Search Results 1-20 of 49

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  • Comparison of high- and low-frequency signal sources for very-long-period seismic events at Asama volcano, Japan

    Maeda Yuta , Takeo Minoru , Kazahaya Ryunosuke

    … We surmise that the HF signal is caused by an inflow of volcanic gas from depth into a semi-vertical crack-like cavity (as imaged in our previous waveform inversion study), and the VLP signal is caused by resultant inflation of the same cavity. … The centroid of inflation (VLP source) is near the roof of the cavity, where gas accumulates, whereas the HF oscillation is emitted more intensely from lower and narrower portions of the cavity. …

    Geophysical Journal International 217(1), 389-404, 2019-04

    IR 

  • Temporal variability and flux estimates of helium isotopes in Kagoshima Bay, southern Japan  [in Japanese]

    Teresa Escobar Ma , Takahata Naoto , Shirai Kotaro , Tanaka Kentaro , Kagoshima Takanori , Obata Hajime , Sano Yuji

    <p>ああ</p>

    Abstracts of Annual Meeting of the Geochemical Society of Japan 66(0), 74, 2019

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  • Fluxes and mechanisms of magmatic volatile releases: Comparison of volcanic gas and hydrothermal fluid  [in Japanese]

    Shinohara Hiroshi

    <p>マグマ中に含まれる揮発性物質は、その大部分は火山ガス、温泉、熱水などとして地表にから放出されている。地殻から地表への放出量は、地殻に対するマグマおよび揮発性物質の供給量やその供給・放出過程を検討するための指標となる。本講演では島弧火山から火山ガスおよび熱水(温泉や地下水経由で放出)として放出されるマグマ性揮発性物質の放出量の推定および組成の比較を行い、放出過程の違いやマグマ性揮発 …

    Abstracts of Annual Meeting of the Geochemical Society of Japan 66(0), 119, 2019

    J-STAGE 

  • Processes Controlling Evolution of Volcanic Activity Deduced from Volcanic Gas Observations  [in Japanese]

    SHINOHARA Hiroshi

    … <p>Volcanic gases are derived from a magma or a hydrothermal system, which are sources of magmatic or phreatic eruptions, respectively. … Changes in a magma or a hydrothermal system, leading to eruptions, likely cause changes in volcanic gas emission rate and compositions. … emission rates correlate well with volcanic activities and precursory changes of the emission rates are also common. …

    BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN 64(2), 121-129, 2019

    J-STAGE 

  • Visualizing Sulfur Dioxide in Volcanic Plumes Using UV CCD Cameras  [in Japanese]

    MORI Toshiya

    <p>火山ガスは,多くの火山現象に鍵となる役割を果たしているため,火山ガスの化学組成や放出率を測定することは,火山活動理解の観点から重要である.従来,火山ガスの放出率観測では紫外分光計を用いて二酸化硫黄が測定されてきたが,現在,火山噴煙の挙動把握や高時間分解能で放出率を観測するために,二酸化硫黄の可視化測定が行われている.火山噴煙中の二酸化硫黄の可視化には,二酸化硫黄の紫外線吸収帯に重 …

    Journal of the Visualization Society of Japan 38(149), 2-6, 2018

    J-STAGE 

  • Mercury evasion fluxes from sea surfaces of the Tsushima Strait and Kuroshio Current in the East China Sea

    Marumoto Kohji , Takeuchi Akinori , Imai Shoko , Kodamatani Hitoshi , Suzuki Noriyuki

    … To obtain information on Hg cycling around the Japanese Islands, dissolved gaseous mercury (DGM) and Hg evasion fluxes from surface seawaters of the Tsushima Strait and East China Sea were investigated using a two-layer gas exchange model. … The TGM concentrations are sometimes increased due to the long-range transport from the Asian continent and volcanic activities on the southern Kyushu Island. …

    GEOCHEMICAL JOURNAL 52(1), 1-12, 2018

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  • Sulfur dioxide flux monitoring using a regular service ferry after the 2014 eruption of Kuchinoerabujima Volcano, Japan

    Mori Toshiya , Morita Masaaki , Iguchi Masato , Fukuoka Regional Headquarters

    … The volcanic island of Kuchinoerabujima recently erupted on Aug. 3, 2014 and on May 29, 2015. … After the 2014 eruption, a gradual increase of sulfur dioxide (SO2) flux from the volcano was observed. … In response to the increase, we built a UV spectrometer system that can be operated semi-automatically without an experienced observer for repetitive flux monitoring. …

