing technique, we have calculated shear wave splitting on and near three active volcanoes in Kyushu, southern Japan (Aso, Unzen and Sakurajima). Shear wave splitting is considered to be caused by aligned cracks and microcracks. The polarisation of the first arriving phase, φ, gives a measure of the crack orientation, which is expected to align with the maximum principal stress. The delay time dt between the two phases depends upon the crack density and the path length. High quality measurements include the following: a) over 1700 from local events recorded and located near Aso Volcano between 2001 and 2008; b) over 2000 from local events recorded and located near Unzen volcano between 1988 and 1997 (spanning the most active period of seismic activity related to the large eruption in 1991); c) over 600 from regional events originating in the subducting Phillipine Sea plate recorded near Sakurajima volcano between 2003 and 2005, (during which time numerous small eruptions have occcurred, and GPS measurements have been modeled as caused by inflation of a Mogi source and a near-vertical crack). Most of the stations were located in boreholes or tunnels, providing excellent signals. Common features at all three volcanoes are that stations closest to the craters yield the fewest good measurements, and even those tend to give varying results at closely spaced stations. Scattering from the volcanic edifice may be making the S waves difficult to pick, and the local stresses may be varied. Stations on the volcanic flanks give many good measurements. Some stations yield variations in φ and dt that depend upon the earthquake location. But at each volcano, some stations show changes that are better explained by variations in time than in space. Where GPS measurements are available, the variations sometimes but not always correlate with previously-modeled inflation or deflation events. The temporal variations in φ are large, ranging

  4. Pb-210 and Po-210 from active volcanoes in Japan

    International Nuclear Information System (INIS)

    Komura, K.; Uchida, K.; Yamamoto, M.; Ueno, K.

    1991-01-01

    The concentration of Pb-210 and Po-210 in the surface air of volcanic areas is of considerable interest from the viewpoints of geochemistry, geophysics and also health physics, because these nuclides are the useful tracers for the estimation of the residence time or life time of aerosols, and give the significant radiation dose due to inhalation and ingestion through food stuffs. Since the establishment of Low Level Radioactivity Laboratory, Kanazawa University, in 1976, the measurement of environmental radioactivity has been one of the main subjects, and the measurement of Pb-210 and Po-210 in the surface air of Kagoshima was begun in 1987 to estimate the contribution from Volcano Sakurajima. In this study, the measurement of Pb-210 and Po-210 in air borne particles collected with air samplers, volcanic ash and lava of volcano Sakurajima of which the age of eruption is known. Moreover, the Po-210 in the volcanic gas and sulfur sublimate in the samples collected in four active volcanoes in Hokkaido was measured. The experiment and the results are reported. (K.I.)

  5. 14C Dating for the Younger Unzen Volcano, Japan

    Science.gov (United States)

    Xu, S.; Xu, S.; Hoshizumi, H.; Ochiai, Y.; Aoki, H.; Uto, K.

    2001-12-01

    Unzen volcano is situated in a volcanotectonic depression, ~70 km west of the volcanic front of SW Japan. The volcanic products of Unzen volcano cover a wide area with many lava domes, thick lava flows, and pyroclastic deposits of andesite to dacite composition. The composite volcanic edifice can be subdivided into Older and Younger Unzen volcanoes. The Older Unzen volcano (500-200 ka) is thought to be a complex volcanic edifice originally centered near the present Younger Unzen volcano, but it has been displaced by several faults and deeply eroded. The Younger Unzen volcano (soil organic carbon of bulk sample underlying the volcanic eruption products. The 14C dating of the bulk soil organic matter is a polemic subject, mainly due to the complexity of the soil formation and to the variable contamination from several sources. The reliabilty of most 14C dates for buried soils in this study was supported by lack of significant age deviations in double organic extracts of soil (humin and humic acid fractions), agreement of dating results obtained for different materials (buried soil and charcoal), and normal sequence in soil-pyroclastic/lava sections. The 14C results based on surface and USDP borehole materials clarified the initial eruption ages of the Younger Unzen volcano, i.e., Myokendake: 35 ka; Fugendake: 25 ka; and Mayuyama: 4.5 ka BP. In particular, the Fugendake volcano is characterized by the repeated eruptions occurred at 24, 20, 19, 14, 11, 10, 9, 7, 4, 1.6 ka BP and recently AD 1300, 1663, 1792 and 1991 ~95.

  6. Airborne Measurement in the Ash Plume from Mount Sakurajima: Analysis of Gravitational Effects on Dispersion and Fallout

    Directory of Open Access Journals (Sweden)

    Jonas Eliasson

    2014-01-01

    Full Text Available Volcanic ash concentrations in the plume from Sakurajima volcano in Japan are observed from airplanes equipped with optical particle counters and GPS tracking devices. The volcano emits several puffs a day. The puffs are also recorded by the Sakurajima Volcanological Observatory. High concentrations are observed in the puffs and fallout driven by vertical air current, called streak fallout. Puffs dispersion is analyzed by the classical diffusion-advection method and a new gravitational dispersion method. The fluid mechanic of the gravitational dispersion, streak fallout, and classical diffusion-advection theory is described in three separate appendices together with methods to find the time gravitational dispersion constant and the diffusion coefficient from satellite photos. The diffusion-advection equation may be used to scale volcanic eruptions so the same eruption plumes can be scaled to constant flux and wind conditions or two eruptions can be scaled to each other. The dispersion analyses show that dispersion of volcanic plumes does not follow either theories completely. It is most likely diffusion in the interface of the plume and the ambient air, together with gravitational flattening of the plumes core. This means larger boundary concentration gradients and smaller diffusion coefficients than state of the art methods can predict.

  7. Carbon dioxide degassing by advective flow from Usu volcano, Japan.

    Science.gov (United States)

    Hernández, P A; Notsu, K; Salazar, J M; Mori, T; Natale, G; Okada, H; Virgili, G; Shimoike, Y; Sato, M; Pérez, N M

    2001-04-06

    Magmatic carbon dioxide (CO2) degassing has been documented before the 31 March 2000 eruption of Usu volcano, Hokkaido, Japan. Six months before the eruption, an increase in CO2 flux was detected on the summit caldera, from 120 (September 1998) to 340 metric tons per day (September 1999), followed by a sudden decrease to 39 metric tons per day in June 2000, 3 months after the eruption. The change in CO2 flux and seismic observations suggests that before the eruption, advective processes controlled gas migration toward the surface. The decrease in flux after the eruption at the summit caldera could be due to a rapid release of CO2 during the eruption from ascending dacitic dikes spreading away from the magma chamber beneath the caldera.

  8. Continuing deflation by fumaroles at Kuju Volcano, Japan

    Science.gov (United States)

    Nakaboh, M.; Ono, H.; Sako, M.; Sudo, Y.; Hashimoto, T.; Hurst, A. W.

    2003-04-01

    A phreatic eruption occurred at Kuju Volcano in October 1995. We deployed an EDM network around the active craters of the volcano just after the eruption. Slope distances of the survey lines in the northern network have tended to contract, whereas those in the southern one extended. The maximum contraction observed in the northern network was 70 cm over 6 years. A spherical volume decrease just beneath a fumarolic area called Iwoyama 700 m north of the new craters is a plausible model for these changes in slope distances. A noteworthy feature is that over 6 years after the phreatic eruption ended, the deflation rate is still approximately linear. We also estimated the thermal energy discharge by fumaroles in the new craters, which proved to be well correlated with the observed deflation rate. It is strongly suggested that deflation of a geothermal reservoir, not any magmatic effect, causes the ground deformation around Iwoyama.

  9. Detection of a crack-like conduit beneath the active crater at Aso Volcano Japan

    Science.gov (United States)

    Yamamoto, Mare; Kawakatsu, Hitoshi; Kaneshima, Satoshi; Mori, Takehiko; Tsutsui, Tomoki; Sudo, Yasuaki; Morita, Yuichi

    To constrain the source of long period tremors (LPTs), we deployed a very dense broadband seismic network consisting of totally twenty-four stations around the active crater of Aso volcano in Kyushu, Japan. The spatial variation of the observed signal amplitudes reveals that the source of LPTs consists of an isotropic expansion (contraction) and an inflation (deflation) of an inclined tensile crack with a strike almost parallel to the chain of craters. The detected crack has a dimension of 1 km and its center is located a few hundred meters southwest of the active crater, at a depth of about 1.8 km. The extension of the crack plane meets the crater chain including the active fumarole at the surface, suggesting that the crack has played an important role in transporting gasses and/or lava to the craters from below. This work also demonstrates a powerful usage of broadband seismometers as geodetic instruments to constrain subsurface structures at active volcanoes.

  10. Volcanoes

    Science.gov (United States)

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

  11. Volcano geodesy: The search for magma reservoirs and the formation of eruptive vents

    Science.gov (United States)

    Dvorak, J.J.; Dzurisin, D.

    1997-01-01

    Routine geodetic measurements are made at only a few dozen of the world's 600 or so active volcanoes, even though these measurements have proven to be a reliable precursor of eruptions. The pattern and rate of surface displacement reveal the depth and rate of pressure increase within shallow magma reservoirs. This process has been demonstrated clearly at Kilauea and Mauna Loa, Hawaii; Long Valley caldera, California; Campi Flegrei caldera, Italy; Rabaul caldera, Papua New Guinea; and Aira caldera and nearby Sakurajima, Japan. Slower and lesser amounts of surface displacement at Yellowstone caldera, Wyoming, are attributed to changes in a hydrothermal system that overlies a crustal magma body. The vertical and horizontal dimensions of eruptive fissures, as well as the amount of widening, have been determined at Kilauea, Hawaii; Etna, Italy; Tolbachik, Kamchatka; Krafla, Iceland; and Asal-Ghoubbet, Djibouti, the last a segment of the East Africa Rift Zone. Continuously recording instruments, such as tiltmeters, extensometers, and dilatometers, have recorded horizontal and upward growth of eruptive fissures, which grew at rates of hundreds of meters per hour, at Kilauea; Izu-Oshima, Japan; Teishi Knoll seamount, Japan; and Piton de la Fournaise, Re??union Island. In addition, such instruments have recorded the hour or less of slight ground movement that preceded small explosive eruptions at Sakurajima and presumed sudden gas emissions at Galeras, Colombia. The use of satellite geodesy, in particular the Global Positioning System, offers the possibility of revealing changes in surface strain both local to a volcano and over a broad region that includes the volcano.

  12. The “anomalous cedar trees” of Lake Ashi, Hakone Volcano, Japan

    Science.gov (United States)

    Oki, Y.

    1984-01-01

    On the bottom of Lake Ashi at Hakone, Japan, there stand great trees that, since ancient times, have been widely known as the "Anomalous Cedar Trees" of Ashi. It is not known why these trees grow on the bottom of the lake, and it remains one of the mysteries of Hakone. It was formerly thought that, at the time Lake Ashi was born, a great forest of cedar trees which was growing in the caldera of the volcano sank into the water. From radioactive carbon dating techniques, it is known that a steam explosion in the Kami Mountains created the caldera approximately 3,000 years ago. The age of the "Anomalous Cedars" is placed at approximately. 

  13. Coseismic rupturing stopped by Aso volcano during the 2016 Mw 7.1 Kumamoto earthquake, Japan.

    Science.gov (United States)

    Lin, A; Satsukawa, T; Wang, M; Mohammadi Asl, Z; Fueta, R; Nakajima, F

    2016-11-18

    Field investigations and seismic data show that the 16 April 2016 moment magnitude (M w ) 7.1 Kumamoto earthquake produced a ~40-kilometer-long surface rupture zone along the northeast-southwest-striking Hinagu-Futagawa strike-slip fault zone and newly identified faults on the western side of Aso caldera, Kyushu Island, Japan. The coseismic surface ruptures cut Aso caldera, including two volcanic cones inside it, but terminate therein. The data show that northeastward propagation of coseismic rupturing terminated in Aso caldera because of the presence of magma beneath the Aso volcanic cluster. The seismogenic faults of the 2016 Kumamoto earthquake may require reassessment of the volcanic hazard in the vicinity of Aso volcano. Copyright © 2016, American Association for the Advancement of Science.

  14. Resuspension of ash after the 2014 phreatic eruption at Ontake volcano, Japan

    Science.gov (United States)

    Miwa, Takahiro; Nagai, Masashi; Kawaguchi, Ryohei

    2018-02-01

    We determined the resuspension process of an ash deposit after the phreatic eruption of September 27th, 2014 at Ontake volcano, Japan, by analyzing the time series data of particle concentrations obtained using an optical particle counter and the characteristics of an ash sample. The time series of particle concentration was obtained by an optical particle counter installed 11 km from the volcano from September 21st to October 19th, 2014. The time series contains counts of dust particles (ash and soil), pollen, and water drops, and was corrected to calculate the concentration of dust particles based on a polarization factor reflecting the optical anisotropy of particles. The dust concentration was compared with the time series of wind velocity. The dust concentration was high and the correlation coefficient with wind velocity was positive from September 28th to October 2nd. Grain-size analysis of an ash sample confirmed that the ash deposit contains abundant very fine particles (fine particles produced by the phreatic eruption. Histogram of polarization factors of each species experimentally obtained. The N is the number of analyzed particles.

  15. Very-long-period pulses at Asama volcano, central Japan, inferred from dense seismic observations

    Science.gov (United States)

    Maeda, Yuta; Takeo, Minoru

    2011-04-01

    We observed seismic events consisting of several one-sided velocity pulses with durations of 5-30 s (hereafter called very-long-period or VLP pulses) using up to 14 broad-band seismometers installed near the summit area of Asama volcano, Japan. Particle motions do not point to a single source location despite their rectilinearities, suggesting a non-isotropic source mechanism, together with path effect. We conducted moment-tensor inversion analyses for these events using the Green's functions of not only translational motions but also of tilt motions. The best-fitting source locations are located north of the crater centre, at depths of 100-150 m below the crater bottom. The principal value ratios of moment-tensor solutions can be approximated as 5:3:2, which is indicative of a combination of a tensile crack and a cylinder, with the strike and dip angle of the crack both being nearly 70°, and symmetry axis of the cylinder being inclined by nearly 30° from the vertical. The time histories of moment-tensors are indicative of an initial sudden pressurization and subsequent gradual depressurization at the source region. We sought to model VLP pulses at Asama volcano by considering the inflow and outflow of gas at the source cavity, compensated by boiling in another deeper reservoir.

  16. Crustal deformation of Iwojima volcano in Japan detected by SAR interferometry

    Science.gov (United States)

    Yarai, H.; Ozawa, T.; Murakami, M.; Tobita, M.; Nakagawa, H.; Fujiwara, S.

    2002-12-01

    Iwojima volcano is one of the most active volcanoes in Japan. Large-scale crustal deformation is ongoing in the island. It is suggested that the island was uplifted about 40m during the recent 200 years (Kaizuka et al., 1985). The crustal deformations are believed to be of volcanic origin and are outstanding in terms of the magnitude and the complexity. It is important to understand the 3-dimensional evolution of the deformation field with time to understand the behavior of the volcanic sources. Although there are 2 permanent GPS sites in the island, they are not sufficient to monitor the extremely complex spatial and temporal patterns of the deformation. We here use JERS-1 SAR data to map the detailed surface displacement field associated with volcanic activity of the island. We processed up to 20 different pairs spanning 1992 to 1998. It is revealed that the rate of surface deformation was not constant but episodic. We also find that the displacements seem to consist of three different subsets of deformation pattern; i.e., Motoyama (north east of Iwojima), Chidorigahara (near an old crater), and Suribachi-yama mountain (south of Iwojima). The spatial pattern of the first subset is simpler than the others and explainable as an inflation and deflation of a spherical point-source. Source depth inferred from the pattern is smaller than 2 km. However, the rate of volume change is not constant and sometimes even changes the polarity, which suggests the complexity of the volcanic source structure and mechanism.

  17. 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).

  18. Observations of eruption clouds from Sakura-zima volcano, Kyushu, Japan, from Skylab 4

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, J.D.; Heiken, G.; Randerson, D.; McKay, D.S.

    1976-01-01

    Hasselblad and Nikon stereographic photographs taken from Skylab between 9 June 1973 and 1 February 1974 give synoptic plan views of several entire eruption clouds emanating from Sakura-zima volcano in Kagoshima Bay, Kyushu, Japan. Analytical plots of these stereographic pairs, studied in combination with meteorological data, indicate that the eruption clouds did not penetrate the tropopause and thus did not create a stratospheric dust veil of long residence time. A horizontal eddy diffusivity of the order of 10/sup 6/ cm/sup 2/ s/sup -1/ and a vertical eddy diffusivity of the order of 10/sup 5/ cm/sup 2/ s/sup -1/ were calculated from the observed plume dimensions and from available meteorological data. These observations are the first, direct evidence that explosive eruption at an estimated energy level of about 10/sup 18/ ergs per paroxysm may be too small under atmospheric conditions similar to those prevailing over Sakura-zima for volcanic effluents to penetrate low-level tropospheric temperature inversions and, consequently, the tropopause over northern middle latitudes. Maximum elevation of the volcanic clouds was determined to be 3.4 km. The cumulative thermal energy release in the rise of volcanic plumes for 385 observed explosive eruptions was estimated to be 10/sup 20/ to 10/sup 21/ ergs (10/sup 13/ to 10/sup 14/ J), but the entire thermal energy release associated with pyroclastic activity may be of the order of 2.5 x 10/sup 22/ ergs (2.5 x 10/sup 15/ J). Estimation of the kinetic energy component of explosive eruptions via satellite observation and meteorological consideration of eruption clouds is thus useful in volcanology as an alternative technique to confirm the kinetic energy estimates made by ground-based geological and geophysical methods, and to aid in construction of physical models of potential and historical tephra-fallout sectors with implications for volcano-hazard prediction.

  19. Electrical Resistivity Structure and Helium Isotopes around Naruko Volcano, Northeastern Japan and Its Implication for the Distribution of Crustal Magma

    Directory of Open Access Journals (Sweden)

    Koichi Asamori

    2010-01-01

    Full Text Available The two-dimensional electrical resistivity structure beneath Naruko volcano was determined using magnetotelluric soundings. The resulting model shows that a prominent conductor exists through the middle crust to the uppermost mantle beneath the volcano. The location of the conductor agrees closely with a seismic low-velocity zone. Low-frequency microearthquakes occur near the conductor around the Moho depth. The cutoff depth of crustal earthquakes is coincident with the upper boundary of the conductor, implying that the conductor has a temperature appreciably higher than 400∘C. Furthermore, new helium isotope data from hot springs around the volcano were obtained. The spatial distribution of the observed 3He/4He ratios reveals the extent of mantle-derived materials beneath Naruko volcano. Consequently, it is apparent that the conductor determined beneath the volcano reflects the presence of high-temperature mantle-derived materials such as magmas and/or related fluids derived from active magmatism in the northeastern Japan subduction zone.

  20. ASTER-SRTM Perspective of Mount Oyama Volcano, Miyake-Jima Island, Japan

    Science.gov (United States)

    2000-01-01

    Mount Oyama is a 820-meter-high (2,700 feet) volcano on the island of Miyake-Jima, Japan. In late June 2000, a series of earthquakes alerted scientists to possible volcanic activity. On June 27, authorities evacuated 2,600 people, and on July 8 the volcano began erupting and erupted five times over that week. The dark gray blanket covering green vegetation in the image is the ash deposited by prevailing northeasterly winds between July 8 and 17. This island is about 180 kilometers (110 miles) south of Tokyo and is part of the Izu chain of volcanic islands that runs south from the main Japanese island of Honshu. Miyake-Jima is home to 3,800 people. The previous major eruptions of Mount Oyama occurred in 1983 and 1962, when lava flows destroyed hundreds of houses. An earlier eruption in 1940 killed 11 people.This image is a perspective view created by combining image data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) aboard NASA's Terra satellite with an elevation model from the Shuttle Radar Topography Mission (SRTM). Vertical relief is exaggerated, and the image includes cosmetic adjustments to clouds and image color to enhance clarity of terrain features.The ASTER instrument is a cooperative project between NASA, JPL, and the Japanese Ministry of International Trade and Industry.Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National

  1. Increasing of Gas Bubbling at Wariishi Flowing Spring, Central Japan, before and after the 2014 Ontake Volcano Eruption

    Science.gov (United States)

    Kimata, F.; Tasaka, S.; Asai, Y.

    2016-12-01

    Wariishi Spa is locating at Atotsugawa active fault, and it is an flowing spring from the 850m depth by the bore hole. The spring is coming from the rain fall through the geological boundary. Discharge was measured 100L/minute by manual every week in 1977. In 1990, measurement system was updated to 1Hz by electromagnetic flowmeter system. Co-seismic discharge rises are measured for about 100 examples of the earthquake occurrence in around area. The discharge rise is decreasing asymptotic convergence with time. In 2011 Tohoku Earthquake, the discharge of spring is a rise of 30 L/minutes, and it took 1 and half year to return to 20 L/minute. Ontake Volcano is one of the active volcanoes in same mountain range, but it is located about 50 km south from the Wariishi spa. There are three active volcanoes between Wariishi Spa and Ontake Volcano. The volcano was erupted in a phreatic explosion on September 27, 2014. There is no observation of the discharge change at the eruption in the hot spring. There are other hot spring systems in Wariishi spa. The spa has a periodic spring with one to two-hour frequencies. The periodic frequencies are depended on the discharge volume. Therefore, at the co-seismic discharge rise, the shortenings of periodic frequencies are observed. Hence, the mechanism of main discharge and periodic spring is located at the depth of 850 m. Based on discussion on time series of discharge spa, there are observed many pulsed noises between the periodic springs. The noises are caused by gas bubbling from the precise examinations. It is suggested that gas bubbling is different mechanism with periodic spring, because no effects on the periodic spring frequency. Bubbling is sourced from more deep than 850 m. Gas bubbling was observed about 50 times between the periodic spa around the Ontake volcano eruption. There is no report on such gas bubbling rise since 2012. Discussed above, it is suggested some changes of strain field at central Japan, especially in

  2. DInSAR/PSInSAR Observations of Kirishima, Shinmoe-dake Volcano, Japan

    Science.gov (United States)

    Miyagi, Yousuke; Ozawa, Taku; Kozono, Tomofumi; Shimada, Masanobu

    2013-04-01

    Shinmoe-dake in the Kirishima volcano group is located in southwestern part of Japan. In January 2011, eruptive activities started from the Shinmoe-dake crater and resulted in sub-Plinian and Vulcanian eruptions and a rapid accumulation of lava within the crater. GPS and DInSAR data acquired before and after the eruption revealed pre-eruptive inflation, co-eruptive deflation, and post-eruptive inflation centered on 5km west of the crater. The eruption phase ceased by the beginning of September, and the post-eruptive inflation also ceased by November 2011. After the 2011 eruption, monitoring by TerraSAR-X have continued. Surface change and surface deformation on the lava within the crater were detected by high-resolution amplitude images and DInSAR data. Especially, the surface deformation after September 2011 revealed a continual shortening of satellite-ground distance even after the end of the main activity. This LOS shortening means uplifts of the lava surface. We estimated the volume increase of the lava after November 2011, using DInSAR processing of TerraSAR-X data, and concluded that the volume increase still continued in December 2012. The volume change rate has decreased with a small fluctuation as an overall trend. PSInSAR and long-term DInSAR results helped us to know deformation around the crater. They show LOS elongation including a subsidence in the northeast flank of the crater. It is interpreted that the subsidence is caused by a deflation of shallow deformation source located just beneath the crater.

  3. Two electrical conductors beneath Kusatsu-Shirane volcano, Japan, imaged by audiomagnetotellurics, and their implications for the hydrothermal system

    Science.gov (United States)

    Nurhasan; Ogawa, Y.; Ujihara, N.; Tank, S. B.; Honkura, Y.; Onizawa, S.; Mori, T.; Makino, M.

    2006-08-01

    Kusatsu-Shirane volcano, Japan, is known for its active phreatic eruptions. We have investigated its hydrothermal system by conducting audio-magnetotelluric soundings at 22 stations along a profile that extends across the volcano. The final two-dimensional model is characterized by two conductors. One is a 300- to 1000-m-thick conductor of 1-10 Ωm, which is located on the eastern slope and covered with 200-m-thick resistive layers of Kusatsu-Shirane lava and pyroclastics. This conductor indicates the presence of a Montmorillonite-rich layer of Pliocene volcanic rocks that may function both as an impermeable floor for the shallow fluid path from the peak to the hot springs to the east and as an impermeable cap for the deeper fluid path from the summit region to the foot of the volcano. The second conductor is found at a depth of 1-2 km from the surface, at the peak of the volcano, and its resistivity is as low as 1 Ωm or less. This low resistivity can be explained by fluids containing high concentrations of chloride and sulfate which were supplied from the magmatic gases. Micro-earthquakes cluster above this conductor, and the cut-off of the earthquakes corresponds to the top of the conductor. This conductor infers the presence of the fluid reservoir, and the upward release of these fluids from the reservoir through the conduit presumably triggers the micro-earthquakes at the peak area of the volcano. Crustal deformation modeling using GPS and leveling data of the past 10 years revealed that the center of the deflation coincides with the top of the second conductor, indicating that the fluid reservoir itself can be hosting the deformation.

  4. Hydrothermal system beneath the crater of Tarumai volcano, Japan : 3-D resistivity structure revealed using audio-magnetotellurics and induction vector

    OpenAIRE

    Yamaya, Yusuke; Mogi, Toru; Hashimoto, Takeshi; Ichihara, Hiroshi

    2009-01-01

    Audio-magnetotelluric (AMT) measurements were recorded in the crater area of Tarumai volcano, northeastern Japan. This survey brought the specific structures beneath the lava dome of Tarumai volcano, enabling us to interpret the relationship between the subsurface structure and fumarolic activity in the vicinity of a lava dome. Three-dimensional resistivity modeling was performed to achieve this purpose. The measured induction vectors pointed toward the center of the dome, implying the topogr...

  5. Diffuse CO_{2} and ^{222}Rn degassing monitoring of Ontake volcano, Japan

    Science.gov (United States)

    Alonso, Mar; Sagiya, Takeshi; Meneses-Gutiérrez, Ángela; Padrón, Eleazar; Hernández, Pedro A.; Pérez, Nemesio M.; Melián, Gladys; Padilla, Germán D.

    2017-04-01

    Mt. Ontake (3067 m.a.s.l.) is a stratovolcano located in central Honsu and around 100 Km northeast of Nagoya, Japan, with the last eruption occurring on September 27, 2014, killing 57 people, and creating a 7-10 km high ash plume (Kagoshima et. al., 2016). There were no significant earthquakes that might have warned authorities in the lead up to the phreatic eruption, caused by ground water flashing to steam in a hydrothermal explosion. At the time of the eruption there was no operational geochemical surveillance program. In order to contribute to the strengthening of this program, the Disaster Mitigation Research Center of Nagoya University and the Volcanological Institute of Canary Islands started a collaborative program. To do so, an automatic geochemical station was installed at Ontake volcano and a survey of diffuse CO2efflux and other volatiles was carried out at the surface environment of selected areas of the volcano. The station was installed 10.9 km east away from the eruptive vent, where some earthquakes occurred, and consists of a soil radon (Rn) monitor (SARAD RTM-2010-2) able to measure 222Rn and 220Rn activities. Monitoring of radon is an important geochemical tool to forecast earthquakes and volcanic eruptions due to its geochemical properties. Rn ascends from the lower to the upper part of earth's crust mainly through cracks or faults and its transport needs the existence of a naturally occurring flux of a carrier gas. Regarding to the soil gas survey, it was carried out in August 2016 with 183 measurement points performed in an area of 136 km2. Measurements of soil CO2 efflux were carried out following the accumulation chamber method by means of a portable soil CO2 efflux instrument. To estimate the total CO2 output, sequential Gaussian simulation (sGs) was used allowing the interpolation of the measured variable at not-sampled sites and assess the uncertainly of the total diffuse emission of carbon dioxide estimated for the entire studied area

  6. Magma reservoir conditions beneath Tsurumi volcano, SW Japan: Evidence from amphibole thermobarometry and seismicity

    Science.gov (United States)

    Nagasaki, Shiho; Ishibashi, Hidemi; Suwa, Yukiko; Yasuda, Atsushi; Hokanishi, Natsumi; Ohkura, Takahiro; Takemura, Keiji

    2017-05-01

    Calcic amphibole phenocrysts in the Tsurumidake summit (TS) lava, which was produced during the most recent eruption at Tsurumi Volcano (SW Japan) at around 7.5-10.5 ka, have been analyzed to determine the pre-eruptive conditions, such as temperature (T), pressure (P), oxygen fugacity (fO2), SiO2 content (SiO2melt), and FeO*/MgO ratio (FeO*/MgOmelt), of coexisting silicate melts in the magma reservoir beneath the volcano. Although most of the amphibole phenocrysts have been completely decomposed to a fine-grained opaque symplectite, 6% of the grains remain intact. The degree of amphibole breakdown (DAB), defined as the ratio of the area of symplectite to the area of symplectite plus relict amphibole in each phenocryst, varies from 20% to 100%. Compositional zoning was not observed in the amphibole grains, however, two distinct groups of amphibole phenocrysts have been identified based on their chemical compositions: group-I amphiboles, which are relatively Si-poor, and [6]Al-rich, and have a relatively high Mg# [100Mg/(Mg + Fe2 +)]; and group-II amphiboles, which are Si-rich, and [6]Al-poor, and have a relatively low Mg#. Empirical equations for geothermobarometry, oxygen barometry and chemometry that exclusively rely on the amphibole composition were applied to estimate the T-P-fO2-SiO2melt-FeO*/MgOmelt conditions of the silicate melts with which the amphibole crystals equilibrated. The results show that group-I and group-II amphiboles equilibrated with andesitic melts (group-I melts) and dacitic-rhyolitic melts (group-II melts), respectively. The T-P-fO2 conditions of group-I melts were estimated as 374-483 MPa ( 13.9-17.9 km depth), 950 °C, and NNO + 1.3, respectively, and those of group-II melts were 93-242 MPa ( 3.4-9.0 km depth), 824-913 °C, and NNO + 0.6-1.7, respectively. The estimated T-P-fO2-SiO2melt-FeO*/MgOmelt conditions were almost constant for group-I melts, whereas the T, ΔNNO, and FeO*/MgOmelt values of group-II melts decreased with increasing

  7. Crustal deformation and volcanic earthquakes associated with the recent volcanic activity of Iwojima Volcano, Japan

    Science.gov (United States)

    Ueda, H.; Fujita, E.; Tanada, T.

    2013-12-01

    Iwojima is an active volcanic island located within a 10 km wide submarine caldera about 1250 km to the south of Tokyo, Japan. The seismometer and GPS network of National Research Institute for Earth Science and Disaster Prevention (NIED) in Iwojima has observed a repeating island wide uplift more than 1 m associated with large number of volcanic earthquakes every several years. During 2006-2012, we observed more than 20000 volcanic earthquakes and an uplift of about 3 m, and precursory volcanic earthquakes and rapid crustal deformation just before the small submarine eruption near the northern coast of Iwojima in April 2012. In a restless volcano such as Iwojima, it is important issue to distinguish whether rapid crustal deformation and intense earthquake activity lead to an eruption or not. According to a long period geodetic observation by Ukawa et al. (2006), the crustal deformation of Iwojima can be classify into 2 phases. The first is an island wide large uplift centering on Motoyama area (the eastern part of the island, the center of the caldera), and the second is contraction and subsidence at local area centering on Motoyama and uplift around that area. They are interpreted by superposition of crustal deformations by a shallow contraction source and a deep seated inflation source beneath Motoyama. The earthquake activity of Iwojima highly correlates with the island wide large uplift, suggesting the earthquakes are almost controlled by a magma accumulation into a deep seated magma chamber. In contrast to the activity, the precursory activity of the eruption in 2012 is deviated from the correlation. The rapid crustal deformation just before and after the eruption in 2012 can be interpreted by rapid inflation and deflation of a shallow sill source about 1km deep, respectively, suggesting that it was caused by a shallow hydrothermal activity. The result shows that we can probably distinguish an abnormal activity related with a volcanic eruption when we observe

  8. Source process of very long period seismic events associated with the 1998 activity of Iwate Volcano, northeastern Japan

    Science.gov (United States)

    Nishimura, Takeshi; Nakamichi, Haruhisa; Tanaka, Satoru; Sato, Minemori; Kobayashi, Tomokatsu; Ueki, Sadato; Hamaguchi, Hiroyuki; Ohtake, Masakazu; Sato, Haruo

    2000-08-01

    We observed very long period seismic events that are associated with the 1998 activity of Iwate Volcano, northeast Japan. The events show a dominant period of 10 s and duration of 30-60 s, often with accompanying short-period waves at the beginning and at the end of the long-period signals. By analyzing the broadband seismograms we find that the source elongates in the east-west direction for ˜4 km at a depth of 2 km beneath the western part of Iwate Volcano. Results of moment tensor inversions show a source mechanism of mutual deflation and inflation of two chambers located at the western and eastern edges of the source region. The source region coincides with the low seismic velocity zone detected by seismic tomography and is very close to the locations of pressure sources estimated from crustal deformation data. On the basis of these results we infer that the very long period seismic events are generated by transportation and movement of magmatic fluid (hot water and/or magma) in a shallow part of the volcano. We further present a simple source model of very long period seismic events based on one-dimensional flow dynamics and propose a new parameter to characterize the size of very long period event: the energy flow rate, which is obtained by dividing the seismic moment by the dominant period. The energy flow rate was estimated as 3.1×1012 J/s for the event on July 29, 1998.

  9. Causes leading to enhancements in sulfur dioxide concentration observed by MAX-DOAS in Kyusyu, Japan

    Science.gov (United States)

    Okuzaki, T.; Irie, H.

    2017-12-01

    We performed continuous observations of sulfur dioxide (SO2) using the Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) at Kasuga in Kyushu, Japan. Spectra measured at 310-320 nm were analyzed with the DOAS method to retrieve mean SO2 concentrations for a 0-1 km layer with a horizontal scale of about 10 km. This spatial scale is expected to provide useful inputs for data assimilation. First, we focused on data acquired in July-August 2014. In the period, seven days were identified as the SO2 level was high (>5 ppbv). Back trajectory analysis indicates that there were two categories; the one from a volcanic origin (the Aso volcano and the Sakurajima volcano) and the other from a continental origin (China and Korea). Based on these results, we performed quantitative analysis using data obtained from January 2014 to December 2016. The mean and the median of the daily maximum SO2 concentrations in the period were 3.3 and 2.1 ppbv, respectively. We investigated the dependence of the observed SO2 level on the size of the range to judge whether the observed air masses passed over volcanoes and found that the higher SO2 concentrations were observed in air masses that passed closer to volcanoes. The mean of the daily maximum SO2 values affected by the Aso volcano was about 6 ppbv, which is larger than that for the Sakurajima volcano (4 ppbv), suggesting that the influence of the Aso volcano was larger. To consider the continental effect, we analyzed relations between SO2 and the length of residence time over China or Korea and between SO2 and the time required for reaching Kasuga from China or Korea. However, no significant correlation was observed. In this case, the mean of the daily maximum SO2 values was about 2.4 ppbv. The results were unchanged even if only influences of urban areas in China or Korea were considered. These results suggest that the impact of long-range transport of air pollution from China or Korea on enhancements in SO2 concentration

  10. Seismic anisotropy and its time variation on active volcanoes

    Science.gov (United States)

    Savage, M. K.; Ohkura, T.; Umakoshi, K.; Shimizu, H.; Iguchi, M.; Johnson, J. H.; Ohminato, T.; Roman, D. C.

    2009-12-01

    Seismic anisotropy, the directional dependence of wave speeds, is caused by stress-oriented cracks and can be used to monitor stresses from magmatic movement. Shear wave splitting fast polarisations (Φ) align with cracks and hence with the compressive stress field. Delay times (dt) measure the density of cracks. Time variations in both Φ and dt on volcanoes have been reported by ourselves and other workers. Here we report results from a new objective automatic technique, developed on Ruapehu, New Zealand and Asama, Japan. We also applied it to Okmok; Soufrière Hills; Aso; Unzen and Sakurajima. Thousands of measurements made on each volcano allow us to determine correlations with other volcano monitoring techniques. We examine volcano-tectonic earthquakes local to each volcano and more distant regional earthquakes. Seismic waves from local earthquakes travel solely through the volcano, so that anisotropy in the mantle or lower crustal mineral alignment will not affect the measurements, but care must be taken because earthquake locations and hence ray paths may change due to magma movement. Spatial changes are thus difficult to disentangle from temporal changes. We analyse families of earthquakes with near-identical waveforms to try to overcome this limitation. Deep regional earthquakes occur mostly in subducted plates and their paths are affected by mantle and lower crustal mineral anisotropy as well as by crustal stress. They are also affected by laterally varying properties, but earthquakes far removed from the volcano should not have systematic variations in location that are correlated with magma movement. Therefore, changes in measurements from regional events that correlate with magma movement can be interpreted as temporal rather than spatial variations. Common features at all volcanoes are that stations closest to the craters yield the fewest good measurements, and even those tend to give varying results at closely spaced stations. Scattering from the

  11. Audio-frequency magnetotelluric, and total magnetic intensity observations in 2014-2016, at Zao volcano, NE Japan

    Science.gov (United States)

    Ichiki, M.; Moriyama, T.; Kaida, T.; Kanda, W.; Demachi, T.; Hirahara, S.; Miura, S.; Nakayama, T.; Ogawa, Y.; Seki, K.; Akutagawa, M.; Ushioda, M.; Kobayashi, T.; Uyeshima, M.; Yamamoto, M.; Matsu'ura, S.; Omori, S.; Ono, K.; Seki, S.

    2017-12-01

    Zao volcano is situated at a distance of about 40 km SW from Sendai in NE Japan. There exists the crater lake, Okama, with about 360 m diameter and about 30 m depth, in the summit area. The seismicity of the low frequency earthquakes deeper than 20 km depth beneath Zao volcano has turned active since middle of 2012. We have also observed shallow (˜5 km) volcanic earthquakes beneath Zao volcano in 2013 to 2017. In the historical records, fumaroles, degassing and phreato-magmatic eruptions occurred close to Okama in 1867 to 1943. Since 1940, fumaroles have observed in about 1 to 1.5 km NE of Okama. Subsurface hydrotherm distribution and geotherm variation are the key feature to forecast future phreatic or phreato-magmatic eruption. In this presentation, we report electrical resistivity distribution and demagnetized region beneath Zao volcano.We observed total magnetic intensity variation of a demagnetized spatial pattern between June and October in 2014. To model a demagnetized region, we carried out a global optimized inversion of grid search assuming ellipsoidal shape and 5 A/m demagnetization intensity. The estimated demagnetized body located in 800 m northeastern side of the center of Okama, and the top surface is 330 m depth. The principal axis length is 500, 425, 190 m, respectively. The demagnetized region locates at the middle points between the recent fumarole region and Okama.AMT data were acquired at 24 sites in the area of 2 km by 2 km. The observation sites do not cover over the demagnetized region described above. We obtained the AMT response of 10 kHz to 0.1 Hz and calculated a 3-D electrical conductivity model beneath around Okama. The conductor (1-30 Ohm-m) is embedded in 200-600 m depth beneath Okama and the lateral dimension is up to 400 m. The conductor is isolated and neither expands in deeper parts nor tends to elongate to the demagnetized region. We interpret the conductor as a hydrothermal alteration zone of the past volcanic activities

  12. Pre-eruptive and co-eruptive deformation of Kirishima volcano, Japan with deep and shallow sources modeling constrained from InSAR and GPS data

    Science.gov (United States)

    Zhang, Y.; Amelug, F.; Albino, F.; Aoki, Y.

    2015-12-01

    Kirishima volcano group is located on the southern part of Kyushu, Japan. Prior to its 2011 magmatic eruption, several phreatic eruptions occurred on August 2008 and March, April, May, June and July 2010. Using time series InSAR from 2007-2011 ALOS PALSAR data, we found a small deflating area around Shinmoe-dake volcano summit and a relatively large inflating area on the northwest of Shinmoe-dake volcano, before 2011 Kirishima, Shinmoe-dake eruption. Modeling constrained from both InSAR and dense regional GPS network data revealed deep and shallow deformation sources for Kirishima volcano. This double sources system would help us better understand the complex process of volcanic deformation.

  13. Tilt change recorded by broadband seismometer prior to small phreatic explosion of Meakan-dake volcano, Hokkaido, Japan

    Science.gov (United States)

    Aoyama, Hiroshi; Oshima, Hiromitsu

    2008-03-01

    We discovered an anomalous very long period (VLP) signal (duration: about 60 s) in the broadband seismic record of the precursory swarm of a small phreatic explosion at the Meakan-dake volcano, Hokkaido, Japan, in 2006; this signal was masked by a short-period tremor in the original velocity waveform, but a considerable DC step appeared in the displacement trace. Since such a step results from a tilt change, we interpreted the observed trace as being a combination of rotational (tilt) and translational (displacement) motions. The apparent displacement step in the VLP signal indicates subsidence of the summit crater. Owing to limited data, we attempted deflating the Mogi source and simulating the seismic record including both motions. When only rotational motion is considered, the simulated waveform explains well the general features of the observed trace. However, the combined trace has incompatible phases, suggesting that a more complicated source process should be considered.

  14. Uplift in the earthquake swarm area of Ontake Volcano, central Japan detected by precise leveling in 2002-2005

    Science.gov (United States)

    Kimata, F.; Miyajima, R.; Murase, M.; Ohta, Y.; Kashiwagi, M.; Ohzono, M.; Kariya, S.; Yamamuro, T.

    2005-12-01

    Earthquake swarm is repeated on the eastern submountain region of Ontake Volcano, Central Japan for 25 years since late 1970s. Ontake Volcano erupted at the summit in 1979, earthquake M6.8 occurred in 1984. However maximum magnitude of the earthquake swarm is limited to M4. We start the precise leveling to detect the vertical movements in the swarm area in 1999 and repeated the leveling every year. As a result of the precise leveling, uplift of few mm is observed. We extend the leveling route to cross the swarm in 2002 and 2004. From the leveling in 2005, we detect the uplift of 5 mm extending circle of 5 km in the just most active segment area of the swarm. Up lift amounts to 10 mm for three years since 2002. It is significant uplift exceeding of the survey error of +- 2.5 mm. One spherical pressure source is estimated at a depth of 3-4 km from the ground surface (2-3 km below sea level) using Mogi solution. Low risibility zone is estimated from AMT observation (Kasaya et al., 2004) and active gas blow of CO2 is observed in the area (Azuma et al., 2004). These observation and uplift ground deformation from our leveling suggest a hydrothermal injection. Vertical deformation is one of important monitor of the earthquake swarm activity.

  15. Understanding volcanic geomorphology from derivatives and wavelet analysis: A case study at Miyakejima Volcano, Izu Islands, Japan

    Science.gov (United States)

    Gomez, C.

    2018-04-01

    From feature recognition to multiscale analysis, the human brain does this computation almost instantaneously, but reproducing this process for effective computation is still a challenge. Although it is a growing field in computational geomorphology, there has been only limited investigation of those issues on volcanoes. For the present study, we investigated Miyakejima, a volcanic island in the Izu archipelago, located 200 km south of Tokyo City (Japan). The island has experienced numerous Quaternary and historical eruptions, which have been recorded in details and therefore provide a solid foundation to experiment remote-sensing methods and compare the results to existing data. In the present study, the author examines the use of DEM derivatives and wavelet decomposition 5 m DEM available from the Geographic Authority of Japan was used. It was pre-processed to generate grid data with QGIS. The data was then analyzed with remote sensing techniques and wavelet analysis in ENVI and Matlab. Results have shown that the combination of 'Elevation' with 'Local Data Range Variation' and 'Relief Mapping' as a RGB image composite provides a powerful visual interpretation tool, but the feature separation remains a subjective analysis provided a more appropriate dataset for computer-based analysis and information extraction and understanding of topographic features at different scales. In order to confirm the usefulness of these topographic derivatives, the results were compared to known geological features and it was found to be in accordance with the data provided by geological, topographic maps and field research at Miyakejima. The protocol presented in the discussion can therefore be re-used at other volcanoes worldwide where less information is available on past-eruption and geology, in order to explain the volcanic geomorphology.

  16. Thermoluminescence age determination of Mt. Fuji lava dome, Takahara volcano, North Kanto, Central Japan

    International Nuclear Information System (INIS)

    Takashima, Isao

    1999-01-01

    Mt. Fuji lava dome thought to be formed by recent action of Takahara volcano, is reported to be due to eruption at the Holocene epoch age on 1,000 or 6,500 years ago. However, on either of them the lava dome did not directly conduct its age measurement, and its age is obtained indirectly from eruption age of tephra estimated to be same age. Recently, precision thermo-luminescence (TL) method is improved and upgraded, by using which formulation of the Mayu-yama in the Unzen volcano was cleared to be about 4,000 years ago which corresponded to be very young. In this paper, by using the TL method for lava dome racks, it was attempted to remove uncertainty forming an indirect age estimation shown as previously. As a result, adopted samples showed 6.5 to 7.4 ka in age value, which showed a good agreement under considering of error. This result was older than 1,000 and some years, and was younger than 20,000 to 25,000 years, which showed a good agreement with 6,500 years ago, obtained by combining closed layer order survey and 14-C age. It is thought to be an important contribution in future forecasting of volcano eruption that the last period action of the Takahara volcano must be at the Holocene epoch age. And, as limited to a quartz containing sample, this can be said to show priority of TL method for a method to directly obtain age of younger dome rock than 10,000 years. (G.K.)

  17. Thermal structure of the yakedake volcano, Japan: Karukaya and Takara geothermal areas

    Science.gov (United States)

    Iriyama, Jun

    1981-07-01

    The hydrothermal water balance and the thermal structure of Yakedake volcano and its vicinity are considered quantitatively. The hydrothermal activity is intense in the valleys at the western foot of the volcano and the Nakanoyu area. The total hot water flow from the discharge area amounts to 2.07 × 10 41/min , about 60% of which discharges from the Shinhodaka area alone. There are some large basins (Abodaira and others) in which the rocks are mainly tuff breccia and volcanic products showing very high permeability for water. The total area of the water recharge zone amounts to 18.2 × 10 6m 3. A model for the hydrothermal system within Yakedake volcano is proposed and from the results of boreholes, the thermal and geological structures of the Karukaya and Takara geothermal areas are also presented. Attempts were also made to estimate the subsurface temperature distribution from the observed near-surface ground temperatures. Results of three-dimensional conduction model calculations indicate that the subsurface temperatures are high in the central part of the crater and in the areas with self-flowing springs along the rivers. The obtained isotherms encircle the volcanic center of Yakedake.

  18. Thermal structure of the Yakedake Volcano, Japan: Karukaya and Takara geothermal areas

    Energy Technology Data Exchange (ETDEWEB)

    Iriyama, J.

    1981-07-01

    The hydrothermal water balance and the thermal structure of Yakedake volcano and its vicinity are considered quantitatively. The hydrothermal activity is intense in the valleys at the western foot of the volcano and the Nakanoyu area. The total hot water flow from the discharge area amounts to 2.07 x 10/sup 4/ l/min, about 60% of which discharges from the Shinhodaka area alone. There are some large basins (Abodaira and others) in which the rocks are mainly tuff breccia and volcanic products showing very high permeability for water. The total area of the water recharge zone amounts to 18.2 x 10/sup 6/m/sup 3/. A model for the hydrothermal system within Yakedake volcano is proposed and from the results of boreholes, the thermal and geological structures of the Karukaya and Takara geothermal areas are also presented. Attempts were also made to estimate the subsurface temperature distribution from the observed near-surface ground temperatures. Results of three-dimensional conduction model calculations indicate that the subsurface temperatures are high in the central part of the crater and in the areas with self-flowing springs along the rivers. The obtained isotherms encircle the volcanic center of Yakedake.

  19. A 3D visualization of spatial relationship between geological structure and groundwater chemical profile around Iwate volcano, Japan: based on the ARCGIS 3D Analyst

    Science.gov (United States)

    Shibahara, A.; Ohwada, M.; Itoh, J.; Kazahaya, K.; Tsukamoto, H.; Takahashi, M.; Morikawa, N.; Takahashi, H.; Yasuhara, M.; Inamura, A.; Oyama, Y.

