Updated on 2024/10/02

写真a

 
YAKIWARA Hiroshi
 
Organization
Research Field in Science, Science and Engineering Area Associate Professor
Research Field in Science, Science and Engineering Area Graduate School of Science and Engineering (Science) Associate Professor
Title
Associate Professor

Degree

  • 博士（理学） ( 2001.3   九州大学 )

Research Interests

  • 火山体浅部プロセス，火山体構造，火山活動，地震活動

Research Areas

  • Natural Science / Solid earth sciences  / 観測火山学・地震学

Education

  • Kyushu University

    1994.4 - 1997.3

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    Country： Japan

  • Kagoshima University

    1992.4 - 1994.3

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    Country： Japan

Research History

  • Kagoshima University   Research Field in Science, Science and Engineering Area Graduate School of Science and Engineering (Science)   Associate Professor

    2018.10

  • Kagoshima University   Research Field in Integrated Studies, Integrated Arts and Sciences Area Research and Education Center for Natural Hazards, Institute for Regional Co-creation in Southern Kyusyu and the Nansei Islands   Associate Professor

    2018.4

  • Kagoshima University

    1997.4

  • Kagoshima University   Research Field in Science, Science and Engineering Area Graduate School of Science and Engineering (Science) Nansei-Toko Observatory for Earthquakes and Volcanoes   Assistant Professor

    1997.4 - 2018.3

Professional Memberships

  • American Geophysical Union

    2015.10

  • 鹿児島県地学会

    2015.10

  • 日本地震学会

    2015.10

  • 日本火山学会

    2015.10

Qualification acquired

  • 第二級海上特殊無線技士

  • Small Craft Control Person

  • Usual Car License (first kind)

 

Papers

  • Tashiro Haruna, Yakiwara Hiroshi .  Peak frequency of harmonic tremor accompanied with volcanic activity at the Showa crater of the Sakurajima volcano .  BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN68 ( 2 ) 75 - 82   2023.6Peak frequency of harmonic tremor accompanied with volcanic activity at the Showa crater of the Sakurajima volcanoReviewed

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    Language：Japanese   Publisher：The Volcanological Society of Japan  

    <p>We investigated temporal changes in the peak frequency of harmonic tremors accompanied by eruptions at the Showa crater of the Sakurajima volcano from January 1 to September 30, 2015. The peak frequency characteristics of harmonic tremors at the summit crater of Minamidake from 1982 to 2002 were also compared. We calculated the running spectrum of the harmonic tremors of eruptions at the Showa crater and detected their peak frequency based on the findings of Maryanto <i>et al.</i> (2008) by modifying the parameters. Based on the value of peak frequency and associated temporal changes, we classified harmonic tremors at the Showa crater into the following three types: nearly constant (NC), positive gliding (PG), negative gliding (NG), and others. A sharp transition, with abrupt peak frequency of the harmonic tremor changes over a brief period, was also observed at the Showa crater. Assuming that the fundamental frequency corresponds to changes in the length of the gas pocket, the length of the gas pocket was estimated to change from 110 m to 220 m at the Showa crater. Compared with the features of peak frequencies of harmonic tremors at the summit crater of Minamidake (Maryanto <i>et al.</i>, 2008), those at the Showa crater present three differences: 1) Compared with HTB of the summit crater of Minamidake (Maryanto <i>et al.</i>, 2008), Depending on the event, NC values had different frequency bands at the Showa crater. HTBs occur several hours after swarms of B-type earthquakes and their peak frequencies remained within a certain range (Maryanto <i>et al.</i>, 2008). 2) The increase in <i>f</i><sub>0</sub> of PG at the Showa crater was smaller than that of HTE at the summit crater of Minamidake. HTEs occur several minutes after an eruption, as well as accompanying remarkably strong eruptions and their peak frequencies showed a gradual increase (Maryanto <i>et al.</i>, 2008). 3) NG and sharp transitions were only recognized in harmonic tremors during volcanic activity at the Showa crater.</p>

    DOI： 10.18940/kazan.68.2_75

  • Miyamachi Hiroki, Kobayashi Reiji, Yakiwara Hiroshi .  Short-time Seismic Swarm Activity in the Wakamiko Caldera in August, 2020 .  BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN67 ( 4 ) 471 - 478   2022.12Short-time Seismic Swarm Activity in the Wakamiko Caldera in August, 2020Reviewed

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    Language：Japanese   Publisher：The Volcanological Society of Japan  

    <p>We carried out a temporary seismic observation using 4 ocean bottom seismographs in and around the Aira caldera to obtain the precise hypocenter distribution, especially in the Wakamiko caldera. During the observation period from July to September 2020, we observed two short-time seismic swarms that occurred inside the Wakamiko caldera and revealed the precise distribution of these hypocenters and the focal mechanism solution. In contrast to our results, the JMA unified hypocenters of the two swarms are widely distributed in the western region outside the Wakamiko caldera. This difference in the hypocenter distributions insists that the seismic observation in the sea area around the Wakamiko caldera is required to reveal the precise seismic activity in the caldera.</p>

    DOI： 10.18940/kazan.67.4_471

  • YANAGIDA Hirotsugu, NAKATANI Yukihiro, YAKIWARA Hiroshi, HIRANO Shuichiro, KOBAYASHI Reiji, YAMASHITA Yusuke, MATSUSHIMA Takeshi, SHIMIZU Hiroshi, UCHIDA Kazunari, UMAKOSHI Kodo, YAGI Mitsuharu, MORII Yasuhiro, NAKAHIGASHI Kazuo, SHINOHARA Masanao .  Aftershock Activity of the 2015 <i>M</i> 7.1 Earthquake and Back-Arc Rifting in the Northern Okinawa Trough .  Zisin (Journal of the Seismological Society of Japan. 2nd ser.)75 ( 0 ) 29 - 41   2022.4Aftershock Activity of the 2015 <i>M</i> 7.1 Earthquake and Back-Arc Rifting in the Northern Okinawa TroughReviewed