    Journal of Natural Disaster Science 38(1), 105-118, 2017

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  • Volcanic plume measurements using a UAV for the 2014 Mt. Ontake eruption

    Mori Toshiya , Hashimoto Takeshi , Terada Akihiko , Yoshimoto Mitsuhiro , Kazahaya Ryunosuke , Shinohara Hiroshi , Tanaka Ryo

    Earth, Planets and Space 68(1), 49, 2016-03-22

    IR 

  • Effect of dairy manure type and supplemental synthetic fertilizer on methane and nitrous oxide emissions from a grassland in Nasu, Japan(Environment)

    MORI Akinori , HOJITO Masayuki

    … We investigated the effects of different types of manure on greenhouse gas (GHG) emissions from grassland for 2 years using a closed chamber method to measure methane (CH_4) and nitrous oxide (N_2O) fluxes from plots that received no nitrogen ("-N" plots), dairy cattle slurry plus synthetic N fertilizers ("slurry" plots) and farmyard manure plus synthetic N fertilizers ("FYM" plots). … Sharp peaks of CH_4 flux were observed shortly after slurry applications, whereas CH_4 fluxes only slightly increased following FYM applications. …

    Soil science and plant nutrition 61(2), 347-358, 2015-04

  • Measurement of volcanic gas flux and composition  [in Japanese]

    Shinohara Hiroshi

    Journal of Japan Society for Atmospheric Environment / Taiki Kankyo Gakkaishi 50(5), A59-A65, 2015

    J-STAGE  Ichushi Web 

  • Mercury emissions from soils and fumaroles of Nea Kameni volcanic centre, Santorini (Greece)

    BAGNATO EMANUELA , TAMBURELLO GIANCARLO , AIUPPA ALESSANDRO , SPROVIERI MARIO , VOUGIOUKALAKIS GEORGE E. , PARKS MICHELLE

    … There have been limited studies to date targeting mercury emissions from volcanic fumarolic systems, and no mercury flux data exist for soil or fumarolic emissions at Santorini volcanic complex, Greece. …

    GEOCHEMICAL JOURNAL 47(4), 437-450, 2013-08-01

    J-STAGE  References (65)

  • Sulfur dioxide emissions during the 2011 eruption of Shinmoedake volcano, Japan

    MORI Toshiya , KATO Koji

    EPS : Earth, Planets and Space 65(6), 573-580, 2013-06-01

    References (43) Cited by (1)

  • Separate Quantification of Volcanic Gas Fluxes from Showa and Minamidake Craters at Sakurajima Volcano, Japan(<Special Section>Sakurajima Special Issue)

    KAZAHAYA Ryunosuke , MORI Toshiya , YAMAMOTO Keigo

    桜島火山にて紫外線カメラ観測装置を用いてガス観測を行い,南岳火口及び昭和火口から放出される二酸化硫黄放出率の分離を行った.二酸化硫黄放出率は各火口の状態を反映していると考えられるため,複数火口が存在する火山でそれらの放出率を個別に測定する事は噴火活動を理解する上で非常に有用である.観測は2007年から2010年に行われた.その結果,昭和火口の放出率は数百トンから数千トンレベルで大きく変動したが,南 …

    BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN 58(1), 183-189, 2013

    J-STAGE  References (19)

  • Volcanic CO2 flux from Japan Arcs  [in Japanese]

    Shinohara Hiroshi

    日本の火山からのCO2の放出量を、火山ガスSO2放出量の集計値と大量に火山ガスを放出している継続脱ガス火山での火山ガス組成測定の結果を基に推定した。推定された火山ガスCO2/SO2比は1.1で、既存の推定値(2.2-6.5)より大幅に低い。CO2放出量は4500 ton/d (or 37 Tmol/y)と推定される.本研究での推定値は高放出量の火山ガス組成から求められた実測値に近い推定値であり、既 …

    Abstracts of Annual Meeting of the Geochemical Society of Japan 59(0), 82, 2012

    J-STAGE 

  • Soil radon flux and concentrations in hydrothermal area of the Tatun Volcano Group, Northern Taiwan

    YANG TSANYAO FRANK , WEN HSIN-YI , FU CHING-CHOU , LEE HSIAO-FEN , LAN TEFANG FAITH , CHEN AI-TI , HONG WEI-LI , LIN SHIH-JUNG , WALIA VIVEK