    2009-12-01

    We established 3D geological and hydrological model around Iwate volcano to visualize 3D relationships between subsurface structure and groundwater profile. Iwate volcano is a typical polygenetic volcano located in NE Japan, and its body is composed of two stratovolcanoes which have experienced sector collapses several times. Because of this complex structure, groundwater flow around Iwate volcano is strongly restricted by subsurface construction. For example, Kazahaya and Yasuhara (1999) clarified that shallow groundwater in north and east flanks of Iwate volcano are recharged at the mountaintop, and these flow systems are restricted in north and east area because of the structure of younger volcanic body collapse. In addition, Ohwada et al. (2006) found that these shallow groundwater in north and east flanks have relatively high concentration of major chemical components and high 3He/4He ratios. In this study, we succeeded to visualize the spatial relationship between subsurface structure and chemical profile of shallow and deep groundwater system using 3D model on the GIS. In the study region, a number of geological and hydrological datasets, such as boring log data and groundwater chemical profile, were reported. All these paper data are digitized and converted to meshed data on the GIS, and plotted in the three dimensional space to visualize spatial distribution. We also inputted digital elevation model (DEM) around Iwate volcano issued by the Geographical Survey Institute of Japan, and digital geological maps issued by Geological Survey of Japan, AIST. All 3D models are converted into VRML format, and can be used as a versatile dataset on personal computer.

  20. Budget of shallow magma plumbing system at Asama Volcano, Japan, revealed by ground deformation and volcanic gas studies

    Science.gov (United States)

    Kazahaya, Ryunosuke; Aoki, Yosuke; Shinohara, Hiroshi

    2015-05-01

    Multiple cycles of the intensive volcanic gas discharge and ground deformation (inflation and deflation) were observed at Asama Volcano, Japan, from 2000 to 2011. Magma budget of the shallow magma plumbing system was estimated on the basis of the volcanic gas emission rates and ground deformation data. Recent inflations observed in 2004 and 2008 were modeled as a dike intrusion to 2-3 km west of Asama Volcano. Previous studies proposed that magma ascends from a midcrustal magma reservoir to the dike and reaches the surface via a sinuous conduit which connects the dike to the summit. The intensive volcanic sulfur dioxide discharge of up to 4600 t/d at the volcano was modeled by magma convective degassing through this magma pathway. The volcano deflates as shrinkage of the magma in a reservoir by volcanic gas discharge. We estimated the volume change of the dike modeled based on the GPS observations, the volume decrease of the magma by the volcanic gas discharge, and the amount of degassed magma produced to calculate the magma budget. The results show that the volume decrease of the magma by the volcanic gas discharge was larger than the volume change of the dike during the inflation periods. This indicates that a significant volume of magma at least more than 2 times larger than the volume change of the dike was supplied from the midcrustal magma reservoir to the dike. The volume decrease of the dike was comparable with the volume decrease of the magma by the volcanic gas discharge during the deflation periods. The long-term deflation trend of the dike and the volume of degassed magma (108-9 m3) suggest that the degassed magma produced is not stored in the dike and the magma is mainly supplied from the midcrustal magma reservoir. In both periods, the volume of degassed magma produced was 1 order of magnitude larger than the volume change of the dike. This indicates that the actual volume of the magma supplied from the midcrustal magma reservoir is up to 1 order of

  1. Chemical and isotopic composition of fumarolic gases at Iwate volcano, Japan, during and after seismic activity in 1998: implications for the modification of ascending volcanic gases

    Directory of Open Access Journals (Sweden)

    Noritoshi Morikawa

    2011-06-01

    Full Text Available In 1998, there were many volcanic earthquakes recorded at Iwate volcano, Japan. Although an eruption was anticipated, it never occurred. Fumarolic gases were sampled at the volcano on six occasions during 1998 and 1999, and were analyzed for their chemical compositions and isotope ratios. The fumarolic gases were again sampled in 2004 and 2006, after the period of seismic activity. The HCl concentrations and isotope ratios of the H2O in the gas samples collected from an active geothermal area at the volcano were high in 1998 and 1999, but decreased significantly after 2004, irrespective of the relatively stable concentrations of CO2 and sulfur-bearing gases. A notable feature of the fumarolic gases is the high isotope ratio of H2O, similar to that of pure magmatic gas, which is typical of andesitic volcanoes, although the temperature at the outlet was less than 146°C in the present case. These features can be explained if the enthalpy of the magmatic gas was equivalent to that of water vapor at 252°C to 370°C under a pressure of 1 bar. The correlations observed among CO2/H2O and HCl/H2O, and the δ18O values of the fumarolic gases suggest partial condensation of H2O vapor during the ascent of the volcanic gas to the surface. The estimated CO2/H2O molar ratio of the magmatic gas was 0.008, which is less than the 0.03 reported previously for magmatic gas sampled during an effusive eruption at Unzen volcano, Japan. These data suggest that the magma at Iwate volcano is depleted in volatiles, because CO2 is preferentially degassed from the silicate melt relative to H2O. Such depletion in CO2 might explain the failed eruption at Iwate volcano in 1998.

  2. Effects of subvolcanic hydrothermal systems on edifice collapses and phreatic eruptions at Tokachidake volcano, Japan

    Science.gov (United States)

    Takahashi, Ryo; Yahata, Masahiro

    2018-02-01

    Subvolcanic hydrothermal alteration often leads to volcanic hazards, such as edifice collapse and phreatic eruption. The 1926 eruption of Tokachidake volcano caused a pyroclastic cone to collapse, and phreatic eruptions have occurred repeatedly. Here, we investigate the hydrothermal system of Tokachidake volcano by examining the characteristics of hydrothermally altered rocks and discuss the effects of the hydrothermal system on volcanic hazards. Beneath the crater area, the dense Tairagadake lavas (Ta lava) at the basement of Tokachidake volcano form piles that are >500 m thick. The Ta lava constrains the flows of volcanic gases and thermal water in the subsurface, and strong hydrothermal alteration occurs in both the underlying and overlying deposits that are more permeable. Above the Ta lava, Tokachidake ejecta are altered in low-temperature acidic environments (gas influx to that water produces sulfuric, acidic thermal water. This acidic mixture weakened the edifice rocks at the boundary with the Tokachidake ejecta. This weakened zone acted as a slip surface in the 1926 eruption. Beneath the Ta lava, a hydrothermal alteration zone with an alunite + kaolinite + pyrophyllite + quartz assemblage formed within the large-scale pyroclastic flow deposits. The alunite in this zone has a high-δ34S value (up to 19.7‰). Thus, we can conclude that the permeation and subsequent condensation of magmatic vapor selectively occurred in the permeable pyroclastic flow deposits, and that condensed vapors produced a high-temperature magmatic-hydrothermal environment (200-300 °C). Phreatic eruptions were rooted in this zone, and thermal water was released from the uppermost part of this zone associated with the 1926 edifice collapse.

  3. Preparatory process preceding the 2014 eruption of Mount Ontake volcano, Japan: insights from precise leveling measurements

    Science.gov (United States)

    Murase, Masayuki; Kimata, Fumiaki; Yamanaka, Yoshiko; Horikawa, Shinichiro; Matsuhiro, Kenjiro; Matsushima, Takeshi; Mori, Hitoshi; Ohkura, Takahiro; Yoshikawa, Shin; Miyajima, Rikio; Inoue, Hiroyuki; Mishima, Taketoshi; Sonoda, Tadaomi; Uchida, Kazunari; Yamamoto, Keigo; Nakamichi, Harushisa

    2016-01-01

    Preparatory activity preceding the 2014 eruption of Mount Ontake volcano was estimated from vertical deformation detected using a precise leveling survey. Notable uplift (2006-2009) and subsidence (2009-2014) were detected on the eastern flank of the volcano. We estimated pressure source models based on the vertical deformation and used these to infer preparatory process preceding the 2014 eruption. Our results suggest that the subsidence experienced between 2009 and 2014 (including the period of the 2014 eruption) occurred as a result of a sill-like tensile crack with a depth of 2.5 km. This tensile crack might inflate prior to the eruption and deflate during the 2014 activity. A two-tensile-crack model was used to explain uplift from 2006 to 2009. The geometry of the shallow crack was assumed to be the same as the sill-like tensile crack. The deep crack was estimated to be 2 km in length, 4.5 km in width, and 3 km in depth. Distinct uplifts began on the volcano flanks in 2006 and were followed by seismic activities and a small phreatic eruption in 2007. From the partially surveyed leveling data in August 2013, uplift might continue until August 2013 without seismic activity in the summit area. Based on the uplift from 2006 to 2013, magma ascended rapidly beneath the summit area in December 2006, and deep and shallow tensile cracks were expanded between 2006 and 2013. The presence of expanded cracks between 2007 and 2013 has not been inferred by previous studies. A phreatic eruption occurred on 27 September 2014, and, following this activity, the shallow crack may have deflated.

  4. Tephra Fallout Hazard Assessment for VEI5 Plinian Eruption at Kuju Volcano, Japan, Using TEPHRA2

    Science.gov (United States)

    Tsuji, Tomohiro; Ikeda, Michiharu; Kishimoto, Hiroshi; Fujita, Koji; Nishizaka, Naoki; Onishi, Kozo

    2017-06-01

    Tephra fallout has a potential impact on engineered structures and systems at nuclear power plants. We provide the first report estimating potential accumulations of tephra fallout as big as VEI5 eruption from Kuju Volcano and calculated hazard curves at the Ikata Power Plant, using the TEPHRA2 computer program. We reconstructed the eruptive parameters of Kj-P1 tephra fallout deposit based on geological survey and literature review. A series of parameter studies were carried out to determine the best values of empirical parameters, such as diffusion coefficient and the fall time threshold. Based on such a reconstruction, we represent probabilistic analyses which assess the variation in meteorological condition, using wind profiles extracted from a 22 year long wind dataset. The obtained hazard curves and probability maps of tephra fallout associated to a Plinian eruption were used to discuss the exceeding probability at the site and the implications of such a severe eruption scenario.

  5. Magma discharge variations during the 2011 eruptions of Shinmoe-dake volcano, Japan, revealed by geodetic and satellite observations

    Science.gov (United States)

    Kozono, Tomofumi; Ueda, Hideki; Ozawa, Taku; Koyaguchi, Takehiro; Fujita, Eisuke; Tomiya, Akihiko; Suzuki, Yujiro J.

    2013-03-01

    We present precise geodetic and satellite observation-based estimations of the erupted volume and discharge rate of magma during the 2011 eruptions of Kirishima-Shinmoe-dake volcano, Japan. During these events, the type and intensity of eruption drastically changed within a week, with three major sub-Plinian eruptions on January 26 and 27, and a continuous lava extrusion from January 29 to 31. In response to each eruptive event, borehole-type tiltmeters detected deflation of a magma chamber caused by migration of magma to the surface. These measurements enabled us to estimate the geodetic volume change in the magma chamber caused by each eruptive event. Erupted volumes and discharge rates were constrained during lava extrusion using synthetic aperture radar satellite imaging of lava accumulation inside the summit crater. Combining the geodetic volume change and the volume of lava extrusion enabled the determination of the erupted volume and discharge rate during each sub-Plinian event. These precise estimates provide important information about magma storage conditions in magma chambers and eruption column dynamics, and indicate that the Shinmoe-dake eruptions occurred in a critical state between explosive and effusive eruption.

  6. Continuous Existence and Evolution of a Magma Chamber Beneath Usu Volcano, Japan: Evidence From Phenocryst Compositions and Textures

    Science.gov (United States)

    Tomiya, A.

    2006-12-01

    A long-lived magma chamber is often postulated beneath a volcano. The continuous existence of the same magma chamber is very difficult to prove, however. There could be a short-lived magma chamber that repeated solidification and remelting. Here, we show evidence of continuous existence of a silicic magma chamber beneath Usu volcano, which is one of the most active volcanoes in Japan. We investigated systematic petrological and petrographic analysis (e.g., Tomiya &Takahashi, 2005: J.Petrol.) of a series of eruptive products (1663, 1769, 1822, 1853, 1943, 1977 and 2000 A.D. eruptions; rhyolite ~ dacite), and revealed the followings: all these products contain similar types of plagioclase and orthopyroxene phenocrysts that consist of a homogeneous core with uniform composition and a zoned mantle; the texture of these phenocrysts changes systematically, showing progressive crystal growth, dissolution and diffusion; the compositions of these phenocrysts vary regularly with time, as well as the bulk-rock compositions. These observations demonstrate the continuous existence of the magma chamber since 1663. Magma Mixing and Evolution of the Magma Chamber. The change of magmatic conditions with time is clearly shown by magnetite composition because magnetite has large diffusion coefficients and should represent magmatic conditions immediately before the eruption. Most pumices from Usu volcano contain two types of magnetite phenocryst, and this means that two magmas mixed shortly before each eruption. There are three combinations of the end-members: (i) rhyolite + basaltic andesite (1663); (ii) dacite ± rhyolite (1769, 1822, 1853); (iii) dacite ± dacite (1977, 2000). Corresponding to these combinations, textures of the rocks are also classified into three categories: (i) nearly aphyric with homogeneous phenocrysts; (ii) porphyritic with inhomogeneous phenocrysts; (iii) nearly aphyric with inhomogeneous phenocrysts. This textural change is quantitatively shown by our CSD

  7. Recent uplift of Iwo-yama volcano, Kirishima Volcanic Complex, southwest Japan, derived from ALOS-2 images

    Science.gov (United States)

    Aoki, Yosuke; Arai, Hiroki

    2017-04-01

    Phreatic eruptions are usually smaller than magmatic eruptions, but they are sometimes a source of major hazards if infrastructures are close by. Here we report on rapid ground uplift in Iwo-yama volcano, one of vents in Kirishima Volcanic Complex, southwest Japan, potentiallly leading to a phreatic eruption. Kirishima Volcanic Complex is a collection of volcanic vents striking northwest-southeast. Shinmoe-dake, one of the vents in the volcanic complex, had sub-Plinian and Vulcanian eruptions in early 2011. Iwo-yama is located about 6 km to the northwest of Shinmoe-dake. In Iwo-yama, elevated surface temperature has been observed since December 2015 and volcanic earthquakes and tremors have been observed in January and February 2016. With this background, we investigated the temporal evolution of the deformation in Iwo-yama volcano inferred from Synthetic Aperture Radar images taken from the ALOS-2 satellite. We first generated interferograms all possible pairs of SAR images. Then we applied a time-series analysis to extract the temporal evolution of deformation of volcanic origin by removing errors due to the uncertainty of Digital Elevation Model and atmospheric disturbance. The time-series analysis reveals an uplift of a region with a diameter of about 500 meters. We found that the uplift started in late 2015 and amounts up to approximately 60 mm as of June 2016. The deformation pattern looks like almost a mirror of the subsidence observed in 1990s by JERS-1 images. These observations by JERS-1 and ALOS-2 suggest a deflation in 1990s and recent inflation of an aquifer located a few hundred meters beneath the summit. Electromagnetic observations also endorse the existence of the shallow acquifer that we suggest is responsible for the observed deformation. We need to note that the recent uplift continues even after a cessation of the volcanic earthquakes and tremors in late February 2016. This indicates that the observation of ground deformation adds insights into

  8. Geothermal Resource Exploration by Stream pH Mapping in Mutsu Hiuchi Dake Volcano, Japan

    Directory of Open Access Journals (Sweden)

    Yota Suzuki

    2017-07-01

    Full Text Available Although pH measurements of hot spring water are taken in conventional geothermal resource research, previous studies have seldom created pH distribution maps of stream and spring waters for an entire geothermal field as a technique for geothermal exploration. In this study, a pH distribution map was created by measuring stream and spring water pH at 75 sites in the Mutsu Hiuchi Dake geothermal field, Japan. Areas of abnormally high pH were detected in midstream sections of the Ohaka and Koaka rivers; these matched the location of the Mutsu Hiuchi Dake East Slope Fault, which is believed to have formed a geothermal reservoir. The abnormally high pH zone is attributed to the trapping of rising volcanic gases in a mature geothermal reservoir with neutral geothermal water. This causes the gas to dissolve and prevents it from reaching the surface. Thus, the mapping of stream water pH distribution in a geothermal field could provide a new and effective method for estimating the locations of geothermal reservoirs. As the proposed method does not require laboratory analysis, and is more temporally and economically efficient than conventional methods, it might help to promote geothermal development in inaccessible and remote regions.

  9. Horizontal and low-angle cross-stratifications from volcaniclastic sedimentary sequences: Outburst flood deposits, Numazawa and Ontake volcanoes, Japan

    Science.gov (United States)

    Kataoka, Kyoko

    2017-04-01

    This talk focuses on the formation and preservation of sedimentary structures such as horizontal and low-angle cross-stratifications in volcaniclastic sedimentary (lahar) sequences. The 5 ka outburst flood deposits in the Tadami river catchment, Numazawa volcano, Japan is presented as a first example. The flood, with a peak discharge of > 37,000-58,000 m^3/s from ignimbrite-dammed valley left pumiceous gravelly sediments with meter-sized boulders in the flow path (Kataoka et al., 2008). Up to 30 m thick sequence attributed to the flood formed a low gradient fan of 10 km long and 1.5-3 km wide, covering an area of 18 km2 with a total volume of > 0.5 km3 at the downstream end of the Tadami River. Outcrop observations accompanied with extensive surveys of Ground Penetrating Radar (GPR) along 200 to 500 m lateral and longitudinal transects over the flood fan revealed bedforms of the deposits. The profiles show large internal cross structures with 2-5 m amplitude and 10s m wavelength indicating lateral/downstream accretion in flood fan deposits. Some of them are slightly inclined towards upstream (backsets) which may suggest upstream migration of bedforms. These cross stratifications in the GPR profiles correspond to low-angle cross-stratifications or horizontal stratifications observed in outcrops. In outcrops, the stratified flood deposits mainly comprises rounded pumice pebble and cobble gravel and sand sized mineral grains. Bedding structures include horizontal stratifications and low-angle, low-amplitude, long wavelength cross-stratifications that occasionally climb. Individual 5 cm to decimeters-thick bed sets are commonly inversely graded. The deposits imply 1) high sediment concentration within a flow and 2) aggradation and bedform migration occurred in relation with traction carpet sedimentation. Especially thick traction carpets were probably formed because of 1) high stream power to drive near bed layer deeper and 2) a density contrast among volcaniclastic

  10. Acoustic and gravity features of mud volcanoes along the seaward part of the Kumano forearc basin, Nankai region, central Japan

    Science.gov (United States)

    Asada, M.

    2017-12-01

    Mud volcanoes (MV) are geological features that are observed all over the world, especially along plate convergent margins. MVs bring fluid and sediment to the surface from depth. MVs around Japan are expected to transport of information from the shallow portions of the seismogenic zone. The Kumano forearc basin (FAB) in the Nankai region is the most studied area in Japan. It is bounded by a shelf on the north, and the Kumano Basin edge fault zone (KBEFZ) on the south. The Kumano FAB has 1-2 km of sediment and overlies the accretionary prism. There are at least 14 MVs in the Kumano Basin. Most of them are found over the northern basin floor, and at least one MV is at the KBEFZ. The MV at the KBEFZ is imaged on a 3D seismic data set as a small topographic feature on seafloor with a disrupted BSR below it. On high-resolution acoustic imagery, it is an 80 100m-high hill with a crater-like depression. It is characterized by a negative ph anomaly detected just above it. High-backscatter seafloor recognized around the MV suggests that harder seafloor exists in that area. To determine whether large subseafloor diapirs exist below active MVs, we try to detect the gravity contrast between the allochthonous materials and basin sediment. Gravity data were collected by research vessels over the area in 2012 2017. After corrections of drift and Etovos effects, absolute gravity, free-air and Bouguer gravity anomalies were calculated. The gravity data do not always show anomalies directly on MVs over the northern basin, thus suggesting that larger diapirs which have gravity contrast over a few milli-Gals do not exist below most of MVs in this basin. Instead, a large negative gravity anomaly is found at the northeastern end of the Kumano Basin. Localized positive anomalies exist along the KBEFZ in the area of theMV. The positive anomaly may suggest that an allochthonous high-density sediment body intrudes along the highly deformed, weak, fault zone.

  11. Long-term geochemical surveillance of fumaroles at Showa-Shinzan dome, Usu volcano, Japan

    Science.gov (United States)

    Symonds, R.B.; Mizutani, Y.; Briggs, P.H.

    1996-01-01

    This study investigates 31 years of fumarole gas and condensate (trace elements) data from Showa-Shinzan, a dacitic dome-cryptodome complex that formed during the 1943-1945 eruption of Usu volcano. Forty-two gas samples were collected from the highest-temperature fumarole, named A-1, from 1954 (800??C) to 1985 (336??C), and from lower-temperature vents. Condensates were collected contemporaneously with the gas samples, and we reanalyzed ten of these samples, mostly from the A-1 vent, for 32 cations and three anions. Modeling using the thermochemical equilibrium program, SOLVGAS, shows that the gas samples are mild disequilibrium mixtures because they: (a) contain unequilibrated sedimentary CH4 and NH3; (b) have unequilibrated meteoric water; or (c) lost CO, either by air oxidation or by absorption by the sodium hydroxide sampling solution. SOLVGAS also enabled us to restore the samples by removing these disequilibrium effects, and to estimate their equilibrium oxygen fugacities and amounts of S2 and CH4. The restored compositions contain > 98% H2O with minor to trace amounts of CO2, H2, HCl, SO2, HF, H2S, CO, S2 and CH4. We used the restored gas and condensate data to test the hypotheses that these time-series compositional data from the dome's fumaroles provide: (1) sufficient major-gas data to analyze long-term degassing trends of the dome's magma-hydrothermal system without the influence of sampling or contamination effects; (2) independent oxygen fugacity-versus-temperature estimates of the Showa-Shinzan dacite; (3) the order of release of trace elements, especially metals, from magma; and (4) useful information for assessing volcanic hazards. The 1954-1985 restored A-1 gas compositions confirm the first hypothesis because they are sufficient to reveal three long-term degassing trends: (1) they became increasingly H2O-rich with time due to the progressive influx of meteoric water into the dome; (2) their C/S and S/Cl ratios decreased dramatically while their Cl

  12. Atmospheric concentrations of 212Pb and an observation of 212Pb originating from the 2000 eruptive activity of Miyake-jima volcano, at Kawasaki, Japan

    International Nuclear Information System (INIS)

    Koike, Yuya; Sato, Jun; Nakamura, Toshihiro

    2002-01-01

    Atmospheric concentrations of 212 Pb were observed with aerosol samples during the period from June, 1999 to December, 2000 at Kawasaki. The atmospheric concentrations of 212 Pb ranged from 20 to 130 mBq/m 3 . Seasonal variations in 212 Pb concentration showed the ''one-peak'' variation pattern: high concentrations appeared in winter season. The atmospheric concentration of 212 Pb and SO 2 after the eruption of Miyake-jima volcano on Aug. 29, 2000 were higher than average value in the season. After the eruption, the variation in the concentration of SO 2 correlates with that of 212 Pb. The atmospheric concentration of 212 Pb showed an unusual and temporal increase in the period from late August to early September, 2000, being inferred to be attributed partly to the 212 Pb fallout originating from the 2000 eruption of Miyake jima volcano, Japan. (author)

  13. Tilt signals associated with a small eruption at Asama Volcano, Japan

    Science.gov (United States)

    Ohminato, T.

    2013-12-01

    It is well known that the acceleration input to a seismometer consists of translational acceleration and tilt-related acceleration. The lower the frequency is, the more contribution is from the tilt-related acceleration. The tilt contribution can be easily extracted from the velocity output of broadband seismometers by the following simple procedure. The roll-off of the transfer function of the broadband seismometer in the frequency range below its characteristic frequency is proportional to the square of frequency. It means that the sensor output in this frequency range is proportional to the time-derivative of the ground acceleration. The result of time integration of the signal in this frequency range is, thus proportional to the ground acceleration, which are proportional to the ground tilt. As long as we concentrate on the low enough frequency range, this simple integration procedure is equivalent to the traditional procedure of sensor-response removal followed by transfer to the tilt response On February 2, 2009, a small eruption occurred at Mt. Asama, central Japan. A broadband seismic network operated by Earthquake Research Institute, University of Tokyo, detected tilt-related signals during the eruption. According to the tilt signals that were extracted by the above mentioned procedure, an inflation started 30 minutes before the summit eruption. The inflation was followed by a rapid deflation due to the summit eruption. At the stations relatively far from the summit, while the tilt changes before the eruption were below noise level and thus were not detected, the tilt changes after the eruption were clearly detected by most of the stations around Mt. Asama. The post eruption tilt signals were oriented not to the summit but to the northwestern side of Mt. Asama. The tilt signals before and during the eruption observed at the near-summit stations are interpreted as an accumulation and release of pressure beneath the summit crater before and after the

  14. Crustal deformations associated with the 1986 fissure eruption of Izu-Oshima volcano, Japan, and their tectonic significance

    Science.gov (United States)

    Hashimoto, Manabu; Tada, Takashi

    We have investigated crustal deformations associated with the 1986 eruption of Izu-Oshima volcano, Japan, which was accompanied by an intensive fissure eruption. Two fissure crater chains, with NW-SE trend were created in the northern part of the caldera and on its northwestern flank. Their trend is consistent with the direction of compressive stress in this region. Depression of > 30 cm in the central zone including the caldera, and in the northwestern and southeastern parts in the island, was detected by precise leveling. On the other hand, uplifts up to 20 cm in the northeastern and southwestern parts were observed. Tide observations revealed that the Okada tide station, the leveling datum in Izu-Oshima, may have subsided by 5 cm after the eruption. An ˜1 m opening of fissure craters was detected by distance measurements of the baselines which cross fissure craters. Horizontal displacements obtained by reoccupation of control points showed a symmetrical pattern which was consistent with the opening of fissure craters. Anomalous strain changes were also observed in the surrounding regions—contractions were observed in the Boso and the Miura peninsula, northeast of Izu-Oshima, and extensions in the Izu peninsula. To interpret these crustal deformations, a model which consists of a nearly vertical tensile fault and a deflation source is presented. The tensile fault lies parallel to the fissures and is divided into two parts according to depth. The deeper part of the tensile fault is 12 km long, 10 km wide, and has 2 km burial depth and 2.7 m opening displacement. The shallower part, which may represent the fissure craters, is 4 km long, 2 km wide, and the amount of opening is estimated to be 1 m. However, the deflation source may be located at a depth of 10 km beneath the northwestern flank of the caldera and depression just above the source is estimated to be 30 cm. A deflation source is required to explain the subsidence at the Okada tide station and the

  15. Frequent but hidden eruptions of Adatara and Bandai volcanoes during the last 50,000 years unraveled by volcanic damlake sediments, northeast Japan

    Science.gov (United States)

    Kataoka, Kyoko; Nagahashi, Yoshitaka

    2017-04-01

    Adatara and Bandai volcanoes in the northeast Japan are very close to each other ( 18 km). Bandai volcano is well known for a large-scale debris avalanche following the phreatic eruption in AD1888 that took more than 400 fatalities. Eruptive history consists of at least 6 more debris avalanche events, 3 more phreatic eruptions, 6 lava flows, and 4 Vulcanian/sub-Plinian eruptions during the last 50,000 years revealed by subaerial proximal deposits. Whereas, the eruptive history of Adatara volcano comprises 6 Vulcanian and 5 phreatic eruptions during the last 10,000 years. The most recent eruption occurred in AD1899-1900. The studied sedimentary core (INW2012) was drilled out from Lake Inawashiro-ko, the largest dammed lake in Japan, that was formed by the 50 ka Okinajima debris avalanche event at Bandai volcano. The lake is 94 m deep, and drilling site is located at the central part of the lake ( 90 m deep). In the 28 m long core sequence, in contrast to background lake sediments deposited under a deep offshore environment, very frequent (70) intercalations of event layers are recognized. Eight types of event layers can be recognized: 1) gray muddy layer (Gm), 2) gray sandy layer (Gs), 3) brown muddy layer (Bm), 4) brown sandy layer (Bs), 5) olive-gray muddy layer, 6) pale-brown sandy layer, and 7) yellow sandy layer, and 8) 2011 earthquake-induced turbidite, based on the characteristics of sedimentary facies, petrography, grainsize, mineral assemblages (XRD) and vertical variation of chemistry (micro-XRF). There are many tephra-fall layers but most of them are extra-basinal origin, i.e., of other volcanoes than Adatara and Bandai. Gm is usually a few millimeters to centimeters thick, blue-gray color, homogenized, and finer than background sediments. Gs is accompanied with coarser subunits and thicker than Gm. Especially, Gm/Gs contain pyrite, sulfate minerals and smectite, and are characterized by high sulfur contents. Bm and Bs are 1 to 6 cm thick and are normally

  16. Japan.

    Science.gov (United States)

    Geiger, Rita; And Others

    The document offers practical and motivating techniques for studying Japan. Dedicated to promoting global awareness, separate sections discuss Japan's geography, history, culture, education, government, economics, energy, transportation, and communication. Each section presents a topical overview; suggested classroom activities; and easily…

  17. Japan.

    Science.gov (United States)

    1989-02-01

    Japan consists of 3900 islands and lies off the east coast of Asia. Even though Japan is one of the most densely populated nations in the world, its growth rate has stabilized at .5%. 94% of all children go to senior high school and almost 90% finish. Responsibility for the sick, aged, and infirmed is changing from the family and private sector to government. Japan was founded in 600 BC and its 1st capital was in Nara (710-1867). The Portuguese, the 1st Westerners to make contact with Japan in 1542, opened trade which lasted until the mid 17th century. US Navy Commodore Matthew Perry forced Japan to reopen in 1854. Following wars with China and Russia in the late 1800s and early 1900s respectively, Japan took part in World Wars I and II. In between these wars Japan invaded Manchuria and China. The US dropped an atomic bomb on Hiroshima and Nagasaki and the Japanese surrendered in September, 1945 ending World War II (WWII). Following, WWII, the Allied Powers guided Japan's establishment as a nonthreatening nation and a democratic parliamentary government (a constitutional monarchy) with a limited defense force. Japan remains one of the most politically stable of all postwar democracies. The Liberal Democratic Party's Noboru Takeshita became prime minister in 1987. Japan has limited natural resources and only 19% of the land is arable. Japanese ingenuity and skill combine to produce one of the highest per hectare crop yields in the world. Japan is a major economic power, and its and the US economies are becoming more interdependent. Its exports, making up only 13% of the gross national product, mainly go to Canada and the US. Many in the US are concerned, however, with the trade deficit with Japan and are seeking ways to make trade more equitable. Japan wishes to maintain good relations with its Asian neighbors and other nations. The US and Japan enjoy a strong, productive relationship.

  18. The geochemical and petrological characteristics of prenatal caldera volcano: a case of the newly formed small dacitic caldera, Hijiori, Northeast Japan

    Science.gov (United States)

    Miyagi, Isoji; Kita, Noriko; Morishita, Yuichi

    2017-09-01

    Evaluating the magma depth and its physical properties is critical to conduct a better geophysical assessment of magma chambers of caldera volcanoes that may potentially cause future volcanic hazards. To understand pre-eruptive conditions of a magma chamber before its first appearance at the surface, this paper describes the case of Hijiori caldera volcano in northeastern Japan, which emerged approximately 12,000 years ago at a place where no volcano ever existed. We estimated the depth, density, bulk modulus, vesicularity, crystal content, and bulk H_2O content of the magma chamber using petrographic interpretations, bulk and microchemical compositions, and thermodynamic calculations. The chemical mass balance calculations and thermodynamic modeling of the erupted magmas indicate that the upper portion of the Hijiori magmatic plumbing system was located at depths between 2 and 4 km, and had the following characteristics: (1) pre-eruptive temperature: about 780 °C; (2) bulk magma composition: 66 ± 1.5 wt% SiO2; (3) bulk magmatic H_2O: approximately 2.5 wt%, and variable characteristics that depend on depth; (4) crystal content: ≤57 vol%; (5) bulk modulus of magma: 0.1-0.8 GPa; (6) magma density: 1.8-2.3 g/cm3; and (7) amount of excess magmatic H_2O: 11-32 vol% or 48-81 mol%. The range of melt water contents found in quartz-hosted melt inclusions (2-9 wt%) suggests the range of depth phenocrysts growth to be wide (2˜13 km). Our data suggest the presence of a vertically elongated magma chamber whose top is nearly solidified but highly vesiculated; this chamber has probably grown and re-mobilized by repeated injections of a small amount of hot dacitic magma originated from the depth.

  19. Global positioning system measurements of ground deformation caused by magma intrusion and lava discharge: the 1990 1995 eruption at Unzendake volcano, Kyushu, Japan

    Science.gov (United States)

    Nishi, K.; Ono, H.; Mori, H.

    1999-04-01

    Global positioning system (GPS) measurements made around Unzendake volcano, Kyushu, Japan, since January 1991 have detected ground deformation caused by magma intrusion and lava discharge. In the intermittent phreatic and phreatomagmatic eruption stage, the ground was inflating. After growth of the lava dome and following frequent pyroclastic flows at Unzendake volcano, the ground began deflating. These ground deformations are explained by the inflation and deflation of a Mogi's source model (a point source model) located about 6 km west of the active crater at a depth of 11 km, at an aseismic region. The observed horizontal displacement vectors pointed radially away from the estimated pressure source during inflation and pointed to the pressure source during deflation. The horizontal displacements at the reference GPS station calculated from contraction of the estimated pressure source coincide well with the actual horizontal displacements observed from other GPS baseline systems. These observations validate our estimates for the pressure source. Based on the relation between the deformation volume of the ground surface and the discharged volume of the lava, it is estimated that during the eruption there was magma supply from the deeper portion as well as magma discharge at the crater. Magma is estimated to be supplied to the reservoir at an average rate of 1.1×10 5 m 3/day; magma intrusion began in December 1989 at the latest and continued for 1.9×10 3 days.

  20. Is uplift of volcano clusters in the Tohoku Volcanic Arc, Japan, driven by magma accumulation in hot zones? A geodynamic modeling study

    Science.gov (United States)

    George, Ophelia A.; Malservisi, Rocco; Govers, Rob; Connor, Charles B.; Connor, Laura J.

    2016-06-01

    In many volcanic arcs, the rate of tectonic uplift cannot be explained by lithospheric plate motion alone but may be associated with dynamic uplift. Buoyant forces associated with underplated magma bodies lift the upper crust and leads to relatively high rates of topographic change. One such region is northern Honshu, Japan, where Quaternary volcano clusters are spatially associated with uplifted crust and isostatic gravity anomalies. Axisymmetric inversion of Bouguer gravity data for the Sengan volcano cluster shows that these gravity anomalies can be modeled by 30 km radius bodies emplaced at ˜15 km depth. Axisymmetric, finite element models, generated using GTECTON, of a layered Earth representative of the Tohoku crust indicate that the deformation of these midcrustal intrusions produces elevated topography on the surface directly above the intrusion that is bounded by a shallow peripheral trough. The wavelengths of vertical deformation produced by these bodies are sensitive to the thickness of the models' elastic layer and relatively insensitive to the models' rheology. This suggests that the amplitude of the vertical deformation represents a trade-off between the size of the intrusion and the thickness of the elastic layer and is less strongly influenced by the rheology of the lithosphere into which the bodies are emplaced. Our results are consistent with hot zone and hot finger models for the arc and indicate that Tohoku Volcanic Arc features such as gravity anomalies and uplifted basement are related to crustal magma intrusions and hot zones rather than directly related to mantle processes.

  1. Japan

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    2013-01-01

    I 1500- og 1600-tallet dannedes tidligt moderne stater i Europa, men samtidig eksisterede der ligeså avancerede statsdannelser uden for Europa, bl.a. i Kina, Indien og Japan. I det følgende ser vi nærmere på dannelsen af den moderne stat i Japan. Hvorfor blev Japan aldrig en europæisk koloni......? Hvordan havde japanske magthavere igennem 300 år forberedt Japan og de mennesker, der boede på de japanske øer, til at kunne udvikle en nation, der skulle blive den stærkeste og rigeste i Asien i mere end 100 år? Hvem bestemte i Japan? Kejseren eller shogunen?...

  2. Ground deformation cycles in a magma-effusive stage, and sub-Plinian and Vulcanian eruptions at Kirishima volcanoes, Japan

    Science.gov (United States)

    Takeo, M.; Maehara, Y.; Ichihara, M.; Ohminato, T.; Kamata, R.; Oikawa, J.

    2013-09-01

    The dynamics of explosive eruptions, such as Plinian, sub-Plinian, Vulcanian, and Strombolian ones, is one of the most fascinating subjects in volcano physics. During the early period of volcanic activity at the Shinmoe-dake Volcano in 2011, various kinds of activities, such as sub-Plinian eruptions, a magma effusion, and Vulcanian eruptions, occurred sequentially. A different kind of tilt motion accompanied each activity. Here we clarify the characteristics of the tilt motions and their time sequences, presenting a new explanation of the triggering mechanism of a Vulcanian eruption. The sub-Plinian and the Vulcanian eruptions at the Shinmoe-dake Volcano were preceded by inflations at shallow depths near the summit. The inflation-deflation cycles were also recorded during the magma-effusive stage, with a typical period of 1 h, synchronized with volcanic tremors or long-period events. Almost all Vulcanian eruptions were preceded by trapezoidal inflations, whose durations systematically lengthened as time progressed, and were followed by various time sequences of tilt motions, which became increasingly more complicated throughout the frequent Vulcanian eruptions. We have found clear linearity with a constant gradient of 0.45 between the logarithm of the preceding duration versus elapsed time for each substage. These observations can be consistently explained based on the assumption that a Vulcanian eruption is induced by a catastrophic rupture of the strongest closed, solid magma frame due to magma degassing overpressure, and the degassing from magma declines exponentially with time.

  3. Modeling of magma descent and volcano deformation during a vulcanian eruption

    Science.gov (United States)

    Minowa, T.; Nishimura, T.

    2013-12-01

    Volcanic edifice generally deflates due to the discharge of magma in the conduit or reservoir when an eruption occurs. Contrary, recent geodetic observations for vulcanian eruptions of Showa crater at Sakurajima, Japan, show uplift toward the crater at the beginning of eruptions (Iguchi, 2013). In this study, we explain such apparently unexpected deformations by considering magma descent processes in a shallow conduit associated with vulcanian eruptions. A vulcanian eruption is simplified to be triggered by a removal of cap-rock that pressurizes magma in the conduit. Magma in the upper part of conduit is fragmented by large pressure differences built up in the conduit to rapidly effuse volcanic ash. The fragmentation surface propagates downward as volcanic ash ejects. Such magma descent during eruption is formulated by Koyaguchi and Mitani (2005). We propose a moving pressure source model for calculating volcano deformation, following their model. The normal stress acting on the conduit wall is reduced after the passage of the fragmentation surface, which acts as a deflation source. Upward drag force works on the conduit wall bellow the fragmentation surface where a high pressure gradient is formed in the magma. These processes are described by seven model parameters: conduit length L, conduit radius, initial overpressure at the top of the conduit, initial position of the magma head, magma porosity, magma viscosity and descent rate of the fragmentation surface, U. We calculate tilt and strain at the foot of volcano with a conical topography with a height of 1km and inclination angle of 11 degrees by using 3-D boundary element method. We assume appropriate parameters for vulcanian eruptions at andesitic volcanoes such as Sakurajima volcano, and set a cylindrical conduit at the summit. Numerical calculations of volcano deformations at 1-4 km distances from the conduit show following characteristics. Uplift toward the crater appears just after an eruption, because

  4. Isolation of aquatic yeasts with the ability to neutralize acidic media, from an extremely acidic river near Japan's Kusatsu-Shirane Volcano.

    Science.gov (United States)

    Mitsuya, Daisuke; Hayashi, Takuya; Wang, Yu; Tanaka, Mami; Okai, Masahiko; Ishida, Masami; Urano, Naoto

    2017-07-01

    The Yukawa River is an extremely acidic river whose waters on the east foot of the Kusatu-Shirane Volcano (in Gunma Prefecture, Japan) contain sulfate ions. Here we isolated many acid-tolerant yeasts from the Yukawa River, and some of them neutralized an acidic R2A medium containing casamino acid. Candida fluviatilis strain CeA16 had the strongest acid tolerance and neutralizing activity against the acidic medium. To clarify these phenomena, we performed neutralization tests with strain CeA16 using casamino acid, a mixture of amino acids, and 17 single amino acid solutions adjusted to pH 3.0, respectively. Strain CeA16 neutralized not only acidic casamino acid and the mixture of amino acids but also some of the acidic single amino acid solutions. Seven amino acids were strongly decomposed by strain CeA16 and simultaneously released ammonium ions. These results suggest strain CeA16 is a potential yeast as a new tool to neutralize acidic environments. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. The 2011 eruptive activity of Shinmoedake volcano, Kirishimayama, Kyushu, Japan—Overview of activity and Volcanic Alert Level of the Japan Meteorological Agency—

    Science.gov (United States)

    Kato, Koji; Yamasato, Hitoshi

    2013-06-01

    Following several years of small phreatic eruption events, Shinmoedake volcano in Kyushu, Japan, began a new phase of activity on 19 January 2011. The eruption commenced with a small phreatomagmatic event followed by subplinian events on 26 and 27 January. Lava emerged as a dome in the summit crater on 27 January and filled the crater until the beginning of February. During the subplinian events and lava dome growth, deflation of the deep magma chamber was observed by tiltmeters and GPS. Eruptive activity began to decrease in March 2011 and no eruptive event occurred after the 7 September 2011 event. In response to the eruption, the Japan Meteorological Agency (JMA) issued warnings repeatedly to prepare local people and infrastructures around Shinmoedake. JMA did not raise the Volcanic Alert Level before the first subplinian event, because of a lack of clear precursory signals. We conclude that a large amount of magma moved in the shallow Shinmoedake plumbing system for a short time, based on a number of geophysical observations. It is important to detect magma movement and understand eruptive phenomena quickly in order to mitigate risks of volcanic hazards.

  6. A rhyolite to dacite sequence of volcanism directly from the heated lower crust: Late Pleistocene to Holocene Numazawa volcano, NE Japan

    Science.gov (United States)

    Yamamoto, Takahiro

    2007-11-01

    Flare-up of silicic volcanism has occurred in the back arc of NE Japan arc since 0.3 Ma; Sunagohara, Numazawa, Kinunuma, Hiuchigatake and Iiji volcanoes have all grown during this time interval. Although arc front volcanism has continued during the Quaternary period, back-arc volcanism varies in space and time. All ejecta of the back-arc volcanoes are medium-K calc-alkaline rhyolite to dacite in composition and 1 to 10 DRE km 3 in volume. The Sr and Nd isotopic ratios of the ejecta vary widely among the individual volcanoes and suggest the origin of the felsic magmas may be generated by anatexis of mafic igneous rocks of the lower crust. Temporal variation in geochemistry of the 5 km 3 Numazawa ejecta shows more details of the anatexis. Numazawa volcano erupted the Shibahara pyroclastics at 110 ka, the Mukuresawa lava at 70 ka, the Mizunuma pyroclastics at 45 ka, the Sozan lava at 40 ka, the Maeyama lava at 20 ka, and the Numazawako pyroclastics at 4.6 ka. The time-accumulated volume diagram of Numazawa volcano shows the increase of magma eruption rate through time. All elements of the Numazawa rhyolite to dacite define time-controlled, discontinuous linear trends. SiO 2, K 2O, Na 2O, Rb, Y, Ba, and Nb decrease with the ascending eruption units, whereas MgO, Fe 2O 3, CaO, Al 2O 3, TiO 2, Sr and V increase. SiO 2 contents are variable from 72% in Nm-MK at 71 ka to 66% in Nm-NK at 4.6 ka. The rhyolite to dacite of the Numazawa ejecta are homogeneous with respect to the isotopic ratios. I show that the temporal linear trends for the bulk compositions of the Numazawa rhyolite to dacite are most plausibly caused by increase of batch partial melting at constant bulk distribution coefficient. The calculated patterns of trace-element abundances show that partial melting of high-alumina basaltic igneous rocks in the lower crust can generate the Numazawa rhyolite to dacite. In this case, the degree of partial melting varies from about 20% at 71 ka to about 60% at 20 ka and 4

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

    Science.gov (United States)

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

    2018-03-01

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

  8. Relationship between volcanic activity and shallow hydrothermal system at Meakandake volcano, Japan, inferred from geomagnetic and audio-frequency magnetotelluric measurements

    Science.gov (United States)

    Takahashi, Kosuke; Takakura, Shinichi; Matsushima, Nobuo; Fujii, Ikuko

    2018-01-01

    Hydrothermal activity at Meakandake volcano, Japan, from 2004 to 2014 was investigated by using long-term geomagnetic field observations and audio-frequency magnetotelluric (AMT) surveys. The total intensity of the geomagnetic field has been measured around the summit crater Ponmachineshiri since 1992 by Kakioka Magnetic Observatory. We reanalyzed an 11-year dataset of the geomagnetic total intensity distribution and used it to estimate the thermomagnetic source models responsible for the surface geomagnetic changes during four time periods (2004-2006, 2006-2008, 2008-2009 and 2013-2014). The modeled sources suggest that the first two periods correspond to a cooling phase after a phreatic eruption in 1998, the third one to a heating phase associated with a phreatic eruption in 2008, and the last one to a heating phase accompanying minor internal activity in 2013. All of the thermomagnetic sources were beneath a location on the south side of Ponmachineshiri crater. In addition, we conducted AMT surveys in 2013 and 2014 at Meakandake and constructed a two-dimensional model of the electrical resistivity structure across the volcano. Combined, the resistivity information and thermomagnetic models revealed that the demagnetization source associated with the 2008 eruptive activity, causing a change in magnetic moment about 30 to 50 times greater than the other sources, was located about 1000 m beneath Ponmachineshiri crater, within or below a zone of high conductivity (a few ohm meters), whereas the other three sources were near each other and above this zone. We interpret the conductive zone as either a hydrothermal reservoir or an impermeable clay-rich layer acting as a seal above the hydrothermal reservoir. Along with other geophysical observations, our models suggest that the 2008 phreatic eruption was triggered by a rapid influx of heat into the hydrothermal reservoir through fluid-rich fractures developed during recent seismic swarms. The hydrothermal reservoir

  9. Evolution of vent system during continuous ash emissions with Strombolian eruptions in 2000-2011 at Suwanosejima volcano, SW Japan

    Science.gov (United States)

    Shimano, T.; Iguchi, M.

    2011-12-01

    Strombolian and vulcanian eruptions are characterized by surface manifestation of unsteadiness such as the alternation of fountaining and successive ash emission with/without explosions. The activity sometimes evolves into much more destructive styles such as plinian eruption. The time evolution of these surface eruptive phenomena is strongly dependent on the history of magmas ascending in volcanic conduits as well as that of conduit condition itself. Suwanosejima volcano has been continuously active for more than several decades. The eruption styles it has shown were strombolian to small vulcanian that emit ash particles with small amount of ballistic bombs. Geological records show that such weak eruptions for several decades seemed to have preceded some major historical sub-plinian eruptions at this volcano. Thus, continuous observation for such kind of activities would be helpful for understanding or predicting the evolution of activity toward major eruptions. Although Suwanosejima is a remote island, with population of ca. 50, we had collected ash fall samples occasionally for ten years. Now we set up automatic ashfall sampling machine at the foot of Suwanosejima and are collecting ashfall sample every 2.5 days to investigate evolution of chemistry and crystallization processes of magma during ascent in conduit. The advantage of observing activities at Suwanosejima is that we can look into active vents from the rim of the caldera, 400 m apart and 300 m higher than the main central vent. We set up a camera to observe surface phenomena in the vicinity of vent, and correlated characteristics of eruptive materials with surface phenomena. The 2000-2011 activity of Suwanosejima volcano can be divided into three phases; phase I from 2000-2003, phase II from 2004-2008, and phase III from 2009-2011. Each phase is alternation of active and quiescent periods for weeks to months. There is a tendency that in active periods glassy particles are dominant whereas crystalline

  10. 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

    The horizontal components of broadband seismometers are known to be susceptible to gravitational acceleration due to slow tilting, and this has been successfully exploited to assess ground deformation at many volcanoes, including Anatahan (Mariana Islands), Meakan-dake (Japan), Santiaguito (Guatemala) and Stromboli (Italy). Tilt can be estimated from seismic velocity by differentiating, scaling to remove gravity, and applying an instrument correction. The fundamental assumption in estimating tilt from broadband data is that the signal recorded is the result of tilt and not translation, thus analysis of tilt require filtering below corner frequencies of seismic instruments, where the response to tilt should be flat. However, processing techniques for deriving tilt are not uniform among researchers. Filter type and passband allowance for the processing of data sets differs from case to case, and the dominant periods of tilt signals may vary from tens to hundreds of seconds. For instance, data from Santiaguito was filtered in the 600-30s passband, while at Anatahan filters spanned 13 hours to 8 minutes. In our study, we investigate tilt from seismic data sets at Karymsky (Kamchatka, Russia), Fuego (Guatemala), Yasur (Vanuatu), and Tungurahua (Ecuador) to understand implementation and limitations of this tool. We examine the importance of filter-type distortion related to filtering on the seismic signal. For example, a comparison of time domain versus frequency domain implementation is explored using a variety of lowpass and bandpass filters. We also investigate the advantages and drawbacks of causal versus acausal filters. In a few cases tiltmeters have been co-located with broadband seismic sensors for direct comparison. Signals at Mt. St. Helens, Stromboli, Sakurajima, and Semeru show a correlation of tilt and seismic records, although records at Karymsky volcano suggest that no tilt is recorded on either instrument. We speculate that strong vent explosions exhibit

  11. Short time scales of magma-mixing processes prior to the 2011 eruption of Shinmoedake volcano, Kirishima volcanic group, Japan

    Science.gov (United States)

    Tomiya, Akihiko; Miyagi, Isoji; Saito, Genji; Geshi, Nobuo

    2013-10-01

    We estimated time scales of magma-mixing processes just prior to the 2011 sub-Plinian eruptions of Shinmoedake volcano to investigate the mechanisms of the triggering processes of these eruptions. The sequence of these eruptions serves as an ideal example to investigate eruption mechanisms because the available geophysical and petrological observations can be combined for interpretation of magmatic processes. The eruptive products were mainly phenocryst-rich (28 vol%) andesitic pumice (SiO2 57 wt%) with a small amount of more silicic pumice (SiO2 62-63 wt%) and banded pumice. These pumices were formed by mixing of low-temperature mushy silicic magma (dacite) and high-temperature mafic magma (basalt or basaltic andesite). We calculated the time scales on the basis of zoning analysis of magnetite phenocrysts and diffusion calculations, and we compared the derived time scales with those of volcanic inflation/deflation observations. The magnetite data revealed that a significant mixing process (mixing I) occurred 0.4 to 3 days before the eruptions (pre-eruptive mixing) and likely triggered the eruptions. This mixing process was not accompanied by significant crustal deformation, indicating that the process was not accompanied by a significant change in volume of the magma chamber. We propose magmatic overturn or melt accumulation within the magma chamber as a possible process. A subordinate mixing process (mixing II) also occurred only several hours before the eruptions, likely during magma ascent (syn-eruptive mixing). However, we interpret mafic injection to have begun more than several tens of days prior to mixing I, likely occurring with the beginning of the inflation (December 2009). The injection did not instantaneously cause an eruption but could have resulted in stable stratified magma layers to form a hybrid andesitic magma (mobile layer). This hybrid andesite then formed the main eruptive component of the 2011 eruptions of Shinmoedake.

  12. The September 14, 2015 phreatomagmatic eruption of Nakadake first crater, Aso Volcano, Japan: Eruption sequence inferred from ballistic, pyroclastic density current and fallout deposits

    Science.gov (United States)

    Miyabuchi, Yasuo; Iizuka, Yoshiyuki; Hara, Chihoko; Yokoo, Akihiko; Ohkura, Takahiro

    2018-02-01

    An explosive eruption occurred at Nakadake first crater, Aso Volcano in central Kyushu, southwestern Japan, on September 14, 2015. The sequence and causes of the eruption were reconstructed from the distribution, textures, grain-size, component and chemical characteristics of the related deposits, and video record. The eruptive deposits are divided into ballistics, pyroclastic density current and ash-fall deposits. A large number of ballistic clasts (mostly < 10 cm in diameter; maximum size 1.6 m) are scattered within about 500 m from the center of the crater. Almost half of the ballistics appear as fresh and unaltered basaltic andesite rocks interpreted to be derived from a fresh batch of magma, while the rest is weakly to highly altered clasts. A relatively thin ash derived from pyroclastic density currents covered an area of 2.3 km2 with the SE-trending main axis and two minor axes to the NE and NW. The pyroclastic density current deposit (maximum thickness < 10 cm even at the crater rim) is wholly fine grained, containing no block-sized clasts. Based on the isopach map, the mass of the pyroclastic density current deposit was estimated at ca. 5.2 × 104 tons. The ash-fall deposit is finer grained and clearly distributed to about 8 km west of the source crater. The mass of the ash-fall deposit was calculated at about 2.7 × 104 tons. Adding the mass of the pyroclastic density current deposit, the total discharged mass of the September 14, 2015 eruption was 7.9 × 104 tons. The September 14 pyroclastic density current and ash-fall deposits consist of glass shards (ca. 30%), crystals (20-30%) and lithic (40-50%) grains. Most glass shards are unaltered poorly crystallized pale brown glasses which probably resulted from quenching of juvenile magma. This suggests that the September 14, 2015 event at the Nakadake first crater was a phreatomagmatic eruption. Similar phreatomagmatic eruptions occurred at the same crater on September 6, 1979 and April 20, 1990 whose

  13. Hokkaido, Japan

    Science.gov (United States)

    2006-01-01

    Cities mingle with rugged hills and a dormant volcano in this image of Hokkaido, Japan. This three-dimensional image comes from observations made by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite on July 23, 2006. The view is toward the north and slightly east. Green indicates vegetation; beige and gray indicate bare ground, paved surfaces, or buildings; and dark blue indicates water. The water body at the top of the image is the Pacific Ocean. Now dormant, Mount Yotei is a stratovolcano--a symmetrical cone composed of alternating layers of hardened lava, solidified ash, and volcanic rocks ejected in previous eruptions. It reaches a height of 1,898 meters (6,227 feet), and its summit sports a 700-meter- (2,297-foot-) wide crater. Snow often caps this volcano, but in this summertime shot, the volcano's summit is snow-free. The volcano is also known as Ezo-Fuji for its resemblance to Mount Fuji. As angular patches of gray and beige indicate, urban areas surround the volcano, most notably the city of Kutchan to the northwest. Even when volcanoes remain active, people often settle close to them, drawn by benefits of good soil and mild climates that appear to outweigh the risks. NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  14. Time-dependent model for volume changes in pressure sources at Asama volcano, central Japan due to vertical deformations detected by precise leveling during 1902 2005

    Science.gov (United States)

    Murase, Masayuki; Ono, Koji; Ito, Takeo; Miyajima, Rikio; Mori, Hitoshi; Aoyama, Hiroshi; Oshima, Hiromitu; Yoshida, Yuka; Terada, Akihiko; Koyama, Eturo; Takeda, Toyotarou; Watanabe, Hidefumi; Kimata, Fumiaki; Fujii, Naoyuki

    2007-07-01

    A time-dependent model for volume changes in pressure sources at Asama volcano is developed from precise leveling data collected since 1902. The optimal source model is determined by comparing five different models (a model with three types of spherical sources, single dike, and dike with a spherical source) during three periods: 1935 to 1939, 1939 to 1950/1953, and 1990 to November 2004. The optimal parameters for each model are estimated by employing a genetic algorithm (GA). The model with two spherical sources was selected as the optimal model. In this model, one of the sources was estimated to be located at a depth of approximately 6 km beneath Kurofu volcano; the other source was estimated to be located close to Maekake volcano at a depth of approximately 2 km. The volume changes in the two spherical sources are calculated using the Akaike's Bayesian information criterion (ABIC) for the period from 1902 to 2005. During the period from 1902 to 1943, a large inflation was estimated in a source at a depth of approximately 6 km beneath Kurofu volcano, which is an older volcano at the base of Asama. After 1943, a rapid deflation continued until 1967. This rapid deflation changed to a marginal inflation that continued from 1967 until 2005. The temporal change in the pressure source beneath Kurofu volcano exhibits a strong positive correlation with the eruption frequency. The leveling data does not suggest a significant volume change in the source beneath Kurofu volcano during the quiet period between 1962 and 2005. During the 20th century, magma appears to have been episodically supplied beneath Asama volcano. In particular, the inflation of the source beneath Kurofu volcano, and probably the magma supply, reached a peak from 1930 to 1940.

  15. Kirishima, Japan Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The shield volcano consists of more than 20 eruptive centers over a 20 x 30 km area that also includes Japan's first national park. Sixty-nine eruptions have been...

  16. Collapsing volcanoes

    Science.gov (United States)

    Francis, Peter; Self, Stephen

    1987-06-01

    A series of studies has been conducted which examined Landsat images of volcanoes in the central Andes in order to identify previously unknown avalanche deposits, with attention to the Socompa volcano in Chile. The occasional, massive collapse of an unstable volcanic cone may be seen as a normal event in the life cycle of a volcano; this is especially true in the case of large 'stratovolcanoes', of which there are many hundreds in the 'Ring of Fire' around the Pacific rim. Stratovolcanoes are susceptible to collapse because of their association with subduction zones. Three kinds of collapse can be distinguished among stratovolcanoes.

  17. Three-dimensional deformation mapping of a dike intrusion event in Sakurajima in 2015 by exploiting the right- and left-looking ALOS-2 InSAR

    Science.gov (United States)

    Morishita, Yu; Kobayashi, Tomokazu; Yarai, Hiroshi

    2017-04-01

    One of the limitations of the interferometric synthetic aperture radar (InSAR) is its one-dimensional measurement capability. Although three-dimensional (3-D) deformation can be studied if there are three or more measurements with different viewing geometries, it has not been executed because almost all SAR data are acquired using a right-looking geometry. For the Sakurajima volcanic activity on 15 August 2015, ALOS-2 conducted SAR observations from four different viewing directions, ascending/descending and right-/left-looking, enabling the retrieval of 3-D deformation data only from the InSAR results. We have retrieved 3-D deformation with high precision and resolution by a weighted least squares approach. Expansive deformation of over 10 cm has been observed with standard errors of 0.8, 3.4, and 0.7 cm for east-west, north-south, and up-down components, respectively. It is inferred that a dike of 1.7 × 106 m3 volume intruded beneath the Showa crater at a depth of 0.4-1.2 km. In addition to the above-mentioned topic, we will demonstrate that the atmospheric noise has a serious effect on the source modeling and the atmosphere-related noise reduction using numerical weather model has worked well. Acknowledgements: ALOS-2 data were provided from the Volcano Working Group under a cooperative research contract with JAXA. The ownership of ALOS-2 data belongs to JAXA. The products of the numerical weather model and GNSS data were provided by JMA, under the agreement between GSI and JMA.

  18. Chemical compositions and Sr, Nd isotope ratios of gabbroic xenoliths in calc-alkali andesites of Naeba and Torikabuto volcanoes, North Fossa Magna, central Japan

    International Nuclear Information System (INIS)

    Shimazu, Mitsuo; Kawano, Yoshinobu; Kaji, Kiyoshi; Igarashi, Satoshi.

    1991-01-01

    Gabbroic, doleritic and basaltic xenoliths found in calc-alkali andesites of Naeba and Torikabuto volcanoes are geochemically divided into three groups. Gabbro A of the group 1 from Naeba is rich in MgO and Ni, poor in alkalis, and shows depleted REE pattern resembling those of Ichinomegata (Sp. No.2232) and Hakone (HKG1, HKG2) volcanoes. On the basis the REE pattern and high Al IV contents in clinopyroxenes, gabbro A is interpreted to have been cumulate from a primary magma generated by partial melting of upper mantle. From REE pattern, gabbros of the group 2 from Ichinomegata (Sp. No.2218) may have derived from low alkali tholeiite magma which have been formed by removal of material such as the group 1 gabbro at shallow depth. Doleritic and basaltic xenoliths of the group 3 from Naeba, gabbroic xenoliths from Torikabuto and Umikawa are poorer in MgO and richer in alkalis than those of the group 1 and show enriched pattern in REE resembling that of high alkali tholeiite and contain clinopyroxenes having low Al IV . Therefore, these rocks are considered to be differentiates of high alkali tholeiite magma at shallow depth. On εNd- 87 Sr/ 86 Sr diagram, isotope data of gabbro A of the group 1 plot near those of andesites from Asama and Myoko volcanoes of the North Fossa Magna. It is interpreted that these rocks have derived from the same mantle source as the Asama and Myoko volcanoes which are richer in incompatible elements than those of MORB. (author)

  19. Caldera deformation in Kyushu island (SW Japan) through InSAR data

    Science.gov (United States)

    Nobile, Adriano; Pepe, Susi; Ruch, Joel; Trippanera, Daniele; Casu, Francesco; Castaldo, Raffaele; Tizzani, Pietro; Aoki, Yosuke; Geshi, Nobuo; Acocella, Valerio; Sansosti, Eugenio; Siniscalchi, Valeria; Borgstrom, Sven; Zoffoli, Simona

    2014-05-01

    Calderas are the surface expression of a long-lived and complex magmatic system, often hosting a shallower hydrothermal system. Most monitored calderas have experienced some forms of unrest, even though only a part of these unrest episodes has culminated in an eruption. This study focuses on surface deformation analysis using InSAR from 1993 to 2013 at two large active calderas, Aso and Aira, located on Kyushu Island (Japan). Despite being closely monitored, our knowledge on the deformation history of both calderas with regard to their activity is poor. ERS, ENVISAT, ALOS and COSMO-SkyMed SAR images have been processed to obtain mean velocity deformation maps and time series through the SBAS technique. Results are then inverted using the simulated annealing technique to evaluate the deformation source parameters. Aso caldera hosts several vents in its central portion. One of these, the Naka Dake crater is the only currently active and erupted 7 times since 1993. From January 1996 to November 1998, after the important 1994 - 1995 eruption, we observed a subsidence of ~1.2 cm/yr at the center of the caldera. Analytical models suggest a deflating source (with various possible shapes) at 5-7 km of depth, implying a magmatic nature for the deformation. Inversion results are consistent with available seismic and GPS data. Aira Caldera hosts the Sakurajima volcano along its southern rim, with a persistent eruptive activity since 1950s. From June 2006 to March 2011, we observed a broad uplift of ~1.5 cm along most of the caldera rim. Analytical inversion of both the entire dataset and a cross-correlated dataset suggests a deformation source at the caldera center, at a depth of 5-9 km (depending on the source shape), implying a magmatic nature of the deformation. Inversion results are in agreement with GPS and InSAR data inversions for other periods of activity. This research has been partially performed within the frame of Italian Space Agency (ASI) and Japan Aerospace

  20. Dynamics of explosive paroxysms at open andesitic systems: high-resolution mass distribution analyses of 2006 tephra from Tungurahua volcano (Ecuador)

    Science.gov (United States)

    Le Pennec, J.; Eychenne, J.; Ramon, P.; Yepes, H.

    2012-12-01

    Many andesitic volcanoes at subduction plate margins can experience in the course of their evolution periods of sub-continuous eruption during years, decades, or centuries. Such long-lived periods may embrace more or less intense outgassing events, extrusion of viscous lava flows and domes (e.g. Colima in Mexico, Merapi in Indonesia, Arenal in Costa Rica), and explosive activity of uneven intensity (e.g. Semeru in Indonesia, Sakurajima in Japan, Sangay in Ecuador). In addition, strong explosive events of short duration may occur, with potential generation of pyroclastic flows on the flanks and beyond, which can pose significant hazards in populated regions. The origin and dynamics of such violent eruptions remain poorly known and may involve a combination of different factors. Tungurahua volcano, Ecuador, reawaken in 1999 and is an example of such open-system behaviour that experienced a strong and deadly andesitic pyroclastic flow-forming event in August 2006. Inspection of the deposits suggested that the event could have been triggered by magma mixing (silicic pumices in the tephra), magma-water interaction (presence of xenolithic clasts) or deep andesitic magma reinjection (based on mineral chemistry). Here we investigate these options by performing a high-resolution mass budget analysis of the scoria fall deposit. This is achieved by analysing componentry compositions and their mass distribution pattern in the layer, which allow us to document and integrate exponential and power laws mass decay rates over wide areas. The results yield a total mass for the tephra layer of ~2 x 1010kg. The pumice mass fraction is far too small (paroxysm. Altogether our results support an explosive event fed by a deep gas-rich andesitic reinjection, which would have incorporated a pocket of older differentiated magma and eroded the upper conduit during the sub-plinian event. The high-resolution mass-based approach reveals useful to decipher the origin of the violent 2006 paroxysm

  1. Observation of atmospheric 210Pb and 212Pb originating from the 2004 eruptive activity of Asama volcano, Japan, and relevant 222Rn releasing from the erupting magma

    International Nuclear Information System (INIS)

    Kukita, Kazuhiko; Koike, Yuya; Nakamura, Toshihiro; Sato, Jun; Saito, Takashi

    2005-01-01

    This paper describes a study of observation of atmospheric 210Pb and 212Pb possibly from the volcano (36 deg N, 138 deg E) activity in the title and of measurement of 222Rn releasing efficiency with the ash-fall deposit collected around the period. The aerosol sample was collected from Sep. 1, an eruption day, on a building terrace (10 m high) of Meiji University at Kawasaki, located at 140 km SE of the volcano, every 24 hr on the glass fiber filter using a high volume air sampler. The filter was cut out to 4 disks, which were packed into acrylic canisters with a window of a thin Mylar film for non-destructive γ-ray measurement. 210Pb and 212Pb radioactivities were determined by the 46.5- and 238.6-keV γ-rays with an LEPS (low energy photon spectrometer) and an HPGe spectrometer, respectively. The ash-fall sample from the eruption Sep. 14, was collected at Kanrakumachi, Gunma Pref., 40 km SE of the volcano, and measurement for the growth curve of 222Rn from the fall started 1 week after the eruption. A well-type HPGe spectrometer was used for determination of the 351.9-keV γ-ray of 222Rn from 214Pb in equilibrium, which was normalized by the 911.1-keV 228Ac γ-ray. 210Pb and 212Pb emitted into the atmosphere were suggested to have been transported 140 km within the time of a few times of the 212Pb half life (10.6 hr) on the northerly wind. 210Pb and 212Pb, and 222Rn were suggested to be a possibly useful tool of monitoring magmatic activities. (S.I.)

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  3. Collateral variations between the concentrations of mercury and other water soluble ions in volcanic ash samples and volcanic activity during the 2014-2016 eruptive episodes at Aso volcano, Japan

    Science.gov (United States)

    Marumoto, Kohji; Sudo, Yasuaki; Nagamatsu, Yoshizumi

    2017-07-01

    During 2014-2016, the Aso volcano, located in the center of the Kyushu Islands, Japan, erupted and emitted large amounts of volcanic gases and ash. Two episodes of the eruption were observed; firstly Strombolian magmatic eruptive episodes from 25 November 2014 to the middle of May 2015, and secondly phreatomagmatic and phreatic eruptive episodes from September 2015 to February 2016. Bulk chemical analyses on total mercury (Hg) and major ions in water soluble fraction in volcanic ash fall samples were conducted. During the Strombolian magmatic eruptive episodes, total Hg concentrations averaged 1.69 ± 0.87 ng g- 1 (N = 33), with a range from 0.47 to 3.8 ng g- 1. In addition, the temporal variation of total Hg concentrations in volcanic ash varied with the amplitude change of seismic signals. In the Aso volcano, the volcanic tremors are always observed during eruptive stages and quiet interludes, and the amplitudes of tremors increase at eruptive stages. So, the temporal variation of total Hg concentrations could provide an indication of the level of volcanic activity. During the phreatomagmatic and phreatic eruptive episodes, on the other hand, total Hg concentrations in the volcanic ash fall samples averaged 220 ± 88 ng g- 1 (N = 5), corresponding to 100 times higher than those during the Strombolian eruptive episode. Therefore, it is possible that total Hg concentrations in volcanic ash samples are largely varied depending on the eruptive type. In addition, the ash fall amounts were also largely different among the two eruptive episodes. This can be also one of the factors controlling Hg concentrations in volcanic ash.

  4. Klyuchevskaya Volcano

    Science.gov (United States)

    2007-01-01

    The Klyuchevskaya Volcano on Russia's Kamchatka Peninsula continued its ongoing activity by releasing another plume on May 24, 2007. The same day, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image, at 01:00 UTC. In this image, a hotspot marks the volcano's summit. Outlined in red, the hotspot indicates where MODIS detected unusually warm surface temperatures. Blowing southward from the summit is the plume, which casts its shadow on the clouds below. Near the summit, the plume appears gray, and it lightens toward the south. With an altitude of 4,835 meters (15,863 feet), Klyuchevskaya (sometimes spelled Klyuchevskoy or Kliuchevskoi) is both the highest and most active volcano on the Kamchatka Peninsula. As part of the Pacific 'Ring of Fire,' the peninsula experiences regular seismic activity as the Pacific Plate slides below other tectonic plates in the Earth's crust. Klyuchevskaya is estimated to have experienced more than 100 flank eruptions in the past 3,000 years. Since its formation 6,000 years ago, the volcano has seen few periods of inactivity. NASA image courtesy the MODIS Rapid Response Team at NASA GSFC. The Rapid Response Team provides daily images of this region.

  5. Estimation of strain sensitivity of seismic velocity changes using the Earth tide: Analyses of seismic small array data at Izu-Oshima volcano, Japan

    Science.gov (United States)

    Takano, T.; Nishimura, T.; Nakahara, H.; Ueda, H.; Fujita, E.

    2017-12-01

    Seismic velocity changes in the crust and/or subsurface have been often observed in association with the occurrences of earthquakes or volcanic activities. Mechanisms of the velocity changes are, for example, non-linear behavior of subsurface, strain changes, ground water level changes etc. To examine the effects of strain changes, the solid earth tide is a good input signal because the strain sensitivity of velocity changes can be measured at many places by using seismic interferometry [Takano et al., 2014; Hillers et al., 2015]. However, there are few reports which detect the velocity changes due to the Earth tide by seismic interferometry. The aim of this study is to estimate the strain sensitivity of velocity changes using the Earth tide at Izu-Oshima volcano, where the small seismic array and seismic network are deployed. We analyze the ambient noises recorded at the seismic array operated by NIED. The array consists of 7 short-period sensors with a diameter of 100 m. The continuous data from 1 Apr. 2014 to 1 Apr. 2015 is analyzed. The tidal strain is extracted from the raw data of the strain-meter deployed by JMA using Baytap-08 [Tamura et al., 1991]. We estimate the velocity changes due to the Earth tide as follows. First, we divide the observation period into five episodes: dilatational and contractional, according to volumetric strain values. CCFs of ambient noise at 2 - 4 Hz are separately stacked for each divided episode. Subsequently, we measure the velocity changes by calculating the phase delay between stacked CCFs at lapse time of less than 6 s. It is recognized that seismic velocity decreases during the dilatational episode with respect to the contractional episode. Strain sensitivity of seismic velocity changes, which is obtained by averaging for six station pairs, is estimated to be (-1.6±0.5)×104 strain-1. The strain sensitivity of the seismic velocity changes is consistent with that at the foot of Mt. Iwate [Takano et al., 2014]. We also

  6. 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

  7. 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

  8. The magma chamber associated with the eruption of Miyakejima Volcano, Japan, since 2000, inferred from crustal deformation data (1983-2004).

    Science.gov (United States)

    Ueda, H.; Fujita, E.; Ukawa, M.; Nishimura, T.; Murakami, M.

    2004-12-01

    Miyakejima Island, an active basaltic stratovolcano lying 170 km to the south of Tokyo, Japan, resumed its volcanic activity in late June 2000 after a quiescence period for 17 years since the last eruption in 1983. The activity changes its eruptive style and still continues with a significant volcanic gas emission from the summit caldera, which has forced the inhabitants of Miyakejima to evacuate from the island. In order to understand the magmatic activity and the gas emission, it is crucial to reveal the magma supply system beneath the island. For this purpose we elucidated locations and geometries of a magma chamber, intruded dikes, and a source related with the gas emission by using the crustal deformation data including GPS, tilt changes and leveling through the period after the 1983 eruption up to now. Following dike intrusions beneath the island at the initial stage of the activity (June 26 - 27, 2000), the observed crustal deformation showed a rapid contraction of the island due to a subsurface magma migration from a magma chamber to the west off the coast. To estimate the location and configuration of the magma chamber, we compared the deformation with various source models. We found that a source model consisting of a spherical deflation source about 8 km deep in the southwestern part of the island and a vertical dike-shaped deflation source on the spherical source is most appropriate for the crustal deformation (June 28 - mid September, 2000). The total amount of the contraction is ~0.4 km3; if it is added to the amount of collapsed summit, which is considered to have penetrated into the chamber [Geshi et al., 2002], the amount of withdrew magma is estimated to be ~1.0 km3. The amount is consistent with the amount of intruded magma at the west off the coast of Miyakejima [Nishimura et al., 2001]. An inflated source model with a similar configuration can explain the crustal deformation observed from 1983 to before the activity of 2000, suggesting the

  9. 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...

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

    International Nuclear Information System (INIS)

    Allis, R.G.

    1994-01-01

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

  11. Shiveluch Volcano, Kamchatka Peninsula, Russia

    Science.gov (United States)

    2001-01-01

    On the night of June 4, 2001, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) captured this thermal image of the erupting Shiveluch volcano. Located on Russia's Kamchatka Peninsula, Shiveluch rises to an altitude of 2,447 meters (8,028 feet). The active lava dome complex is seen as a bright (hot) area on the summit of the volcano. To the southwest, a second hot area is either a debris avalanche or hot ash deposit. Trailing to the west is a 25-kilometer (15-mile) ash plume, seen as a cold 'cloud' streaming from the summit. At least 60 large eruptions have occurred here during the last 10,000 years; the largest historical eruptions were in 1854 and 1964.Because Kamchatka is located along the major aircraft routes between North America/Europe and Asia, this area is constantly monitored for potential ash hazards to aircraft. The area is part of the 'Ring of Fire,' a string of volcanoes that encircles the Pacific Ocean.The lower image is the same as the upper, except it has been color-coded: red is hot, light greens to dark green are progressively colder, and gray/black are the coldest areas.The image is located at 56.7 degrees north latitude, 161.3 degrees east longitude. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

  12. Chiliques volcano, Chile

    Science.gov (United States)

    2002-01-01

    A January 6, 2002 ASTER nighttime thermal infrared image of Chiliques volcano in Chile shows a hot spot in the summit crater and several others along the upper flanks of the edifice, indicating new volcanic activity. Examination of an earlier nighttime thermal infrared image from May 24,2000 showed no thermal anomaly. Chiliques volcano was previously thought to be dormant. Rising to an elevation of 5778 m, Chiliques is a simple stratovolcano with a 500-m-diameter circular summit crater. This mountain is one of the most important high altitude ceremonial centers of the Incas. It is rarely visited due to its difficult accessibility. Climbing to the summit along Inca trails, numerous ruins are encountered; at the summit there are a series of constructions used for rituals. There is a beautiful lagoon in the crater that is almost always frozen.The daytime image was acquired on November 19, 2000 and was created by displaying ASTER bands 1,2 and 3 in blue, green and red. The nighttime image was acquired January 6, 2002, and is a color-coded display of a single thermal infrared band. The hottest areas are white, and colder areas are darker shades of red. Both images cover an area of 7.5 x 7.5 km, and are centered at 23.6 degrees south latitude, 67.6 degrees west longitude.Both images cover an area of 7.5 x 7.5 km, and are centered at 23.6 degrees south latitude, 67.6 degrees west longitude.These images were acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan

  13. 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

  14. Volcano infrasound: A review

    Science.gov (United States)

    Johnson, Jeffrey Bruce; Ripepe, Maurizio

    2011-09-01

    Exploding volcanoes, which produce intense infrasound, are reminiscent of the veritable explosion of volcano infrasound papers published during the last decade. Volcano infrasound is effective for tracking and quantifying eruptive phenomena because it corresponds to activity occurring near and around the volcanic vent, as opposed to seismic signals, which are generated by both surface and internal volcanic processes. As with seismology, infrasound can be recorded remotely, during inclement weather, or in the dark to provide a continuous record of a volcano's unrest. Moreover, it can also be exploited at regional or global distances, where seismic monitoring has limited efficacy. This paper provides a literature overview of the current state of the field and summarizes applications of infrasound as a tool for better understanding volcanic activity. Many infrasound studies have focused on integration with other geophysical data, including seismic, thermal, electromagnetic radiation, and gas spectroscopy and they have generally improved our understanding of eruption dynamics. Other work has incorporated infrasound into volcano surveillance to enhance capabilities for monitoring hazardous volcanoes and reducing risk. This paper aims to provide an overview of volcano airwave studies (from analog microbarometer to modern pressure transducer) and summarizes how infrasound is currently used to infer eruption dynamics. It also outlines the relative merits of local and regional infrasound surveillance, highlights differences between array and network sensor topologies, and concludes with mention of sensor technologies appropriate for volcano infrasound study.

  15. Visions of Volcanoes

    Directory of Open Access Journals (Sweden)

    David M. Pyle

    2017-12-01

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

  16. Chemical compositions of lavas from Myoko volcano group

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  17. Analysis of Distribution of Volcanoes around the Korean Peninsula and the Potential Effects on Korea

    Science.gov (United States)

    Choi, Eun-kyeong; Kim, Sung-wook

    2017-04-01

    Since the scale and disaster characteristics of volcanic eruptions are determined by their geological features, it is important not only to grasp the current states of the volcanoes in neighboring countries around the Korean Peninsula, but also to analyze the tectonic settings, tectonic regions, geological features, volcanic types, and eruption histories of these volcanoes. Volcanic data were based on the volcano information registered with the Global Volcanism Program at the Smithsonian Institute. We created a database of 289 volcanoes around Korea, Japan, China, Taiwan, and the Kamchatka area in Russia, and then identified a high-risk group of 29 volcanoes that are highly likely to affect the region, based on conditions such as volcanic activity, types of rock at risk of eruption, distance from Seoul, and volcanoes having Plinian eruption history with volcanic explosivity index (VEI) of 4 or more. We selected 29 hazardous volcanoes, including Baekdusan, Ulleungdo, and 27 Japanese volcanoes that can cause widespread ashfall on the Korean peninsula by potentially explosive eruptions. In addition, we identified ten volcanoes that should be given the highest priority, through an analysis of data available in literature, such as volcanic ash dispersion results from previous Japanese eruptions, the definition of a large-scale volcano used by Japan's Cabinet Office, and examination of cumulative magma layer volumes from Japan's quaternary volcanoes. We expect that predicting the extent of the spread of ash caused by this hazardous activity and analyzing its impact on the Korean peninsula will be help to predict volcanic ash damage as well as provide direction for hazard mitigation research. Acknowledgements This research was supported by a grant [MPSS-NH-2015-81] through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

  18. What Are Volcano Hazards?

    Science.gov (United States)

    ... 000 square miles in the Western United States. Heavy ash fall can collapse buildings, and even minor ash fall can damage crops, electronics, and machinery. Volcanic Gases Volcanoes emit gases during eruptions. Even ...

  19. Japan 2003

    DEFF Research Database (Denmark)

    Ørstrup, Finn Rude; Hvass, Sven

    2003-01-01

    Kompendium udarbejdet til en studierejse til Japan  2003 Kunstakademiets Arkitektskole, Studieafdeling 10......Kompendium udarbejdet til en studierejse til Japan  2003 Kunstakademiets Arkitektskole, Studieafdeling 10...

  20. Alaska - Kamchatka Connection in Volcano Monitoring, Research, and Education

    Science.gov (United States)

    Izbekov, P. E.; Gordeev, E.; Eichelberger, J. C.; Neal, C. A.

    2009-12-01

    The Aleutian-Kamchatka portion of the Pacific Rim of Fire spans ~4400 km. This segment contains more than 80 active volcanoes and averages 4-6 eruptions per year. Resulting ash clouds travel for hundreds to thousands of kilometers defying political borders. To mitigate volcano hazard to aviation and local communities, the Alaska Volcano Observatory (AVO) and the Institute of Volcanology and Seismology (IVS), in partnership with the Kamchatkan Branch of the Geophysical Survey of the Russian Academy of Sciences (KBGS), have established a collaborative program with three important components: (1) volcano monitoring with rapid information exchange, (2) cooperation in research projects at active volcanoes, and (3) a series of volcanological schools for students and young scientists. Cooperation in volcano monitoring includes dissemination of daily information on the state of volcanic activity in neighboring regions, satellite and visual data exchange, as well as sharing expertise and technologies between AVO and the Kamchatkan Volcanic Eruption Response Team (KVERT), formed in 1993 under the auspices of both IVS and KBGS. Collaboration in scientific research is best illustrated by involvement of AVO, IVS, and KBGS faculty and graduate students in mutual international studies. One of the most recent examples is the NSF-funded Partnerships for International Research and Education (PIRE)-Kamchatka project focusing on multi-disciplinary study of Bezymianny volcano in Kamchatka. This international project is one of many that have been initiated as a direct result of a bi-annual series of meetings known as Japan-Kamchatka-Alaska Subduction Processes (JKASP) workshops that we organize together with colleagues from Hokkaido University, Japan. The most recent JKASP meeting was held in June 2009 in Fairbanks, Alaska and brought together more than 150 scientists and students. The key educational component of our collaborative program is the continuous series of international

  1. 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....

  2. Ice-clad volcanoes

    Science.gov (United States)

    Waitt, Richard B.; Edwards, B.R.; Fountain, Andrew G.; Huggel, C.; Carey, Mark; Clague, John J.; Kääb, Andreas

    2015-01-01

    An icy volcano even if called extinct or dormant may be active at depth. Magma creeps up, crystallizes, releases gas. After decades or millennia the pressure from magmatic gas exceeds the resistance of overlying rock and the volcano erupts. Repeated eruptions build a cone that pokes one or two kilometers or more above its surroundings - a point of cool climate supporting glaciers. Ice-clad volcanic peaks ring the northern Pacific and reach south to Chile, New Zealand, and Antarctica. Others punctuate Iceland and Africa (Fig 4.1). To climb is irresistible - if only “because it’s there” in George Mallory’s words. Among the intrepid ascents of icy volcanoes we count Alexander von Humboldt’s attempt on 6270-meter Chimborazo in 1802 and Edward Whymper’s success there 78 years later. By then Cotopaxi steamed to the north.

  3. 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).

  4. Anatomy of a volcano

    NARCIS (Netherlands)

    Hooper, A.; Wassink, J.

    2011-01-01

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

  5. Spying on volcanoes

    Science.gov (United States)

    Watson, Matthew

    2017-07-01

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

  6. 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

  7. 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.

  8. Alaska - Russian Far East connection in volcano research and monitoring

    Science.gov (United States)

    Izbekov, P. E.; Eichelberger, J. C.; Gordeev, E.; Neal, C. A.; Chebrov, V. N.; Girina, O. A.; Demyanchuk, Y. V.; Rybin, A. V.

    2012-12-01

    The Kurile-Kamchatka-Alaska portion of the Pacific Rim of Fire spans for nearly 5400 km. It includes more than 80 active volcanoes and averages 4-6 eruptions per year. Resulting ash clouds travel for hundreds to thousands of kilometers defying political borders. To mitigate volcano hazard to aviation and local communities, the Alaska Volcano Observatory (AVO) and the Institute of Volcanology and Seismology (IVS), in partnership with the Kamchatkan Branch of the Geophysical Survey of the Russian Academy of Sciences (KBGS), have established a collaborative program with three integrated components: (1) volcano monitoring with rapid information exchange, (2) cooperation in research projects at active volcanoes, and (3) volcanological field schools for students and young scientists. Cooperation in volcano monitoring includes dissemination of daily information on the state of volcanic activity in neighboring regions, satellite and visual data exchange, as well as sharing expertise and technologies between AVO and the Kamchatkan Volcanic Eruption Response Team (KVERT) and Sakhalin Volcanic Eruption Response Team (SVERT). Collaboration in scientific research is best illustrated by involvement of AVO, IVS, and KBGS faculty and graduate students in mutual international studies. One of the most recent examples is the NSF-funded Partnerships for International Research and Education (PIRE)-Kamchatka project focusing on multi-disciplinary study of Bezymianny volcano in Kamchatka. This international project is one of many that have been initiated as a direct result of a bi-annual series of meetings known as Japan-Kamchatka-Alaska Subduction Processes (JKASP) workshops that we organize together with colleagues from Hokkaido University, Japan. The most recent JKASP meeting was held in August 2011 in Petropavlovsk-Kamchatsky and brought together more than 130 scientists and students from Russia, Japan, and the United States. The key educational component of our collaborative program

  9. Shiveluch and Klyuchevskaya Volcanoes

    Science.gov (United States)

    2007-01-01

    A distance of about 80 kilometers (50 miles) separates Shiveluch and Klyuchevskaya Volcanoes on Russia's Kamchatka Peninsula. Despite this distance, however, the two acted in unison on April 26, 2007, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite caught them both erupting simultaneously. ASTER 'sees' a slightly different portion of the light spectrum than human eyes. Besides a portion of visible light, ASTER detects thermal energy, meaning it can detect volcanic activity invisible to human eyes. Inset in each image above is a thermal infrared picture of the volcano's summit. In these insets, dark red shows where temperatures are coolest, and yellowish-white shows where temperatures are hottest, heated by molten lava. Both insets show activity at the crater. In the case of Klyuchevskaya, some activity at the crater is also visible in the larger image. In the larger images, the landscapes around the volcanoes appear in varying shades of blue-gray. Dark areas on the snow surface are likely stains left over from previous eruptions of volcanic ash. Overhead, clouds dot the sky, casting their shadows on the snow, especially southeast of Shiveluch and northeast of Klyuchevskaya. To the northwest of Klyuchevskaya is a large bank of clouds, appearing as a brighter white than the snow surface. Shiveluch (sometimes spelled Sheveluch) and Klyuchevskaya (sometimes spelled Klyuchevskoy or Kliuchevskoi) are both stratovolcanoes composed of alternating layers of hardened lava, solidified ash, and rocks from earlier eruptions. Both volcanoes rank among Kamchatka's most active. Because Kamchatka is part of the Pacific 'Ring of Fire,' the peninsula experiences regular seismic activity as the Pacific Plate slides below other tectonic plates in the Earth's crust. Large-scale plate tectonic activity causing simultaneous volcanic eruptions in Kamchatka is not uncommon.

  10. Volcanoes can generate devastating waves

    Science.gov (United States)

    1988-01-01

    Explosions. Noxious gases. Lava fountains and flows. Avalanches of superheated pyroclastics. Although volcanic eruptions can cause all these frightening phenomena, it is often the power of the sea that causes many volcano-related deaths. this destruction comes from tsunamis (huge volcano-generated waves) Roughly one-fourth of the deaths occurring during volcanic eruptions have been the result of tsunamis. Moreover a tsunami can transmit the volcano's energy to areas well outside the reach of the eruption itself. 

  11. Dangers Files Data: January-February 1979

    Science.gov (United States)

    1979-05-01

    001 010 740 000 000 001 004 002 002 0C6 001 JAPAN NATURAL DISASTER: One of the three volcanoes In Sakura-jima, a southern peninsula in Japan’s...004 NUCLEAR ARMS PROTEST: The USA nuclear submarine Haddo is boarded by a man protesting nuclear arms as It enters Auckland Harbor for a six day visit...INDONESIA VOLCANO : The M . SinIla volcano In central 2ava Is erupting, spewing out poisonous gases and lava that have kIlled at least 155 persons and

  12. Using thermal remanent magnetisation (TRM) to distinguish block and ash flow and debris flow deposits, and to estimate their emplacement temperature: 1991-1995 lava dome eruption at Mt. Unzen Volcano, Japan

    Science.gov (United States)

    Uehara, D.; Cas, R. A. F.; Folkes, C.; Takarada, S.; Oda, H.; Porreca, M.

    2015-09-01

    The 1991-1995 Mt. Unzen eruption (Kyushu, Japan) produced 13 lava domes, approximately 9400 block and ash pyroclastic flows (BAF) resulting from lava dome collapse events and syn- and post-dome collapse debris flow (DF) events. In the field, it can be very difficult to distinguish from field facies characteristics which deposits are primary hot BAF, cold BAF or rock avalanche, or secondary DF deposits. In this study we use a combination of field observations and thermal remanent magnetisation (TRM) analysis of juvenile, lava dome derived clasts from seven deposits of the 1991-1995 Mt. Unzen eruption in order to distinguish between primary BAF deposits and secondary DF deposits and to determine their emplacement temperature. Four major TRM patterns were identified: (1) Type I: clasts with a single magnetic component oriented parallel to the Earth's magnetic field at time and site of emplacement. This indicates that these deposits were deposited at very high temperature, between the Curie temperature of magnetite (~ 540 °C) and the glass transition temperature of the lava dome (~ 745 °C). These clasts are found in high temperature BAF deposits. (2) Type II: clasts with two magnetic components of magnetisation. The lower temperature magnetic components are parallel to the Earth's magnetic field at time of the Unzen eruption. Temperature estimations for these deposits can range from 80 to 540 °C. We found this paleomagnetic behaviour in moderate temperature BAF or warm DF deposits. (3) Type III: clasts with three magnetic components, with a lower temperature component oriented parallel to the Earth's magnetic field at Unzen. The individual clast temperatures estimated for this kind of deposit are usually less than 300 °C. We interpret this paleomagnetic behaviour as the effect of different thermal events during their emplacement history. There are several interpretations for this paleomagnetic behaviour including remobilisation of moderate temperature BAF, warm DF

  13. Networking Japan

    DEFF Research Database (Denmark)

    Hansen, Annette Skovsted

    and activities in Japan. One concrete example was the earthquake relief Japan received from alumni in 2011. The exchanges have also already inspired an explicit focus on private sector and middle income countries in the Japanese Development Cooperation Charter announced in February 2015.......Human Resource Development was the first and remains an important pillar in Japanese foreign aid. I will argue that Japan has access to a global network of alumni who will co-define Japanese foreign aid in the future, because Japan has encouraged alumni societies and networking since 1965. A total...... of more than a million people in more than 100 countries have attended courses in Japan funded fully or partly by Japanese ODA since the inception of the technical assistance programs in 1954 through the Colombo Plan and since 1959 through the Association of Overseas Technical Scholarships (AOTS from 2009...

  14. ‘New’ Antarctic volcanos

    Science.gov (United States)

    Two previously unknown volcanos that show evidence o f recent eruptions were discovered in March on the east side of the Antarctic Peninsula, according to the National Science Foundation. The discovery brings to five the number of known active volcanos on the continent.Volcanic debris still covers a large swath of the adjacent Larsen Ice Shelf, pointing to very recent activity. In addition, one of the volcanos was steaming when the discovery was made, reports Oscar Gonzalez-Ferran of the University of Chile at Santiago. He made the discovery while doing a geophysical survey by helicopter of the Antarctic Peninsula. The two volcanos constitute the southernmost extension of the eastern side of the ‘ring of fire,’ a ring of volcanos that is believed to mark the active subduction zone on the periphery of the Pacific Ocean.

  15. 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

  16. Volcano spacing and plate rigidity

    Science.gov (United States)

    ten Brink, Uri S.

    1991-01-01

    In-plane stresses, which accompany the flexural deformation of the lithosphere under the load of adjacent volcanoes, may govern the spacing of volcanoes in hotspot provinces. Specifically, compressive stresses in the vicinity of a volcano prevent new upwelling in this area, forcing a new volcano to develop at a minimum distance that is equal to the distance in which the radial stresses change from compressional to tensile (the inflection point). If a volcano is modeled as a point load on a thin elastic plate, then the distance to the inflection point is proportional to the thickness of the plate to the power of 3/4. Compilation of volcano spacing in seven volcanic groups in East Africa and seven volcanic groups of oceanic hotspots shows significant correlation with the elastic thickness of the plate and matches the calculated distance to the inflection point. In contrast, volcano spacing in island arcs and over subduction zones is fairly uniform and is much larger than predicted by the distance to the inflection point, reflecting differences in the geometry of the source and the upwelling areas.

  17. 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.

  18. Radar Image, Hokkaido, Japan

    Science.gov (United States)

    2000-01-01

    The southeast part of the island of Hokkaido, Japan, is an area dominated by volcanoes and volcanic caldera. The active Usu Volcano is at the lower right edge of the circular Lake Toya-Ko and near the center of the image. The prominent cone above and to the left of the lake is Yotei Volcano with its summit crater. The city of Sapporo lies at the base of the mountains at the top of the image and the town of Yoichi -- the hometown of SRTM astronaut Mamoru Mohri -- is at the upper left edge. The bay of Uchiura-Wan takes up the lower center of the image. In this image, color represents elevation, from blue at the lowest elevations to white at the highest. The radar image has been overlaid to provide more details of the terrain. Due to a processing problem, an island in the center of this crater lake is missing and will be properly placed when further SRTM swaths are processed. The horizontal banding in this image is a processing artifact that will be removed when the navigation information collected by SRTM is fully calibrated. This image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC. Size: 100 by 150 kilometers (62

  19. 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...

  20. Volcano warning systems: Chapter 67

    Science.gov (United States)

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

    2015-01-01

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

  1. 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...

  2. Mechanism of Phreatic Eruptions at Aso Volcano Inferred from Near-Field Broadband Seismic Observations

    Science.gov (United States)

    Kaneshima, Satoshi; Kawakatsu, Hitoshi; Matsubayashi, Hirotoshi; Sudo, Yasuaki; Tsutsui, Tomoki; Ohminato, Takao; Ito, Hisao; Uhira, Koichi; Yamasato, Hitoshi; Oikawa, Jun; Takeo, Minoru; Lidaka, Takashi

    1996-08-01

    Broadband seismometers deployed at Aso volcano in Japan have detected a hydrothermal reservoir 1 to 1.5 kilometers beneath the crater that is continually resonating with periods as long as 15 seconds. When phreatic eruptions are observed, broadband seismograms elucidate a dynamic interplay between the reservoir and discharging flow along the conduit: gradual pressurization and long-period (~20 seconds) pulsations of the reservoir during the 100 to 200 seconds before the initiation of the discharge, followed by gradual deflation of the reservoir concurrent with the discharging flow. The hydrothermal reservoir, where water and heat from the deeper magma chamber probably interact, appears to help control the surface activity at Aso volcano.

  3. "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

  4. Thermal surveillance of volcanoes

    Science.gov (United States)

    Friedman, J. D. (Principal Investigator)

    1972-01-01

    The author has identified the following significant results. A systematic aircraft program to monitor changes in the thermal emission from volcanoes of the Cascade Range has been initiated and is being carried out in conjunction with ERTS-1 thermal surveillance experiments. Night overflights by aircraft equipped with thermal infrared scanners sensitive to terrestrial emission in the 4-5.5 and 8-14 micron bands are currently being carried out at intervals of a few months. Preliminary results confirm that Mount Rainier, Mount Baker, Mount Saint Helens, Mount Shasta, and the Lassen area continue to be thermally active, although with the exception of Lassen which erupted between 1914 and 1917, and Mount Saint Helens which had a series of eruptions between 1831 and 1834, there has been no recent eruptive activity. Excellent quality infrared images recorded over Mount Rainier, as recently as April, 1972, show similar thermal patterns to those reported in 1964-1966. Infrared images of Mount Baker recorded in November 1970 and again in April 1972 revealed a distinct array of anomalies 1000 feet below the crater rim and associated with fumaroles or structures permitting convective heat transfer to the surface.

  5. Japan 2014

    DEFF Research Database (Denmark)

    Selmer, Finn

    2014-01-01

    In March 2014 a group of teachers and students from the Royal Danish Academy of Fine Arts Schools of Architecture, Design and Conservation, School of Architecture, Study Dept. 3 went on a study trip to Japan. This publication collects observations and reflections that the participants of the trip...