    … <sup>222</sup>Rn (radon) is the major radioactive gas in volcanic area. … The study of radon concentration variations in volcanic areas has been considered as a useful tool to investigate the volcanic activity in one area. … Tatun Volcano Group, where close to Taipei basin and exhibits active fumaroles and hot springs, was chosen for first time systematical study of radon gas in Hsiao-You-Keng hydrothermal area of northern Taiwan. …

    GEOCHEMICAL JOURNAL 45(6), 483-490, 2011-12-01

    J-STAGE  References (56) Cited by (9)

  • A heating process of Kuchi-erabu-jima volcano, Japan, as inferred from geomagnetic field variations and electrical structure

    Kanda Wataru , Utsugi Mitsuru , Tanaka Yoshikazu , Hashimoto Takeshi , Fujii Ikuko , Hasenaka Toshiaki , Shigeno Nobuaki

    … A time series analysis has shown that the variations in the geomagnetic field since 2001 have a strong relationship to an increase in volcanic activity. … In the initial stage, high-temperature volcanic gases supplied from the deep-seated magma remained temporarily at the level around the lower part of the less permeable deep conductor since the ascent path had not yet been established. …

    Journal of Volcanology and Geothermal Research 189(1-2), 158-171, 2010-01-01

    IR  Cited by (1)

  • Imaging Density Distribution of a Big Object by Muography and its Application to the Analysis of Gas-liquid Two-phase Flow in a Conduit during Volcanic Eruption

    KOZONO Tomofumi , TANAKA Hiroyuki , KOYAGUCHI Takehiro

    … This paper reviews the principle of cosmic-ray muon radiography (muography) and its application to the analysis of gas-liquid two-phase flow in a conduit during volcanic eruption. … According to numerical modeling of gas-liquid two-phase flow in the volcanic conduit during a dome-forming eruption, magma porosity (i.e., density) inside the conduit largely changes depending on magma flux even if the porosity at the surface is kept low. …

    JAPANESE JOURNAL OF MULTIPHASE FLOW 24(1), 45-56, 2010

    J-STAGE 

  • Temporal variation in chemical composition of the volcanic plume from Aso volcano, Japan, measured by remote FT-IR spectroscopy

    MORI TOSHIYA , NOTSU KENJI

    … Remote measurements of chemical compositions of the Aso volcanic plume using an FT-IR spectral radiometer were carried out at the 1st crater of Mt. Nakadake, Aso volcano, Japan, for six times from 1996 to 2003. … We have succeeded in detecting 6 volcanic gas species (SO<sub>2</sub>, HCl, HF, CO, CO<sub>2</sub>, COS) using the InSb detector. …

    GEOCHEMICAL JOURNAL 42(1), 133-140, 2008-02-01

    J-STAGE  References (26)

  • Relationship between geological structure and helium isotopes in deep ground-water from the Osaka Basin: Application to deep groundwater hydrology

    MORIKAWA NORITOSHI , KAZAHAYA KOHEI , MASUDA HARUE , OHWADA MICHIKO , NAKAMA ATSUKO , NAGAO KEISUKE , SUMINO HIROCHIKA

    … Although this area shows no Quaternary volcanic activity, nearly upper mantle-like <sup>3</sup>He/<sup>4</sup>He ratio (1.1 × … The flux of mantle He through the Uemachi thrust fault into the aquifers in the east block (hanging wall of the fault) of the Osaka Basin will be smaller than those in the west block (foot wall), because mantle He through this fault encountered the aquifers in the west block and dissolved in this aquifer. …

    GEOCHEMICAL JOURNAL 42(1), 61-74, 2008

    J-STAGE 

  • Fluxes of volatiles (H2O, CO2, N2, Cl, F) from arc volcanoes

    FISCHER TOBIAS P.

    … The gas compositions of high temperature (>500°C) fumaroles are compiled and used to derive magmatic H<sub>2</sub>O/SO<sub>2</sub>, CO<sub>2</sub>/SO<sub>2</sub>, HCl/SO<sub>2</sub> … The estimate of F flux from arcs is two orders of magnitude smaller than the amount of F released from mid ocean ridges whereas the arc Cl flux exceeds the ridge flux. …

    GEOCHEMICAL JOURNAL 42(1), 21-38, 2008

    J-STAGE 

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