  6. An unusual volcano on Venus

    Science.gov (United States)

    Moore, H. J.; Plaut, J. J.; Schenk, P. M.; Head, J. W.

    1992-01-01

    Materials that issued from an unusual Venusian volcano produced (1) a complex domical structure about 100 km across with thick, broad flow lobes up to 41 wide, (2) an extensive sheet of thick flows, and (3) radar-bright surfaces that extend to 360-400 km from the volcano. Altimetry indicates that the relief of the domical structure is about 0.5-1.1 km. The lobes and flows have prominant regularly spaced ridges about 686-820 m apart. Thick flows with large ridge separations and broad lobes are rare on Venus. The viscosities of these flows were larger than those of most lava flows on Venus. Comparisons of the dimensions of the volcano's lobes with lava flows on earth suggest that the Venusian lavas may have large silica contents. Radar-bright surfaces around the volcano may represent the result of an explosive eruption or very thin deposits of low-viscosity lavas. Thus, the radar-bright surfaces and lavas of the volcano were derived from a magma that differentiated within the crust or mantle of Venus. The differentiation produced (1) a gas-rich low-viscosity phase, (2) high-viscosity lavas, and (3) a residual primary magma.

  7. Lifespans of Cascade Arc volcanoes

    Science.gov (United States)

    Calvert, A. T.

    2015-12-01

    Compiled argon ages reveal inception, eruptive episodes, ages, and durations of Cascade stratovolcanoes and their ancestral predecessors. Geologic mapping and geochronology show that most Cascade volcanoes grew episodically on multiple scales with periods of elevated behavior lasting hundreds of years to ca. 100 kyr. Notable examples include the paleomag-constrained, few-hundred-year-long building of the entire 15-20 km3 Shastina edifice at Mt. Shasta, the 100 kyr-long episode that produced half of Mt. Rainier's output, and the 30 kyr-long episode responsible for all of South and Middle Sister. Despite significant differences in timing and rates of construction, total durations of active and ancestral volcanoes at discrete central-vent locations are similar. Glacier Peak, Mt. Rainier, Mt. Adams, Mt. Hood, and Mt. Mazama all have inception ages of 400-600 ka. Mt. St. Helens, Mt. Jefferson, Newberry Volcano, Mt. Shasta and Lassen Domefield have more recent inception ages of 200-300 ka. Only the Sisters cluster and Mt. Baker have established eruptive histories spanning less than 50 kyr. Ancestral volcanoes centered 5-20 km from active stratocones appear to have similar total durations (200-600 kyr), but are less well exposed and dated. The underlying mechanisms governing volcano lifecycles are cryptic, presumably involving tectonic and plumbing changes and perhaps circulation cycles in the mantle wedge, but are remarkably consistent along the arc.

  8. Global Volcano Hazard Frequency and Distribution

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Volcano Hazard Frequency and Distribution is a 2.5 minute gridded data set based upon the National Geophysical Data Center (NGDC) Volcano Database spanning...

  9. Global Volcano Mortality Risks and Distribution

    Data.gov (United States)

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

  10. Global Volcano Proportional Economic Loss Risk Deciles

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Volcano Proportional Economic Loss Risk Deciles is a 2.5 minute grid of volcano hazard economic loss as proportions of Gross Domestic Product (GDP) per...

  11. Global Volcano Total Economic Loss Risk Deciles

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Volcano Total Economic Loss Risk Deciles is a 2.5 minute grid of global volcano total economic loss risks. First, subnational distributions of Gross Domestic...

  12. 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

  13. 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.

  14. Volcano Hazards - A National Threat

    Science.gov (United States)

    ,

    2006-01-01

    When the violent energy of a volcano is unleashed, the results are often catastrophic. The risks to life, property, and infrastructure from volcanoes are escalating as more and more people live, work, play, and travel in volcanic regions. Since 1980, 45 eruptions and 15 cases of notable volcanic unrest have occurred at 33 U.S. volcanoes. Lava flows, debris avalanches, and explosive blasts have invaded communities, swept people to their deaths, choked major riverways, destroyed bridges, and devastated huge tracts of forest. Noxious volcanic gas emissions have caused widespread lung problems. Airborne ash clouds have disrupted the health, lives, and businesses of hundreds of thousands of people; caused millions of dollars of aircraft damage; and nearly brought down passenger flights.

  15. Multiphase modelling of mud volcanoes

    Science.gov (United States)

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

    2015-04-01

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

  16. Of Rings and Volcanoes

    Science.gov (United States)

    2002-01-01

    show it. The bright spot close to the equator is the remnant of a giant storm in Saturn's extended atmosphere that has lasted more than 5 years. The present photo provides what is possibly the sharpest view of the ring system ever achieved from a ground-based observatory . Many structures are visible, the most obvious being the main ring sections, the inner C-region (here comparatively dark), the middle B-region (here relatively bright) and the outer A-region, and also the obvious dark "divisions", including the well-known, broad Cassini division between the A- and B-regions, as well as the Encke division close to the external edge of the A-region and the Colombo division in the C-region. Moreover, many narrow rings can be seen at this high image resolution , in particular within the C-region - they may be compared with those seen by the Voyager spacecraft during the flybys, cf. the weblinks below. This image demonstrates the capability of NAOS-CONICA to observe also extended objects with excellent spatial resolution. It is a composite of four short-exposure images taken through the near-infrared H (wavelength 1.6 µm) and K (2.2 µm) filters. This observation was particularly difficult because of the motion of Saturn during the exposure. To provide the best possible images, the Adaptive Optics system of NAOS was pointed towards the Saturnian moon Tethys , while the image of Saturn was kept at a fixed position on the CONICA detector by means of "differential tracking" (compensating for the different motions in the sky of Saturn and Tethys). This is also why the (faint) image of Tethys - visible south of Saturn (i.e., below the planet in PR Photo 04a/02 ) - appears slightly trailed. Io - volcanoes and sulphur ESO PR Photo 04b/02 ESO PR Photo 04b/02 [Preview - JPEG: 400 x 478 pix - 39k] [Normal - JPEG: 800 x 955 pix - 112k] ESO PR Photo 04c/02 ESO PR Photo 04c/02 [Preview - JPEG: 400 x 469 pix - 58k] [Normal - JPEG: 800 x 937 pix - 368k] Caption : PR Photo 04b/02 shows

  17. Okinawa, Japan

    Science.gov (United States)

    1991-01-01

    The southern half of the island of Okinawa, Japan (26.5N, 128.0E) can be seen in this nearly cloud free view. Okinawa is part of the Ryuku Islands which extend from Taiwan northeastward to Kyushu, southernmost of the Japanese Home Islands. The large military base at Kadena, with large runways, is visible near the center of the scene. Kadena is one of several emergency landing sites around the world for the space shuttle.

  18. What Happened to Our Volcano?

    Science.gov (United States)

    Mangiante, Elaine Silva

    2006-01-01

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

  19. Morphometry of terrestrial shield volcanoes

    Science.gov (United States)

    Grosse, Pablo; Kervyn, Matthieu

    2018-03-01

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

  20. Wind Energy Japan

    Energy Technology Data Exchange (ETDEWEB)

    Komatsubara, Kazuyo [Embassy of the Kingdom of the Netherlands, Tokyo (Japan)

    2012-06-15

    An overview is given of wind energy in Japan: Background; Wind Energy in Japan; Japanese Wind Energy Industry; Government Supports; Useful Links; Major Japanese Companies; Profiles of Major Japanese Companies; Major Wind Energy Projects in Japan.

  1. Preliminary Volcano-Hazard Assessment for Redoubt Volcano, Alaska

    Science.gov (United States)

    Waythomas, Christopher F.; Dorava, Joseph M.; Miller, Thomas P.; Neal, Christina A.; McGimsey, Robert G.

    1997-01-01

    Redoubt Volcano is a stratovolcano located within a few hundred kilometers of more than half of the population of Alaska. This volcano has erupted explosively at least six times since historical observations began in 1778. The most recent eruption occurred in 1989-90 and similar eruptions can be expected in the future. The early part of the 1989-90 eruption was characterized by explosive emission of substantial volumes of volcanic ash to altitudes greater than 12 kilometers above sea level and widespread flooding of the Drift River valley. Later, the eruption became less violent, as developing lava domes collapsed, forming short-lived pyroclastic flows associated with low-level ash emission. Clouds of volcanic ash had significant effects on air travel as they drifted across Alaska, over Canada, and over parts of the conterminous United States causing damage to jet aircraft. Economic hardships were encountered by the people of south-central Alaska as a result of ash fallout. Based on new information gained from studies of the 1989-90 eruption, an updated assessment of the principal volcanic hazards is now possible. Volcanic hazards from a future eruption of Redoubt Volcano require public awareness and planning so that risks to life and property are reduced as much as possible.

  2. 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...

  3. Venus - Volcano With Massive Landslides

    Science.gov (United States)

    1992-01-01

    This Magellan full-resolution mosaic which covers an area 143 by 146 kilometers (89 by 91 miles) is centered at 55 degrees north latitude, 266 degrees east longitude. The bright feature, slightly south of center is interpreted to be a volcano, 15-20 kilometers (9.3 to 12.4 miles) in diameter with a large apron of blocky debris to its right and some smaller aprons to its left. A preferred explanation is that several massive catastrophic landslides dropped down steep slopes and were carried by their momentum out into the smooth, dark lava plains. At the base of the east-facing or largest scallop on the volcano is what appears to be a large block of coherent rock, 8 to 10 kilometers (5 to 6 miles) in length. The similar margin of both the scallop and block and the shape in general is typical of terrestrial slumped blocks (masses of rock which slide and rotate down a slope instead of breaking apart and tumbling). The bright lobe to the south of the volcano may either be a lava flow or finer debris from other landslides. This volcanic feature, characterized by its scalloped flanks is part of a class of volcanoes called scalloped or collapsed domes of which there are more than 80 on Venus. Based on the chute-like shapes of the scallops and the existence of a spectrum of intermediate to well defined examples, it is hypothesized that all of the scallops are remnants of landslides even though the landslide debris is often not visible. Possible explanations for the missing debris are that it may have been covered by lava flows, the debris may have weathered or that the radar may not be recognizing it because the individual blocks are too small

  4. JAPAN'S TECHNOLOGY TRADE

    OpenAIRE

    Hagiwara, Taiji

    1994-01-01

    Japan's technology balance of trade has improved over the last twenty years. The position of Japan is examined through (1) comparison with other OECD countries, (2) the historical change in Japan's technology trade at the industry level, (3) Toshiba's technology trade as a typical case. The conclusion is that Japan is still behind the frontier of innovation.

  5. The Pressure Sources Beneath Unzen Volcano Inferred From Geodesic Survey

    Science.gov (United States)

    Kohno, Y.; Matsushima, T.; Shimizu, H.

    2004-12-01

    Unzen Volcano, which is located on Shimabara Peninsula, west Kyushu Island, Japan, erupted from 1990 to 1995. The ground deformations caused by volcanic activity were observed by several methods, such as Leveling survey, GPS and Tilt meters. In particular, it turned out from leveling data that the west coast area of Shimabara Peninsula sank about 8 cm since eruption had started. Joint Research Team of the national Universities suggested in 1992 that the model which has three pressure sources, could explain the ground deformation data in those days. But this model couldn_ft explain the leveling data which was observed after the eruption had stopped. In order to explain this latest leveling data, we had to add the fourth deeper pressure source beneath the Chidiwa Bay, confronted in the west seashore of the Shimabara peninsula (Matsushima et al., 2003; Kohno et al., 2003). In this study, we re-consider the source model beneath Unzen Volcano, using 1991-2001 and 2004 Leveling data along the northern flank of Unzen Volcano and the western coast of Shimabara peninsula. Also we use GPS data monitored by Kyushu University and Geographical Survey Institute. In calculation, both vertical and horizontal displacement was calculated applying the point source model (e.g. Mogi, 1958), and we get the best-fit source parameters. Parameters of the pressure sources are the location and the volume changes of pressure sources. Through the model calculation, the half-infinite surface was made for every height of each observation point, and geographical feature was reproduced in approximation. Analysis showed that after 1995 shallower source had started to deflate, on the other hand, two deeper sources still had kept expanding caused by intrusion of magma. After 1999, three shallower sources had begun to contract, and the only deepest (a depth of 15 km) source had expanded. But it is inferred from the 2004 Leveling that the deepest source turned to contract since 2001, and the all

  6. 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

  7. Volcano Flank Terraces on Mars

    Science.gov (United States)

    Byrne, P. K.; van Wyk de Vries, B.; Murray, J. B.; Troll, V. R.

    2008-12-01

    Flank terraces are bulge-like structures that occur on the slopes of at least nine large shield volcanoes on Mars, and three on Earth. Terraces have a convex-upward, convex-outward morphology, with an imbricate "fish scale" stacking pattern in plan. They occur at all elevations, are scale-invariant structures, and have similar proportions to thrust faults on Earth. Suggested mechanisms of formation include elastic self-loading, lithospheric flexure, magma chamber tumescence, flank relaxation, and shallow gravitational slumping. Terrace geometries predicted by most of these mechanisms do not agree with our observations, however. Only lithospheric flexure can fully account for terrace geometry on Mars and Earth, and so is the most likely candidate mechanism for flank terrace formation. To verify this hypothesis, we conducted scaled analogue modelling experiments, and investigated the structures formed during flexure. Cones of a sand-gypsum mix were placed upon a deep layer of silicone gel, to simulate volcanic loads upon viscoelastic Martian crust. Key parameters were varied across our experimental program. In all cases convex topographic structures developed on the cones' flanks, arranged in an imbricate, overlapping plan-view pattern. These structures closely resemble flank terraces observed on Mars, and our results provide for a basic kinematic model of terrace formation. Analogue volcanoes experienced a decrease in upper surface area whilst volume was conserved; the contractional surface strain was accommodated by outward verging, circumferentially striking thrusts. The morphology of experimental structures suggests an orientation of the principal stress axes of σ1 = radial, σ2 = concentric, and σ3 = vertical. Elsewhere (J. B. Murray et al., this volume) we detail the relationship between flank terraces and other structures such as pit craters and gräben, using Ascraeus Mons as a case study. We suggest that terraces may influence the distribution and location

  8. 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.

  9. The 2014 eruptions of Pavlof Volcano, Alaska

    Science.gov (United States)

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

    2017-12-22

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

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

    African Journals Online (AJOL)

    AJL

    association between the mud volcanoes suggests different nature and depth of parent layers and fluids feeding the mud volcanoes in gulf of Cadiz. Key word: Mud volcano, clay mineralogy, geochemistry, mud breccias, North Moroccan Atlantic margin. INTRODUCTION. The study of marine mud volcanoes is of large interest ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Furumoto, A. S.

    1974-01-01

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

  12. 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

  13. Monitoring eruption activity using temporal stress changes at Mount Ontake volcano.

    Science.gov (United States)

    Terakawa, Toshiko; Kato, Aitaro; Yamanaka, Yoshiko; Maeda, Yuta; Horikawa, Shinichiro; Matsuhiro, Kenjiro; Okuda, Takashi

    2016-02-19

    Volcanic activity is often accompanied by many small earthquakes. Earthquake focal mechanisms represent the fault orientation and slip direction, which are influenced by the stress field. Focal mechanisms of volcano-tectonic earthquakes provide information on the state of volcanoes via stresses. Here we demonstrate that quantitative evaluation of temporal stress changes beneath Mt. Ontake, Japan, using the misfit angles of focal mechanism solutions to the regional stress field, is effective for eruption monitoring. The moving average of misfit angles indicates that during the precursory period the local stress field beneath Mt. Ontake was deviated from the regional stress field, presumably by stress perturbations caused by the inflation of magmatic/hydrothermal fluids, which was removed immediately after the expulsion of volcanic ejecta. The deviation of the local stress field can be an indicator of increases in volcanic activity. The proposed method may contribute to the mitigation of volcanic hazards.

  14. Improved detection of preeruptive seismic velocity drops at the Piton de La Fournaise volcano

    Science.gov (United States)

    Rivet, Diane; Brenguier, Florent; Cappa, Frédéric

    2015-08-01

    The unexpected 2014 and 2015 Ontake (Japan) and Calbuco (Chile) eruptions proved that improving volcanic eruption prediction is still a great challenge. Decreases of seismic velocities of the Piton de la Fournaise volcano inferred from seismic noise correlations have been shown to precede eruptions. However, seismic velocities are strongly influenced by rainfall and subsequent pore pressure perturbations. Here we increase the detection of precursory seismic velocity changes to an eruption by removing the effects of pore pressure changes. During 2011-2013, the volcano exhibits a low eruptive activity during which we observe seismic velocity variations well correlated with rainfall episodes. We estimated the transfer function between fluid pressure and seismic velocity changes. We use these results to correct seismic velocity change time series for pore pressure changes, due to rainfall and found a preeruptive velocity drop (0.15%) associated with the 21 June 2014 eruption that was undetected before correction.

  15. Volcanoes

    Science.gov (United States)

    ... About CDC.gov . Natural Disasters and Severe Weather Earthquakes Being Prepared Emergency Supplies Home Hazards Indoor Safety ... Are You Prepared? Information for Specific Groups Disaster Evacuation Centers Infection Control Infection Control Guidance for Community ...

  16. 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.

  17. Mud Volcanoes - Analogs to Martian Cones and Domes (by the thousands !)

    Science.gov (United States)

    Allen, C.; Oehler, D.

    2010-12-01

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

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

    Science.gov (United States)

    Allen, Carlton C.; Oehler, Dorothy

    2010-01-01

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

  19. Earthquake sources near Uturuncu Volcano

    Science.gov (United States)

    Keyson, L.; West, M. E.

    2013-12-01

    Uturuncu, located in southern Bolivia near the Chile and Argentina border, is a dacitic volcano that was last active 270 ka. It is a part of the Altiplano-Puna Volcanic Complex, which spans 50,000 km2 and is comprised of a series of ignimbrite flare-ups since ~23 ma. Two sets of evidence suggest that the region is underlain by a significant magma body. First, seismic velocities show a low velocity layer consistent with a magmatic sill below depths of 15-20 km. This inference is corroborated by high electrical conductivity between 10km and 30km. This magma body, the so called Altiplano-Puna Magma Body (APMB) is the likely source of volcanic activity in the region. InSAR studies show that during the 1990s, the volcano experienced an average uplift of about 1 to 2 cm per year. The deformation is consistent with an expanding source at depth. Though the Uturuncu region exhibits high rates of crustal seismicity, any connection between the inflation and the seismicity is unclear. We investigate the root causes of these earthquakes using a temporary network of 33 seismic stations - part of the PLUTONS project. Our primary approach is based on hypocenter locations and magnitudes paired with correlation-based relative relocation techniques. We find a strong tendency toward earthquake swarms that cluster in space and time. These swarms often last a few days and consist of numerous earthquakes with similar source mechanisms. Most seismicity occurs in the top 10 kilometers of the crust and is characterized by well-defined phase arrivals and significant high frequency content. The frequency-magnitude relationship of this seismicity demonstrates b-values consistent with tectonic sources. There is a strong clustering of earthquakes around the Uturuncu edifice. Earthquakes elsewhere in the region align in bands striking northwest-southeast consistent with regional stresses.

  20. 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.

  1. Eruption of Alaska volcano breaks historic pattern

    Science.gov (United States)

    Larsen, Jessica; Neal, Christina A.; Webley, Peter; Freymueller, Jeff; Haney, Matthew; McNutt, Stephen; Schneider, David; Prejean, Stephanie; Schaefer, Janet; Wessels, Rick L.

    2009-01-01

    In the late morning of 12 July 2008, the Alaska Volcano Observatory (AVO) received an unexpected call from the U.S. Coast Guard, reporting an explosive volcanic eruption in the central Aleutians in the vicinity of Okmok volcano, a relatively young (~2000-year-old) caldera. The Coast Guard had received an emergency call requesting assistance from a family living at a cattle ranch on the flanks of the volcano, who reported loud "thunder," lightning, and noontime darkness due to ashfall. AVO staff immediately confirmed the report by observing a strong eruption signal recorded on the Okmok seismic network and the presence of a large dark ash cloud above Okmok in satellite imagery. Within 5 minutes of the call, AVO declared the volcano at aviation code red, signifying that a highly explosive, ash-rich eruption was under way.

  2. Moessbauer Spectroscopy study of Quimsachata Volcano materials

    International Nuclear Information System (INIS)

    Dominguez, A.G.B.

    1988-01-01

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

  3. Eruption of Alaska Volcano Breaks Historic Pattern

    Science.gov (United States)

    Larsen, Jessica; Neal, Christina; Webley, Peter; Freymueller, Jeff; Haney, Matthew; McNutt, Stephen; Schneider, David; Prejean, Stephanie; Schaefer, Janet; Wessels, Rick

    2009-05-01

    In the late morning of 12 July 2008, the Alaska Volcano Observatory (AVO) received an unexpected call from the U.S. Coast Guard, reporting an explosive volcanic eruption in the central Aleutians in the vicinity of Okmok volcano, a relatively young (˜2000-year-old) caldera. The Coast Guard had received an emergency call requesting assistance from a family living at a cattle ranch on the flanks of the volcano, who reported loud “thunder,” lightning, and noontime darkness due to ashfall. AVO staff immediately confirmed the report by observing a strong eruption signal recorded on the Okmok seismic network and the presence of a large dark ash cloud above Okmok in satellite imagery. Within 5 minutes of the call, AVO declared the volcano at aviation code red, signifying that a highly explosive, ash-rich eruption was under way.

  4. 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.

  5. Volcano Inflation prior to Gas Explosions at Semeru Volcano, Indonesia

    Science.gov (United States)

    Nishimura, T.; Iguchi, M.; Kawaguchi, R.; Surono, S.; Hendrasto, M.; Rosadi, U.

    2010-12-01

    Semeru volcano in east Java, Indonesia, is well known to exhibit small vulcanian eruptions at the summit crater. Such eruptive activity stopped on April 2009, but volcanic earthquakes started to occur in August and a lava dome was found in the summit crater on November. Since then, lava sometimes flows downward on the slope and small explosions emitting steams from active crater frequently occur every a few to a few tens of minutes. Since the explosions repeatedly occur with short intervals and the active crater is located close to the summit with an altitude of 3676m, the explosions are considered to originate from the gas (steams) from magma itself in the conduit and not to be caused by interactions of magma with the underground water. We installed a tiltmeter at the summit on March 2010 to study the volcanic eruption mechanisms. The tiltmeter (Pinnacle hybrid type, accuracy of measurement is 1 nrad ) was set at a depth of about 1 m around the summit about 500 m north from the active crater. The data stored every 1 s in the internal memory was uploaded every 6 hours by a small data logger with GPS time correction function. More than one thousand gas explosion events were observed for about 2 weeks. We analyze the tilt records as well as seismic signals recorded at stations of CVGHM, Indonesia. The tilt records clearly show uplift of the summit about 20 to 30 seconds before each explosion. Uplifts before large explosions reach to about 20 - 30 n rad, which is almost equivalent to the volume increase of about 100 m^3 beneath the crater. To examine the eruption magnitude dependence on the uplift, we classify the eruptions into five groups based on the amplitudes of seismograms associated with explosions. We stack the tilt records for these groups to reduce noises in the signals and to get general characteristics of the volcano inflations. The results show that the amplitudes of uplifts are almost proportional to the amplitudes of explosion earthquakes while the

  6. 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

  7. Growth History of Kaena Volcano, the Isolated, Dominantly Submarine, Precursor Volcano to Oahu, Hawaii

    Science.gov (United States)

    Sinton, J. M.; Eason, D. E.

    2014-12-01

    The construction of O'ahu began with the recently recognized, ~3.5-4.9 Ma Ka'ena Volcano, as an isolated edifice in the Kaua'i Channel. Ka'ena remained submarine until, near the end of its lifetime as magma supply waned and the volcano transitioned to a late-shield stage of activity, it emerged to reach a maximum elevation of ~1000 m above sea level. We estimate that Ka'ena was emergent only for the last 15-25% of its lifespan, and that subaerial lavas make up < 5% of the total volume (20-27 x 103 km3). O'ahu's other volcanoes, Wai'anae (~3.9-2.85 Ma) and Ko'olau (~3.0-1.9 Ma), were built at least partly on the flanks of earlier edifices and both were active subaerial volcanoes for at least 1 Ma. The constructional history of Ka'ena contrasts with that of Wai'anae, Ko'olau, and many other Hawaiian volcanoes, which likely emerge within a few hundred kyr after inception, and with subaerial lavas comprising up to 35 volume % of the volcano. These relations suggest that volcano growth history and morphology are critically dependent on whether volcanic initiation and growth occur in the deep ocean floor (isolated), or on the flanks of pre-existing edifices. Two other volcanoes that likely formed in isolation are West Moloka'i and Kohala, both of which have long submarine rift zones, and neither attained great heights above sea level despite having substantial volume. The partitioning of volcanism between submarine and subaerial volcanism depends on the distance between volcanic centers, whether new volcanoes initiate on the flanks of earlier ones, and the time over which neighboring volcanoes are concurrently active. Ka'ena might represent an end-member in this spectrum, having initiated far from its next oldest neighbor and completed much of its evolution in isolation.

  8. An experimental study of the volcano-sagging to volcano-spreading transition

    Science.gov (United States)

    Holohan, Eoghan; Poppe, Sam; Kervyn, Matthieu; Delcamp, Audray; Byrne, Paul; van Wyk de Vries, Benjamin

    2013-04-01

    Volcanoes on Earth and other planets undergo gravitational deformation on a variety of timescales. Two end-member modes of gravity-driven deformation are volcano sagging (or volcano flexure) and volcano spreading. It has been long known that the mechanical and geometric properties of the basement rocks below the volcano strongly influence such gravitational deformation modes. One key mechanical property is the presence of a zone or layer that is sufficiently widespread and that has an effective viscosity low enough to produce ductile behavior in response to the load of the overlying volcanic edifice. Key geometric properties include the ratios between (1) volcano height and ductile basement thickness and (2) volcano height and brittle basement thickness. Despite such longstanding knowledge, a thorough parametric exploration of these properties has hitherto not been carried out experimentally. Consequently, the circumstances under which one gravitational deformation mode transitions to the other (i.e. the recently proposed spreading-sagging continuum) is imprecisely defined. To address this issue, we conducted a series of scaled analogue experiments involving a sand-plaster cone overlying a simple basement structure that comprises a single sand-plaster (brittle) layer and a single silicone (ductile) layer. By systematically varying the above-mentioned geometric ratios, we comprehensively define the transition from volcano-spreading through to volcano-sagging for a simple conically-loaded two-layer basement system. These results form a more robust experimental basis for distinguishing and interpreting the structural and morphological features of volcanoes subject to combined gravitational deformation processes, as observed in the field or in remote sensing data.

  9. Classification of Martian Volcanoes on Basis of Volcano Ground Ice Interaction

    Science.gov (United States)

    Helgason, J.

    2000-08-01

    Most Martian volcanoes have common morphological features indicating mass wasting and erosion compatible with large scale break down of ground ice. While some features suggest the ground ice melted rapidly resulting in catastrophic erosive events, other features indicate a slow melting process (e.g sublimation) resulting in collapse structures. To determine relative volcano age and activity on Mars it is suggested that volcano interactions with an overlying ice sheet may be helpful. Examples of the various morphological features indicating volcano-ice interaction are drawn from the literature: (1) valley formation that probably formed in response to joekulhlaups and subglacial volcanism, (2) isolated thermocarst depressions probably formed by geothermal melting of ground ice, (3) large scale sublimation of distal strata, (4) small fluvial valleys, (5) large scale failure of volcano flanks through aureole development, (6) rimless craters without ash collars, (7) rampart craters on volcanoes, (8) channels, (9) mud flows or lahars. A Viking Orbiter image showing possible thermocarst landscape on the flank of the volcano Hadriaca Patera (Dao Vallis). Although various other explanations can account for some of these features they are all compatible with a ground ice-volcano interaction. These features suggests that to an extent most Martian volcanoes are covered with sheet of ground ice of variable thickness. Over a vast time interval this ground ice layer (or ice sheet) has been failing to a variable extent and in a number of ways depending on different volcano characteristics. As a result it is suggested that Martian volcanoes can be classified or assigned an evolutionary status depending on how widespread their interaction is with the ground ice layer. Thus, for example, within the Tharsis region the volcanoes Olympus Mons and Arsia Mons can be regarded as two evolutionary end points. Volcanism in the former has completely built up through and destroyed the ice sheet

  10. Effects of Volcanoes on the Natural Environment

    Science.gov (United States)

    Mouginis-Mark, Peter J.

    2005-01-01

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

  11. Technology Education in Japan.

    Science.gov (United States)

    Murata, Shoji; Stern, Sam

    1993-01-01

    Describes the history, current status, and future direction of technology education in Japan, including the process of curriculum transition, secondary and postsecondary structure, and lack of resources. (SK)

  12. IRBA SERIES : Accounting In Japan

    OpenAIRE

    Arai, Kiyomitsu

    1994-01-01

    Preface / Legal and Conceptual Framework of Accounting in Japan / Setting Accounting Standards in Japan - The American Influence and The Present Status / Accounting Education and Profession in Japan / The International Harmonization of Accounting Standards / The Accounting Standard Setting in Japan and Its Responses to International Accounting Standards / Selected Bibliography for Accounting in Japan

  13. Instant snapshot of the internal structure of Unzen lava dome, Japan with airborne muography

    Science.gov (United States)

    Tanaka, Hiroyuki K. M.

    2016-12-01

    An emerging elementary particle imaging technique called muography has increasingly been used to resolve the internal structures of volcanoes with a spatial resolution of less than 100 m. However, land-based muography requires several days at least to acquire satisfactory image contrast and thus, it has not been a practical tool to diagnose the erupting volcano in a real time manner. To address this issue, airborne muography was implemented for the first time, targeting Heisei-Shinzan lava dome of Unzen volcano, Japan. Obtained in 2.5 hours, the resultant image clearly showed the density contrast inside the dome, which is essential information to predict the magnitude of the dome collapse. Since airborne muography is not restricted by topographic conditions for apparatus placements, we anticipate that the technique is applicable to creating images of this type of lava dome evolution from various angles in real time.

  14. Tephrostratigraphy of Changbaishan volcano, northeast China, since the mid-Holocene

    Science.gov (United States)

    Sun, Chunqing; Liu, Jiaqi; You, Haitao; Nemeth, Karoly

    2017-12-01

    A detailed tephrostratigraphy of an active volcano is essential for evaluating its eruptive history, forecasting future eruptions and correlation with distal tephra records. Changbaishan volcano is known for its Millennium eruption (ME, AD 940s; VEI 7) and the ME tephra has been detected in Greenland ice cores ∼9000 km from the vent. However, the pre-Millennium (pre-ME) and post-Millennium (post-ME) eruptions are still poorly characterized. In this study, we present a detailed late Holocene eruptive sequence of Changbaishan volcano based on single glass shard compositions from tephra samples collected from around the caldera rim and flanks. Tephra ages are constrained by optically stimulated luminescence (OSL) and AMS 14C dates. Tephra from the mid-Holocene pre-ME eruption can be divided into two pyroclastic fall subunits, and it cannot be correlated with any known Changbaishan-sourced tephra recorded in the Japan Sea based on major element composition of glass shards, such as the B-J (Baegdusan-Japan Basin) and B-V (Baegdusan-Vladivostok-oki) tephras. ME pyroclastic fall deposits from the caldera rims and volcanic flanks can be correlated to the juvenile pumice lapilli or blocks within the pyroclastic density current (PDC) deposits deposited in the valleys around the volcano based on glass shard compositions. Our results indicate that the glass shard compositions of proximal ME tephra are more varied than previously thought and can be correlated with distal ME tephra. In addition, widely-dispersed mafic scoria was ejected by the ME Plinian column and deposited on the western and southern summits and the eastern flank of the volcano. Data for glass from post-ME eruptions, such as the historically-documented AD 1403, AD 1668 and AD 1702 eruptions, are reported here for the first time. Except for the ME, other Holocene eruptions, including pre-ME and post-ME eruptions, had the potential to form widely-distributed tephra layers around northeast Asia, and our dataset

  15. 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…

  16. 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…

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

    Science.gov (United States)

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

    2000-01-01

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

  18. Interdisciplinary studies of eruption at Chaiten Volcano, Chile

    Science.gov (United States)

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

    2010-01-01

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

  19. Volcanoes muon imaging using Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-21

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

  20. 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

  1. Tottori earthquakes and Daisen volcano: Effects of fluids, slab melting and hot mantle upwelling

    Science.gov (United States)

    Zhao, Dapeng; Liu, Xin; Hua, Yuanyuan

    2018-03-01

    We investigate the 3-D seismic structure of source areas of the 6 October 2000 Western Tottori earthquake (M 7.3) and the 21 October 2016 Central Tottori earthquake (M 6.6) which occurred near the Daisen volcano in SW Japan. The two large events took place in a high-velocity zone in the upper crust, whereas low-velocity (low-V) and high Poisson's ratio (high-σ) anomalies are revealed in the lower crust and upper mantle. Low-frequency micro-earthquakes (M 0.0-2.1) occur in or around the low-V and high-σ zones, which reflect upward migration of magmatic fluids from the upper mantle to the crust under the Daisen volcano. The nucleation of the Tottori earthquakes may be affected by the ascending fluids. The flat subducting Philippine Sea (PHS) slab has a younger lithosphere age and so a higher temperature beneath the Daisen and Tottori area, facilitating the PHS slab melting. It is also possible that a PHS slab window has formed along the extinct Shikoku Basin spreading ridge beneath SW Japan, and mantle materials below the PHS slab may ascend to the shallow area through the slab window. These results suggest that the Daisen adakite magma was affected by the PHS slab melting and upwelling flow in the upper mantle above the subducting Pacific slab.

  2. Medical genetics in Japan.

    Science.gov (United States)

    Matsuo, M

    1995-01-01

    In Japan genetic diseases are getting more popular in medicine, because of increased awareness of the role of genetic determinants of diseases. Care for patients with inherited disease is one of the current big problems. In this review, programs developed to support Duchenne muscular dystrophy patients are described as an example of medical services available for genetic diseases in Japan.

  3. Reform: Learning from Japan.

    Science.gov (United States)

    Barnes, Michael

    1999-01-01

    Examining differences between education in the United States and in Japan means analyzing cultural dissimilarities. An overview of Japan's educational makeup, curriculum, and graduation rates provides background in comparing educational systems for future reforms. This paper examines Japanese school structures, government support, institutional…

  4. Renewable energies in Japan

    International Nuclear Information System (INIS)

    Rosello-Garcia, M.

    2003-04-01

    Dependent upon its energy supplies, the Japan aims to develop its renewable energies production. This evolution will also agrees the engagements of the Kyoto protocol to reduce the carbon dioxide emissions. To reach in 2010 7% of the energy consumption by a ''clean energy'', the Japan supports and finances many research projects on the renewable energies. (A.L.B.)

  5. The origin of the Hawaiian Volcano Observatory

    International Nuclear Information System (INIS)

    Dvorak, John

    2011-01-01

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

  6. 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

  7. Ionospheric "Volcanology": Ionospheric Detection of Volcano Eruptions

    Science.gov (United States)

    Astafyeva, E.; Shults, K.; Lognonne, P. H.; Rakoto, V.

    2016-12-01

    It is known that volcano eruptions and explosions can generate acoustic and gravity waves. These neutral waves further propagate into the atmosphere and ionosphere, where they are detectable by atmospheric and ionospheric sounding tools. So far, the features of co-volcanic ionospheric perturbations are not well understood yet. The development of the global and regional networks of ground-based GPS/GNSS receivers has opened a new era in the ionospheric detection of natural hazard events, including volcano eruptions. It is now known that eruptions with the volcanic explosivity index (VEI) of more than 2 can be detected in the ionosphere, especially in regions with dense GPS/GNSS-receiver coverage. The co-volcanic ionospheric disturbances are usually characterized as quasi-periodic oscillations. The Calbuco volcano, located in southern Chile, awoke in April 2015 after 43 years of inactivity. The first eruption began at 21:04UT on 22 April 2015, preceded by only an hour-long period of volcano-tectonic activity. This first eruption lasted 90 minutes and generated a sub-Plinian (i.e. medium to large explosive event), gray ash plume that rose 15 km above the main crater. A larger second event on 23 April began at 04:00UT (01:00LT), it lasted six hours, and also generated a sub-Plinian ash plume that rose higher than 15 km. The VEI was estimated to be 4 to 5 for these two events. In this work, we first study ionospheric TEC response to the Calbuco volcano eruptions of April 2015 by using ground-based GNSS-receivers located around the volcano. We analyze the spectral characteristics of the observed TEC variations and we estimate the propagation speed of the co-volcanic ionospheric perturbations. We further proceed with the normal mode summation technique based modeling of the ionospheric TEC variations due to the Calbuco volcano eruptions. Finally, we attempt to localize the position of the volcano from the ionospheric measurements, and we also estimate the time of the

  8. Augustine Volcano, Cook Inlet, Alaska (January 12, 2006)

    Science.gov (United States)

    2006-01-01

    Since last spring, the U.S. Geological Survey's Alaska Volcano Observatory (AVO) has detected increasing volcanic unrest at Augustine Volcano in Cook Inlet, Alaska near Anchorage. Based on all available monitoring data, AVO regards that an eruption similar to 1976 and 1986 is the most probable outcome. During January, activity has been episodic, and characterized by emission of steam and ash plumes, rising to altitudes in excess of 9,000 m (30,000 ft), and posing hazards to aircraft in the vicinity. An ASTER image was acquired at 12:42 AST on January 12, 2006, during an eruptive phase of Augustine. The perspective rendition shows the eruption plume derived from the ASTER image data. ASTER's stereo viewing capability was used to calculate the 3-dimensional topography of the eruption cloud as it was blown to the south by prevailing winds. From a maximum height of 3060 m (9950 ft), the plume cooled and its top descended to 1900 m (6175 ft). The perspective view shows the ASTER data draped over the plume top topography, combined with a base image acquired in 2000 by the Landsat satellite, that is itself draped over ground elevation data from the Shuttle Radar Topography Mission. The topographic relief has been increased 1.5 times for this illustration. Comparison of the ASTER plume topography data with ash dispersal models and weather radar data will allow the National Weather Service to validate and improve such models. These models are used to forecast volcanic ash plume trajectories and provide hazard alerts and warnings to aircraft in the Alaska region. 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 provides scientists in numerous disciplines with

  9. Partners in International Research and Education: Student Contributions to the Collaborative Investigation of Bezymianny, Shiveluch, and Karymsky Volcanoes, Kamchatka, Russia and Mount St. Helens, WA, USA.

    Science.gov (United States)

    Shipman, J. S.; Kayzar, T. M.; Team, P.

    2008-12-01

    Undergraduate and graduate students as well as senior researchers from the U.S., Russia, and Japan are investigating volcanism as participants of the National Science Foundation initiative Partners in International Research and Education (PIRE). The goal of this study is to use the benefits of global comparisons to increase our understanding of explosive volcanism while at the same time developing international collaboration between scientists in the U.S., Russia, and Japan. International collaboration is established through field work in Kamchatka, Russia investigating the active systems of Bezymianny, Shiveluch, and Karymsky volcanoes with a specific focus on historic collapse-blast type eruptions. The Kamchatka volcanic arc provides unique access to multiple active volcanic systems that can be compared and contrasted to the well-studied behavior at Mount St. Helens, WA., USA. Conversely, Mount St. Helens also provides a field setting for Russian and Japanese students to be incorporated in U.S. research. Student participants employ their respective techniques in geochemistry, geophysics, petrology, and remote sensing to study the eruption response of Bezymianny and Shiveluch volcanoes, which have experienced edifice collapse. During the 2008 field season, the increased activity at Bezymianny volcano shortened a planned field expedition. In order to preserve the integrity of the program and provide a safer environment for researchers, alternative field studies began at Karymsky volcano. In July, an anonymously large eruption at Karymsky volcano permitted the collection of unique real-time data of the eruptive event. Here we present student research from three field seasons in the Kamchatka volcanic arc and associated workshops at Mount St. Helens, WA. Results include estimates of magma storage depth, gas emissions measurements, evidence for dynamic thermal regime changes in fresh volcanic deposits, and data constraining magma inputs and sources at each volcano. By

  10. The changing shapes of active volcanoes: History, evolution, and future challenges for volcano geodesy

    Science.gov (United States)

    Poland, Michael P.; Hamburger, Michael W.; Newman, Andrew V.

    2006-01-01

    At the very heart of volcanology lies the search for the 'plumbing systems' that form the inner workings of Earth’s active volcanoes. By their very nature, however, the magmatic reservoirs and conduits that underlie these active volcanic systems are elusive; mostly they are observable only through circumstantial evidence, using indirect, and often ambiguous, surficial measurements. Of course, we can infer much about these systems from geologic investigation of materials brought to the surface by eruptions and of the exposed roots of ancient volcanoes. But how can we study the magmatic processes that are occurring beneath Earth’s active volcanoes? What are the geometry, scale, physical, and chemical characteristics of magma reservoirs? Can we infer the dynamics of magma transport? Can we use this information to better forecast the future behavior of volcanoes? These questions comprise some of the most fundamental, recurring themes of modern research in volcanology. The field of volcano geodesy is uniquely situated to provide critical observational constraints on these problems. For the past decade, armed with a new array of technological innovations, equipped with powerful computers, and prepared with new analytical tools, volcano geodesists have been poised to make significant advances in our fundamental understanding of the behavior of active volcanic systems. The purpose of this volume is to highlight some of these recent advances, particularly in the collection and interpretation of geodetic data from actively deforming volcanoes. The 18 papers that follow report on new geodetic data that offer valuable insights into eruptive activity and magma transport; they present new models and modeling strategies that have the potential to greatly increase understanding of magmatic, hydrothermal, and volcano-tectonic processes; and they describe innovative techniques for collecting geodetic measurements from remote, poorly accessible, or hazardous volcanoes. To provide

  11. 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.

  12. Of volcanoes, saints, trash, and frogs

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

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

  13. Carbonate assimilation at Merapi volcano, Java Indonesia

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  14. Biological Studies on a Live Volcano.

    Science.gov (United States)

    Zipko, Stephen J.

    1992-01-01

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

  15. 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).

  16. Probing magma reservoirs to improve volcano forecasts

    Science.gov (United States)

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

    2017-01-01

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

  17. 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...

  18. Seismicity at Baru Volcano, Western Panama, Panama

    Science.gov (United States)

    Camacho, E.; Novelo-Casanova, D. A.; Tapia, A.; Rodriguez, A.

    2008-12-01

    The Baru volcano in Western Panama (8.808°N, 82.543°W) is a 3,475 m high strato volcano that lies at about 50 km from the Costa Rican border. The last major eruptive event at this volcano occurred c.1550 AD and no further eruptive activity from that time is known. Since the 1930´s, approximately every 30 years a series of seismic swarms take place in the surroundings of the volcanic edifice. Theses swarms last several weeks alarming the population who lives near the volcano. The last of these episodes occurred on May 2006 and lasted one and a half months. More than 20,000 people live adjacent to the volcano and any future eruption has the potential to be very dangerous. In June 2007, a digital seismic monitoring network of ten stations, linked via internet, was installed around the volcano in a collaborative project between the University of Panama and the Panamanian Government. The seismic data acquisition at the sites is performed using LINUX-SEISLOG and the events are recorded by four servers at different locations using the Earth Worm system. In this work we analyze the characteristics of the volcano seismicity recorded from May 4th, 2006 to July 31st, 2008 by at least 4 stations and located at about 15 km from the summit. To determine the seismic parameters, we tested several crustal velocity models and used the seismic analysis software package SEISAN. Our final velocity model was determined using seismic data for the first four km obtained from a temporal seismic network deployed in 1981 by the British Geological Survey (BGS) as part of geothermal studies conducted at Cerro Pando, Western Panama Highlands. Our results indicate that all the events recorded in the quadrant 8.6-9.0°N and 82.2-82.7°W are located in the depth range of 0.1 to 8 km. Cross sections show vertical alignments of hypocenters below the summit although most of the seismicity is concentrated in its eastern flank reaching the town of Boquete. All the calculated focal mechanisms are of

  19. Nuclear energetics of Japan

    International Nuclear Information System (INIS)

    Sivintsev, Yu.V.

    2001-01-01

    Data on the current state and development of the nuclear energetics of Japan are reviewed. Preference of the strategy of tolerant development of the nuclear energetics of Japan including creation of the power nuclear energetics with the closed nuclear fuel cycle is noted. Realization and development of the program for the creating fast breeder reactor will provide to achieve total independence from import of any types of energy carriers including the fuel for nuclear fuel cycle. Scientific elaborations in Japan are conjectured the correlation of different types of fuel (oxide, metal, nitride), energy carriers (sodium, heavy metals, gas and water) and reactor power (large NPP, middle and small power plants) [ru

  20. Microelectronics in Japan

    Science.gov (United States)

    Boulton, William R.

    1995-02-01

    The purpose of this JTEC study is to evaluate Japan's electronic manufacturing and packaging capabilities within the context of global economic competition. To carry out this study, the JTEC panel evaluated the framework of the Japanese consumer electronics industry and various technological and organizational factors that are likely to determine who will win and lose in the marketplace. This study begins with a brief overview of the electronics industry, especially as it operates in Japan today. Succeeding chapters examine the electronics infrastructure in Japan and take an in-depth look at the central issues of product development in order to identify those parameters that will determine future directions for electronic packaging technologies.

  1. Space communications in Japan

    Science.gov (United States)

    Mori, T.

    This paper outlines some of the planned satellite comunication projects in Japan over the next 5-7 years. In addition, Japanese space development policies are set out along with a historic review of the development of artificial satellites.

  2. K-Ar ages of the Nyuto-Takakura volcanic products, southern part of the Sengan geothermal area, northeast Japan

    International Nuclear Information System (INIS)

    Suto, Shigeru; Uto, Kozo; Uchiumi, Shigeru

    1990-01-01

    The K-Ar age determination of the volcanic rocks from the Nyuto-Takakura volcano group, northeast Japan, was carried out. Nyuto-Takakura volcanoes are situated in the southern part of the Sengan geothermal area. And the Young Volcanic Rocks in the area were already divided into the Early stage volcanics (erupted in Matsuyama reversed epoch or more older epoch) and the Later stage volcanics (erupted in Brunhes normal epoch) by accumulated paleomagnetic and K-Ar age data. The results in this study are as follows; Nyuto Volcano: 0.63±0.06, 0.36±0.07 Ma, Sasamoriyama Volcano: 0.09±0.07, 0.3±0.3 Ma, Marumori Lava Dome: 0.4±0.3, 0.31±0.12 Ma, Mikadoyama Lava Dome: <1 Ma, Takakurayama-Kotakakurayama volcano: 1.4±0.5, 1.0±0.4, <0.4 Ma. The determinated ages are concordant with the volcanic stratigraphy and the paleomagnetic data. Nyuto Volcano, Sasamoriyama Volcano, Marumori Lava Dome, Mikadoyama Lava Dome and upper part of the Takakurayama-Kotakakurayama Volcano are interpreted to be erupted in Brunhes normal epoch. The volcanic rocks from the lower part of the Takakurayama-Kotakakurayama volcano show normal magnetic polarity, so they are interpreted to be erupted in Jaramillo normal polarity event. The Early stage volcanics and the Later stage volcanics in the studied area are tend to be distributed in the central part and the outer part of the area, respectively. But the determinated ages in this study show that there is no simple migration of the eruption center of the volcanic rocks from the central part to the peripheral part. There is no geothermal manifestation or alteration area around the Sasamoriyama Volcano and the Marumori Lava Dome, which are the youngest volcanoes in the studied area. So it is concluded that there is no direct correlation between the eruption age of the nearest volcano and the geothermal activity. (author)

  3. Mobile Marketing in Japan

    OpenAIRE

    Noah H. N. Lynn; Paul D. Berger

    2014-01-01

    In this paper we describe the state of mobile marketing in Japan. We consider the various aspects of mobile marketing in Japan and what has led to the overwhelming adoption by Japanese youth, and to a degree Japanese society as a whole, of social media and associated activities. This growth of mobile marketing has dramatic, positive implications for marketing, in general, as well as for the sale of selected product classes. We also consider markers for suggesting what the future of mobile mar...

  4. VSATs in Japan

    Science.gov (United States)

    Fujii, Akira

    1993-08-01

    In Japan, VSAT private domestic communications satellites, JCSAT and SuperBird, carrying Ku-band transponders, were launched in 1989. To expedite a wider use of these VSAT systems, regulations were amended in June 1989 to permit simplified licensing procedures for the VSATs which conformed to technical standards. This contribution describes the usage of VSAT systems in Japan along with the licensing procedures and the technical standards.

  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. Monitoring remote volcanoes: The 2010-2012 unrest at Sotará volcano (Colombia)

    Science.gov (United States)

    Alpala, Jorge; Alpala, Rosa; Battaglia, Maurizio

    2017-09-01

    Sotará is a little known andesitic-dacitic stratovolcano in southern Colombia (Central Cordillera, Cauca Department). Its remote location and the lack of accessible roads make studying and monitoring Sotará volcano difficult. No historical eruptions are known, though there is current geothermal activity. Between the fall of 2010 and the fall of 2012 a small magma intrusion (depth 1 km, ΔV 105 m3) triggered surface deformation and volcano-tectonic earthquakes but failed to reach the surface. This episode of unrest started with the volcano-tectonic earthquake of September 2010 (ML 4.4). Although one electronic tiltmeter recorded significant deformation between Jan 2011 and July 2012 (137 ± 7 μrad), seismic activity remained at background levels until May 2012. Between June and September 2012, seismicity increased dramatically with an average of 120 volcano-tectonic events per day of magnitude up to 2.2. The epicenters of these events were initially located 6 km NE of the volcano but then migrated along a linear fracture towards the NW summit of the volcano. At the same time, the hypocenters moved closer to the surface as well: from a depth of 3-6 km for the initial events to a depth of 1-4 km for the events at the end of the summer. Although the dike intrusion did not culminate in an eruption, and seismicity and deformation returned close to background levels by January 2013, this episode of unrest is a reminder that Sotará is an active volcano and should be carefully monitored.

  7. Japan's nuclear power tightrope

    International Nuclear Information System (INIS)

    Cross, M.

    1991-01-01

    This paper reports that early in February, just as Japan's nuclear energy program was regaining a degree of popular support after three years of growing opposition, an aging pressurized-water reactor at Mihama in western Japan sprang a leak in its primary cooling system. The event occasioned Japan's first nontest use of an emergency core-cooling system. It also elicited a forecast of renewed public skepticism about nuclear power form the Ministry of International Trade and Industry (MITI), the Government body responsible for promoting and regulating Japan's ambitious nuclear power program. Public backing for this form of energy has always been a delicate flower in Japan, where virtually every school child visits the atomic bomb museums at Hiroshima and Nagasaki. Yet the country, which imports 80 percent of its energy and just about all its oil, is behind only the United States, France, and the Soviet Union in installed nuclear capacity. In fiscal 1989, which started in April, Japan's 39 nuclear power stations accounted for 25.5 percent of electricity generated - the largest contribution - followed b coal and natural gas. Twelve more plants are under construction

  8. Industrial lasers in Japan

    Science.gov (United States)

    Karube, Norio

    1991-03-01

    I am to report on some aspects of industrial lasers in Japan. Mostly centering on the market. In Japan, the history of laser developnent is rather profound. And long. Ever since the first invention of the laser in this country in 1960. This is partly because of the fact that in Japan the spectroscopic studies of the ruby was very popular in the late 1950's. Ever since niost of the work has been done in the research laboratories of the industry, not in the universities or not in the governmental laboratories. And since that time our first activity was mainly centering on the basic research, but after that time we have the evolution of the technology. One of the features in Japan is that the activity of developement and research of laser technology from the very basic phase up to the present commercialization has been done by the same group of people, including ine. We had a national project which ended about six years ago which was sponsored by MITI. MITI is Ministry of International Trade and Industry in Japan. And because of this national project, the effect of this project had a very enlightening effect in Japan. And after that our Japanese laser market became very flourishing.

  9. Common processes at unique volcanoes - a volcanological conundrum

    Science.gov (United States)

    Cashman, Katharine; Biggs, Juliet

    2014-11-01

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

  10. HUBBLE SPACE TELESCOPE RESOLVES VOLCANOES ON IO

    Science.gov (United States)

    2002-01-01

    This picture is a composite of a black and white near infrared image of Jupiter and its satellite Io and a color image of Io at shorter wavelengths taken at almost the same time on March 5, 1994. These are the first images of a giant planet or its satellites taken by NASA's Hubble Space Telescope (HST) since the repair mission in December 1993. Io is too small for ground-based telescopes to see the surface details. The moon's angular diameter of one arc second is at the resolution limit of ground based telescopes. Many of these markings correspond to volcanoes that were first revealed in 1979 during the Voyager spacecraft flyby of Jupiter. Several of the volcanoes periodically are active because Io is heated by tides raised by Jupiter's powerful gravity. The volcano Pele appears as a dark spot surrounded by an irregular orange oval in the lower part of the image. The orange material has been ejected from the volcano and spread over a huge area. Though the volcano was first discovered by Voyager, the distinctive orange color of the volcanic deposits is a new discovery in these HST images. (Voyager missed it because its cameras were not sensitive to the near-infrared wavelengths where the color is apparent). The sulfur and sulfur dioxide that probably dominate Io's surface composition cannot produce this orange color, so the Pele volcano must be generating material with a more unusual composition, possibly rich in sodium. The Jupiter image, taken in near-infrared light, was obtained with HST's Wide Field and Planetary Camera in wide field mode. High altitude ammonia crystal clouds are bright in this image because they reflect infrared light before it is absorbed by methane in Jupiter's atmosphere. The most prominent feature is the Great Red Spot, which is conspicuous because of its high clouds. A cap of high-altitude haze appears at Jupiter's south pole. The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced

  11. Uzon-Geysernaya volcano-tectonic depression: geodynamics phenomena last years

    Science.gov (United States)

    Kugaenko, Yulia

    2010-05-01

    (swarm) type. - The majority of earthquakes are connected with areas of hydrothermal activity in western slop of Kikhpinych volcanic massif. - Seismicity is located in part of caldera displacement, discovered by INSAR data. - By our mind, the seismicity and Uzon caldera inflation (as a result of activation of magma chamber or hydrothermal system) effected and destructed the caldera slop by activation of fissures and by change of pore-fracture configuration. Summarizing data about the tectonics, the raising of east slope of depression, the landsliding and local seismicity, we can suppose that all these phenomena are connected with the deep processes under Uzon-Geysernaya depression and Kikhpinuch volcano are the reason of all these events. It is the indication of the renewal of the dynamics within eastern part of the calderas. References: Belousov, V. I., E. N. Grib, and V. L. Leonov (1984), The geological setting of the hydrothermal systems in the Geysers Valley and Uzon caldera, Volcanol. Seismol., 5, 67-81. Kugaenko, Yu. (2008), Geodynamic processes as the risk factor of June 3, 2007 landslide in the Valley of the Geysers (Kamchatka, Russia), Proceedings of the First World Landslide Forum. 18-21 November 2008, Tokio, Japan, 333-336. Leonov, V. L., E. N. Grib, G. A. Karpov, V. M. Sugrobov, N. G. Sugrobova, and Z. I. Zubin (1991). Uzon caldera and Valley of Geysers, in Active Volcanoes of Kamchatka, edited by S. A. Fedotov and Y. P. Masurenkov, Nauka, Moscow, 92- 141. Leonov, V.L. (2007) Valley of the Geysers struck by large destructive landslide and related flood. Bulletin of the Global Volcanism Network (BGVN 32:07). 07/2007. Lundgren, P., Lu, Zh. (2006) Inflation model of Uzon caldera, Kamchatka, constrained by satellite radar interferometry observations. Geophysical Research Letters. 33, L06301, doi:10.1029/2005GL025181

  12. 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

  13. Volcano hazard mitigation program in Indonesia

    Science.gov (United States)

    Sudradjat, A.

    1990-01-01

    Volcanological investigations in Indonesia were started in the 18th century, when Valentijn in 1726 prepared a chronological report of the eruption of Banda Api volcno, Maluku. Modern and intensive volcanological studies did not begin until the catastrophic eruption of Kelut volcano, East Java, in 1919. The eruption took 5,011 lives and destroyed thousands of acres of coffee plantation. An eruption lahar generated by the crater lake water mixed with volcanic eruptions products was the cause of death for a high number of victims. An effort to mitigate the danger from volcanic eruption was first initiated in 1921 by constructing a tunnel to drain the crater lake water of Kelut volcano. At the same time a Volcanological Survey was established by the government with the responsibility of seeking every means for minimizing the hazard caused by volcanic eruption. 

  14. Bubble mobility in mud and magmatic volcanoes

    Science.gov (United States)

    Tran, Aaron; Rudolph, Maxwell L.; Manga, Michael

    2015-03-01

    The rheology of particle-laden fluids with a yield stress, such as mud or crystal-rich magmas, controls the mobility of bubbles, both the size needed to overcome the yield stress and their rise speed. We experimentally measured the velocities of bubbles and rigid spheres in mud sampled from the Davis-Schrimpf mud volcanoes adjacent to the Salton Sea, Southern California. Combined with previous measurements in the polymer gel Carbopol, we obtained an empirical model for the drag coefficient and bounded the conditions under which bubbles overcome the yield stress. Yield stresses typical of mud and basaltic magmas with sub-mm particles can immobilize millimeter to centimeter sized bubbles. At Stromboli volcano, Italy, a vertical yield stress gradient in the shallow conduit may immobilize bubbles with diameter ≲ 1 cm and hinder slug coalescence.

  15. Decision Analysis Tools for Volcano Observatories

    Science.gov (United States)

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

    2005-12-01

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

  16. Electrical structure of Newberry Volcano, Oregon

    Science.gov (United States)

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

    1988-01-01

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

  17. 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.

  18. Japan steel mill perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)

    2004-07-01

    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  19. Petrogenesis of a voluminous Quaternary adakitic volcano: the case of Baru volcano

    Science.gov (United States)

    Hidalgo, Paulo J.; Rooney, Tyrone O.

    2014-09-01

    The origin of adakite magmas remains controversial because initially the term adakite had petrogenetic significance implying an origin by direct melting of the eclogitized subducting oceanic crust. Many models have been produced for their origin, and until now there has not been a straightforward method to discriminate between these models in a given adakite suite. Here, we use detailed chronological and geochemical studies of selected adakitic edifices that allows for the determination of the magmatic output rate parameter (Qe), which has been correlated with the rates of magma generation deep within subduction zones. By providing temporal and eruption rate estimates, we provide constraints on the possible petrogenetic processes involved in the generation of adakite-like signatures. Adakite magmas derived from the melting of the subducting slab should be volumetrically insignificant when compared to the adakite-like magmas produced by typical arc magma generation processes. In this study, we use this observation and the extraordinary stratigraphic exposure from Miocene to present in an adakitic volcano in Panama and to study the temporal and chemical variation in erupted magmas to estimate rates of magma generation. Detailed chemical and geochronological analyses of Baru volcano indicate that the volcanic edifice was constructed in its entirety during the Quaternary and magmas display adakite-like features such as steep rare earth elements patterns, pronounced depletions in the heavy rare earth elements, low Y, high Sr, and high Sr/Y. The magmatic output rates (Qe) that we have calculated show that compared to other typical adakitic volcanoes, most of the volcanic edifice of Baru volcano was constructed extremely rapidly (Baru volcano is more representative of a typical arc volcano than a small-volume melt of the subducting oceanic crust. The technique we outline may have broader application in determining the petrogenetic conditions of other adakite suites.

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

    Science.gov (United States)

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

    2017-04-01

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

  1. Mud volcanoes of the Orinoco Delta, Eastern Venezuela

    Science.gov (United States)

    Aslan, A.; Warne, A. G.; White, W. A.; Guevara, E. H.; Smyth, R. C.; Raney, J. A.; Gibeaut, J. C.

    2001-12-01

    Mud volcanoes along the northwest margin of the Orinoco Delta are part of a regional belt of soft sediment deformation and diapirism that formed in response to rapid foredeep sedimentation and subsequent tectonic compression along the Caribbean-South American plate boundary. Field studies of five mud volcanoes show that such structures consist of a central mound covered by active and inactive vents. Inactive vents and mud flows are densely vegetated, whereas active vents are sparsely vegetated. Four out of the five mud volcanoes studied are currently active. Orinoco mud flows consist of mud and clayey silt matrix surrounding lithic clasts of varying composition. Preliminary analysis suggests that the mud volcano sediment is derived from underlying Miocene and Pliocene strata. Hydrocarbon seeps are associated with several of the active mud volcanoes. Orinoco mud volcanoes overlie the crest of a mud-diapir-cored anticline located along the axis of the Eastern Venezuelan Basin. Faulting along the flank of the Pedernales mud volcano suggests that fluidized sediment and hydrocarbons migrate to the surface along faults produced by tensional stresses along the crest of the anticline. Orinoco mud volcanoes highlight the proximity of this major delta to an active plate margin and the importance of tectonic influences on its development. Evaluation of the Orinoco Delta mud volcanoes and those elsewhere indicates that these features are important indicators of compressional tectonism along deformation fronts of plate margins.

  2. The critical role of volcano monitoring in risk reduction

    Science.gov (United States)

    Tilling, R.I.

    2008-01-01

    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. Helens (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-ofthe-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.

  3. 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.

  4. Mud volcanoes of the Orinoco Delta, Eastern Venezuela

    Science.gov (United States)

    Aslan, A.; Warne, A.G.; White, W.A.; Guevara, E.H.; Smyth, R.C.; Raney, J.A.; Gibeaut, J.C.

    2001-01-01

    Mud volcanoes along the northwest margin of the Orinoco Delta are part of a regional belt of soft sediment deformation and diapirism that formed in response to rapid foredeep sedimentation and subsequent tectonic compression along the Caribbean-South American plate boundary. Field studies of five mud volcanoes show that such structures consist of a central mound covered by active and inactive vents. Inactive vents and mud flows are densely vegetated, whereas active vents are sparsely vegetated. Four out of the five mud volcanoes studied are currently active. Orinoco mud flows consist of mud and clayey silt matrix surrounding lithic clasts of varying composition. Preliminary analysis suggests that the mud volcano sediment is derived from underlying Miocene and Pliocene strata. Hydrocarbon seeps are associated with several of the active mud volcanoes. Orinoco mud volcanoes overlie the crest of a mud-diapir-cored anticline located along the axis of the Eastern Venezuelan Basin. Faulting along the flank of the Pedernales mud volcano suggests that fluidized sediment and hydrocarbons migrate to the surface along faults produced by tensional stresses along the crest of the anticline. Orinoco mud volcanoes highlight the proximity of this major delta to an active plate margin and the importance of tectonic influences on its development. Evaluation of the Orinoco Delta mud volcanoes and those elsewhere indicates that these features are important indicators of compressional tectonism along deformation fronts of plate margins. ?? 2001 Elsevier Science B.V. All rights reserved.

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

    Science.gov (United States)

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

    2010-01-01

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

  6. Data assimilation strategies for volcano geodesy

    Science.gov (United States)

    Zhan, Yan; Gregg, Patricia M.

    2017-09-01

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

  7. Cultural Astronomy in Japan

    Science.gov (United States)

    Renshaw, Steven L.

    While Japan is known more for its contributions to modern astronomy than its archaeoastronomical sites, there is still much about the culture's heritage that is of interest in the study of cultural astronomy. This case study provides an overview of historical considerations necessary to understand the place of astronomy in Japanese society as well as methodological considerations that highlight traditional approaches that have at times been a barrier to interdisciplinary research. Some specific areas of study in the cultural astronomy of Japan are discussed including examples of contemporary research based on interdisciplinary approaches. Japan provides a fascinating background for scholars who are willing to go beyond their curiosity for sites of alignment and approach the culture with a desire to place astronomical iconography in social context.

  8. Antisana volcano : a representative andesitic volcano of the eastern cordillera of Ecuador : petrography, chemistry, tephra and glacial stratigraphy

    OpenAIRE

    Hall, M. L.; Mothes, P. A.; Samaniego, Pablo; Militzer, A.; Beate, B.; Ramon, P.; Robin, Claude

    2017-01-01

    Antisana volcano is representative of many active andesitic strato-volcanoes of Pleistocene age in Ecuador's Eastern Cordillera. This study represents the first modern geological and volcanological investigation of Antisana since the late 1890's; it also summarizes the present geochemical understanding of its genesis. The volcano's development includes the formation and destruction of two older edifices (Antisana I and II) during some 400 + ka. Antisana II suffered a sector collapse about 15,...

  9. Yoga Therapy in Japan.

    Science.gov (United States)

    Kimura, Keishin

    2017-11-01

    This perspective piece gives an overview of the current situation of yoga therapy in Japan today. Traditional yoga in Japan suffered a serious setback in 1995 with a nerve gas terrorist attack on the Tokyo subway, which was carried out by a cult that recruited members through yoga classes. But with the increase in popularity with modern forms of yoga such as Iyengar yoga, Ashtanga yoga and hot yoga in the West, the general public in Japan today is forgetting its aversion to yoga and considers it to be something that can contribute to good health. In 2012, the Japan Yoga Therapy Society (JYTS) conducted a study on adverse events in yoga classes throughout Japan with the University of Kyushu School of Medicine, with support from the Ministry of Health, Labour and Welfare. This study indicated that more than half of people attending yoga classes have some form of chronic illness, with 42.3% receiving outpatient care. This survey was the beginning of growing interest from both the government and universities in yoga therapy. JYTS is beginning to make inroads into bringing yoga therapy into cancer and palliative care, senior citizen homes, alcohol and drug addiction rehabilitation, cardiovascular rehabilitation, and research on trauma and schizophrenia. While there are still limited opportunities for yoga therapists to work in mainstream healthcare services, there is growing interest among medical professionals in both physical and mental health. JYTS is beginning to make inroads into bringing yoga therapy into cancer and palliative care, senior citizen homes, alcohol and drug addiction rehabilitation, cardiovascular rehabilitation, and research on trauma and schizophrenia. While there are still limited opportunities for yoga therapists to work in mainstream healthcare services, there is growing interest among medical professionals in both physical and mental health. This perspective piece introduces some of the developments in yoga therapy research and practice in

  10. The internationalization of Japan

    International Nuclear Information System (INIS)

    Kuroki, T.E.

    1989-01-01

    There are growing tensions and frictions between the U.S. and Japan. Among them are science and technology issues that relate to the development of superconductor technology, as well as economic, trade and agricultural issues. The structure of this friction is very complex. There are many interconnected issues that cannot be resolved one by one. This article focuses on the relationship between the U.S. and Japan. Some of the complexities behind the issues are discussed by defining different notions of internationalization and by presenting the positive and negative aspects of the Japanese approach that affects the future cooperation and competition between our nations in the area of superconductivity

  11. Probable dynamic triggering of phreatic eruption in the Tatun volcano group of Taiwan

    Science.gov (United States)

    Lin, Cheng-Horng

    2017-11-01

    On 16 March 2014 (UTC), a small phreatic eruption occurred in the Tatun volcano group (TVG) of Taiwan, although it was not reported until analysis of both seismic and acoustic data revealed that the source was in the vicinity of the Hsiaoyukeng fumarole. A replay of the acoustic data accelerated ∼60-fold reveals that the gradual decrease in frequency that was recorded produces a volcanic whistle, similar to the jet of steam released from a heating kettle. The phreatic eruption may have been dynamically triggered by a M6.7 earthquake in Chile. A similar phenomenon occurred on 5 January 2015, when a phreatic eruption was recorded in the TVG immediately after the generation of dynamic seismic waves by an M5.0 earthquake in Japan. This is the first scientific report of a phreatic eruption detected in the TVG, indicating that these volcanoes are still active. As a result, it is important to monitor their volcanic activity and identify volcanic reservoirs beneath the TVG to mitigate future possible volcanic impact.

  12. Language Testing in Japan.

    Science.gov (United States)

    Brown, James Dean, Ed.; Yamashita, Sayoko Okada, Ed.

    Papers on second language testing in Japan include: "Differences Between Norm-Referenced and Criterion-Referenced Tests" (James Dean Brown); "Criterion-Referenced Test Construction and Evaluation" (Dale T. Griffe); "Behavioral Learning Objectives as an Evaluation Tool" (Judith A. Johnson); "Developing Norm-…

  13. Liquid hydrogen in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Yasumi, S. [Iwatani Corp., Osaka (Japan). Dept. of Overseas Business Development

    2009-07-01

    Japan's Iwatani Corporation has focused its attention on hydrogen as the ultimate energy source in future. Unlike the United States, hydrogen use and delivery in liquid form is extremely limited in the European Union and in Japan. Iwatani Corporation broke through industry stereotypes by creating and building Hydro Edge Co. Ltd., Japan's largest liquid hydrogen plant. It was established in 2006 as a joint venture between Iwatani and Kansai Electric Power Group in Osaka. Hydro Edge is Japan's first combined liquid hydrogen and ASU plant, and is fully operational. Liquid oxygen, liquid nitrogen and liquid argon are separated from air using the cryogenic energy of liquefied natural gas fuel that is used for power generation. Liquid hydrogen is produced efficiently and simultaneously using liquid nitrogen. Approximately 12 times as much hydrogen in liquid form can be transported and supplied as pressurized hydrogen gas. This technology is a significant step forward in the dissemination and expansion of hydrogen in a hydrogen-based economy.

  14. Biomagnetism in Japan.

    Science.gov (United States)

    Kotani, M; Mori, H; Kuriki, S; Uchikawa, Y; Chiyotani, K; Nemoto, I

    1987-01-01

    The study of biomagnetic fields originating in a biological body is called biomagnetism. Among various fields of biomagnetism, this paper reviews the research and clinical works in magnetocardiogram, neuromagnetism, magneto-oculogram, magnetopneumogram and magnetic measurement for cell motility carried out in Japan.

  15. Japan's electronic packaging technologies

    Science.gov (United States)

    Tummala, Rao R.; Pecht, Michael

    1995-01-01

    The JTEC panel found Japan to have significant leadership over the United States in the strategic area of electronic packaging. Many technologies and products once considered the 'heart and soul' of U.S. industry have been lost over the past decades to Japan and other Asian countries. The loss of consumer electronics technologies and products is the most notable of these losses, because electronics is the United States' largest employment sector and is critical for growth businesses in consumer products, computers, automobiles, aerospace, and telecommunications. In the past there was a distinction between consumer and industrial product technologies. While Japan concentrated on the consumer market, the United States dominated the industrial sector. No such distinction is anticipated in the future; the consumer-oriented technologies Japan has dominated are expected to characterize both domains. The future of U.S. competitiveness will, therefore, depend on the ability of the United States to rebuild its technological capabilities in the area of portable electronic packaging.

  16. China, South Korea, Japan

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    Intended for Canadian readers, this popular account was suggested by the Sixth Pacific Basin Nuclear Conference. Economic, political, geographic, sociological and historical aspects of the nuclear programmes of China, South Korea and Japan are discussed. The importance of past, present and future Canadian nuclear trade with the area is indicated

  17. Nuclear Power in Japan.

    Science.gov (United States)

    Powell, John W.

    1983-01-01

    Energy consumption in Japan has grown at a faster rate than in any other major industrial country. To maintain continued prosperity, the government has embarked on a crash program for nuclear power. Current progress and issues/reactions to the plan are discussed. (JN)

  18. Photovoltaics in Japan

    Science.gov (United States)

    Shimada, K.

    1985-01-01

    Report surveys status of research and development on photovoltaics in Japan. Report based on literature searches, private communications, and visits by author to Japanese facilities. Included in survey are Sunshine Project, national program to develop energy sources; industrial development at private firms; and work at academic institutions.

  19. Political Corruption in Japan.

    Science.gov (United States)

    Reed, Steven R.; And Others

    1996-01-01

    Provides an overview of political corruption and its place in Japanese culture and society. Discusses recent scandals and efforts at political reform. These efforts are moving Japan from a "boss-patronage" system to a "civic-culture." Includes a table of post-war Japanese prime ministers and corruption scandals. (MJP)

  20. Japan Report, No. 184.

    Science.gov (United States)

    1983-11-10

    Text] No Progress in "Agricultural" Issue [Moderator] On 7 and 8 July, a 2-day conference of Japanese-U.S. business- men was held at the Ritz ... Carlton Hotel in Chicago; among those attending from Japan was Yoshihiro Inayama, chairman of the Keidanren [federation of economic organizations

  1. Japan's electronic packaging technologies

    Science.gov (United States)

    Tummala, Rao R.; Pecht, Michael

    1995-02-01

    The JTEC panel found Japan to have significant leadership over the United States in the strategic area of electronic packaging. Many technologies and products once considered the 'heart and soul' of U.S. industry have been lost over the past decades to Japan and other Asian countries. The loss of consumer electronics technologies and products is the most notable of these losses, because electronics is the United States' largest employment sector and is critical for growth businesses in consumer products, computers, automobiles, aerospace, and telecommunications. In the past there was a distinction between consumer and industrial product technologies. While Japan concentrated on the consumer market, the United States dominated the industrial sector. No such distinction is anticipated in the future; the consumer-oriented technologies Japan has dominated are expected to characterize both domains. The future of U.S. competitiveness will, therefore, depend on the ability of the United States to rebuild its technological capabilities in the area of portable electronic packaging.

  2. Dutch surgery in Japan

    NARCIS (Netherlands)

    van Gulik, Thomas M.; Nimura, Yuji

    2005-01-01

    An isolation policy was adopted in feudal Japan from 1639 to 1853 owing to the fear of foreign influence. During those 200 years of isolation, all foreigners were withheld from the country with the exception of the Dutch, who were permitted to establish a trading post on a small island in the Bay of

  3. Educational Technology in Japan.

    Science.gov (United States)

    Sakamoto, Takashi

    1987-01-01

    This overview of the current state of educational technology in Japan includes discussions of professional associations; academic and popular journals; diffusion of media and the budget in elementary and secondary schools; recent trends in government policies; educational technology research; a literature review; and suggestions of future trends.…

  4. Higher Education in Japan

    Science.gov (United States)

    Kida, Hiroshi

    1975-01-01

    Describes and quantifies Japan's present state of development of higher education noting the predominance of private establishments, variety of courses available, wide social base from which students are drawn, highly competitive nature of the entry procedures, and the many challenges including the linked problems of management and finance.…

  5. Private Universities in Japan.

    Science.gov (United States)

    Akira, Ninomiya

    The historical development of private universities in Japan is traced, with special attention to the Imperial Ordinance of University of 1918, and postwar developments. The present state of private universities is examined, considering especially their role in national education, finances and financial support, and public support of the…

  6. The role of dyking and fault control in the rapid onset of eruption at Chaitén volcano, Chile.

    Science.gov (United States)

    Wicks, Charles; de la Llera, Juan Carlos; Lara, Luis E; Lowenstern, Jacob

    2011-10-19

    Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2 May 2008 at Chaitén Volcano, located in Chile's southern Andean volcanic zone, rhyolitic magma migrated from more than 5 km depth in less than 4 hours (ref. 1) and erupted explosively with only two days of detected precursory seismic activity. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults.

  7. The role of dyking and fault control in the rapid onset of eruption at Chaitén Volcano, Chile

    Science.gov (United States)

    Wicks, Charles; De La, Llera; Lara, L.E.; Lowenstern, J.

    2011-01-01

    Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2 May 2008 at Chaitén Volcano, located in Chile’s southern Andean volcanic zone, rhyolitic magma migrated from more than 5 km depth in less than 4 hours and erupted explosively with only two days of detected precursory seismic activity. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults.

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

    Science.gov (United States)

    Gaddis, Ben; Kauahikaua, James P.

    2018-03-26

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

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

    Science.gov (United States)

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

    2017-12-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

  11. 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.

  12. Globalization and Education in Japan

    Science.gov (United States)

    Ohkura, Kentaro; Shibata, Masako

    2009-01-01

    In this paper, the authors contend that globalization in Japan is the gradual process in which Japan's positioning of "self" within international relations, which had formerly been dominated by the West, has changed. Accordingly, Japan's relationships with the West and the rest of the world, for example, Asia, have also been reviewed and…

  13. Atribacteria from the Subseafloor Sedimentary Biosphere Disperse to the Hydrosphere through Submarine Mud Volcanoes

    Directory of Open Access Journals (Sweden)

    Tatsuhiko Hoshino

    2017-06-01

    Full Text Available Submarine mud volcanoes (SMVs are formed by muddy sediments and breccias extruded to the seafloor from a source in the deep subseafloor and are characterized by the discharge of methane and other hydrocarbon gasses and deep-sourced fluids into the overlying seawater. Although SMVs act as a natural pipeline connecting the Earth’s surface and subsurface biospheres, the dispersal of deep-biosphere microorganisms and their ecological roles remain largely unknown. In this study, we investigated the microbial communities in sediment and overlying seawater at two SMVs located on the Ryukyu Trench off Tanegashima Island, southern Japan. The microbial communities in mud volcano sediments were generally distinct from those in the overlying seawaters and in the well-stratified Pacific margin sediments collected at the Peru Margin, the Juan de Fuca Ridge flank off Oregon, and offshore of Shimokita Peninsula, northeastern Japan. Nevertheless, in-depth analysis of different taxonomic groups at the sub-species level revealed that the taxon affiliated with Atribacteria, heterotrophic anaerobic bacteria that typically occur in organic-rich anoxic subseafloor sediments, were commonly found not only in SMV sediments but also in the overlying seawater. We designed a new oligonucleotide probe for detecting Atribacteria using the catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH. CARD-FISH, digital PCR and sequencing analysis of 16S rRNA genes consistently showed that Atribacteria are abundant in the methane plumes of the two SMVs (0.58 and 1.5 × 104 cells/mL, respectively but not in surrounding waters, suggesting that microbial cells in subseafloor sediments are dispersed as “deep-biosphere seeds” into the ocean. These findings may have important implications for the microbial transmigration between the deep subseafloor biosphere and the hydrosphere.

  14. Seismicity of the Earth 1900-2007, Japan and Vicinity

    Science.gov (United States)

    Rhea, Susan; Tarr, Arthur C.; Hayes, Gavin P.; Villaseñor, Antonio; Benz, Harley

    2010-01-01

    This map shows details of Japan and vicinity not visible in an earlier publication, U.S. Geological Survey Scientific Investigations Map 3064. Japan and its island possessions lie across four major tectonic plates: Pacific plate, North America plate; Eurasia plate; and Philippine Sea plate. The Pacific plate is subducted into the mantle, beneath Hokkaido and northern Honshu, along the eastern margin of the Okhotsk microplate, a proposed subdivision of the North America plate (Bird, 2003). Farther south, the pacific plate is subducted beneath volcanic islands along the eastern margin of the Philippine Sea plate. This 2,200 km-long zone of subduction of the Pacific plate is responsible for the creation of the deep offshore Ogasawara and Japan trenches as well as parallel chains of islands and volcanoes, typical of the Circumpacific island arcs. Similarly, the Philippine Sea plate is itself subducting under the Eurasia plate along a zone, extending from Taiwan to southern Honshu, that comprises the Ryuku Islands and the Nansei-Shonto trench.

  15. 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

  16. High resolution three-dimensional magnetization mapping in Tokachidake Volcano using low altitude airborne magnetic survey data

    Science.gov (United States)

    Iwata, M.; Mogi, T.; Okuma, S.; Nakatsuka, T.

    2016-12-01

    Tokachidake Volcano, central Hokkaido, Japan erupted in 1926, 1962 and 1988-1989 in the 20th century from the central part. In recent years, expansions of the edifice of the volcano at shallow depth and increases of the volcanic smoke in the Taisho crater were observed (Meteorological Agency of Japan, 2014). Magnetic changes were observed at the 62-2 crater by repeated magnetic measurements in 2008-2009, implying a demagnetization beneath the crater (Hashimoto at al., 2010). Moreover, a very low resistivity part was found right under the 62-2 crater from an AMT survey (Yamaya et al., 2010). However, since the station numbers of the survey are limited, the area coverage is not sufficient. In this study, we have re-analyzed high-resolution aeromagnetic data to delineate the three-dimensional magnetic structure of the volcano to understand the nature of other craters.A low altitude airborne magnetic survey was conducted in 2014 mainly over the active areas of the volcano by the Ministry of Land, Infrastructure, Transport and Tourism to manage land slide risk in the volcano. The survey was flown at an altitude of 60 m above ground by a helicopter with a Cesium magnetometer in the towed-bird 30m below the helicopter. The low altitude survey enables us to delineate the detailed magnetic structure. We calculated magnetic anomaly distribution on a smooth surface assuming equivalent anomalies below the observation surface. Then the 3D magnetic imaging method (Nakatsuka and Okuma, 2014) was applied to the magnetic anomalies to reveal the three-dimensional magnetic structure.As a result, magnetization highs were seen beneath the Ground crater, Suribachi crater and Kitamuki crater. This implies that magmatic activity occurred in the past at these craters. These magma should have already solidified and acquired strong remanent magnetization. Relative magnetization lows were seen beneath the 62-2 crater and the Taisho crater where fumarolic activity is active. However a

  17. 36 CFR 7.25 - Hawaii Volcanoes National Park.

    Science.gov (United States)

    2010-07-01

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

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

    African Journals Online (AJOL)

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

  19. 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…

  20. 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...

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

    African Journals Online (AJOL)

    AJL

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

  2. Global data collection and the surveillance of active volcanoes

    Science.gov (United States)

    Ward, P.L.

    1990-01-01

    Data relay systems on existing earth-orbiting satellites provide an inexpensive way to collect environmental data from numerous remote sites around the world. This technology could be used effectively for fundamental monitoring of most of the world's active volcanoes. Such global monitoring would focus attention on the most dangerous volcanoes that are likely to significantly impact the geosphere and the biosphere. ?? 1990.

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

    International Nuclear Information System (INIS)

    Brenes-Andre, Jose

    2014-01-01

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

  4. Ensemble methods for Etna volcano warning system

    Science.gov (United States)

    Scandura, Danila; Cannavò, Flavio; Aliotta, Marco; Cassisi, Carmelo; Montalto, Placido

    2017-04-01

    The large amount of signals used for volcanic monitoring allow detecting volcano criticalities with unprecedented reliability. At the same time, the use of different monitoring networks makes essential the development of a system that synthesizes into a single information the overall state of the volcano. In this context, the ensemble learning techniques can play a useful role accepting different nature inputs and synthesizing the information in a single output. In broad terms, these techniques use many weak learning algorithms to achieve the best predictive performance compared to any obtained from classical learning algorithms. By averaging the results of each weak learner, the ensemble algorithms reduce the risk of using a single non-discriminative weak learning algorithm and allows for a more accurate classification. Here we used the ensemble techniques to classify three different states of Etna volcano: 1) Quiet; 2) Strombolian activity; 3) Lava fountain. We carried out several simulations using a large data set spanning the 2011-2015 time interval, including the records of most part of monitored geophysical parameters and the corresponding volcanic state. Simulations were performed subdividing the available data into training and test sets. We checked the ability of the proposed method to recognize automatically the lava fountain episodes. To this purpose, we tested different ensemble techniques changing associated parameters and weak learners. The found system was able to identify the lava fountain episode with a reliability over 70% and to detect the beginning of lava fountain episode in the totality of the test cases. Results suggest that the proposed system can be seen as a promising tool for civil protection purposes.

  5. 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.

  6. 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.

  7. Optical satellite data volcano monitoring: a multi-sensor rapid response system

    Science.gov (United States)

    Duda, Kenneth A.; Ramsey, Michael; Wessels, Rick L.; Dehn, Jonathan

    2009-01-01

    In this chapter, the use of satellite remote sensing to monitor active geological processes is described. Specifically, threats posed by volcanic eruptions are briefly outlined, and essential monitoring requirements are discussed. As an application example, a collaborative, multi-agency operational volcano monitoring system in the north Pacific is highlighted with a focus on the 2007 eruption of Kliuchevskoi volcano, Russia. The data from this system have been used since 2004 to detect the onset of volcanic activity, support the emergency response to large eruptions, and assess the volcanic products produced following the eruption. The overall utility of such integrative assessments is also summarized. The work described in this chapter was originally funded through two National Aeronautics and Space Administration (NASA) Earth System Science research grants that focused on the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument. A skilled team of volcanologists, geologists, satellite tasking experts, satellite ground system experts, system engineers and software developers collaborated to accomplish the objectives. The first project, Automation of the ASTER Emergency Data Acquisition Protocol for Scientific Analysis, Disaster Monitoring, and Preparedness, established the original collaborative research and monitoring program between the University of Pittsburgh (UP), the Alaska Volcano Observatory (AVO), the NASA Land Processes Distributed Active Archive Center (LP DAAC) at the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, and affiliates on the ASTER Science Team at the Jet Propulsion Laboratory (JPL) as well as associates at the Earth Remote Sensing Data Analysis Center (ERSDAC) in Japan. This grant, completed in 2008, also allowed for detailed volcanic analyses and data validation during three separate summer field campaigns to Kamchatka Russia. The second project, Expansion and synergistic use

  8. 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.

  9. 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.

  10. The deep structure of Axial Volcano

    Science.gov (United States)

    West, Michael Edwin

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

  11. 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

  12. Cataloging tremor at Kilauea Volcano, Hawaii

    Science.gov (United States)

    Thelen, W. A.; Wech, A.

    2013-12-01

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

  13. Measurements of radon and chemical elements: Popocatepetl volcano

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  14. 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.

  15. The First Historical Eruption of Kambalny Volcano in 2017 .

    Science.gov (United States)

    Gordeev, E.

    2017-12-01

    The first historical eruption at Kambalny volcano began about 21:20 UTC on March 24, 2017 with powerful ash emissions up to 6 km above sea level from the pre-summit crater. According to tephrochronological data, it is assumed that the strong eruptions of the volcano occurred 200 (?) and 600 years ago. KVERT (Kamchatka Volcanic Eruption Response Team) of the Institute of Volcanology and Seismology FEB RAS has been monitoring Kambalny volcano since 2002. KVERT worked closely with AMC Elizovo and Tokyo VAAC during the eruption at Kambalny volcano in 2017. The maximum intensity of ash emissions occurred on 25-26 March: a continuous plume laden with ash particles spread over several thousand kilometers, changing the direction of propagation from the volcano from the south-west to the south and south-east. On 27-29 March, the ash plume extended to the west, on 30 March - to the southeast of the volcano. On March 31 and April 01, the volcano was relatively quiet. The resumption of the volcano activity after two days of rest was expressed in powerful ash emissions up to 7 km above sea level. Gas-steam plumes containing some amount of ash were noted on 02-05 April, and powerful ash emissions up to 7 km above sea level occurred on 09 April. The explosive activity at the volcano ended on 11 April. The area of ash deposits was about 1500 km2, the total area covered by ash falls, for example, on 25 March, was about 650 thousand km2. To monitor and study the Kambalny volcano eruption we mainly used satellite images of medium resolution available in the information system "Monitoring volcanic activity in Kamchatka and Kurile Islands" (VolSatView). This work was supported by the Russian Science Foundation, project No. 16-17-00042.

  16. 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.

  17. New Perspectives on the Climatic Impact of the 1600 Eruption of Huaynaputina Volcano, Peru

    Science.gov (United States)

    Verosub, K. L.; Lippman, J.

    2007-05-01

    A critical test of the new understanding of volcanic aerosols developed since 1982 is to determine if it can predict the effects of larger eruptions than those that have occurred since El Chichon. To do that, requires detailed information about the effects of specific large eruptions. We have been investigating the human and climatic impacts of the 1600 eruption of Huaynaputina volcano in Peru. The estimated Volcanic Explosivity Index for this eruption is 6, which is comparable to that of the 1815 eruption of Tambora volcano in Indonesia, which produced global cooling and led to crop failures, famine and social unrest. On the basis of tree-ring data, Briffa et al. (1998) suggested that the most severe short-term Northern Hemisphere cooling event of the past 600 years occurred in 1601, the year following the Huaynaputina eruption. In order gain a better understanding of the nature and extent of this cooling, we have been collecting annual time series that provide information about climatic conditions during time intervals that bracket the Huaynaputina eruption. Among the time series that we have examined (or plan to examine) are ice conditions in the harbors of Tallinn, Estonia, and Riga, Latvia and in Lake Suwa in Japan: cherry blossom blooming (sakura) dates from Kyoto, Japan; records of agricultural production from China and Russia; tithe records from the Spanish colonial empire; dates of the beginning of the wine harvest in France and the rye harvest in Sweden; prices of agricultural commodities in Europe; and river flows from the Nile and the Colorado. Often, in the records we have examined, 1601 shows up as one of the coldest years, if not the coldest year. In addition, the worst famines in Russian history took place between 1601 and 1603, which eventually led to the overthrow of Tsar Boris Gudonov. Thus, there is considerable evidence that the climatic impacts of the Huaynaputina eruption were comparable to those from the Tambora eruption. This result is

  18. International Volcanological Field School in Kamchatka and Alaska: Experiencing Language, Culture, Environment, and Active Volcanoes

    Science.gov (United States)

    Eichelberger, J. C.; Gordeev, E.; Ivanov, B.; Izbekov, P.; Kasahara, M.; Melnikov, D.; Selyangin, O.; Vesna, Y.

    2003-12-01

    The Kamchatka State University of Education, University of Alaska Fairbanks, and Hokkaido University are developing an international field school focused on explosive volcanism of the North Pacific. An experimental first session was held on Mutnovsky and Gorely Volcanoes in Kamchatka during August 2003. Objectives of the school are to:(1) Acquaint students with the chemical and physical processes of explosive volcanism, through first-hand experience with some of the most spectacular volcanic features on Earth; (2) Expose students to different concepts and approaches to volcanology; (3) Expand students' ability to function in a harsh environment and to bridge barriers in language and culture; (4) Build long-lasting collaborations in research among students and in teaching and research among faculty in the North Pacific region. Both undergraduate and graduate students from Russia, the United States, and Japan participated. The school was based at a mountain hut situated between Gorely and Mutnovsky Volcanoes and accessible by all-terrain truck. Day trips were conducted to summit craters of both volcanoes, flank lava flows, fumarole fields, ignimbrite exposures, and a geothermal area and power plant. During the evenings and on days of bad weather, the school faculty conducted lectures on various topics of volcanology in either Russian or English, with translation. Although subjects were taught at the undergraduate level, lectures led to further discussion with more advanced students. Graduate students participated by describing their research activities to the undergraduates. A final session at a geophysical field station permitted demonstration of instrumentation and presentations requiring sophisticated graphics in more comfortable surroundings. Plans are underway to make this school an annual offering for academic credit in the Valley of Ten Thousand Smokes, Alaska and in Kamchatka. The course will be targeted at undergraduates with a strong interest in and

  19. Monitoring volcano activity through Hidden Markov Model

    Science.gov (United States)

    Cassisi, C.; Montalto, P.; Prestifilippo, M.; Aliotta, M.; Cannata, A.; Patanè, D.

    2013-12-01

    During 2011-2013, Mt. Etna was mainly characterized by cyclic occurrences of lava fountains, totaling to 38 episodes. During this time interval Etna volcano's states (QUIET, PRE-FOUNTAIN, FOUNTAIN, POST-FOUNTAIN), whose automatic recognition is very useful for monitoring purposes, turned out to be strongly related to the trend of RMS (Root Mean Square) of the seismic signal recorded by stations close to the summit area. Since RMS time series behavior is considered to be stochastic, we can try to model the system generating its values, assuming to be a Markov process, by using Hidden Markov models (HMMs). HMMs are a powerful tool in modeling any time-varying series. HMMs analysis seeks to recover the sequence of hidden states from the observed emissions. In our framework, observed emissions are characters generated by the SAX (Symbolic Aggregate approXimation) technique, which maps RMS time series values with discrete literal emissions. The experiments show how it is possible to guess volcano states by means of HMMs and SAX.

  20. Characterization of debris flows by rainstorm condition at a torrent on the Mount Yakedake volcano, Japan

    Science.gov (United States)

    Okano, Kazuyuki; Suwa, Hiroshi; Kanno, Tadahiro

    2012-01-01

    We analyzed rainstorm control on debris-flow magnitude and flow characteristics using the 14 sets of rainstorm and debris-flow data obtained from 1980 to 2005 at the Kamikamihorizawa Creek of Mount Yakedake. With the principal component analysis on five parameters of debris flows: frontal velocity, peak velocity, peak flow depth, peak discharge and total discharge, and with video-record of boulder-dams in motion, and the preceding rainfall intensities, we conclude that the 14 debris flows could be categorized into three groups. The flows in the first group have large hydraulic magnitude and massive and turbulent boulder-dams filled with slurry matrix. The flows in the second group have small hydraulic magnitude and boulder-dams scarcely filled with slurry matrix, and the dam is observed to alternate between stopping and starting. The flows in the third group have small hydraulic magnitude and boulder dams filled with slurry matrix. Analysis of hillslope hydrology and debris-flow data asserted that the antecedent rainfall conditions control not only the hydraulic magnitude of debris flows but also the boulder-dam features. Large rainstorms of high intensity and durations as short as 10 minutes induces fast and large storm runoff to the headwaters and the source reaches of debris flow, while rainstorms with durations as long as 24 h raises water content in the bottom deposits along the debris-flow growth reaches and generates substantial runoff from the tributaries. Classification of the three groups is done based on water availability to debris flows on the source and growth reaches at the occurrence of debris flow.

  1. Volcano Monitoring in Ecuador: Three Decades of Continuous Progress of the Instituto Geofisico - Escuela Politecnica Nacional

    Science.gov (United States)

    Ruiz, M. C.; Yepes, H. A.; Hall, M. L.; Mothes, P. A.; Ramon, P.; Hidalgo, S.; Andrade, D.; Vallejo Vargas, S.; Steele, A. L.; Anzieta, J. C.; Ortiz, H. D.; Palacios, P.; Alvarado, A. P.; Enriquez, W.; Vasconez, F.; Vaca, M.; Arrais, S.; Viracucha, G.; Bernard, B.

    2014-12-01

    In 1988, the Instituto Geofisico (IG) began a permanent surveillance of Ecuadorian volcanoes, and due to activity on Guagua Pichincha, SP seismic stations and EDM control lines were then installed. Later, with the UNDRO and OAS projects, telemetered seismic monitoring was expanded to Tungurahua, Cotopaxi, Cuicocha, Chimborazo, Antisana, Cayambe, Cerro Negro, and Quilotoa volcanoes. In 1992 an agreement with the Instituto Ecuatoriano de Electrificacion strengthened the monitoring of Tungurahua and Cotopaxi volcanoes with real-time SP seismic networks and EDM lines. Thus, background activity levels became established, which was helpful because of the onset of the 1999 eruptive activity at Tungurahua and Guagua Pichincha. These eruptions had a notable impact on Baños and Quito. Unrest at Cotopaxi volcano was detected in 2001-2002, but waned. In 2002 Reventador began its eruptive period which continues to the present and is closely monitored by the IG. In 2006 permanent seismic BB stations and infrasound sensors were installed at Tungurahua and Cotopaxi under a cooperative program supported by JICA, which allowed us to follow Tungurahua's climatic eruptions of 2006 and subsequent eruptions up to the present. Programs supported by the Ecuadorian Secretaria Nacional de Ciencia y Tecnologia and the Secretaria Nacional de Planificacion resulted in further expansion of the IG's monitoring infrastructure. Thermal and video imagery, SO2 emission monitoring, geochemical analyses, continuous GPS and tiltmeters, and micro-barometric surveillance have been incorporated. Sangay, Soche, Ninahuilca, Pululahua, and Fernandina, Cerro Azul, Sierra Negra, and Alcedo in the Galapagos Islands are now monitored in real-time. During this time, international cooperation with universities (Blaise Pascal & Nice-France, U. North Carolina, New Mexico Tech, Uppsala-Sweden, Nagoya, etc.), and research centers (USGS & UNAVCO-USA, IRD-France, NIED-Japan, SGC-Colombia, VAAC, MIROVA) has introduced

  2. Surface Deformation Caused by a Shallow Magmatic Source at Okmok Volcano, Aleutian Arc

    Science.gov (United States)

    Miyagi, Y.; Freymueller, J. T.; Kimata, F.; Sato, T.; Mann, D.; Kasahara, M.

    2001-12-01

    Okmok Volcano, located on Umnak Island in the eastern Aleutian arc, last erupted in 1997. Okmok consists of a 10 km wide caldera with several cones located inside. Significant surface deformation before, during and after the eruption has been measured using InSAR. However, the area of coherent data has been limited to the northern part of the caldera, with some additional coherent areas along the outer flanks of the volcano. With support from NASDA (National Space Development Agency of Japan) and the International Arctic Research Center, we carried out GPS campaigns in 2000 and 2001 to supplement the InSAR data with 3D measurements of deformation at well-distributed points. We surveyed 24 sites on and around Okmok in 2000, and 31 sites in 2001. As of this date, no SAR data from suitable passes has been acquired in the summer of 2001; if any are acquired, we will also analyze this data. InSAR data for the period 1997-2000 show what appears to be a radially-symmetric pattern of displacements, consistent with the inflation of a shallow (3-4 km) pressure (Mogi) source located beneath the geoemtric center of the caldera. A deflation source at the same location and depth was inferred from an interferogram spanning the eruption. The 2000-2001 GPS data, on the other hand, show evidence for rapid horizontal extension between sites in center of the caldera. This signal cannot be explained by a Mogi source, and may represent the intrusion of a shallow dike. In addition to this probable dike source, it appears that overall inflation of the volcano continues. The proposed dike extends from roughly the center of the caldera toward the 1997 eruptive vent. In May 2001, a swarm of micro-earthquakes occurred somewhere close to Okmok Volcano (location errors are very large as the closest permanent seismic site is ~100 km from Okmok). It is possible that this small earthquake swarm could have been associated with the intrusion of the shallow dike.

  3. Infrasound as a Long Standing Tool for Monitoring Continental Ecuadorean Volcanoes

    Science.gov (United States)

    Ruiz, M. C.; Ortiz, H. D.; Hernandez, S.; Palacios, P.; Anzieta, J. C.

    2017-12-01

    In the last 10 years, infrasound and seismic methods have been successfully used in the continuous monitoring of eruptive activity at Tunguruhua, Reventador, Sangay and Cotopaxi volcanoes. After a dormant period of 81 years, Tungurahua woke up in 1999 and has since been characterized by vulcanian and strombolian eruptions. Beginning in July 2006, a permanent seismo-infrasonic network with 5 collocated seismic and infrasound sensors was installed through a cooperation with Japan International Cooperation Agency (JICA). It recorded more than 6,000 explosions at Tungurahua with reduced amplitudes larger than 270 Pa at 1 km from the active crater, including 3 explosions greater than 6000 Pa associated with short-lived explosions. Major and long sustained eruptions (July 14-15, 2006; August 16-17, 2006; February 6-8, 2008, May 28, 2010; December 4, 2010; December 3-4, 2011; August 18, 2012) generated seismic and infrasound tremors with complex waveforms. In 2002, Reventador volcano produced the largest eruption in Ecuador in the last century (VEI-4). Since September 2012, alternating periods of strombolian activity and short-lived vulcanian explosions are monitored by seismic and microbarometer sensors located on the south-east border of the caldera rim. Non-steady activity with fluctuations between quiescence and frequent explosions, tremor, and chugging events is recorded. Infrasound of explosions ranges from 75 to 6350 Pa in reduced peak-to-peak amplitudes. Sangay, a remote and very active volcano, is monitored by a broadband seismometer and microbarometer collocated at 8 km from the summit. Active periods during the last few months are characterized by explosion events followed by lava flows and small ash emissions. In March 2016, more than 100 explosions were recorded in a single day. Finally, in 2015 Cotopaxi volcano began its recent eruptive period after 138 years of quiescence. One month after the initiation of its eruptive activity, 76 harmonic infrasound

  4. [Gambling disorder in Japan].

    Science.gov (United States)

    Tanabe, Hitoshi

    2015-09-01

    Gambling disorder is a psychiatric disorder characterized by persistent and recurrent problematic gambling behavior, associated with impaired functioning, reduced quality of life, and frequent divorce and bankruptcy. Gambling disorder is reclassified in the category Substance-Related and Addictive Disorders in the DSM-5 because its clinical features closely resemble those of substance use disorders, and gambling activates the reward system in brain in much the same way drugs do. Prevalence of gambling disorder in Japan is high rate because of slot machines and pachinko game are very popular in Japan. The author recommend group psychotherapy and self-help group (Gamblers Anonymous), because group dynamics make them accept their wrongdoings related to gambling and believe that they can enjoy their lives without gambling.

  5. Safeguards activities in Japan

    International Nuclear Information System (INIS)

    Osabe, Takeshi

    1998-01-01

    Current Japanese State System for Accountancy and Control (SSAC) has been developing and fully satisfies requirements of both IAEA Safeguards and bilateral partners. However, the public attention on the national and international safeguards activities were increased and the safeguards authorities were required to promote the objective assessment of safeguards implementation to avoid mistrust in safeguards activities which directly influence the public acceptance of nuclear energy in itself. Additionally, since Japan has promoted to complete nuclear fuel cycle including spent fuel reprocessing, enrichment and mixed oxide fuel fabrication this would require further assurance of Japanese non-proliferation commitment. Japan supports the introduction of strengthened safeguards. In this context it is particularly important to strengthen the relationship between national and the IAEA safeguards to contribute actively to the IAEA safeguards in development and utilization of new technologies towards more effective and efficient IAEA safeguards

  6. Moral Education in Japan

    DEFF Research Database (Denmark)

    Roesgaard, Marie Højlund

    ‘religion’ is not a subject in schools. So, how do the Japanese go about the business of teaching values and morality? Using the Japanese example, this volume looks at moral education from the basic point of view of universal and common human values, with due attention given to culture-specific traits....... It places moral education within the context of globalization and cosmopolitanism and shows, that moral education in Japan is a useful key to understanding how globalization and cosmopolitanism can work within a specific system, in this case Japanese values education. In recent years various changes...... values. How are the new requirements and the renewed focus on moral education met in schools and by educators? This volume will describe the history of moral education in Japan, analyse the recent changes of the curriculum, analyse the practices in selected schools via fieldwork and case-studies and take...

  7. Common characteristics of paired volcanoes in northern Central America

    Science.gov (United States)

    Halsor, Sid P.; Rose, William I.

    1988-05-01

    Four pairs of active volcanoes along the northern Central American volcanic front have erupted basalt-andesite magmas that show consistent intrapair behavioral and compositional differences. These differences are found in records of volcanic activity and complete major and minor element data on over 200 samples. From northwest to southeast along the volcanic front the four volcano pairs are Cerro Quemado-Santa María, Tolimán-Atitlán, Acatenango-Fuego, and Santa Ana-Izalco. The volcano pair relations help explain compositional differences, apart from those reflecting variation in crustal thickness of about 15 km along the volcanic front, providing insight into across-arc variations and closely spaced subvolcanic plumbing systems. Intravolcano pair spacing is less than 5 km compared with an average intervolcano spacing of 25 km along the entire volcanic front. Within each volcano pair, the seaward volcano has had more frequent historic activity, erupting magmas that are generally more mafic, lower in large ion lithophile elements and higher in Na2O/K2O than magmas erupted from its landward counterpart. Each paired volcano site lies in close proximity to a rhyolitic caldera, situated north or northeast of the volcano pair. However, rare earth element data at the Tolimán-Atitlán volcano pair imply that mixing between caldera rhyolite and the mafic magma of the paired volcanoes does not occur. Petrographie, isotopic, and other geochemical data from the Tolimán-Atitlán volcano pair suggest that separate but contemporaneous magma bodies beneath each volcano evolve and pass through the crust at different rates. Atitlán magmas are processed through the crust more efficiently and with greater frequency than Tollman magmas, which undergo longer periods of stagnation interrupted by mafic injection and rapid eruption. This relation appears to hold at the other paired volcano sites and is further evidence that closely spaced volcanoes, with similar subcrustal magma

  8. Nuclear situation in Japan

    International Nuclear Information System (INIS)

    2006-01-01

    This analysis takes stock on the nuclear situation in Japan. It discusses the ambitious equipment program in collaboration with the France, the destabilization of the japanese nuclear industry following the accidents and the energy policy evolutions. It presents the projects of the japanese nuclear industry: the Monju reactor restart, the Pluthermal project, the reprocessing power plant of Rokkasho Mura, the new reactors, the russian weapons dismantling, the ITER site selection and the buy out of Westinghouse by Toshiba. (A.L.B.)

  9. Psychology in Japan.

    Science.gov (United States)

    Imada, Hiroshi; Tanaka-Matsumi, Junko

    2016-06-01

    The purpose of this article is to provide information about Japan and its psychology in advance of the 31st International Congress of Psychology (ICP), to be held in Yokohama, Japan, in 2016. The article begins with the introduction of the Japanese Psychological Association (JPA), the hosting organization of the ICP 2016, and the Japanese Union of Psychological Associations consisting of 51 associations/societies, of which the JPA is a member. This is followed by a brief description of a history of psychology of Japan, with emphasis on the variation in our approach to psychology in three different periods, that is, the pre- and post-Pacific War periods, and the post-1960 period. Next, the international contributions of Japanese psychology/psychologists are discussed from the point of view of their visibility. Education and training in psychology in Japanese universities is discussed with a final positive remark about the long-awaited enactment of the Accredited Psychologist Law in September, 2015. © 2016 International Union of Psychological Science.

  10. Japan's fuel recycling policy

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The Atomic Energy Commission (AEC) has formulated Japanese nuclear fuel recycling plan for the next 20 years, based on the idea that the supply and demand of plutonium should be balanced mainly through the utilization of plutonium for LWRs. The plan was approved by AEC, and is to be incorporated in the 'Long term program for development and utilization of nuclear energy' up for revision next year. The report on 'Nuclear fuel recycling in Japan' by the committee is characterized by Japanese nuclear fuel recycling plan and the supply-demand situation for plutonium, the principle of the possession of plutonium not more than the demand in conformity with nuclear nonproliferation attitude, and the establishment of a domestic fabrication system of uranium-plutonium mixed oxide fuel. The total plutonium supply up to 2010 is estimated to be about 85 t, on the other hand, the demand will be 80-90 t. The treatment of plutonium is the key to the recycling and utilization of nuclear fuel. By around 2000, the private sector will commercialize the fabrication of the MOX fuel for LWRs at the annual rate of about 100 t. Commitment to nuclear nonproliferation, future nuclear fuel recycling program in Japan, MOX fuel fabrication system in Japan and so on are reported. (K.I.)

  11. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-02-01

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

  13. Rhyolitic volcano-ice interactions in Iceland

    Science.gov (United States)

    McGarvie, Dave

    2009-09-01

    Iceland contains an abundance and diversity of rhyolitic edifices produced during volcano-ice interactions (glaciovolcanism) that is unmatched by any other volcanic province, with an estimated 350 km 3 erupted during the past 0.8 Ma from at least fifteen volcanic systems. This review summarises research undertaken during the past decade and provides a new summary of the distribution of rhyolitic glaciovolcanic rocks erupted during the past 0.8 Ma. Descriptions of effusion-dominated edifices focus on the two best-studied edifices — the c.0.6 km 3 and 570 m high Prestahnúkur edifice and the smaller-volume (walls. A particular feature of Prestahnúkur is its sheet-like lava bodies which are interpreted as sills that intruded the ice-edifice interface. Rhyolitic tuyas are products of sustained eruptions into thick ice, and form distinctive steep-sided edifices with flat or broad dome-like tops. They are 300-700 m high with volumes up to 2 km 3 (though 0.5-1.0 km 3 is more typical). Initial vigorous phreatomagmatic eruptions within well-drained ice vaults build steep-sided piles of tephra confined by ice walls. Gradual upwards increases in inflated clasts point to the decreasing involvement of meltwater and the increasing ability of the magma to vesiculate. As the eruption progresses and terminates, non-explosive degassing produces lava caps up to 300 m thick. Öræfajökull is a stratovolcano illustrating complex volcano-ice interactions generated when rhyolitic lavas erupt onto steeper slopes and encounter ice of variable thickness and properties (e.g. fracturing). Eruptive units record dramatic ice thickness fluctuations of up to 500 m in valley glaciers between eruptions, which emphasises that useful palaeoenvironmental information can be gleaned from detailed studies of volcano-ice interactions. Considerable value is added when palaeoenvironmental information is combined with Ar-Ar dating. For example Ar-Ar dating of two rhyolitic tuyas at Torfajökull reveal

  14. 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

  15. 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

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

    Science.gov (United States)

    Lin, Cheng-Horng

    2017-07-01

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

  17. 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).

  18. 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

  19. 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.

  20. JPRS Report, Science & Technology, Japan

    Science.gov (United States)

    1988-10-05

    This is Japan Report with Science and Technology. It contains the issues with different topics on biotecnology , defense industry, nuclear engineering, Marine technology, science and technology policy.

  1. The graying of Japan.

    Science.gov (United States)

    Martin, L G

    1989-07-01

    Japan's rapidly aging population has become a top policy issue, especially as the increasing costs of pensions and medical care are debated. With the highest life expectancy on earth, the Japanese potentially face long periods of retirement, as well as the possibility of long periods of disability. Although family support of the elderly is thought to have been strong traditionally, the recent decline in co-residence with children is 1 indication that the way support is given may be changing. This issue is of particular concern to the government, which wants to avoid any greater responsibility for the elderly than is necessary given the dramatic population aging yet to come. The government is also encouraging employers to provide more employment opportunities for the elderly at the same time that it is trying to raise the eligibility age for the receipt of public pensions. There is resistance on the part of employers, however, because wages and retirement allowances in Japan are positively related to length of employment. Furthermore, it is not clear whether elderly Japanese of the future will be as willing to work, if they learn to enjoy increased leisure early in their careers. Nevertheless, it is unlikely that population aging will lead to Japan's economic decline. Although the savings rate may decline somewhat, restructuring of the economy and continued overseas investment should keep the economy growing in the long run. Important in both the care of the frail elderly and the continued growth of the economy will be the roles played by middle-aged Japanese women.

  2. PRECURSORY SLOPE DEFORMATION AROUND LANDSLIDE AREA DETECTED BY INSAR THROUGHOUT JAPAN

    Directory of Open Access Journals (Sweden)

    T. Nakano

    2016-06-01

    Full Text Available Interferometric Synthetic Aperture Radar (InSAR technique is able to detect a slope deformation around landslide (e.g., Singhroy et al., 2004; Une et al., 2008; Riedel and Walther, 2008; Sato et al., 2014. Geospatial Information Authority (GSI of Japan has been performing the InSAR analysis regularly by using ALOS/PALSAR data and ALOS-2/PALSAR-2 data throughout Japan. There are a lot of small phase change sites except for crustal deformation with earthquake or volcano activity in the InSAR imagery. Most of the phase change sites are located in landslide area. We conducted field survey at the 10 sites of those phase change sites. As a result, we identified deformation of artificial structures or linear depressions caused by mass movement at the 9 sites. This result indicates that InSAR technique can detect on the continual deformation of landslide block for several years. GSI of Japan will continue to perform the InSAR analysis throughout Japan. Therefore, we will be able to observe and monitor precursory slope deformation around landslide areas throughout Japan.

  3. Holography In Japan

    Science.gov (United States)

    Tsujiuchi, Jumpei

    1985-08-01

    The present status of activities of research and application of holography in Japan is reviewed. The most active field is metrology, and many applications in automobile, aircraft, electronic industries as well as basic researches are found. Information processing and optical memory are still in laboratory level, and suitable applications are looked for. Optical elements are promising, and applications in POS scanning systems are already in practical use. Applications in 3-D image display are spreading among the public, and applications for medical purpose have started. Acoustical holography is applied in mechanical engineering, and electron holography becomes a very attractive tool for experimental physics.

  4. Skiing research in Japan.

    Science.gov (United States)

    Watanabe, K

    1981-01-01

    Skiing and skiing techniques were introduced by the Austrians to Japanese soldiers in 1911. After that, skiing spread beyond the original purpose and recently produced the ski sciences. From a sports biomechanical aspect, the development of the study of ski jumping, alpine skiing, and the basic movement in skiing is introduced in this paper. One of the characteristic points of these studies in Japan was that the ski sciences were supported not only by biomechanists and physiologists, but also basically by physicists and engineers. The fundamental research and studies from divergent fields are supporting each other and being integrated into ski science.

  5. Nyheder i Japan

    DEFF Research Database (Denmark)

    Sejrup, Jens

    2016-01-01

    Kan man stole på, hvad folk siger, når man ikke ved, hvem de er? Forholdet mellem kildeanonymitet og troværdighed er forskelligt i mediesystemer rundt om i verden. Troværdighed er ingen universel størrelse, men en retorisk effekt der opstår på baggrund af faktorer som er kulturelt og systemisk in...... indlejret. I Japan har seriøse nyhedsmedier et specielt forhold til udsagn fra anonyme kilder, og udstrakt brug af uidentificerede informanter står ikke i modsætning til journalistisk kvalitet og pålidelighed....

  6. Domestic violence in Japan.

    Science.gov (United States)

    Kozu, J

    1999-01-01

    Traditionally, domestic violence in Japan referred to children's physical and emotional violence against their parents. However, in recent years, the general public's awareness of and actions toward other types of domestic violence, especially violence against women and children, has increased. Following a brief description of filial violence and elderly abuse, both spousal abuse and child abuse are discussed in terms of their prevalence and cultural and historical backgrounds. The article concludes with current and future challenges in the intervention of violence, particularly against women and children, in the Japanese family.

  7. Nuclear services for Japan

    International Nuclear Information System (INIS)

    Anderson, B.

    1991-01-01

    The UK Atomic Energy Authority (UKAEA) became AEA Technology in April 1990. The commercial interests are focussed through 4 business units: AEA Reactor Services, with whom several contracts have been won from Japanese customers for high resolution Field Emission Gun Scanning Transmission Electron Microscopy (FEGSTEM); AEA Fuel Services, a contract is being negotiated with an existing Japanese customer; AEA Decommissioning and Radwaste, with whom further development of an alternative approach to evaporation of liquid waste effluent for specific application in Japan is in progress; AEA Fusion. 1 fig

  8. Evidence for explosive volcanic density currents on certain Martian volcanoes

    Science.gov (United States)

    Reimers, C. E.; Komar, P. D.

    1979-01-01

    The morphologies of certain of the smaller Martian volcanoes are discussed as possible results of explosive volcanic density currents. An examination of newly-photographed flank and caldera features of the Martian volcanoes Ceraunius Tholus, Uranius Tholus, Uranius Patera and Hecates Tholus, including steep slope angles, Krakatoa-type caldera morphologies, erosional features (radial channels and anastamosing gullies) and constructional features (blanketed flanks and possible lava deltas) reveals their similarity to terrestrial cones and composite volcanoes such as Barcena Volcano. Crater age data from the surface of Martian domes and shields indicates that such explosive activity occurred more frequently early in Martian geologic history, consistent with the view that the volcanic density currents were base surges rather than nuees ardentes, with the melting of permafrost supplying the water required in base surge generation.

  9. Geomagnetic excursion captured by multiple volcanoes in a monogenetic field

    Science.gov (United States)

    Cassidy, John

    2006-11-01

    Five monogenetic volcanoes within the Quaternary Auckland volcanic field are shown to have recorded a virtually identical but anomalous paleomagnetic direction (mean inclination and declination of 61.7° and 351.0°, respectively), consistent with the capture of a geomagnetic excursion. Based on documented rates of change of paleomagnetic field direction during excursions this implies that the volcanoes may have all formed within a period of only 50-100 years or less. These temporally linked volcanoes are widespread throughout the field and appear not to be structurally related. However, the general paradigm for the reawakening of monogenetic fields is that only a single new volcano or group of closely spaced vents is created, typically at intervals of several hundred years or more. Therefore, the results presented show that for any monogenetic field the impact of renewed eruptive activity may be significantly under-estimated, especially for potentially affected population centres and the siting of sensitive facilities.

  10. Sunset Crater Volcano National Monument : Acoustical Monitoring 2010

    Science.gov (United States)

    2013-05-01

    During the summer of 2010 (July - August), the Volpe Center collected baseline acoustical data at Sunset Crater Volcano National Monument (SUCR) at a site deployed for approximately 30 days. The baseline data collected during this period will help pa...

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

    Data.gov (United States)

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

  12. Examining the interior of Llaima Volcano with receiver functions

    Science.gov (United States)

    Bishop, J. W.; Lees, J. M.; Biryol, C. B.; Mikesell, T. D.; Franco, L.

    2018-02-01

    Llaima Volcano in Chile is one of the largest and most active volcanoes in the southern Andes, with over 50 eruptions since the 1600s. After years of persistent degassing, Llaima most recently erupted in a series of violent Strombolian eruptions in 2007-2009. This period had few precursory signals, which highlights the need to obtain accurate magma storage information. While petrologic advancements have been made in understanding magma degassing and crystallization trends, a comprehensive seismic study has yet to be completed. Here, we present results of a receiver function survey utilizing a dense seismic array surrounding Llaima volcano. Application of H-κ stacking and common conversion point stacking techniques reveals a new Moho estimate and two structural anomalies beneath Llaima Volcano. We interpret a low velocity zone between 8 and 13 km depth as a newly imaged magma body.

  13. Haakon Mosby Mud Volcano provides unusual example of venting

    Science.gov (United States)

    Vogt, P. R.; Cherkashev, G.; Ginsburg, G.; Ivanov, G.; Milkov, A.; Crane, K.; Sundvor, A.; Pimenov, N.; Egorov, A.

    A seafloor mud volcano north of Norway is presenting researchers with an uncommon example of venting and is raising important questions. Seafloor aqueous vents, gas vents, mud volcanoes, and mud diapirs are found in a variety of geological settings. However, scientists did not expect to discover venting at the northern site, now known as the Haakon Mosby Mud Volcano (HMMV). It is considered especially unusual because of its Arctitc Location (72°N), its development largely within glacial marine sediments, and its lack of association either with salt tectonics or with plate subduction. Further, the volcano is posing questions for investigators about the relationship of methane generation and mud volcanism to thick, rapidly deposited sediments; sediment failure; and gas hydrates (GH).

  14. Temporary seismic networks on active volcanoes of Kamchatka (Russia)

    Science.gov (United States)

    Jakovlev, Andrey; Koulakov, Ivan; Abkadyrov, Ilyas; Shapiro, Nikolay; Kuznetsov, Pavel; Deev, Evgeny; Gordeev, Evgeny; Chebrov, Viktor

    2016-04-01

    We present details of four field campaigns carried out on different volcanoes of Kamchatka in 2012-2015. Each campaign was performed in three main steps: (i) installation of the temporary network of seismic stations; (ii) autonomous continuous registration of three component seismic signal; (III) taking off the network and downloading the registered data. During the first campaign started in September 2012, 11 temporary stations were installed over the Avacha group of volcanoes located 30 km north to Petropavlovsk-Kamchatsky in addition to the seven permanent stations operated by the Kamchatkan Branch of the Geophysical Survey (KBGS). Unfortunately, with this temporary network we faced with two obstacles. The first problem was the small amount of local earthquakes, which were detected during operation time. The second problem was an unexpected stop of several stations only 40 days after deployment. Nevertheless, after taking off the network in August 2013, the collected data appeared to be suitable for analysis using ambient noise. The second campaign was conducted in period from August 2013 to August 2014. In framework of the campaign, 21 temporary stations were installed over Gorely volcano, located 70 km south to Petropavlovsk-Kamchatsky. Just in time of the network deployment, Gorely Volcano became very seismically active - every day occurred more than 100 events. Therefore, we obtain very good dataset with information about thousands of local events, which could be used for any type of seismological analysis. The third campaign started in August 2014. Within this campaign, we have installed 19 temporary seismic stations over Tolbachik volcano, located on the south side of the Klyuchevskoy volcano group. In the same time on Tolbachik volcano were installed four temporary stations and several permanent stations operated by the KBGS. All stations were taking off in July 2015. As result, we have collected a large dataset, which is now under preliminary analysis

  15. The shallow magma pathway geometry at Mt. Etna volcano

    OpenAIRE

    Patanè, D.; Di Grazia, G.; Cannata, A.; Montalto, P.; Boschi, E.

    2008-01-01

    A fundamental goal of volcano seismology is to understand the dynamics of active magmatic systems in order to assess eruptive behavior and the associated hazard. Imaging of magma conduits, quantification of magma transport and investigation of long-period seismic sources, together with their temporal variations, are crucial for the comprehension of eruption-triggering mechanisms. At Mt. Etna volcano, several intense episodes of tremor activity were recorded during 2007, in association wit...

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

    Science.gov (United States)

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

    2017-11-01

    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.

  17. Geochemical signatures of tephras from Quaternary Antarctic Peninsula volcanoes

    OpenAIRE

    Kraus,Stefan; Kurbatov,Andrei; Yates,Martin

    2013-01-01

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

  18. Food irradiation in Japan

    International Nuclear Information System (INIS)

    Ito, Hitoshi

    1995-01-01

    The basic research on food irradiation in Japan was begun around 1955 by universities and national laboratories. In 1967, food irradiation was designated to the specific general research on atomic energy, and the national project on large scale was continued until 1983. As the result, the treatment of germination prevention for potatoes was approved by the Ministry of Health and Welfare in 1972. The Co-60 gamma ray irradiation facility of Shihoro Agricultural Cooperative is famous as the facility that succeeded in the practical use of food irradiation for the first time in the world. But the practical use of food irradiation stagnates and the research activities were reduced in Japan due to the circumstances thereafter. The effect of radiation to foods and living things is explained. The features of the radiation treatment of foods are small temperature rise, large transmissivity, no residue, the small loss of nutrition and large quantity, continuous treatment. The safety of irradiated foods is explained. The subjects for hereafter are discussed. (K.I.)

  19. Volcanic Successions of the Jebal Remah Volcano, Northeast Jordan

    Directory of Open Access Journals (Sweden)

    AHMAD AL-MALABEH

    2010-06-01

    Full Text Available Jebal Remah volcano is one of huge but very poorly known tephra cones exposed on the basalt province of Harra El-Jabban. Detailed investigations indicate that this volcano is topographically distinct and structurally well-developed. It consists of voluminous air-fall scoria, arranged in three distinct horizons; namely lower black lapilli horizon, middle banded yellow horizon and upper brown blocky horizon. Each horizon consists of friable, loose and well bedded ejecta. Agglutination and lithification are limited to the upper horizon. A comparison among the volcanic successions of three horizons show different volcanic features that nevertheless retain a comparable overall character from one horizon to another. In spite of some similarity in the type of ejecta, actually these differ in total thickness, number of beds and internal stratification. This dissimilarity within volcanic successions of the volcano support the overall increase in fluidity, temperature and decrease in volatile content of the magma with the time. Thus, volcano shows a complete range of thermal facies. The studied volcano appears to have resulted from one prolonged eruptive phase. Its volcanic activity consisted of a series of discrete explosion intervals, separated by quiet periods. Field criteria indicate that the volcano is of strombolian type of volcanicity and resulted in a magmatic fragmentation mode.

  20. Recent Seismicity in the Ceboruco Volcano, Western Mexico

    Science.gov (United States)

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

    2017-12-01

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

  1. 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.

  2. Safety Concerns of Tourism Business in Japan

    Directory of Open Access Journals (Sweden)

    Irina P. Karavaeva

    2012-05-01

    Full Text Available The article is focused on the current state of tourism industry in Japan after the nuclear disaster of 2011. A focus is made on networking activities of Japan Government aimed at boosting leisure travel flows to Japan.

  3. 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.

  4. Higher Education Studies in Japan

    Science.gov (United States)

    Kaneko, Motohisa

    2010-01-01

    The rapid development of higher education in the postwar period has given rise to various problems, and higher education studies in Japan have developed in response to them. What have been the major issues, and how did academic research respond to them, in postwar Japan? This article delineates an outline of higher education studies in general,…

  5. 21 CFR 186.1555 - Japan wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Japan wax. 186.1555 Section 186.1555 Food and Drugs... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan...

  6. Spent fuel management in Japan

    International Nuclear Information System (INIS)

    Shirahashi, K.; Maeda, M.; Nakai, T.

    1996-01-01

    Japan has scarce energy resources and depends on foreign resources for 84% of its energy needs. Therefore, Japan has made efforts to utilize nuclear power as a key energy source since mid-1950's. Today, the nuclear energy produced from 49 nuclear power plants is responsible for about 31% of Japan's total electricity supply. The cumulative amount of spent fuel generated as of March 1995 was about 11,600 Mg U. Japan's policy of spent fuel management is to reprocess spent nuclear fuel and recycle recovered plutonium and uranium as nuclear fuel. The Tokai reprocessing plant continues stable operation keeping the annual treatment capacity or around 90 Mg U. A commercial reprocessing plant is under construction at Rokkasho, northern part of Japan. Although FBR is the principal reactor to use plutonium, LWR will be a major power source for some time and recycling of the fuel in LWRs will be prompted. (author). 3 figs

  7. 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

  8. Japan and the global environment

    International Nuclear Information System (INIS)

    Miller, A.S.; Moore, C.

    1993-01-01

    In many areas, the word most often used to describe Japanese policy is open-quotes enigma.close quotes In some ways, Japan's record on environmental policy also has elements of mystery and contradiction. On the one hand, Japan's history and culture often are associated with a reverence for nature. Indeed, Japan does lead the world in certain environmental areas, such as reduction of conventional air pollutants and compensation of air pollution victims. On the other hand, Japan has been widely criticized for its poor record in preserving its domestic environment, contribution to tropical deforestation, and unwillingness to protect endangered species. Today, the international community clamors for Japan to take its share of responsibility, as an economic superpower, for the global environment. To secure its place in world affairs, Japan slowly has begun to respond to this pressure on issues ranging from ivory importation to reduction of CFC emissions. There is some hope that the government's particular willingness to address global warming may be a sign of significant changes to come in Japanese environmental policy. However, international pressure remains on the many environmental issues Japan has yet to resolve, including tropical deforestation and financing of Third World development projects that harm the environment. Japan's environmental policy is most effective when government and industry cooperate to find technical solutions to environmental problems. Although in recent years Japan's energy consumption has risen sharply, the Japanese have developed numerous technologies to reduce pollution and increase economic growth by improving energy efficiency. It is in these technologies that Japan has made the greatest strides and has the most to offer the global environment

  9. Small-scale volcanoes on Mars: distribution and types

    Science.gov (United States)

    Broz, Petr; Hauber, Ernst

    2015-04-01

    Volcanoes differ in sizes, as does the amount of magma which ascends to a planetary surface. On Earth, the size of volcanoes is anti-correlated with their frequency, i.e. small volcanoes are much more numerous than large ones. The most common terrestrial volcanoes are scoria cones (Nepenthes/Amenthes region, Arena Colles and inside Lederberg crater), and alternative interpretations (mud volcanoes) seem possible. Other relatively rare volcanoes seem to be lava domes, reported only from two regions (Acracida Planitia and Terra Sirenum). On the other hand, small shields and rootless cones (which are not primary volcanic landforms) represent widely spread phenomena recognized in Tharsis and Elysium. Based on these new observations, the distribution of small volcanoes on Mars seems to be much more widespread than anticipated a decade ago. There are sometimes significant differences in the final morphologies between Martian hypothesized and possible terrestrial analogs, despite fact that the physical processes behind volcano formation should be similar on both planets. For example, Martian scoria cones are ~2.6 times wider than terrestrial analogues, as lower gravity and atmospheric pressure enable wider dispersion of pyroclasts from the vent. In addition, exit velocities of ejected particles should be increased on Mars because the lower atmospheric pressure favors more rapid exsolution of dissolved gases from the magma, which also favors a wider dispersion of ejected particles. Therefore, care must be taken when applying terrestrial morphometric relationships to the interpretation of hypothesized volcanic features on Mars and other terrestrial bodies. As on Earth, small-scale volcanoes on Mars display diverse shapes and hence provide insight into diverse volcanic processes responsible for such variations. Those diverse processes may point to various mechanisms of magma ascent and eruption styles in dependency on magma properties (e.g., amount of volatiles) and the paleo

  10. The Powell Volcano Remote Sensing Working Group Overview

    Science.gov (United States)

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

    2017-12-01

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

  11. Magma Dynamics in Dome-Building Volcanoes

    Science.gov (United States)

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

    2014-12-01

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

  12. 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

  13. Kinematic variables and water transport control the formation and location of arc volcanoes.

    Science.gov (United States)

    Grove, T L; Till, C B; Lev, E; Chatterjee, N; Médard, E

    2009-06-04

    The processes that give rise to arc magmas at convergent plate margins have long been a subject of scientific research and debate. A consensus has developed that the mantle wedge overlying the subducting slab and fluids and/or melts from the subducting slab itself are involved in the melting process. However, the role of kinematic variables such as slab dip and convergence rate in the formation of arc magmas is still unclear. The depth to the top of the subducting slab beneath volcanic arcs, usually approximately 110 +/- 20 km, was previously thought to be constant among arcs. Recent studies revealed that the depth of intermediate-depth earthquakes underneath volcanic arcs, presumably marking the slab-wedge interface, varies systematically between approximately 60 and 173 km and correlates with slab dip and convergence rate. Water-rich magmas (over 4-6 wt% H(2)O) are found in subduction zones with very different subduction parameters, including those with a shallow-dipping slab (north Japan), or steeply dipping slab (Marianas). Here we propose a simple model to address how kinematic parameters of plate subduction relate to the location of mantle melting at subduction zones. We demonstrate that the location of arc volcanoes is controlled by a combination of conditions: melting in the wedge is induced at the overlap of regions in the wedge that are hotter than the melting curve (solidus) of vapour-saturated peridotite and regions where hydrous minerals both in the wedge and in the subducting slab break down. These two limits for melt generation, when combined with the kinematic parameters of slab dip and convergence rate, provide independent constraints on the thermal structure of the wedge and accurately predict the location of mantle wedge melting and the position of arc volcanoes.

  14. Safety regulations in Japan

    International Nuclear Information System (INIS)

    Kondo, S.

    1987-01-01

    In Japan, it is provided in the Law for Regulations of Nuclear Source Material, Nuclear Fuel Material and Reactors (referred as LRNR) that the licensee shall establish the safety regulations for individual plant by themselves regarding the operating management of nuclear reactor facility to secure the concrete safety of the nuclear power plant, that he shall receive an authorization of responsible government agencies (Minister of International Trade and Industry for commercial power station) and that this regulation shall be kept by the licensee and its employees. Furthermore, it is also provided in the same law that the licensee shall voluntarily nominate a chief reactor engineer to supervise the safety of reactor operation and that those who are engaged to the reactor operation shall obey the chief reactor engineer's instruction for the safety of reactor operation. These two factors are the base of the voluntary security system for reactor safety

  15. Radiation processing in Japan

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2001-01-01

    Economic scale of radiation application in the field of industry, agriculture and medicine in Japan in 1997 was investigated to compare its economic impacts with that of nuclear energy industry. Total production value of radiation application accounted for 54% of nuclear industry including nuclear energy industry and radiation applications in three fields above. Industrial radiation applications were further divided into five groups, namely nondestructive test, RI instruments, radiation facilities, radiation processing and ion beam processing. More than 70% of the total production value was brought about by ion beam processing for use with IC and semiconductors. Future economic prospect of radiation processing of polymers, for example cross-linking, EB curing, graft polymerization and degradation, is reviewed. Particular attention was paid to radiation vulcanization of natural rubber latex and also to degradation of natural polymers. (S. Ohno)

  16. Energy budget of the volcano Stromboli, Italy

    Science.gov (United States)

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

    1979-01-01

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

  17. 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.

  18. Permafrost on tropical Maunakea volcano, Hawaii

    Science.gov (United States)

    Leopold, Matthias; Schorghofer, Norbert; Yoshikawa, Kenji

    2017-04-01

    Maunakea volcano on Hawaii Island is known for one of the most unusual occurrences of sporadic permafrost. It was first documented in two cinder cone craters in the 1970's near the summit of the mountain where mean annual air temperatures are currently around +4 deg. Our study investigates the current state of this permafrost, by acquiring multi-year ground temperature data and by applying electrical resistivity tomography and ground penetrating radar techniques along several survey lines. Both of the previously known ice bodies still exist, but one of them has dramatically shrunken in volume. Based on current warming trends it might disappear soon. In addition insolation modelling, temperature probing, and geomorphological indicators were used to prospect for additional permafrost bodies on the wider summit region, however, none was found. It seems that permafrost preferentially appears in the interiors of cinder cones, even though there are exterior slopes that receive less sunlight annually. We hypothesis that snow cover with its high albedo, and a layer of coarse boulders where cold air settles in the pore space during calm nights, play a significant role in cooling the subsurface. Due to the relatively simple setting, the study site is an ideal model system and may also serve as an analogue to Mars.

  19. Dynamics of magma supply, storage and migration at basaltic volcanoes: Geophysical studies of the Galapagos and Hawaiian volcanoes

    Science.gov (United States)

    Bagnardi, Marco

    Basaltic shields forming ocean island volcanoes, in particular those of Hawai'i and of the Galapagos Islands, constitute some of the largest volcanic features on Earth. Understanding subsurface processes such as those controlling magma supply, storage and migration at these volcanoes, is essential to any attempt to anticipate their future behavior. This dissertation presents a series of studies carried out at Hawaiian and Galapagos volcanoes. InSAR measurements acquired between 2003 and 2010 at Fernandina Volcano, Galapagos, are used to study the structure and the dynamics of the shallow magmatic system of the volcano (Chapter 3). Spatial and temporal variations in the measured displacements reveal the presence of two hydraulically connected areas of magma storage, and the modeling of the deformation data provides an estimate of their location and geometry. The same dataset also provides the first geodetic evidence for two subvolcanic sill intrusions (in 2006 and 2007) deep beneath the volcano's flank. The lateral migration of magma from the reservoirs during these intrusions could provide an explanation for enigmatic volcanic events at Fernandina such as the 1968 caldera collapse without significant eruption. Space-geodetic measurements of the surface deformation produced by the most recent eruptions at Fernandina, reveal that all have initiated with the intrusion of subhorizontal sills from the shallow magma reservoir (Chapter 4). A synthetic aperture radar (SAR) image acquired 1-2 h before the start of a radial fissure eruption in 2009 captures one of these sills in the midst of its propagation toward the surface. Galapagos eruptive fissures of all orientations have previously been presumed to be fed by vertical dikes, but these new findings allow a reinterpretation of the internal structure and evolution of Galapagos volcanoes and of similar basaltic shields elsewhere on Earth and on other planets. A joint analysis of InSAR and groud-based microgravity data

  20. The Cogema group in Japan

    International Nuclear Information System (INIS)

    1998-12-01

    The partnership between the Cogema group and Japan in the domain of fuel cycle started about 20 years ago and the 10 Japanese nuclear operators are all clients of the Cogema group. The 1997 turnover realized with Japan reached 3.6 billions of francs (11% of the total turnover of the group). This short paper presents briefly the nuclear program of Japan (nuclear park, spent fuels reprocessing-recycling strategy) and the contracts between Cogema and the Japanese nuclear operators (natural uranium, uranium conversion and enrichment, spent fuel reprocessing, plutonium recycle and MOX fuel production markets). (J.S.)

  1. Positioning Indian Emigration to Japan

    DEFF Research Database (Denmark)

    D'Costa, Anthony

    2013-01-01

    that act as significant barriers to the entry of foreign skilled professionals. The paper brings out the source and pattern of foreign professionals and students in Japan as a proxy for talent. Though India’s presence in Japan is currently limited, its share of technical professionals to the total number...... as other IT-strong developing countries, are to supply technical talent, whose availability in Japan is constrained by the secular demographic crisis and changing educational and occupational preferences. The challenges for India are the institutional barriers, in particular, Japanese business practices...

  2. Observations of Local Seismicity and Harmonic Tremor Using an Ocean Bottom Hydrophone Array at Brothers Volcano, South Kermadec Arc.

    Science.gov (United States)

    Haxel, J. H.; Dziak, R. P.; Lau, T. K.; Matsumoto, H.

    2005-12-01

    The submarine Brothers volcano is an important link in the volcanic chain of the southern Kermadec Arc system in the Southwest Pacific Ocean north of New Zealand. The 3-3.5 km wide caldera has a center depth of 1850m and steep surrounding walls of 300-450m. Active hydrothermal venting distinguished Brothers as a point of focus for the New Zealand American Submarine Ring of Fire (NZASRoF) expeditions in 2004 and 2005. Due to its remote location, moderate to small magnitude seismicity around the Brothers area is largely unknown. In late September 2004, four ocean bottom hydrophones (OBHs) were deployed on the caldera floor. In April 2005, three of the four instruments were recovered intact. These three OBHs continuously recorded, for seven months, the low frequency (0-110Hz) acoustic field around Brothers volcano, in particular seismic P- and S-waves propagating through the crust and acoustic T-waves in the water column . Preliminary analysis reveals seismicity rates on the order of 106 earthquakes per month. In addition to seismic arrivals, low frequency harmonic tremor is frequently and independently observed on each of the OBH instruments, often occurring subsequent to the larger seismic events. Qualitative comparisons of these signals with tremor observed from the Volcano Islands south of Japan (Dziak and Fox, 2002) show them to be nearly equivalent in frequency structure, suggesting the origin of the tremor observed at Brothers may also be attributed to resonance of a magma-gas mixture in a large chamber or conduit near the water/ seafloor boundary.

  3. Eruptions of Hawaiian volcanoes - Past, present, and future

    Science.gov (United States)

    Tilling, Robert I.; Heliker, Christina; Swanson, Donald A.

    2010-01-01

    Viewing an erupting volcano is a memorable experience, one that has inspired fear, superstition, worship, curiosity, and fascination since before the dawn of civilization. In modern times, volcanic phenomena have attracted intense scientific interest, because they provide the key to understanding processes that have created and shaped more than 80 percent of the Earth's surface. The active Hawaiian volcanoes have received special attention worldwide because of their frequent spectacular eruptions, which often can be viewed and studied with relative ease and safety. In January 1987, the Hawaiian Volcano Observatory (HVO), located on the rim of Kilauea Volcano, celebrated its 75th Anniversary. In honor of HVO's Diamond Jubilee, the U.S. Geological Survey (USGS) published Professional Paper 1350 (see list of Selected Readings, page 57), a comprehensive summary of the many studies on Hawaiian volcanism by USGS and other scientists through the mid-1980s. Drawing from the wealth of data contained in that volume, the USGS also published in 1987 the original edition of this general-interest booklet, focusing on selected aspects of the eruptive history, style, and products of two of Hawai'i's active volcanoes, Kilauea and Mauna Loa. This revised edition of the booklet-spurred by the approaching Centennial of HVO in January 2012-summarizes new information gained since the January 1983 onset of Kilauea's Pu'u 'O'o-Kupaianaha eruption, which has continued essentially nonstop through 2010 and shows no signs of letup. It also includes description of Kilauea's summit activity within Halema'uma'u Crater, which began in mid-March 2008 and continues as of this writing (late 2010). This general-interest booklet is a companion to the one on Mount St. Helens Volcano first published in 1984 and revised in 1990 (see Selected Readings). Together, these publications illustrate the contrast between the two main types of volcanoes: shield volcanoes, such as those in Hawai'i, which generally

  4. 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.

  5. Multibeam Bathymetry of the Håkon Mosby Mud Volcano

    Science.gov (United States)

    Beyer, Andreas; Rathlau, Rike; Schenke, Hans Werner

    2005-03-01

    The Håkon Mosby Mud Volcano is a natural laboratory to study geological, geochemical, and ecological processes related to deep-water mud volcanism. High resolution bathymetry of the Håkon Mosby Mud Volcano was recorded during RV Polarstern expedition ARK XIX/3 utilizing the multibeam system Hydrosweep DS-2. Dense spacing of the survey lines and slow ship speed (5 knots) provided necessary point density to generate a regular 10 m grid. Generalization was applied to preserve and represent morphological structures appropriately. Contour lines were derived showing detailed topography at the centre of the Håkon Mosby Mud Volcano and generalized contours in the vicinity. We provide a brief introduction to the Håkon Mosby Mud Volcano area and describe in detail data recording and processing methods, as well as the morphology of the area. Accuracy assessment was made to evaluate the reliability of a 10 m resolution terrain model. Multibeam sidescan data were recorded along with depth measurements and show reflectivity variations from light grey values at the centre of the Håkon Mosby Mud Volcano to dark grey values (less reflective) at the surrounding moat.

  6. Can wolves help save Japan's mountain forests?

    Science.gov (United States)

    Barber-meyer, Shannon

    2017-01-01

    Japan’s wolves were extinct by 1905. Today Japan's mountain forests are being killed by overabundant sika deer and wild boars. Since the early 1990s, the Japan Wolf Association has proposed wolf reintroduction to Japan to restore rural ecology and to return a culturally important animal. In this article I discuss whether the return of wolves could help save Japan's mountain forests.

  7. Big mantle wedge, anisotropy, slabs and earthquakes beneath the Japan Sea

    Science.gov (United States)

    Zhao, Dapeng

    2017-09-01

    The Japan Sea is a part of the western Pacific trench-arc-backarc system and has a complex bathymetry and intense seismic activities in the crust and upper mantle. Local seismic tomography revealed strong lateral heterogeneities in the crust and uppermost mantle beneath the eastern margin of the Japan Sea, which was determined using P and S wave arrival times of suboceanic earthquakes relocated precisely with sP depth phases. Ambient-noise tomography revealed a thin crust and a thin lithosphere beneath the Japan Sea and significant low-velocity (low-V) anomalies in the shallow mantle beneath the western and eastern margins of the Japan Sea. Observations with ocean-bottom seismometers and electromagnetometers revealed low-V and high-conductivity anomalies at depths of 200-300 km in the big mantle wedge (BMW) above the subducting Pacific slab, and the anomalies are connected with the low-V zone in the normal mantle wedge beneath NE Japan, suggesting that both shallow and deep slab dehydrations occur and contribute to the arc and back-arc magmatism. The Pacific slab has a simple geometry beneath the Japan Sea, and earthquakes occur actively in the slab down to a depth of ∼600 km beneath the NE Asian margin. Teleseismic P and S wave tomography has revealed that the Philippine Sea plate has subducted aseismically down to the mantle transition zone (MTZ, 410-660 km) depths beneath the southern Japan Sea and the Tsushima Strait, and a slab window is revealed within the aseismic Philippine Sea slab. Seismic anisotropy tomography revealed a NW-SE fast-velocity direction in the BMW, which reflects corner flows induced by the fast deep subduction of the Pacific slab. Large deep earthquakes (M > 7.0; depth > 500 km) occur frequently beneath the Japan Sea western margin, which may be related to the formation of the Changbai and Ulleung intraplate volcanoes. A metastable olivine wedge is revealed within the cold core of the Pacific slab at the MTZ depth, which may be related

  8. Contraception in Japan: Current trends.

    Science.gov (United States)

    Yoshida, Honami; Sakamoto, Haruka; Leslie, Asuka; Takahashi, Osamu; Tsuboi, Satoshi; Kitamura, Kunio

    2016-06-01

    High proportion of Japanese uses condoms; lower proportion uses oral contraceptive pills (OCPs). We examined the longitudinal patterns for contraceptive usage in Japan and evaluated differences before and after OCP government approval. We accessed nationally representative survey data for women aged 16-49years from 1950 to 2014. Usage of condoms and OCP was 83.4% and 3.0%, respectively in 2014. OCP use before (1.21%) and after (1.97%) government approval did not differ significantly (p=.58). The prevalence of OCP usage remains low in Japan. A wide gap in use between Japan and other developed countries exists. Through a wide gap in OCP use between Japan and other countries, we revealed how choices of contraceptive methods and their benefits could be openly available for women of reproductive age, and how health care professionals disseminate appropriate knowledge about contraception for women in need. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Nuclear power development in Japan

    International Nuclear Information System (INIS)

    Sugawara, A.

    1994-01-01

    The energy situation in Japan is briefly outlined. Vulnerability in energy structure of the country is shown by a comparison of primary energy supply patterns of Japan and Western countries. Japan's energy policy consists in reducing dependence on oil, promoting efficient use of energy and increasing use of non-fossil fuels. Nuclear power is a core of alternative energy for petroleum because of stable supply of nuclear fuel, low detrimental emissions and less dependence on the fuel. A short historical review of nuclear power development in Japan is presented. Some future issues as development of entire nuclear fuel cycle, social acceptance, reactor safety and nuclear power economics are also discussed. 6 figs. (R.T.)

  10. Radioactivity survey data in Japan

    International Nuclear Information System (INIS)

    1981-06-01

    Strontium-90 and cesium-137 in Japan were determined in rain and dry fallout, airborne dust, service water, total diet, rice, milk, vegetables, sea fish, shellfish, and seaweeds. The results were shown in tables. (J.P.N.)

  11. Tremor Source Location at Okmok Volcano

    Science.gov (United States)

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

    2007-12-01

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

  12. Whistleblowing in Japan.

    Science.gov (United States)

    Davis, Anne J; Konishi, Emiko

    2007-03-01

    This article, written from research data, focuses on the possible meaning of the data rather than on detailed statistical reporting. It defines whistleblowing as an act of the international nursing ethical ideal of advocacy, and places it in the larger context of professional responsibility. The experiences, actions, and ethical positions of 24 Japanese nurses regarding whistleblowing or reporting a colleague for wrongdoing provide the data. Of these respondents, similar in age, educational level and clinical experience, 10 had previously reported another nurse and 12 had reported a physician for a wrongful act. These data raise questions about overt actions to expose a colleague in a culture that values group loyalty and saving face. Additional research is needed for an in-depth understanding of whistleblowing, patient advocacy and professional responsibility across cultures, especially those that value group loyalty, saving face and similar concepts to the Japanese Ishin Denshin, where the value is on implicit understanding requiring indirect communication. Usually, being direct and openly discussing sensitive topics is not valued in Japan because such behavior disrupts the most fundamental value, harmony (wa).

  13. Dysphagia Rehabilitation in Japan.

    Science.gov (United States)

    Inoue, Makoto

    2015-01-01

    In Japan, one of the most common causes of death in elderly people is aspiration pneumonia. Maintenance of oral hygiene and feeding functions are important elements, especially in patients with dysphagia caused by stroke, neurological diseases, and after operations on the head and neck cancer, as well as in the elderly to prevent aspiration pneumonia. It should also be noted that not only oral health care and physical therapy related to feeding functions but also dental treatment is included in the clinical management during interventions whenever needed. On the other hand, for the patients and/or elderly in need of assistance in maintaining a safe diet, it is recommended that a specialized team comprising physicians, dentists, and speech therapists in functional rehabilitation observes meal conditions of the subjects and evaluates such factors as meal contents, posture during meals, usage of dishes and cutlery, meal times, status of consciousness, perception, and motivation. First, I will present the clinical interventions to those patients, which include oral health care, dental treatment, physical therapy and meal assistance, as well as team approaches in those circumstances. In addition, clinical and basic research results will be introduced, which are expected to foster the understanding of physiology in chewing and swallowing. These results are also expected to develop the clinical technology to maintain or recover the feeding functions.

  14. Globalization in Japan

    DEFF Research Database (Denmark)

    Roesgaard, Marie Højlund

    2014-01-01

    of development and discourse on morality, values and identity. I propose seeing the contents of moral education as a reaction to the challenges of globalization, as a reaction to the risks experienced in modern globalized society and to the anxiety born out of the challenges, ‘real’ or ‘imagined,’ perceived......Abstract for Nichibunken Copenhagen Symposium August 2012 Globalization in Japan – the case of moral education. 日本とグローバル化 - 道徳教育の件 Marie H. Roesgaard, Department of Cross-Cultural and Regional Studies, University of Copenhagen. This paper attempts to trace the history of global influence...... on Japanese education by using moral education as a case. Moral education, known as shūshin before World War II, has been prominent in Japanese education since its formalization in Meiji times. From Meiji on shûshin underwent various changes, reflected in the textbooks of different periods. 1903...

  15. Fusion Studies in Japan

    Science.gov (United States)

    Ogawa, Yuichi

    2016-05-01

    A new strategic energy plan decided by the Japanese Cabinet in 2014 strongly supports the steady promotion of nuclear fusion development activities, including the ITER project and the Broader Approach activities from the long-term viewpoint. Atomic Energy Commission (AEC) in Japan formulated the Third Phase Basic Program so as to promote an experimental fusion reactor project. In 2005 AEC has reviewed this Program, and discussed on selection and concentration among many projects of fusion reactor development. In addition to the promotion of ITER project, advanced tokamak research by JT-60SA, helical plasma experiment by LHD, FIREX project in laser fusion research and fusion engineering by IFMIF were highly prioritized. Although the basic concept is quite different between tokamak, helical and laser fusion researches, there exist a lot of common features such as plasma physics on 3-D magnetic geometry, high power heat load on plasma facing component and so on. Therefore, a synergetic scenario on fusion reactor development among various plasma confinement concepts would be important.

  16. The photovoltaic energy in Japan

    International Nuclear Information System (INIS)

    Georgel, O.

    2005-07-01

    Today the Japan is the leader of the photovoltaic energy. The first reason of this success is an action of the government integrating subventions for the installation of photovoltaic systems and a support of the scientific research. To explain this success, the author presents the energy situation in Japan, details the national programs, the industrial sector (market, silicon needs, recycling, manufacturers, building industry) and presents the main actors. (A.L.B.)

  17. Understanding Japan's Capital Goods Exports

    OpenAIRE

    THORBECKE, Willem

    2015-01-01

    Japan is the leading supplier of sophisticated capital goods to East Asian countries. These goods embody advanced technologies and facilitate learning and productivity growth. Capital goods also represent 30%-40% of Japan's exports. This paper investigates the determinants of these exports. Results from dynamic ordinary least squares estimation indicate that exports depend on exchange rates, income in the importing countries, and downstream countries' exports to the rest of the world. Results...

  18. Japan Sports Arbitration Agency (JSAA

    Directory of Open Access Journals (Sweden)

    Ekaterina P. Rusakova

    2015-12-01

    Full Text Available In this article author analyzes the activities of Japan Sports Arbitration Agency. Author considers the goals, objectives and procedure for dealing with disputes relating to the use of performance-enhancing drugs by athletes. Author study the regulation of Japan Sports Arbitration Agency, to resolve disputes relating to the use of doping, as well as the procedure for application and acceptance of its agency, the choice of arbitrators, counterclaim, protection of evidence.

  19. The cogeneration market in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Watabe, Masaki [Cogeneration Research Society of Japan, Tokyo (Japan). Research Dept.

    1997-09-01

    Conventional power generation is only around 35% efficient at demand side in Japan. Cogeneration increases the overall energy efficiency up to 85%. Other merits of cogeneration are energy saving, improvement of the environment, greenhouse gas emission (CO{sub 2}) can be reduced. The energy conditions in Japan are overviewed and the trends for cogeneration - both commercial and industrial - are evaluated. Finally, statutory regulations regarding cogeneration systems are considered. (R.P.)

  20. Japan Sports Arbitration Agency (JSAA)

    OpenAIRE

    Ekaterina P. Rusakova

    2015-01-01

    In this article author analyzes the activities of Japan Sports Arbitration Agency. Author considers the goals, objectives and procedure for dealing with disputes relating to the use of performance-enhancing drugs by athletes. Author study the regulation of Japan Sports Arbitration Agency, to resolve disputes relating to the use of doping, as well as the procedure for application and acceptance of its agency, the choice of arbitrators, counterclaim, protection of evidence.

  1. Japan's approach to monetary policy

    OpenAIRE

    Giovanni P. Olivei

    2002-01-01

    The goal of monetary policy as conducted by the Bank of Japan is to contribute to the sound development of the national economy through the pursuit of price stability. The objective of price stability, however, is not precisely defined as it has been for other central banks. Following the implementation of the new Bank of Japan Law in 1998, the monetary policy framework is characterized by central bank independence, the primacy of the price stability objective, instrument independence, and po...

  2. Investigating the potential for volcano flank instability triggered by recent dike intrusions at Fogo volcano, Cape Verde

    Science.gov (United States)

    Bagnardi, Marco; González, Pablo; Hooper, Andrew; Wright, Tim

    2015-04-01

    Gravitational flank-collapses at volcanoes are rare but catastrophic events that have rarely been witnessed by humans (e.g., Mount St. Helens in 1980). It has been proposed that gravitationally unstable volcanic flanks can be classified in two different types based on the flanks slope: volcanoes characterized by gentle slopes (Hawaiian-like) and that have very dynamic flanks exhibiting high rates of deformation and, conversely, steep-sided volcanoes (Macaronesian-like) showing minimal ground deformation. The two types of volcanoes could therefore reach the stable-state through different mechanisms and experience different mass-wasting processes. Numerous giant debris-avalanche deposits have been identified offshore the volcanoes of the Canary Islands and Cape Verde. Given the steep slopes of these volcanoes, the mass-wasting events may have occurred suddenly and with minimal precursory signals. Several mechanisms have been proposed as potential triggers and among these the intrusion of shallow dikes feeding fissure eruptions is one of the best candidates. In this work, we investigate this hypothesis in the light of new and revised results derived from the analysis of geodetic observations at Fogo volcano (Cape Verde). Fogo has erupted twice in the last 20 years (1995 and 2014-2015) and in both occasions the volcano erupted along fissures that seem to be fed by dykes intruding the shallow crust and the volcanic edifice. We re-process radar data from the ERS satellite to obtain state-of-the-art deformation maps spanning the 1995 eruption and revisit previously proposed models of the magmatic system. Our results indicate that both eruptions were fed by sub-vertical dikes, steeply dipping to the SE, and radiating from the Pico do Fogo volcanic cone to the SW. We also study the effect of such magmatic intrusions in terms of the stress regime that they generate and analyze whether the 1995 and 2014 intrusions could potentially destabilize the structures along which a

  3. Volcano outreach and education at GEOTOP

    Science.gov (United States)

    Gaonach, H.

    2004-05-01

    Within research centers, there is a growing consensus about the importance of public outreach programs and the need for them to comprise a science education component. This requires the focused efforts of a wide spectrum of specialists, including scientists. At the GEOTOP center in Quebec we are seeking to bring our unique science perspective to educators and the public. GEOTOP is an interuniversity center whose research covers a many areas of geoscience and includes researchers from diverse specialities (www.geotop.uqam.ca). The main outreach effort is to publicize the center's research; a recent intiative focuses on the young public via the Vicki Volka (www.vickivolka.uqam.ca) web site. Volcanic activities on the Earth and in our solar system hold an extraordinary attraction for the general public. In recent years, volcanic news has frequently been disseminated through the media. But the understanding of these news items is beyond the nonspecialist so that the news itself is often reduced to the human impacts - such as the evacuation of thousands of inhabitants or the closure of an airport - to the detriment of a scientific understanding of the natural processes at work. Volcanoes provide a unique angle from which many different aspects of our world can be viewed including not only its geography, politics and culture, but also its internal dynamics as well as geodynamics elsewhere in the solar system, Through the outreach to Francophone internauts, GEOTOP has begun to improve its public relations. This includes visits to primary schools aimed at educating the young public about volcanic activities as well as bringing the results of research projects to the general public. This provides a dynamic approach to better integrating real-time volcanic news with existing educational standards as well as a scientific methodology and latest research efforts. While francophones regularly visit the web site, there is a growing demand to enlarge the site to include other

  4. 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

  5. Crustal Seismic Vs and Vs anisotropy of Northeast Japan Revealed by Ambient Noise Tomography

    Science.gov (United States)

    Chen, K. X.; Gung, Y.; Kuo, B. Y.; Huang, T. Y.

    2017-12-01

    We present 3D crustal models of Vs and Vs azimuthal anisotropy of the Tohoku region, Japan. We employ the Welch's method to derive the empirical Green's functions (EGF) of Rayleigh waves from one year of continuous records of 123 short-period stations of the dense high-sensitivity seismograph network (Hi-net). We compute EGFs for about 4000 station pairs with interstation distance less than 300 km. For each qualified EGF, we measure the dispersion in the period range from 3 to 16 seconds. We then construct the models by using a wavelet-based multi-scale inversion technique. In the resulting models, characteristics of Vs variations and Vs azimuthal anisotropy are closely related to surface geology, Quaternary volcano activities, and plate motions. For the Vs variations in the shallow crust (well correlated to the volcano belt. For the Vs anisotropy, the strength and the patterns of fast polarization directions (FPD) are depth-dependent. In the shallow crust, the anisotropy is strong, and are dominated by the typical orogeny parallel anisotropy, with FPDs parallel to the main strikes of the mountain range. While in the lower crust, the FPDs are generally parallel to the absolute plate motion. Interestingly, the distribution of PFDs is rather chaotic and strength of anisotropy is weak in the middle crust ( 8 - 20 km). We propose that the weak and random anisotropy in this layer is likely related to the presence of magma reservoirs beneath the volcano belt, as the associated active volcanism may cause the destruction of the alignment of crustal fabrics Key words: Tohoku, ambient noise, seismic anisotropy, surface wave tomography, volcano activities

  6. 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.

  7. 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.

  8. Multiple Active Volcanoes in the Northeast Lau Basin

    Science.gov (United States)

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

    2010-12-01

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

  9. Gas hydrate accumulation at the Hakon Mosby Mud Volcano

    Science.gov (United States)

    Ginsburg, G.D.; Milkov, A.V.; Soloviev, V.A.; Egorov, A.V.; Cherkashev, G.A.; Vogt, P.R.; Crane, K.; Lorenson, T.D.; Khutorskoy, M.D.

    1999-01-01

    Gas hydrate (GH) accumulation is characterized and modeled for the Hakon Mosby mud volcano, ca. 1.5 km across, located on the Norway-Barents-Svalbard margin. Pore water chemical and isotopic results based on shallow sediment cores as well as geothermal and geomorphological data suggest that the GH accumulation is of a concentric pattern controlled by and formed essentially from the ascending mud volcano fluid. The gas hydrate content of sediment peaks at 25% by volume, averaging about 1.2% throughout the accumulation. The amount of hydrate methane is estimated at ca. 108 m3 STP, which could account for about 1-10% of the gas that has escaped from the volcano since its origin.

  10. 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.

  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. 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.

  13. Volcanoes: effusions and explosions. Interactive exhibits to understand how volcanoes work.

    Science.gov (United States)

    Nostro, C.; Freda, L.; Castellano, C.; Arcoraci, L.; Baroux, E.

    2009-04-01

    The Educational & Outreach Group (EOG) of the Istituto Nazionale di Geofisica & Vulcanologia created a portable museum to provide educational opportunities in volcanology, volcanic risk and Earth science for students and visitors. The EOG developed this project for the "Festival della Scienza", organized in Genoa, Italy, in October - November, 2007, which was a parade of over 200 events, including scientific and technological exhibitions, workshops, meetings, lectures, books and video presentations. In this museum visitors can successively see many posters and movies and play with interactive exhibits. A little 3D-movie shows the Big Bang, the formation of Solar System and, in particular the formation of the Earth. Many interactive exhibits illustrate why, where and when earthquakes and volcanic eruptions occur around the world and allow to introduce the visitor to the plate tectonics theory. A 3D magnetic plate tectonic puzzle can be put down and reconstructed by visitors to understand the Earth's surface configuration. Then two other 3D Earth models show what drives the plates and the inner Earth structure. An interactive program illustrates where and when earthquakes and volcanic eruptions occur in accelerated time on maps of various areas around the world. Playing with a block diagram it is possible to produce an earthquake along a 1 meter long strike slip fault in a destroying all the man-made constructions close to it. A little movie introduces to volcanoes' world. Two small interactive exhibits allow visitors to understand the mechanism for the explosive and the effusive eruptions. Two other exciting interactive exhibits allow visitors to "create" two different eruptions: the explosive and the effusive ones. It is possible to get inside a volcano (a 2 meter high interactive exhibit) to attend an eruption from the magmatic chamber to the Earth surface. A big hall is completed dedicated to Italian volcanoes (Vesuvio, Campi Flegrei, Etna, Stromboli, Vulcano

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

    Science.gov (United States)

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

    2015-04-01

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

  15. 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

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

    Science.gov (United States)

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

    2016-12-01

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

  17. Expert Systems for Real-Time Volcano Monitoring

    Science.gov (United States)

    Cassisi, C.; Cannavo, F.; Montalto, P.; Motta, P.; Schembra, G.; Aliotta, M. A.; Cannata, A.; Patanè, D.; Prestifilippo, M.

    2014-12-01

    In the last decade, the capability to monitor and quickly respond to remote detection of volcanic activity has been greatly improved through use of advanced techniques and semi-automatic software applications installed in most of the 24h control rooms devoted to volcanic surveillance. Ability to monitor volcanoes is being advanced by new technology, such as broad-band seismology, microphone networks mainly recording in the infrasonic frequency band, satellite observations of ground deformation, high quality video surveillance systems, also in infrared band, improved sensors for volcanic gas measurements, and advances in computer power and speed, leading to improvements in data transmission, data analysis and modeling techniques. One of the most critical point in the real-time monitoring chain is the evaluation of the volcano state from all the measurements. At the present, most of this task is delegated to one or more human experts in volcanology. Unfortunately, the volcano state assessment becomes harder if we observe that, due to the coupling of highly non-linear and complex volcanic dynamic processes, the measurable effects can show a rich range of different behaviors. Moreover, due to intrinsic uncertainties and possible failures in some recorded data, precise state assessment is usually not achievable. Hence, the volcano state needs to be expressed in probabilistic terms that take account of uncertainties. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management) work, we have developed an expert system approach to estimate the ongoing volcano state from all the available measurements and with minimal human interaction. The approach is based on hidden markov model and deals with uncertainties and probabilities. We tested the proposed approach on data coming from the Mt. Etna (Italy) continuous monitoring networks for the period 2011-2013. Results show that this approach can be a valuable tool to aid the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-15

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

  19. 2004 Deformation of Okmok Volcano,Alaska, USA

    Science.gov (United States)

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

    2004-12-01

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

  20. Pyroclastic sulphur eruption at Poas Volcano, Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    Francis, P.W.; Thorpe, R.S.; Brown, G.C.; Glasscock, J.

    1980-01-01

    The recent Voyager missions to Jupiter have highlighted the role of sulphur in volcanic processes on io. Although fumarolic sulphur and SO/sub 2/ gas are almost universal in terrestrial active volcanoes, and rare instances of sulphur lava flows have been reported, sulphur in a pyroclastic form has only been described from Poas Volcano, Costa Rica. Here we amplify the original descriptions by Bennett and Raccichini and describe a recent eruption of pyroclastic sulphur scoria and ejected blocks that are characterised by miniature sulphur stalactites and stalagmites.

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

    Science.gov (United States)

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

    2017-12-01

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

  2. Monitoring Volcanoes by Use of Air-Dropped Sensor Packages

    Science.gov (United States)

    Kedar, Sharon; Rivellini, Tommaso; Webb, Frank; Blaes, Brent; Bracho, Caroline; Lockhart, Andrew; McGee, Ken

    2003-01-01

    Sensor packages that would be dropped from airplanes have been proposed for pre-eruption monitoring of physical conditions on the flanks of awakening volcanoes. The purpose of such monitoring is to gather data that could contribute to understanding and prediction of the evolution of volcanic systems. Each sensor package, denoted a volcano monitoring system (VMS), would include a housing with a parachute attached at its upper end and a crushable foam impact absorber at its lower end (see figure). The housing would contain survivable low-power instrumentation that would include a Global Positioning System (GPS) receiver, an inclinometer, a seismometer, a barometer, a thermometer, and CO2 and SO2 analyzers. The housing would also contain battery power, control, data-logging, and telecommunication subsystems. The proposal for the development of the VMS calls for the use of commercially available sensor, power, and telecommunication equipment, so that efforts could be focused on integrating all of the equipment into a system that could survive impact and operate thereafter for 30 days, transmitting data on the pre-eruptive state of a target volcano to a monitoring center. In a typical scenario, VMSs would be dropped at strategically chosen locations on the flanks of a volcano once the volcano had been identified as posing a hazard from any of a variety of observations that could include eyewitness reports, scientific observations from positions on the ground, synthetic-aperture-radar scans from aircraft, and/or remote sensing from aboard spacecraft. Once dropped, the VMSs would be operated as a network of in situ sensors that would transmit data to a local monitoring center. This network would provide observations as part of an integrated volcano-hazard assessment strategy that would involve both remote sensing and timely observations from the in situ sensors. A similar strategy that involves the use of portable sensors (but not dropping of sensors from aircraft) is

  3. Geophysical Observations Supporting Research of Magmatic Processes at Icelandic Volcanoes

    Science.gov (United States)

    Vogfjörd, Kristín. S.; Hjaltadóttir, Sigurlaug; Roberts, Matthew J.

    2010-05-01

    Magmatic processes at volcanoes on the boundary between the European and North American plates in Iceland are observed with in-situ multidisciplinary geophysical networks owned by different national, European or American universities and research institutions, but through collaboration mostly operated by the Icelandic Meteorological Office. The terrestrial observations are augmented by space-based interferometric synthetic aperture radar (InSAR) images of the volcanoes and their surrounding surface. Together this infrastructure can monitor magma movements in several volcanoes from the base of the crust up to the surface. The national seismic network is sensitive enough to detect small scale seismicity deep in the crust under some of the voclanoes. High resolution mapping of this seismicity and its temporal progression has been used to delineate the track of the magma as it migrates upwards in the crust, either to form an intrusion at shallow levels or to reach the surface in an eruption. Broadband recording has also enabled capturing low frequency signals emanating from magmatic movements. In two volcanoes, Eyjafjallajökull and Katla, just east of the South Iceland Seismic Zone (SISZ), seismicity just above the crust-mantle boundary has revealed magma intruding into the crust from the mantle below. As the magma moves to shallower levels, the deformation of the Earth‘s surface is captured by geodetic systems, such as continuous GPS networks, (InSAR) images of the surface and -- even more sensitive to the deformation -- strain meters placed in boreholes around 200 m below the Earth‘s surface. Analysis of these signals can reveal the size and shape of the magma as well as the temporal evolution. At near-by Hekla volcano flanking the SISZ to the north, where only 50% of events are of M>1 compared to 86% of earthquakes in Eyjafjallajökull, the sensitivity of the seismic network is insufficient to detect the smallest seismicity and so the volcano appears less

  4. Nuclear power in Japan

    International Nuclear Information System (INIS)

    Kishida, J.

    1990-01-01

    The Japanese movement against nuclear energy reached a climax in its upsurge in 1988 two years after the Chernobyl accident. At the outset of that year, this trend was triggered by the government acknowledgement that the Tokyo market was open to foods contaminated by the fallout from Chernobyl. Anti-nuclear activists played an agitating role and many housewives were persuaded to join them. Among many public opinion surveys conducted at that time by newspapers and broadcasting networks, I would like to give you some figures of results from the poll carried out by NHK: Sixty percent of respondents said that nuclear power 'should be promoted', either 'vigorously' 7 or 'carefully' 53%). Sixty-six percent doubted the 'safety of nuclear power', describing it as either 'very dangerous' 20%) or 'rather dangerous' (46%). Only 27% said it was 'safe'. In other words, those who acknowledged the need for nuclear power were almost equal in number with those who found it dangerous. What should these figures be taken to mean? I would take note of the fact that nearly two-thirds of valid responses were in favor of nuclear power even at the time when public opinion reacted most strongly to the impact of the Chernobyl accident. This apparently indicates that the majority of the Japanese people are of the opinion that they would 'promote nuclear power though it is dangerous' or that they would 'promote it, but with the understanding that it is dangerous'. But the anti-nuclear movement is continuing. It remains a headache for both the government and the electric utilities. But we can regard the anti-nuclear movement in Japan as not so serious as that faced by other industrial nations

  5. 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.

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

    Science.gov (United States)

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

    2012-07-01

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

  7. 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.

  8. Magma-plumbing System of Asama Volcano after 2004 Eruption, Estimated from Vertical Deformation above the Presumed Pressure Sources

    Science.gov (United States)

    Kimata, F.

    2012-12-01

    Asama volcano is one of the active volcanoes in Japan, and it erupted on September 1, 2004. A shallow dike intrusion is estimated in the Takamine, 4 - 5 km west of the Asama crater from the ground deformation detected by GPS measurements (Aoki et al., 2005). Ground deformation observation close to the pressure source should clarify the depth and volume change of pressure sources. We establish the precise leveling routes ranging to Mt. Takamine above the presumed pressure source from Oiwake, at the southern foot of Asama volcano in May 2005.The precise levelings have practiced seven times for five years since May 2005 to June 2011. We calculated the vertical deformation for six-months or two-years between leveling epochs. Generally, deformations detected by the precise leveling are small of 10 mm. Deformations detected in the periods of May 2005 - Nov.2005. - May 2006 - May 2009 - June 2010 - June 2011, are grouping two patterns. One is definite subsidence, and another is slight uplift. Murakami (2005) discusses the line length changes between two GPS sites of Tsumagoi and Tobu, and he shows that the extension of line length just before the eruption in 2004 and 2009 and contraction between the eruption. Slight uplifts in the periods of May 2005 - May 2006 are corresponding to the period observed the extension, and subsidence in the periods of May 2006 - May 2007, May 2009 - June 2010, and June 2010 - June 2011. Two pressures sources are estimated from the ground deformation detected by precise leveling. One is a deeper spherical deflation source in the 6 km BSL depth beneath the mountainside, and another is the shallow dike intrusion beneath Mt. Takamine. A pressure source model was previously estimated from the leveling data for last 100 years (Murase et al., 2007), and it is suggestive a dominant source of the Asama volcano. They suggest a slight inflation after 1960, however our results show the deflation of -6.6 km3/6yr in the deeper sources for five years after

  9. Long-lasting Dike Intrusion in the 2000 Eruption of Miyake-Jima Volcano: Creep or Chamber deflation?

    Science.gov (United States)

    Yamaoka, K.; Kudo, T.; Kawamura, M.; Fujii, N.

    2002-12-01

    The model for the 2000 intrusive event between Kozu-jima and Miyake-jima volcano, Japan, was reinvestigated. After the sudden earthquake swarm in Miyake-jima volcano, a dike intrusion of large volume lasting for two months was detected by the nation wide GPS network (Geonet). We extracted the step-wise displacement of the GPS station by fitting a function which represents a step, a linear trend and an annual sinusoidal variation. The displacements due to the dike intrusion were detected with stations in the area with a radius of about 200km. The displacement we obtained shows a distribution that is consistent with the idea that the source is located near Miyake-jima volcano. The displacement apparently indicates that a dyke of large volume was intruded between Miyake-jima and the neighboring Kozu-jima volcano. However, the displacement cannot be reproduce solely by the dike even with some earthquakes associated with the intrusive event. Therefore, Yamaoka et al. (2000) and Nishimura et al. (2001) introduced an aseismic creep near the dike tip opposite to Miyake-jima. The magnitude of the creep that is required corresponds to M7 which is anomalously large. As there is no evidence which support such a large aseismic creep, we tried to explain the deformation with another model. We, here, introduced a deflation model, which is well know as Mogi model, instead of creep source. We searched for the optimum values for the model with parameter search. We assumed a vertical dike with the length of 20km centerred at the middle of earthquake swarm region. We searched for the azimuth, the depth of the top, the depth extent of the dike and the tensile dislocation for the dike. For the deflation source we assumed that it locates beneath the dike between the depth of 15km and 40km. The optimum solution we obtained for the dike is 42 degree for the azimuth, 2.5 km for the top depth, 14km for the depth extent and 6m for the tensile dislocation. These values correspond to the volume

  10. MATLAB tools for improved characterization and quantification of volcanic incandescence in Webcam imagery; applications at Kilauea Volcano, Hawai'i

    Science.gov (United States)

    Patrick, Matthew R.; Kauahikaua, James P.; Antolik, Loren

    2010-01-01

    Webcams are now standard tools for volcano monitoring and are used at observatories in Alaska, the Cascades, Kamchatka, Hawai'i, Italy, and Japan, among other locations. Webcam images allow invaluable documentation of activity and provide a powerful comparative tool for interpreting other monitoring datastreams, such as seismicity and deformation. Automated image processing can improve the time efficiency and rigor of Webcam image interpretation, and potentially extract more information on eruptive activity. For instance, Lovick and others (2008) provided a suite of processing tools that performed such tasks as noise reduction, eliminating uninteresting images from an image collection, and detecting incandescence, with an application to dome activity at Mount St. Helens during 2007. In this paper, we present two very simple automated approaches for improved characterization and quantification of volcanic incandescence in Webcam images at Kilauea Volcano, Hawai`i. The techniques are implemented in MATLAB (version 2009b, Copyright: The Mathworks, Inc.) to take advantage of the ease of matrix operations. Incandescence is a useful indictor of the location and extent of active lava flows and also a potentially powerful proxy for activity levels at open vents. We apply our techniques to a period covering both summit and east rift zone activity at Kilauea during 2008?2009 and compare the results to complementary datasets (seismicity, tilt) to demonstrate their integrative potential. A great strength of this study is the demonstrated success of these tools in an operational setting at the Hawaiian Volcano Observatory (HVO) over the course of more than a year. Although applied only to Webcam images here, the techniques could be applied to any type of sequential images, such as time-lapse photography. We expect that these tools are applicable to many other volcano monitoring scenarios, and the two MATLAB scripts, as they are implemented at HVO, are included in the appendixes

  11. Urgent Safety Measures in Japan after Great East Japan Earthquake

    International Nuclear Information System (INIS)

    Taniura, W.; Otani, H.

    2012-01-01

    Due to tsunami triggered by the Great East Japan Earthquake on March 11, 2011, the operating and refueling reactor facilities at Fukushima Dai-ichi and Dai-ni Nuclear Power Plants of Tokyo Electric Power Co. caused a nuclear hazard. Japanese electric power companies voluntarily began to compile various urgent measures against tsunami within the week the hazard was caused. As for the urgent safety measures of each licensee, it is clarified that effective measures have been appropriately implemented as a result of the inspection of the national government, the verification based on the guideline of the Japan Society of Maintenology and the stress test. (author)

  12. 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.

  13. 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.

  14. 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

  15. Volcanic Ash from the 1999 Eruption of Mount Cameroon Volcano ...

    African Journals Online (AJOL)

    Volcanic ash from the 1999 eruption of Mount Cameroon volcano has been characterized for its particle size and shape (by scanning electron microscopy, SEM), and mineralogy (by X-ray diffractometry, XRD). Also the total fluorine (F) content of the ash was determined by the selective ion electrode method. The results ...

  16. Observing Volcanoes from the Seafloor in the Central Mediterranean Area

    Directory of Open Access Journals (Sweden)

    Gabriele Giovanetti

    2016-04-01

    Full Text Available The three volcanoes that are the object of this paper show different types of activity that are representative of the large variety of volcanism present in the Central Mediterranean area. Etna and Stromboli are sub-aerial volcanoes, with significant part of their structure under the sea, while the Marsili Seamount is submerged, and its activity is still open to debate. The study of these volcanoes can benefit from multi-parametric observations from the seafloor. Each volcano was studied with a different kind of observation system. Stromboli seismic recordings are acquired by means of a single Ocean Bottom Seismometer (OBS. From these data, it was possible to identify two different magma chambers at different depths. At Marsili Seamount, gravimetric and seismic signals are recorded by a battery-powered multi-disciplinary observatory (GEOSTAR. Gravimetric variations and seismic Short Duration Events (SDE confirm the presence of hydrothermal activity. At the Etna observation site, seismic signals, water pressure, magnetic field and acoustic echo intensity are acquired in real-time thanks to a cabled multi-disciplinary observatory (NEMO-SN1 . This observatory is one of the operative nodes of the European Multidisciplinary Seafloor and water-column Observatory (EMSO; www.emso-eu.org research infrastructure. Through a multidisciplinary approach, we speculate about deep Etna sources and follow some significant events, such as volcanic ash diffusion in the seawater.

  17. The Active Lava Flows of Kilauea Volcano, Hawaii

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 6. The Active Lava Flows of Kilauea Volcano, Hawaii. Hetu Sheth. General Article Volume 8 Issue 6 June 2003 pp 24-33. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/06/0024-0033. Keywords.

  18. 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.

  19. Stem Cells: A Dormant Volcano Within Our Body?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 3. Stem Cells: A Dormant Volcano Within Our Body? Devaveena Dey Annapoorni Rangarajan. General Article Volume 12 Issue 3 March 2007 pp 27-34. Fulltext. Click here to view fulltext PDF. Permanent link:

  20. Puffers and Chuggers: Statistical Curiosities in Volcano World

    Science.gov (United States)

    Lees, J. M.

    2002-12-01

    Several on-going, low level volcanic explosions exhibit background phenomena commonly known as puffing, or in some cases chugging. Recently these events have been scrutinized because of the initiation of infrasonic monitoring, whereas earlier the events may have gone undetected. The activity associated with a puffer at a volcanic vent is generally small in magnitude and is often not observed audibly. The low frequency signals are readily observed on sensitive acoustic instrumentation and they provide a new dimension for our understanding of volcanic processes at volcanoes like Stromboli and Etna that have constant puffing signals. At other volcanoes, like Karymsky volcano in Kamchatka and Sangay Volcano in Ecuador, chugging signals associated with Strombolian style eruptions also provides new insights into the physics of the conduit systems. Here we present a statistical method of event detection, and event cluster association. When multiple vents work in unison it may be difficult to separate out chugging and puffing signals between spatially separated vents. The cluster analysis automatically differentiates between the vents based on waveform characteristics in the acoustic and seismic wavefields. Data examples from May, 2001, at Stromboli and Etna, show extensive periods of puffing (1-5 second frequency) superimposed on a background of vigorous, small-scale explosive activity. At Karymsky and Sangay non-linear, dynamic models explain the fluid flow through vents which gives rise to chugging. Furthermore, the frequency of chugging events appears to be associated with the intensity of lava flows and eruption rate.

  1. Natural sources of greenhouse gases: carbon dioxide emissions from volcanoes

    Science.gov (United States)

    Gerlach, Terrence

    1990-01-01

    Volcanic degassing of carbon dioxide plays an important role in keeping the atmosphere-ocean portion of the carbon geochemical cycle in balance. The atmosphere-ocean carbon deficit requires replenishment of 6??1012 mol CO2/yr, and places an upper limit on the output of carbon dioxide from volcanoes. The CO2 output of the global mid-oceanic ridge system is ca. 0.7??1012 mol/yr, thus supplying only a fraction of the amount needed to balance the carbon deficit. The carbon dioxide flux from subaerial volcanoes is poorly known, but it appears to be at least as large as the mid-oceanic ridge flux. Much (perhaps most) of the CO2 emitted from volcanoes is degassed noneruptively. This mode of degassing may lead to impacts on the environment and biosphere that are fundamentally different in character from those envisioned in published scenarios, which are based on the assumption that CO2 degassing occurs predominantly by eruptive processes. Although the flux of carbon dioxide from volcanoes is poorly constrained at present, it is clearly two orders of magnitude lower than the anthropogenic output of CO2.

  2. Clasts from mud volcanoes from the eastern Mediterranean

    NARCIS (Netherlands)

    Huguen, C.; Benkhelil, J.; Giresse, P.; Mascle, J.; Muller, C.L.C.; Woodside, J.M.; Zitter, T.A.C.

    2001-01-01

    In the eastern Mediterranean, numerous argilo-kinetic manifestations, commonly named 'mud volcanoes', have been identified and studied in some detail during the last twenty years using several techniques. The Medinaut survey (December 1998) has provided new insights into this phenomenon through

  3. Volcan Baru: Eruptive History and Volcano-Hazards Assessment

    Science.gov (United States)

    Sherrod, David R.; Vallance, James W.; Tapia Espinosa, Arkin; McGeehin, John P.

    2008-01-01

    Volcan Baru is a potentially active volcano in western Panama, about 35 km east of the Costa Rican border. The volcano has had four eruptive episodes during the past 1,600 years, including its most recent eruption about 400?500 years ago. Several other eruptions occurred in the prior 10,000 years. Several seismic swarms in the 20th century and a recent swarm in 2006 serve as reminders of a restless tectonic terrane. Given this history, Volcan Baru likely will erupt again in the near or distant future, following some premonitory period of seismic activity and subtle ground deformation that may last for days or months. Future eruptions will likely be similar to past eruptions?explosive and dangerous to those living on the volcano?s flanks. Outlying towns and cities could endure several years of disruption in the wake of renewed volcanic activity. Described in this open-file report are reconnaissance mapping and stratigraphic studies, radiocarbon dating, lahar-inundation modeling, and hazard-analysis maps. Existing data have been compiled and included to make this report as comprehensive as possible. The report is prepared in coooperation with National Secretariat for Science, Technology and Innovation (SENACYT) of the Republic of Panama and the U.S. Agency for International Development (USAID).

  4. 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.

  5. Volcano ecology: flourishing on the flanks of Mount St. Helens

    Science.gov (United States)

    Rhonda Mazza; Charlie Crisafulli

    2016-01-01

    Mount St. Helens’ explosive eruption on May 18, 1980, was a pivotal moment in the field of disturbance ecology. The subsequent sustained, integrated research effort has shaped the development of volcano ecology, an emerging field of focused research. Excessive heat, burial, and impact force are some of the disturbance mechanisms following an eruption. They are also...

  6. Dike Intrusion Process of 2000 Miyakejima - Kozujima Event estimated from GPS measurements in Kozujima - Niijima Islands, central Japan

    Science.gov (United States)

    Murase, M.; Nakao, S.; Kato, T.; Tabei, T.; Kimata, F.; Fujii, N.

    2003-12-01

    Kozujima - Niijima Islands of Izu Volcano Islands are located about 180 km southeast of Tokyo, Japan. Although the last volcano eruptions in Kozujima and Niijima volcanoes are recorded more than 1000 year before, the ground deformation of 2-3 cm is detected at Kozujima - Niijima Islands by GPS measurements since 1996. On June 26, 2000, earthquake swarm and large ground deformation more than 20 cm are observed at Miyakejima volcano located 40 km east-southeastward of Kozu Island, and volcano eruption are continued since July 7. Remarkable earthquake swarm including five earthquakes more than M5 is stretching to Kozushima Island from Miyakejima Island. From the rapid ground deformation detected by continuous GPS measurements at Miyakejima Island on June 26, magma intrusion models of two or three dikes are discussed in the south and west part of Miyakejima volcano by Irwan et al.(2003) and Ueda et al.(2003). They also estimate dike intrusions are propagated from southern part of Miyakejima volcano to western part, and finally dike intrusion is stretching to 20 km distance toward Kozujima Island. From the ground deformation detected by GPS daily solution of Nation-wide dense GPS network (GEONET), some dike intrusion models are discussed. Ito et al.(2002) estimate the huge dike intrusion with length of about 20 km and volume of 1 km3 in the sea area between the Miyake Island and Kozu Island. (And) Nishimura et al.(2001) introduce not only dike but also aseismic creep source to explain the deformation in Shikinejima. Yamaoka et al.(2002) discuss the dike and spherical deflation source under the dike, because of no evidence supported large aseismic creep. They indicate a dike and spherical deflation source model is as good as dike and creep source model. In case of dike and creep, magma supply is only from the chamber under the Miyakejima volcano. In dike and spherical deflation source model, magma supply is from under Miyakejima volcano and under the dike. Furuya et al

  7. Positioning Indian Emigration to Japan

    DEFF Research Database (Denmark)

    D'Costa, Anthony

    2013-01-01

    The purpose of this paper is to show how the Indian IT industry could position itself in the Japanese market. But in order to accomplish this, it is necessary to identify the key challenges and opportunities the Indian IT industry faces in the Japanese market. The opportunities for India, as well...... as other IT-strong developing countries, are to supply technical talent, whose availability in Japan is constrained by the secular demographic crisis and changing educational and occupational preferences. The challenges for India are the institutional barriers, in particular, Japanese business practices...... that act as significant barriers to the entry of foreign skilled professionals. The paper brings out the source and pattern of foreign professionals and students in Japan as a proxy for talent. Though India’s presence in Japan is currently limited, its share of technical professionals to the total number...

  8. Precise Hypocenter Distribution of Seismic Signals Associated with the 2000 Volcanic Unrest of Mount Bandai, Northeastern Japan

    Science.gov (United States)

    Nishimura, T.; Ueki, S.; Yamawaki, T.; Tanaka, S.; Hashino, H.; Sato, M.; Nakamichi, H.; Hamaguchi, H.

    2001-12-01

    We precisely determine hypocenters of volcanic earthquakes and tremor and compare their distribution with 3-D seismic structure and low resisitivity zones of the volcano to understand the 2000 volcanic unrest of Mount Bandai, Japan. Many volcano tectonic earthquakes (VT), volcanic tremor and very long period events (VLP) have been recorded by our broad band seismic network closely deployed around the volcano since April 2000. VT earthquakes are characterized by high frequency (>10Hz) signals with clear onsets of P and S phases, and volcanic tremor by long coda having a frequency ranging from a few Hz to more than 10 Hz. Waveforms of VLP consist of very long period (about 10s) signals preceded by short period ( less than 1 s ) signals. Absolute locations of their hypocenters are precisely determined by using the 3-D seismic structure that is obtained from P-wave arrival times of about 290 seismic stations for eight active sources that was conducted in 1997 as a national project of the program of prediction for volcanic eruptions. The results show that: hypocenters of VT earthquakes are concentrated in two clusters at a depth of 0-2 km beneath the summit and the northwestern area of the volcano; hypocenters of the volcanic tremor and the source of the short period signals of VLPs are located in a gap of the two clusters of volcano tectonic earthquakes. Since the gap of VT earthquakes is very close to a low resistivity zone detected by magnetotelluric soundings, we infer that volcanic tremor and the short period signals of VLPs are very closely related with magmatic fluid (hot water and/or magma) activity at the shallow part of the volcano. On the other hand, very long period signals of the VLPs are located at 5 km beneath the north-northwestern flank, which is more than 2 km far from the short period source of VLPs. These results imply that the activity of the shallow part of the volcano is dynamically related with inflation and deflation motions of the VLP source.

  9. 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

  10. 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).

  11. Geofluid Systems of Koryaksky-Avachinsky Volcanoes (Kamchatka, Russia

    Directory of Open Access Journals (Sweden)

    A. Kiryukhin

    2017-01-01

    Full Text Available The Koryaksky-Avachinsky volcanogenic basin, which has an area of 2530 km2, is located 25 km from Petropavlovsk-Kamchatsky City and includes five Quaternary volcanoes (two of which, Avachinsky (2750 masl and Koryaksky (3456 masl, are active, and is located within a depression that has formed atop Cretaceous basement rocks. Magma injection zones (dikes and chamber-like shapes are defined by plane-oriented clusters of local earthquakes that occur during volcanic activity (mostly in 2008–2011 below Koryaksky and Avachinsky volcanoes at depths ranging from −4.0 to −2.0 km and +1.0 to +2.0 km, respectively. Water isotopic (δD, δ18O data indicate that these volcanoes act as recharge areas for their adjacent thermal mineral springs (Koryaksky Narzans, Isotovsky, and Pinachevsky and the wells of the Bystrinsky and Elizovo aquifers. Carbon δ13С data in СО2 from CO2 springs in the northern foothills of Koryaksky Volcano reflect the magmatic origin of CO2. Carbon δ13С data in methane CH4 reservoirs penetrated by wells in the Neogene-Quaternary layer around Koryaksky and Avachinsky volcanoes indicate the thermobiogenic origin of methane. Thermal-hydrodynamic TOUGH2 conceptual modeling is used to determine what types of hydrogeologic boundaries and heat and mass sources are required to create the temperature, pressure, phase, and CO2 distributions observed within the given geological conditions of the Koryaksky-Avachinsky volcanic geofluid system.

  12. Volcano geodesy: Challenges and opportunities for the 21st century

    Science.gov (United States)

    Dzurisin, D.

    2000-01-01

    Intrusions of magma beneath volcanoes deform the surrounding rock and, if the intrusion is large enough, the overlying ground surface. Numerical models generally agree that, for most eruptions, subsurface volume changes are sufficient to produce measurable deformation at the surface. Studying this deformation can help to determine the location, volume, and shape of a subsurface magma body and thus to anticipate the onset and course of an eruption. This approach has been successfully applied at many restless volcanoes, especially basaltic shields and silicic calderas, using various geodetic techniques and sensors. However, its success at many intermediate-composition strato-volcanoes has been limited by generally long repose intervals, steep terrain, and structural influences that complicate the history and shape of surface deformation. These factors have made it difficult to adequately characterize deformation in space and time at many of the world's dangerous volcanoes. Recent technological advances promise to make this task easier by enabling the acquisition of geodetic data of high spatial and temporal resolution from Earth-orbiting satellites. Synthetic aperture radar interferometry (InSAR) can image ground deformation over large areas at metre-scale resolution over time-scales of a month to a few years. Global Positioning System (GPS) stations can provide continuous information on three-dimensional ground displacements at a network of key sites -information that is especially important during volcanic crises. By using InSAR to determine the shape of the displacement field and GPS to monitor temporal changes at key sites, scientists have a much better chance to capture geodetic signals that have so far been elusive at many volcanoes. This approach has the potential to provide longer-term warnings of impending volcanic activity than is possible with other monitoring techniques.

  13. Morphological analysis of Cerro Bravo Volcano, Central Andes of Colombia

    Science.gov (United States)

    Arango-Palacio, E.; Murcia, H. F.; Robayo, C.; Chica, P.; Piedrahita, D. A.; Aguilar-Casallas, C.

    2017-12-01

    Keywords: Cerro Bravo Volcano, Volcanic landforms, Craters. Cerro Bravo Volcano (CBV) belongs to the San Diego-Cerro Machín Volcano - Tectonic Province in the Central Andes of Colombia. CVB is located 150 km NW from Bogotá, the capital of Colombia, and 25 km E from Manizales city ( 350,00 inhabitants). The volcanic activity of CBV began at 50,000 years ago and has been characterized by produce effusive and explosive (subplinian to plinian) eruptions with dacitic and andesitic in composition products. The effusive activity is evidenced by lava flows and lava domes, while the explosive activity is evidenced by pyroclastic density current deposits and pyroclastic fall deposits; some secondary deposits such as debris avalanches and lahares has been also recognised. Currently, the CBV is considered as a hazard for the Manizales city. In order to characterise the volcanic edifice, a morphological analysis was carried out and a map was created from a digital elevations model (DEM) with 12.5 m resolution as well as aerial photographs. Thus, it was possible to associate the landforms with the evolution of the volcano. Based on this analysis, it was possible to identify the base and top of the CBV edifice as 2400 and 4020 m.a.s.l., respectively, with a diameter in its major axis of 5.8 km. The volcanic edifice has four main craters opening to the north. The craters are apart from each other by heights and distances between 120 m.a.s.l. and 1 km, respectively; this geomorphology is an evidence of different eruptive stages of the volcano construction. Morphological analysis has shown that some craters were created from explosive eruptions, however the different heights between each crater suggest the creation of lava domes and their collapse as a response of the final effusive activity.

  14. Gas geochemical survey of long dormant Ciomadul volcano (South Harghita Mts., Romania): constraints on the flux and origin of fluids

    Science.gov (United States)

    Kis, Boglárka-Mercedesz; Ionescu, Artur; Harangi, Szabolcs; Palcsu, László; Etiope, Giuseppe; Baciu, Cǎlin

    2016-04-01

    The Ciomadul, located in the South Harghita Mountains (Eastern Carpathians, Romania) is the youngest volcano built by the Neogene volcanism in the Carpathian-Pannonian Region. The volcanic activity was characterized by an initial extrusive lava dome building period from about 200 ka to 100 ka followed by a more explosive eruption stage from 57 to 32 ka. Although the volcano seems to be inactive, several features (e.g. geophysical anomalies in the crust; fast remobilization of near solidus long lasting crystal mush prior to the past eruptions) suggest that melt-bearing magmatic body could still exist beneath the Ciomadul. This is supported by the abundance of dry gas emanations (CO2, CH4, H2S), CO2 rich mineral water springs and bubbling pools. The long-term observation of seemingly inactive, dormant volcanoes has become important in the past years (Ontake volcano-Japan, Colli Albani volcano-Italy). Gas-geochemical survey and monitoring (noble gases, isotopic composition of carbon species, flux measurements) of such volcanoes is an adequate tool in detecting changes in their volcanic plumbing system. Starting from 2015 we commenced a gas-monitoring study to constrain the origin of fluids at Ciomadul by measuring the flux of two gas-species and collecting the gas-phase from several mofettes and mineral water springs. A total of 46 sites have been surveyed, including 29 gas emanations (mofettes and bubbling pools), 3 drilled wells, 11 springs and 3 surface water sites. We provide the first complex CO2 and CH4 flux measurements in the area considering mofettes and bubbling pools. The CO2 flux values range between 10 and 264 kg/day while the CH4 flux has a range between 125 and 4723 g/day. Estimates of total CO2 and CH4 output into the atmosphere are ~229 and ~1.3 t/year, respectively. These values are consistent with other geothermal systems in Europe. The chemical composition of samples indicate CO2 content of up to 96.77%, CH4 content up to 1.42% and He content up to

  15. Japan og Singapore i Arktis

    DEFF Research Database (Denmark)

    Tonami, Aki; Watters, Stewart

    2013-01-01

    are interested in the Arctic. Looking at the Arctic engagement of Japan and Singapore, this paper finds that their interest in the Polar Regions is not necessarily a new phenomenon and that Arctic policy, as with the development of other foreign policy objectives, is a complex mix of national, bureaucratic...... and group interests. For Greenlandic and Danish policymakers, it may be useful to understand the genesis of Japan and Singapore’s Arctic policies and that their interest is complex and multi-faceted....

  16. Recycling of plastics in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Masaki, K. [Clean Japan Center, Tokyo (Japan). PET Bottle Recycling Project Dept.

    1998-10-01

    The Clean Japan Center is an NGO concerned with recycling. This article presents an overview of methods for recyling products made of various types of plastic. A number of such methods are in use or being studied. Emphasis is given to the state of plastics recycling in Japan. The uses of waste plastics as materials in other industrials is outlined - these include waste plastics as a reducer in blast furnaces, replacing coke and pulverized coal; waste plastics as a source of heat in cement kilns as an alternative to pulverized coal; and waste plastics being incinerated to generate power. 3 figs.

  17. The educational system in Japan

    Science.gov (United States)

    Spearman, M. L.

    1986-01-01

    The rapid economic growth of Japan since World War II has resulted in Japan becoming a reference point for developing nations and the West. This remarkable growth results from a combination of factors, one of which has been unyielding attention to education in order to cultivate the human talent necessary to provide the productivity for economic growth. The Japanese education system emphasizes quality of instruction and rewards hard work. Some of the principles of the system are outlined together with a summary of the content of the curriculum, the quantity and quality of instruction, and the influence of culture and environment.

  18. Local Government System in Japan

    Directory of Open Access Journals (Sweden)

    Vladimir V. Redko

    2016-12-01

    Full Text Available The article is devoted to the issues of the activities of the local government of Japan. Particular attention is drawn to the legal framework and the material basis for the functioning of local self-government bodies. The system of local self-government is considered as a special form of self-government with a specific functional and meaning; system of municipal management and delegation of authority, as well as features of interaction between civil and imperious levels. The allocation of the city with a special status, as well as the financial structure of the local government of Japan, is considered in detail.

  19. [[Fertility in Japan: 1990

    Science.gov (United States)

    Hirosima, K; Yamamoto, C

    1992-04-01

    Japan's number of births for 1990 was 1,229,044, which was 25,000 less than 1989. The decrease, however, was smaller than the decrease which occurred between 1988 and 1989. Table 1 shows total number of births of Japanese and number of births of non-Japanese. Since 1987 number of births of non-Japanese has been slightly over 7000 every year, constituting 0.6% of total births. Table 2 shows total number of Japanese births, number of those with Japanese parents, number of those with non-Japanese mothers and number of those with non-Japanese fathers. The number of those with at least one non-Japanese parent was slightly over 1% in 1990. Table 3 shows in thousands, (1) number of births, (2) married female population ages 20-34, (3) female population ages 20-34, (4) total population. The second wave of baby boomers is now beginning to get married and reproduce, which has resulted in a slight increase in child births among women below 24. Child births among those below age 23 were 94,871 in 1988, 95,102 in 1989, and 98,632 in 1990. The same data for those below age 24 was 143,495 in 1989 and 147,037 in 1990. 1990's number of births was 63.1% of 1970's, which showed the onset of a second baby boom. This is due to a lower rate of currently married women, lower number of women ages 20 to 34, and lower fertility rate among currently married women. Total fertility rate dropped from 2.18 to 1.47 for males, from 2.13 to 1.53 for females, from 2.16 to 1.50 for the total. Ever-married total fertility rate went from 2.08 to 1.95 for males, from 2.13 to 1.98 for females. The reason why TFR was so low in 1980's was that total first marriage rate was as low as 70%. Between 1989 and 1990 age-specific fertility rates for males 34 years and above and for females 31 years and above, as well as that for both males and females 22 years and under, increased. 31-year-old males and 28-year-old females showed the highest age-specific fertility rate in 1990. Between 1975 and 1990 average age

  20. Newberry Volcano EGS Demonstration: Plans and Results

    Science.gov (United States)

    Cladouhos, T. T.; Petty, S.; Moore, M.; Nordin, Y.; De Rocher, T.; Callahan, O.; Perry, D.

    2012-12-01

    Engineered or Enhanced Geothermal Systems (EGS) have the potential to expand the availability of clean renewable, baseload energy beyond conventional geothermal areas. An EGS reservoir is created by injecting large volumes of cold water into hot, low-permeability rock to induce seismic slip and enhance the permeability of pre-existing fractures. To date, EGS demonstrations have been limited to a single stimulation per well and sub-economic production rates because a method to isolate the first fracture in a hot well has been lacking. In addition, some recent EGS demonstrations have been negatively impacted by induced seismicity felt by area residents. The Newberry Volcano Enhanced Geothermal System (EGS) Demonstration in central Oregon, funded in part by DOE Grant DE-EE0002777, is now in the field operations phase after two years of planning. The stimulation well, NWG 55-29 drilled in 2008, has very little natural permeability but is very hot, with a bottom hole temperature over 300°C. The Demonstration will test recent technological advances designed to reduce the cost of power generated by EGS and the risk of felt seismicity. First, the stimulation pumps used were designed to run for weeks with little downtime and deliver large volumes of water (1000 gpm, 63 l/s) at relatively low well-head pressure (max. 3000 psi, 20 MPa). This pump specification is based on the rock mechanics-based model of hydroshearing, reduction of effective normal stress and friction on existing fractures, which promotes shear slip and enhances permeability. In contrast, pumps used in hydrofracking, creation of permeability through tensile failure of the rock, operate for shorter periods at much lower volumes and higher pressures. Second, multiple zone stimulation in the open-hole sections of EGS wells would significantly reduce the cost of EGS power production by increasing the productivity of each well. To facilitate multiple zone stimulation, AltaRock Energy has developed a suite of

  1. Sulfur Dioxide Emissions from Congo Volcanoes

    Science.gov (United States)

    2002-01-01

    The Earth Probe Total Ozone Mapping Spectrometer (TOMS) detected a sulfur dioxide cloud associated with the January 2002 eruption of Nyiragongo as it flew over the region at around 11 a.m. local time (0900 UTC) on January 17. The sensor detected no significant amounts of ash in the eruption cloud. At the time of the TOMS overpass the cloud extended up to roughly 200 km (124 miles) northwest of Nyiragongo and was still attached to the volcano. This observation is consistent with nearly coincident MODIS imagery which shows an opaque cloud of gas and steam in the same location. The TOMS measurements show that the amount of sulfur dioxide in the Nyiragongo's plume range from about 10 to 30 kilotons. Please note that TOMS mass retrievals are dependent on the altitude of the cloud and may be adjusted as more information becomes available. Since the cloud may still have been developing at the time of the TOMS overpass, the final sulfur dioxide burden may have been greater. Wind trajectory data (courtesy of Leslie Lait, SSAI) suggest that part of the cloud may have reached at least mid- to upper-tropospheric altitudes of up to 12 km (7 miles), but scientists suspect no significant stratospheric injection of sulfur dioxide as a result of this eruption since the gas was not visible over the Democratic Republic of the Congo region in subsequent TOMS data acquired on January 18. Production of sulfur dioxide without a significant ash cloud is commonly observed during effusive eruptions such as the Nyiragongo event. Although dense low-level ash may be produced during such eruptions, these particulates usually fall out fairly quickly and elude detection by satellite. The size of the January 17 Nyiragongo cloud and the estimated sulfur dioxide tonnage are fairly modest, and at least an order of magnitude smaller than values typically measured by TOMS during eruptions of nearby Nyamuragira during its frequent outbursts (e.g., on February 6, 2001). Sulfur dioxide column amounts

  2. 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

  3. DOD Milk Plants in the Pacific Japan

    National Research Council Canada - National Science Library

    1996-01-01

    .... Army Kanagawa milk plant in Japan. Since 1947, the Army has maintained a (Government-owned, contractor-operated milk plant in Yokohama, Japan, to provide milk and other dairy products to DoD personnel and their families...

  4. 75 FR 57980 - Polychloroprene Rubber From Japan

    Science.gov (United States)

    2010-09-23

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Polychloroprene Rubber From Japan AGENCY: United States International Trade Commission. ACTION... whether revocation of the antidumping duty finding on polychloroprene rubber from Japan would be likely to...

  5. BioBank Japan project: Epidemiological study

    OpenAIRE

    Kubo, Michiaki

    2017-01-01

    Highlights ? For precision medicine, genetic, clinical and environmental information is crucial. ? Biobank Japan project constructed a clinical database of 200,000 patients. ? This supplement reported the epidemiological studies in the Biobank Japan.

  6. July 1993 Hokkaido, Japan Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — On July 12, 1993, a magnitude 7.6 Ms (7.7 Mw) (HRV) earthquake at 13:17 UT in the Sea of Japan near Hokkaido caused a back-arc tsunami that caused damage in all of...

  7. Medical Education in Japan, 1969

    Science.gov (United States)

    Brooks, Thomas J., Jr.

    1970-01-01

    Although Japan's 19th century feudalistic education system was abolished at the close of World War II and the country has wrought the greatest economic miracle in world history, the Japanese still assign low priorities to health and medical education. (IR)

  8. BWR Stability Issues in Japan

    Directory of Open Access Journals (Sweden)

    Hideaki Ikeda

    2008-01-01

    Full Text Available The present paper reviews activates relevant to the boiling water reactor (BWR stability phenomenon, which has a coupled neutronic and thermal-hydraulic nature, from the viewpoint of model and code developments and their applications to the BWR stability solution methodology in Japan.

  9. Entrepreneurship and unemployment in Japan

    NARCIS (Netherlands)

    van Stel, A.; Thurik, R.; Verheul, I.; Baljeu, L.

    2008-01-01

    We examine the relationship between entrepreneurship (as measured by fluctuations in the business ownership rate) and unemployment in Japan for the period between 1972 and 2002. We find that, although Japan’s unemployment rate has been influenced by specific exogenous shocks, the effects of

  10. Radioactivity survey data in Japan

    International Nuclear Information System (INIS)

    1981-09-01

    Strontium-90 and cesium-137 in Japan were determined in rain and dry fallout, airborne dust, service water, freshwater, soils, total diet, milk, vegetables, tea, sea fish, freshwater fish, shellfish, and seaweeds. The results were shown in tables. (J.P.N.)

  11. [Marriage and divorce in Japan].

    Science.gov (United States)

    Haderka, J

    1986-01-01

    Marriage patterns in Japan are analyzed using data from secondary sources. The author notes that although legislation affecting marriage and the family is derived from European models, traditional Japanese attitudes concerning the subservient role of women have a significant impact. The problems faced by women experiencing divorce are noted. (SUMMARY IN ENG AND RUS)

  12. JPRS Report. Science & Technology: Japan.

    Science.gov (United States)

    1988-12-09

    Acoustic performance of buildings, research on environmental psychology -Research on refuge, safety in times of disaster -Research and development of...Assigning Environmental Psychology Sector to Independent Laboratory Also Planned " Environmental psychology , for instance, is not something originally...plan to develop this environmental psychology sector further into an independent laboratory. Only in Japan is there a construction company that has

  13. Light water reactors in Japan

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The economy shifted to a low growth rate, and energy conservation advanced, accordingly, the growth rate of electric power demand is expected to be 3 %. As the result, nuclear power must be more economical. From the perspective of the national security, the continuous development of nuclear power is essential for Japan, as nuclear power is a quasi-domestically produced energy source, and Japan must reduce the dependence on oil. The commercial power plants in Japan are a gas-cooled reactor plant of 166 MW capacity, 16 BWR plants of 12,917 MW total capacity and 15 PWR plants of 11,438 MW total capacity, totaling 32 plants of 24,521 MW. Those in the construction or planning stage are 8 BWR plants of 8,245 MW and 8 PWR plants of 7,928 MW, totaling 16 plants of 16,173 MW. As of the end of March, 1986, nuclear power generating facilities were 16 % of the total facilities in Japan, which generated 26 % of the total electric power generated in fiscal year 1985. The capacity factor exceeded 70 % since 1982. The improvement and standardization program of LWRs and its results, the effort to develop ALWRs, the further advance in LWRs, the use of plutonium and so on are discussed. The further improvement of the economy and reliability of nuclear power plants is urgently required. (Kako, I.)

  14. Geothermal country update of Japan

    International Nuclear Information System (INIS)

    Higo, M.

    1990-01-01

    This paper reports on the status of geothermal energy in Japan. Topics covered include: present and planned production of electricity, present utilization of geothermal energy for direct heat, information about geothermal localities, and wells drilled for electrical utilization of geothermal resources to January 1, 1990

  15. Urban and spatial planning in Japan

    Directory of Open Access Journals (Sweden)

    Marin Tominaga

    2011-12-01

    Full Text Available This paper aims to introduce the urban and spatial planning inJapan. According to the national planning system of Japan, chapter 2, the planning system has 3 administrative levels and each territorial region has its own regulation. This paper introduces especially about planning and regulation system in city region in Japan.

  16. 75 FR 38119 - Polychloroprene Rubber From Japan

    Science.gov (United States)

    2010-07-01

    ... COMMISSION Polychloroprene Rubber From Japan AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty finding on polychloroprene rubber from Japan... antidumping duty finding on polychloroprene rubber from Japan would be likely to lead to continuation or...

  17. Legislative Basis of Pedagogical Education in Japan

    Science.gov (United States)

    Kuchai, Tetiana

    2014-01-01

    Legal framework policy of Japan in the field of education has been analyzed. The problem of influence of legislative materials on the development of education in Japan, its legislative support has been considered. It has been defined that directive materials affect the development of education system in Japan. Legislation policy of the country is…

  18. Assessing Hazards Related to Volcano-Ice Interactions at POPOCATÉPETL Volcano (mexico): Determination of Physical Parameters of 1999-2000 Laharic Flows

    Science.gov (United States)

    Delgado Granados, H.; Oropeza Villalobos, B.; Gonzalez Huesca, A.

    2010-12-01

    During glacier-ice melting by eruptions laharic flows form in proportions that may impose a threat to the surrounding populations. So, it is important to identify the potential at ice-capped volcanoes to produce lahars. In Mexico, the largest mountains glacier-clad, active volcanoes so, the interactions between eruptive activity and ice in Mexico should be evaluated for hazards assessment and building up preventing and mitigating programs. Popocatépetl volcano has produced laharic flows due to the interaction of the eruptive activity with the ice. The nearest village to the volcano, called Santiago Xalitzintla was threatened by these flows several times between June 1997 and the year 2000. The signals recorded by an acoustic flow monitoring (AFM) network allowed to determine the main physical parameters of lahars occurring between January 1999 and October 2000. We determined magnitude, acoustic flow, velocity and discharge. We obtained velocities of seismic data and the military-personnel descriptions by the Mexican Army station posted specifically to observe laharic flows. This threat has disappeared due to the extinction of glaciers at the volcano, although ice-bodies (seracs) still remain on the higher slopes of the volcano. According to these results, at the present level of eruptive magnitude, risk associated with laharic flows consists mainly in passive inundation of zones nearby the Huiloac ravine in the NE sector of the volcano. These results however might be used for further networks at other volcanoes in the country.

  19. Matrix Approach of Seismic Wave Imaging: Application to Erebus Volcano

    Science.gov (United States)

    Blondel, T.; Chaput, J.; Derode, A.; Campillo, M.; Aubry, A.

    2017-12-01

    This work aims at extending to seismic imaging a matrix approach of wave propagation in heterogeneous media, previously developed in acoustics and optics. More specifically, we will apply this approach to the imaging of the Erebus volcano in Antarctica. Volcanoes are actually among the most challenging media to explore seismically in light of highly localized and abrupt variations in density and wave velocity, extreme topography, extensive fractures, and the presence of magma. In this strongly scattering regime, conventional imaging methods suffer from the multiple scattering of waves. Our approach experimentally relies on the measurement of a reflection matrix associated with an array of geophones located at the surface of the volcano. Although these sensors are purely passive, a set of Green's functions can be measured between all pairs of geophones from ice-quake coda cross-correlations (1-10 Hz) and forms the reflection matrix. A set of matrix operations can then be applied for imaging purposes. First, the reflection matrix is projected, at each time of flight, in the ballistic focal plane by applying adaptive focusing at emission and reception. It yields a response matrix associated with an array of virtual geophones located at the ballistic depth. This basis allows us to get rid of most of the multiple scattering contribution by applying a confocal filter to seismic data. Iterative time reversal is then applied to detect and image the strongest scatterers. Mathematically, it consists in performing a singular value decomposition of the reflection matrix. The presence of a potential target is assessed from a statistical analysis of the singular values, while the corresponding eigenvectors yield the corresponding target images. When stacked, the results obtained at each depth give a three-dimensional image of the volcano. While conventional imaging methods lead to a speckle image with no connection to the actual medium's reflectivity, our method enables to

  20. 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

  1. Wave field decomposition of volcanic tremor at Pacaya Volcano, Guatemala

    Science.gov (United States)

    Lanza, F.; Waite, G. P.; Kenyon, L. M.

    2013-12-01

    A dense, small-aperture array of 12 short-period seismometers was deployed on the west flank of Pacaya volcano (Guatemala) and operated for 14 days in January 2011. The data were used to investigate the properties of the volcanic tremor wave field at the volcano. Volcanic tremor has been proven to be a powerful tool for eruption forecasting, therefore, identifying its source locations may shed new light on the dynamics of the volcano system. A preliminary spectral analysis highlights that most of the seismic energy is associated with six narrow spectral peaks between 1 and 6 Hz. After taking topography into account, we performed frequency-slowness analyses using the MUSIC algorithm and the semblance technique with the aim to define and locate the different components contributing to the wave field. Results show a complex wave field, with possibly multiple sources. We identify peaks at frequencies < 2 Hz as being related to anthropogenic sources coming from the N- NW direction where the geothermal plant and San Vincente Pacaya village are located. Azimuth measurements indicate that the 3 Hz signal propagates from the SE direction and it has been attributed to the new vent on the southeast flank of Pacaya Volcano. However, the presence of secondary peaks with azimuths of ˜ 200°, 150° and 70° seems to suggest either nonvolcanic sources or perhaps the presence of structural heterogeneities that produce strong scattered waves. At higher frequencies, results show effects of array aliasing, and therefore have not been considered in this study. The dispersive properties of the wave field have been investigated using the Spatial Auto-Correlation Method (SPAC). The dispersion characteristics of Rayleigh waves have been then inverted to find a shallow velocity model beneath the array, which shows a range of velocities from about 0.3 km/s to 2 km/s, in agreement with slowness values of the frequency bands considered. In detail, apparent velocities of 1-2 km/s dominate at

  2. Geochemical and Geophysical Signatures of Poas Volcano, Costa Rica

    Science.gov (United States)

    Martinez, M.; van Bergen, M.; Fernandez, E.; Takano, B.; Barboza, V.; Saenz, W.

    2007-05-01

    Among many research fields in volcanology, prediction of eruptions is the most important from the hazard- mitigation point of view. Most geophysicists have sought for the best physical parameters for this objective: various kinds of wave signals and geodesic data are two of such parameters. Being able to be remotely monitored gives them advantage over many other practical methods for volcano monitoring. On the other hand, increasing volcanic activity is always accompanied by mass transfer. The most swiftly-moving materials are volcanic gases which are the target geochemists have intensively studied although monitoring gases is rather tedious and limited for active volcanoes hosting crater lakes. A Japanese group lead by Bokuichiro Takano has recently developed an indirect method for monitoring gas injection into volcanic crater lakes. Polythionates are formed when SO2 and H2S are injected into the lake from subaqueous fumaroles. Such polythionates consist of chains of 4 to 6 sulphur atoms, the terminal ones of which are bonded with three oxygen atoms. The general formula for these anions is SxO62- (x= 4 to 6). Important to note is that SO2 input into the lake also depends upon the plumbing system of the volcanoes: conduits, cracks and hydrothermal reservoirs beneath the lake that usually differ from volcano to volcano. Despite such site-specific characters some general statements can be made on the behaviour of these chemical species. For example, at low volcanic activity S6O62- predominates while S4O62- and S5O62- become predominant with increasing SO2 that increases with volcanic activity. At higher SO2 input and high temperature polythionates disappear in the lake through interaction with aqueous SO2 (sulfitolysis). Thus, the ratios of the three polythionates or their absence serve as an indicator for various stages of volcanic activity. Monitoring polythionates is an independent method that can be compared with results from geophysical methods. However, it

  3. Volcanic strain change prior to an earthquake swarm observed by groundwater level sensors in Meakan-dake, Hokkaido, Japan

    Science.gov (United States)

    Takahashi, Hiroaki; Shibata, Tomo; Yamaguchi, Teruhiro; Ikeda, Ryuji; Okazaki, Noritoshi; Akita, Fujio

    2012-02-01

    We installed and operated a low-cost groundwater level observation system at intermittent hot spring wells in order to monitor volcanic strain signals from the active Meakan-dake volcano in eastern Hokkaido, Japan. Data are sampled at 1 Hz and are transmitted to the data center in real time. Evaluation of the water level time series with theoretical predictive tidal strain and coseismic static strain changes has suggested that the wells penetrate to the artesian aquifer and act as a volumetric strain sensor. An active earthquake swarm with more than 400 events occurred at the shallower part of the volcano from January 9 to 11, 2008. Three independent wells recorded pre- to co-swarm groundwater drops simultaneously, which represented a decrease in volumetric strain. The total volumetric strain change during the three active days was estimated to be from 6 to 7 × 10- 7. The observed data, including changes in volumetric strain, absence of deformation in the GPS coordinates, and activation of deep low-frequency earthquakes, might imply possible deflation of a source deeper than 10 km, and these preceding deeper activities might induce an earthquake swarm in a shallower part of the Meakan-dake volcano.

  4. Urgent Safety Measures in Japan after Great East Japan Earthquake

    International Nuclear Information System (INIS)

    Taniura, Wataru; Otani, Hiroyasu

    2012-01-01

    Due to tsunami triggered by the Great East Japan Earthquake, the operating and refueling reactor facilities at Fukushima Dai-ichi and Dai-ni Nuclear Power Plants caused a nuclear hazard. Given the fact, Japanese electric power companies voluntarily began to compile various urgent measures against tsunami. And then the Nuclear and Industrial Safety Agency (NISA) ordered the licensees to put into practice the voluntarily compiled urgent safety measures, in order to ensure the effectiveness of the means for recovering cooling functions along with avoiding the release of radioactive substances to the possible minimum, even if a huge tsunami following a severe earthquake hits nuclear power plants. The following describes the state and the effect of the urgent safety measures implemented for 44 reactors (under operation) and 1 reactor (under construction) in Japan and also describes the measures to be implemented by the licensees of reactor operation in the future.

  5. Japan`s refiner/marketers headed for major shakeout

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-26

    Japan`s downstream oil industry is in a state of crisis and headed for a major shakeout. The major catalyst for this was a dramatic deregulation step during April 1996 that allowed refined petroleum product imports by non-refiners. The move, together with a sharp drop in refining margins, falling retail gasoline prices, and a service station sector on the brink of collapse, are all leading to massive changes in the way the country`s refiners and marketers do business. This paper reviews the collapse of corporate profits during this period of deregulation; the development of a new price system geared toward bringing the prices of gasoline, fuel oil, and kerosene into line with each other to offset the fall in gasoline prices; and industry restructuring including mergers, acquisitions, and marketing consolidation. The paper then makes predictions on the outcome of these changes on the Japanese oil industry.

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

    Science.gov (United States)

    Fee, David; Haney, Matthew M; Matoza, Robin S; Van 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. Copyright © 2017, American Association for the Advancement of Science.

  7. 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.

  8. Volcano plots in hydrogen electrocatalysis – uses and abuses

    Science.gov (United States)

    Quaino, Paola; Juarez, Fernanda; Santos, Elizabeth

    2014-01-01

    Summary 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. PMID:24991521

  9. Evolution of a Quaternary peralkaline volcano: Mayor Island, New Zealand

    Science.gov (United States)

    Houghton, Bruce F.; Weaver, S.D.; Wilson, C.J.N.; Lanphere, M.A.

    1992-01-01

    Mayor Island is a Holocene pantelleritic volcano showing a wide range of dispersive power and eruptive intensity despite a very limited range in magma composition of only 2% SiO2. The primary controls on this range appear to have been the magmatic gas content on eruption and a varying involvement of basaltic magma, rather than major-element chemistry of the rhyolites. The ca. 130 ka subaerial history of the volcano contains portions of three geochemical cycles with abrupt changes in trace-element chemistry following episodes of caldera collapse. The uniform major-element chemistry of the magma may relate to a fine balance between rates of eruption and supply and the higher density of the more evolved (Ferich) magmas which could be tapped only after caldera-forming events had removed significant volumes of less evolved but lighter magma. ?? 1992.

  10. 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.

  11. Eruption Forecasting: Success and Surprise at Kasatochi and Okmok Volcanoes

    Science.gov (United States)

    Prejean, S.; Power, J.; Brodsky, E.

    2008-12-01

    In the summer of 2008, the Alaska Volcano Observatory (AVO) successfully forecast eruption at an unmonitored volcano, Kasatochi, and was unable to forecast eruption at a well monitored volcano, Okmok. We use these case studies to explore the limitations and opportunities of seismically monitored and unmonitored systems and to evaluate situations when we can expect to succeed and when we must expect to fail in eruption forecasting. Challenges in forecasting eruptions include interpreting seismicity in context of volcanic history, developing a firm understanding of distance scales over which pre- and co-eruptive seismic signals are observed, and improving our ability to discriminate processes causing tremor. Kasatochi Volcano is a 3 km wide island in the central Aleutian Islands with no confirmed historical activity. Little is known about the eruptive history of the volcano. It was not considered an immediate threat until 3 days prior to eruption. A report of ground shaking by a biology field crew on the island on August 4 was the first indication of unrest. On August 6 a vigorous seismic swarm became apparent on the nearest seismic stations 40 km distant. The aviation color code/volcano alert level at Kasatochi was increased to Yellow/Advisory in response to increasing magnitude and frequency of earthquakes. The color code/alert level was increased to Orange/Watch on August 7 when volcanic tremor was observed in the wake of the largest earthquake in the sequence, a M 5.6. Three hours after the onset of volcanic tremor, eruption was confirmed by satellite data and the color code/alert level increased to Red/Warning. Eruption forecasting was possible only due to the exceptionally large moment release of pre-eruptive seismicity. The key challenge in evaluating the situation was distinguishing between tectonic activity and a volcanic swarm. It is likely there were weeks to months of precursory seismicity, however little instrumental record exists due to the lack of a

  12. The Influence of Plumbing System Structure on Volcano Dimensions and Topography

    Science.gov (United States)

    Castruccio, Angelo; Diez, Mikel; Gho, Rayen

    2017-11-01

    Volcano morphology has been traditionally studied from a descriptive point of view, but in this work we took a different more quantitative perspective. Here we used volcano dimensions such as height and basal radius, together with the topographic profile as indicators of key plumbing system properties. We started by coupling models for the ascent of magma and extrusion of lava flows with those for volcano edifice construction. We modeled volcanic edifices as a pile of lavas that are emitted from a single vent and reduce in volume with time. We then selected a number of arc-volcano examples to test our physical relationships and estimate parameters, which were compared with independent methods. Our results indicate that large volcanoes (>2,000 m height and base radius >10 km) usually are basaltic systems with overpressured sources located at more than 15 km depth. On the other hand, smaller volcanoes (morphology of the volcanic edifice.

  13. Volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory 1993

    Science.gov (United States)

    Neal, Christina A.; McGimsey, Robert G.; Doukas, Michael P.

    1996-01-01

    During 1993, the Alaska Volcano Observatory (AVO) responded to episodes of eruptive activity or false alarms at nine volcanic centers in the state of Alaska. Additionally, as part of a formal role in KVERT (the Kamchatkan Volcano Eruption Response Team), AVO staff also responded to eruptions on the Kamchatka Peninsula, details of which are summarized in Miller and Kurianov (1993). In 1993, AVO maintained seismic instrumentation networks on four volcanoes of the Cook Inlet region--Spurr, Redoubt, Iliamna, and Augustine--and two stations at Dutton Volcano near King Cove on the Alaska Peninsula. Other routine elements of AVO's volcano monitoring program in Alaska include periodic airborne measurement of volcanic SO2 and CO2 at Cook Inlet volcanoes (Doukas, 1995) and maintenance of a lightning detection system in Cook Inlet (Paskievitch and others, 1995).

  14. 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.

  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. Geochemistry of mud volcano fluids in the Taiwan accretionary prism

    International Nuclear Information System (INIS)

    You Chenfeng; Gieskes, Joris M.; Lee, Typhoon; Yui Tzenfu; Chen Hsinwen

    2004-01-01

    Taiwan is located at the collision boundary between the Philippine Sea Plate and the Asian Continental Plate and is one of the most active orogenic belts in the world. Fluids sampled from 9 sub-aerial mud volcanoes distributed along two major geological structures in southwestern Taiwan, the Chishan fault and the Gutingkeng anticline, were analyzed to evaluate possible sources of water and the degree of fluid-sediment interaction at depth in an accretionary prism. Overall, the Taiwanese mud volcano fluids are characterized by high Cl contents, up to 347 mM, suggesting a marine origin from actively de-watering sedimentary pore waters along major structures on land. The fluids obtained from the Gutingkeng anticline, as well as from the Coastal Plain area, show high Cl, Na, K, Ca, Mg and NH 4 , but low SO 4 and B concentrations. In contrast, the Chishan fault fluids are much less saline (1/4 seawater value), but show much heavier O isotope compositions (δ 18 O=5.1-6.5 %o). A simplified scenario of mixing between sedimentary pore fluids and waters affected by clay dehydration released at depth can explain several crucial observations including heavy O isotopes, radiogenic Sr contents ( 87 Sr/ 86 Sr=0.71136-0.71283), and relatively low salinities in the Chishan fluids. Gases isolated from the mud volcanoes are predominantly CH 4 and CO 2 , where the CH 4 -C isotopic compositions show a thermogenic component of δ 13 C=-38 %o. These results demonstrate that active mud volcano de-watering in Taiwan is a direct product of intense sediment accretion and plate collision in the region

  17. 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.

  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. Evidence for dike emplacement beneath Iliamna Volcano, Alaska in 1996

    Science.gov (United States)

    Roman, D.C.; Power, J.A.; Moran, S.C.; Cashman, K.V.; Doukas, M.P.; Neal, C.A.; Gerlach, T.M.

    2004-01-01

    Two earthquake swarms, comprising 88 and 2833 locatable events, occurred beneath Iliamna Volcano, Alaska, in May and August of 1996. Swarm earthquakes ranged in magnitude from -0.9 to 3.3. Increases in SO2 and CO2 emissions detected during the fall of 1996 were coincident with the second swarm. No other physical changes were observed in or around the volcano during this time period. No eruption occurred, and seismicity and measured gas emissions have remained at background levels since mid-1997. Earthquake hypocenters recorded during the swarms form a cluster in a previously aseismic volume of crust located to the south of Iliamna's summit at a depth of -1 to 4 km below sea level. This cluster is elongated to the NNW-SSE, parallel to the trend of the summit and southern vents at Iliamna and to the regional axis of maximum compressive stress determined through inversion of fault-plane solutions for regional earthquakes. Fault-plane solutions calculated for 24 swarm earthquakes located at the top of the new cluster suggest a heterogeneous stress field acting during the second swarm, characterized by normal faulting and strike-slip faulting with p-axes parallel to the axis of regional maximum compressive stress. The increase in earthquake rates, the appearance of a new seismic volume, and the elevated gas emissions at Iliamna Volcano indicate that new magma intruded beneath the volcano in 1996. The elongation of the 1996-1997 earthquake cluster parallel to the direction of regional maximum compressive stress and the accelerated occurrence of both normal and strike-slip faulting in a small volume of crust at the top of the new seismic volume may be explained by the emplacement and inflation of a subvertical planar dike beneath the summit of Iliamna and its southern satellite vents. ?? 2003 Elsevier B.V. All rights reserved.

  20. Advances(?) in mitigating volcano hazards in Latin America

    Science.gov (United States)

    Hall, M.L.

    1991-01-01

    The 1980's were incredible years for volcanology. As a consequence of the Mount St. Helens and other eruptions, major advances in our understanding of volcanic processes and eruption dynamics were made. the decade also witnessed the greatest death toll caused by volcanism since 1902. Following Mount St. Helens, awareness of volcano hazards increased throughout the world; however, in Latin America, subsequent events showed that much was still to be learned. 

  1. 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.

  2. Multiresolution pattern recognition of small volcanos in Magellan data

    Science.gov (United States)

    Smyth, P.; Anderson, C. H.; Aubele, J. C.; Crumpler, L. S.

    1992-01-01

    The Magellan data is a treasure-trove for scientific analysis of venusian geology, providing far more detail than was previously available from Pioneer Venus, Venera 15/16, or ground-based radar observations. However, at this point, planetary scientists are being overwhelmed by the sheer quantities of data collected--data analysis technology has not kept pace with our ability to collect and store it. In particular, 'small-shield' volcanos (less than 20 km in diameter) are the most abundant visible geologic feature on the planet. It is estimated, based on extrapolating from previous studies and knowledge of the underlying geologic processes, that there should be on the order of 10(exp 5) to 10(exp 6) of these volcanos visible in the Magellan data. Identifying and studying these volcanos is fundamental to a proper understanding of the geologic evolution of Venus. However, locating and parameterizing them in a manual manner is very time-consuming. Hence, we have undertaken the development of techniques to partially automate this task. The goal is not the unrealistic one of total automation, but rather the development of a useful tool to aid the project scientists. The primary constraints for this particular problem are as follows: (1) the method must be reasonably robust; and (2) the method must be reasonably fast. Unlike most geological features, the small volcanos of Venus can be ascribed to a basic process that produces features with a short list of readily defined characteristics differing significantly from other surface features on Venus. For pattern recognition purposes the relevant criteria include the following: (1) a circular planimetric outline; (2) known diameter frequency distribution from preliminary studies; (3) a limited number of basic morphological shapes; and (4) the common occurrence of a single, circular summit pit at the center of the edifice.

  3. VOLCANIC ENVIRONMENTS MONITORING BY DRONES MUD VOLCANO CASE STUDY

    Directory of Open Access Journals (Sweden)

    S. Amici

    2013-08-01

    Full Text Available 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.

  4. Forecasting deflation, intrusion and eruption at inflating volcanoes

    Science.gov (United States)

    Blake, Stephen; Cortés, Joaquín A.

    2018-01-01

    A principal goal of volcanology is to successfully forecast the start of volcanic eruptions. This paper introduces a general forecasting method, which relies on a stream of monitoring data and a statistical description of a given threshold criterion for an eruption to start. Specifically we investigate the timing of intrusive and eruptive events at inflating volcanoes. The gradual inflation of the ground surface is a well-known phenomenon at many volcanoes and is attributable to pressurised magma accumulating within a shallow chamber. Inflation usually culminates in a rapid deflation event caused by magma escaping from the chamber to produce a shallow intrusion and, in some cases, a volcanic eruption. We show that the ground elevation during 15 inflation periods at Krafla volcano, Iceland, increased with time towards a limiting value by following a decaying exponential with characteristic timescale τ. The available data for Krafla, Kilauea and Mauna Loa volcanoes show that the duration of inflation (t*) is approximately equal to τ. The distribution of t* / τ values follows a log-logistic distribution in which the central 60% of the data lie between 0.99 deflation event starting during a specified time interval to be estimated. The time window in which there is a specified probability of deflation starting can also be forecast, and forecasts can be updated after each new deformation measurement. The method provides stronger forecasts than one based on the distribution of repose times alone and is transferable to other types of monitoring data and/or other patterns of pre-eruptive unrest.

  5. Looking inside volcanoes with the Imaging Atmospheric Cherenkov Telescopes

    Science.gov (United States)

    Del Santo, M.; Catalano, O.; Cusumano, G.; La Parola, V.; La Rosa, G.; Maccarone, M. C.; Mineo, T.; Sottile, G.; Carbone, D.; Zuccarello, L.; Pareschi, G.; Vercellone, S.

    2017-12-01

    Cherenkov light is emitted when charged particles travel through a dielectric medium with velocity higher than the speed of light in the medium. The ground-based Imaging Atmospheric Cherenkov Telescopes (IACT), dedicated to the very-high energy γ-ray Astrophysics, are based on the detection of the Cherenkov light produced by relativistic charged particles in a shower induced by TeV photons interacting with the Earth atmosphere. Usually, an IACT consists of a large segmented mirror which reflects the Cherenkov light onto an array of sensors, placed at the focal plane, equipped by fast electronics. Cherenkov light from muons is imaged by an IACT as a ring, when muon hits the mirror, or as an arc when the impact point is outside the mirror. The Cherenkov ring pattern contains information necessary to assess both direction and energy of the incident muon. Taking advantage of the muon detection capability of IACTs, we present a new application of the Cherenkov technique that can be used to perform the muon radiography of volcanoes. The quantitative understanding of the inner structure of a volcano is a key-point to monitor the stages of the volcano activity, to forecast the next eruptive style and, eventually, to mitigate volcanic hazards. Muon radiography shares the same principle as X-ray radiography: muons are attenuated by higher density regions inside the target so that, by measuring the differential attenuation of the muon flux along different directions, it is possible to determine the density distribution of the interior of a volcano. To date, muon imaging of volcanic structures has been mainly achieved with detectors made up of scintillator planes. The advantage of using Cherenkov telescopes is that they are negligibly affected by background noise and allow a consistently improved spatial resolution when compared to the majority of the current detectors.

  6. 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.

  7. 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.

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

    Science.gov (United States)

    Browning, John; Drymoni, Kyriaki; Gudmundsson, Agust

    2015-10-28

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

  9. Climbing in the high volcanoes of central Mexico

    Science.gov (United States)

    Secor, R. J.

    1984-01-01

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

  10. 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.

  11. Design of Deformation Monitoring System for Volcano Mitigation

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  12. 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.

  13. Compositional variations revealed by ASTER image analysis of the Viedma Volcano, southern Andes Volcanic Zone

    OpenAIRE

    Kobayashi,Chiaki; Orihashi,Yuji; Hiarata,Daiji; Naranjo,José A; Kobayashi,Makoto; Anma,Ryo

    2010-01-01

    We conducted a lithological mapping of the Viedma volcano, one of five volcanoes in the Andean Austral Volcanic Zone (AVZ), using remote sensing techniques. We used data of the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER) sensor which is highly effective in geological research, to understand build-up processes and to deduce compositional variation of the Viedma volcano emerging from the South Patagonian ice field. The volcanic edifice was divided into bright parts th...

  14. A magma chamber model beneath Unzen Volcano inferred from geodetic and seismic data using FEM

    Science.gov (United States)

    Kohno, Y.; Matsumoto, S.; Matsushima, T.; Uehira, K.; Umakoshi, K.; Shimizu, H.

    2008-12-01

    A supplying system of the magma beneath Unzen volcano has been proposed using both geodetic and seismic data simultaneously. Spatial variation of geodetic data is affected by change of magma body in both of shape and pressure. In most cases, relative stress field is able to be inferred from focal mechanisms of earthquakes. This changing also disturbs stress field in the region around the magma chamber. A model about shape and internal pressure of magma chamber is constrained by mean of both grounds deformation and focal mechanism. Unzen Volcano is the massive volcanic complex, located in the middle part of Kyushu Island, Japan, erupted accompanying by pyroclastic flows and formed a huge lava dome at the summit during 1990-1995. Based on geodetic data during period 1991-2004, a magma chamber model composed of four pressure sources was constructed by grid search method (Kohno et al., 2008). For the data with greater crustal deformation observed in 1992-93 and 1993-94, we applied finite element method (FEM) to model the magma chamber. Especially, shape of a pressure source at a depth of 7 km (C-source) was also estimated in this searching process. C-source during 1992-93 has an oblate spheroid with south-southwest dip oriented made good correlation with observation data. Regards only from ground deformation data, the length of the major axis is smaller than 3km. The shape sustains to an idea that magma ascends easily toward the shallower chamber. The best solution of C-source in 1993-94 was obtained as a prolate spheroid source with north dip oriented. This latter source is smaller size and dipping to opposite side with the previous one. Although they are separated at distance of 1 km, this is not far to call different magma chamber each other. Different shape indicated that inhomogeneous structure of magma chamber. From this arrangement of the sources, we considered a model that the magma chamber at a depth of about 7 km could be composed of small magma chambers like

  15. Formation processes of the 1909 Tarumai and the 1944 Usu lava domesin Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    I. Yokoyama

    2004-06-01

    Full Text Available The formation of the two particular lava domes in Hokkaido, Japan is described and interpreted mainly from geophysical viewpoints. The 1909 eruption of Tarumai volcano was not violent but produced a lava dome over four days. The growth rate of the dome is discussed under the assumption that the lava flow was viscous and plastic fluid during its effusion. By Hagen-Poiseuille?s Law, the length of the conduit of the lava dome is rather ambiguously determined as a function of viscosity of the magma and diameter of the conduit. The 1944 Usu dome extruded as a parasitic cone of Usu volcano, not in the crater, but in a flat cornfield at the foot of the volcano. From the beginning to the end for more than 17 months, seismometric and geodetic observations of the dome activity were carried out by several pioneering geophysicists. Utilizing their data, pseudo growth curves of the dome at each stage can be drawn. The lava ascended rather uniformly, causing uplift of the ground surface until half-solidified lava reached the surface six months after the deformation began. Thereafter, the lava dome added lateral displacements and finally achieved its onion structure. These two lava domes are of contrasting character, one is andesitic and formed quickly while the other is dacitic and formed slowly, but both of them behaved as viscous and plastic flows during effusion. It is concluded that both the lava domes formed by uplift of magma forced to flow through the conduits, analogous to squeezing toothpaste out of a tube.

  16. Volcano-sedimentary processes operating on a marginal continental arc: the Archean Raquette Lake Formation, Slave Province, Canada

    Science.gov (United States)

    Mueller, W. U.; Corcoran, P. L.

    2001-06-01

    The 200-m thick, volcano-sedimentary Raquette Lake Formation, located in the south-central Archean Slave Province, represents a remnant arc segment floored by continental crust. The formation overlies the gneissic Sleepy Dragon Complex unconformably, is laterally interstratified with subaqueous mafic basalts of the Cameron River volcanic belt, and is considered the proximal equivalent of the turbidite-dominated Burwash Formation. A continuum of events associated with volcanism and sedimentation, and controlled by extensional tectonics, is advocated. A complex stratigraphy with three volcanic and three sedimentary lithofacies constitute the volcano-sedimentary succession. The volcanic lithofacies include: (1) a mafic volcanic lithofacies composed of subaqueous pillow-pillow breccia, and subaerial massive to blocky flows, (2) a felsic volcanic lithofacies representing felsic flows that were deposited in a subaerial environment, and (3) a felsic volcanic sandstone lithofacies interpreted as shallow-water, wave- and storm-reworked pyroclastic debris derived from explosive eruptions. The sedimentary lithofacies are represented by: (1) a conglomerate-sandstone lithofacies consistent with unconfined debris flow, hyperconcentrated flood flow and talus scree deposits, as well as minor high-energy stream flow conglomerates that formed coalescing, steep-sloped, coarse-clastic fan deltas, (2) a sandstone lithofacies, interpreted as hyperconcentrated flood flow deposits that accumulated at the subaerial-subaqueous interface, and (3) a mudstone lithofacies consistent with suspension sedimentation in a small restricted lagoon-type setting. The Raquette Lake Formation is interpreted as a fringing continental arc that displays both high-energy clastic sedimentation and contemporaneous effusive and explosive mafic and felsic volcanism. Modern analogues that develop along active plate margins in which continental crust plays a significant role include Japan and the Baja California

  17. Another Neolithic in Holocene Japan

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    Masaki Nishida

    2002-12-01

    Full Text Available In the Japanese Islands, small sedentary villages sustained by hunting, gathering, fish- ing and cultivation emerged around 10 000 years ago. This life style of the Jomon people continued for around 7000 years without any drastic changes in material culture, subsistence strategy and vil- lage size until the diffusion of continental civilization into Japan approximately 2500 years ago. This indicates that the incipient sedentary society of the Jomon Period was very stable, a state which is not indicative of civilized society after that time. After the prehistoric situation in Japan, we are able to classify sedentary society into two phases; sedentism with stability and sedentism with instability (civilized society. Therefore it is possible to say that the emergence of sedentism and cultivation are not direct factors which promote the emergence of civilization.

  18. WDC Activities in Japan, 2008

    Directory of Open Access Journals (Sweden)

    Takashi Watanabe

    2009-06-01

    Full Text Available This paper briefly reviews the activities of the International Council for Science (ICSU World Data Centers (WDCs in Japan at a time of great change in the data and information structures of the ICSU ? the creation of the World Data System (WDS in 2009. Seven WDCs are currently operating in Japan: the WDC for Airglow, the WDC for Cosmic Rays, the WDC for Geomagnetism, Kyoto, the WDC for Ionosphere, the WDC for Solar Radio Emission, and the WDC for Space Science Satellites. Although these WDCs are highly active, along-term support system must be established to ensure the stewardship and provision of quality-assessed data and data services to the international science community.

  19. Japan reforms its nuclear safety

    International Nuclear Information System (INIS)

    Anon.

    2013-01-01

    The Fukushima Daiichi NPP accident deeply questioned the bases of nuclear safety and nuclear safety regulation in Japan. It also resulted in a considerable loss of public confidence in the safety of nuclear power across the world. Although the accident was caused by natural phenomena, institutional and human factors also largely contributed to its devastating consequences, as shown by the Japanese Diet's and Government's investigation reports. 'Both regulators and licensees were held responsible and decided to fully reconsider the existing approaches to nuclear safety. Consequently, the regulatory system underwent extensive reform based on the lessons learned from the accident,' Yoshihiro Nakagome, the President of Japan Nuclear Energy Safety Organisation, an ETSON member TSO, explains. (orig.)

  20. Fruit harvesting robots in Japan.

    Science.gov (United States)

    Kondo, N; Monta, M; Fujiura, T

    1996-01-01

    We have developed harvesting robots for tomato, petty-tomato, cucumber and grape in Japan. These robots mainly consist of manipulators, end-effectors, visual sensors and traveling devices. These mechanisms of the robot components were developed based on the physical properties of the work objects. The robots must work automatically by themselves in greenhouses or fields, since we are considering for one operator to tend several robots in the production system. The system is modeled after Japanese agriculture which is commonly seen to produce many kinds of crops in greenhouses a