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    Language：Japanese   Publisher：SEISMOLOGICAL SOCIETY OF JAPAN  

    <p>A magnitude 7.1 earthquake occurred west off Satsuma Peninsula, Japan in 2015, which was the largest earthquake ever recorded in the northern Okinawa Trough (OT). The northern OT is assumed to be in a beginning stage of a back-arc rifting that drives crustal extension, and the occurrence of the 2015 mainshock-aftershock sequence might be associated with such tectonics. In order to understand the rifting process that controls the seismicity, we precisely determined hypocenters and focal mechanisms of the aftershocks listed in the Japan Meteorological Agency catalog using both offshore and onshore seismic data. Initial hypocenters were determined using manual picks of P and S phases and a 1-D velocity structure. We then applied station correction terms to the P- and S-arrival times so as to consider low-velocity sedimentary layers beneath each station, especially beneath the offshore stations. Finally, the relative hypocenters were refined by the double-difference location method. The average root-mean-square residuals of the double differences decreased from 489 ms to 39 ms. The relocated hypocenter distribution clearly shows three linear alignments: one in the N95°E direction, consisting of left-lateral strike-slip fault events, and two in the N15-20°E direction, consisting of normal fault events. The tension axes for almost all the solutions lie in a common direction (NW-SE). The well-determined aftershocks mainly located in the upper crust with focal depths of 0-15 km. The results from our ocean-bottom seismic observation indicate that the two alignments consisting of normal fault events might be caused by crustal extension related to the back-arc rifting in the northern OT because the direction of the hypocenter distribution is consistent with the strike of the existing normal faults imaged by the multichannel seismic reflection survey. The left-lateral strike-slip fault alignment could be explained by along-axis variations in the back-arc spreading rate and presence of a transcurrent fault.</p>

    DOI： 10.4294/zisin.2021-12

  • TAMEGURI Takeshi, YAKIWARA Hiroshi, TSUTSUI Tomoki, IGUCHI Masato .  High Resolution Three-dimensional Seismic Velocity Imaging below Aira Caldera .  BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN67 ( 1 ) 69 - 76   2022.3High Resolution Three-dimensional Seismic Velocity Imaging below Aira CalderaReviewed

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    Language：Japanese   Publisher：The Volcanological Society of Japan  

    <p>We obtain a three-dimensional seismic velocity structure below the Aira caldera at a depth shallower than 15 km, southwest Japan, applying seismic tomography inversion method to analyze 14,652 P-wave onsets and 10,935 S-wave onsets of natural earthquakes observed by 45 seismic stations, and 3,121 P-wave onsets generated by artificial explosions. An anomalous zone of low S-wave velocity is discriminated at depths deeper than 12 km below the center of the Aira caldera. The S wave velocity is 18-55 % lower than the surrounding area. The volume of the anomalous zone is 139～255 km<sup>3</sup> at shallower depths than 15 km, and the anomalous zone includes about 7 % melt (10～18 km<sup>3</sup>). Accumulation of magma in the anomalous zone activates a pressure source at the top of the zone, where velocity contrast of the S-wave is intense, and the pressure source induces inflationary ground deformation around the Aira caldera.</p>

    DOI： 10.18940/kazan.67.1_69

  • Tagami A., Matsuno M., Okada T., Sakai S., Ohzono M., Katsumata K., Kosuga M., Yamanaka Y., Katao H., Matsushima T., Yakiwara H., Hirahara S., Kono T., Hori S., Matsuzawa T., Kimura S., Nakayama T. .  Stress field in northeastern Japan and its relationship with faults of recent earthquakes .  Earth, Planets and Space76 ( 1 )   2024.12

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    Language：Japanese   Publisher：Earth, Planets and Space  

    Inversion tectonics, in which old normal faults act as reverse faults in current stress fields, are frequently observed in northeastern Japan (Tohoku District); however, the conditions that control these fault activities remain unclear. To improve the identification of faults that are more favorable to slip under current stress conditions, the regional fault mechanisms in the Tohoku District must be better understood. The stress field in the Tohoku District and the likelihood of fault activities were thus estimated using slip tendency (ST) analysis. The results show that in the eastern margin of the Japan Sea (EMJS), the reverse fault type is dominant in the stress field. The maximum horizontal direction changes clockwise from E–W to NW–SE from the northern to the southern regions and counterclockwise from NW–SE to E–W from the Japan Sea to the inland area. In the Tohoku inland area, the estimated direction of the maximum horizontal axis changed after the 2011 Tohoku-Oki earthquake, from E–W to WNW–ESE. ST values were calculated for seven events in the EMJS area. To avoid the influence of the Tohoku-Oki earthquake, only stress field data prior to the 2011 Tohoku-Oki earthquake were used to determine ST values for four of the events in the Tohoku inland area. The results showed eastward-dipping fault planes with low dip angles (approximately 30°–45°) and large ST values (approximately > 0.7). The large ST values indicate that the stress field fault is favorable to slip and the results were consistent with the actual fault plane in the EMJS area. However, in the Tohoku inland area and the southern part of fault model of the 1993 Hokkaido Nansei-Oki earthquake, fault planes with large ST values were found to be inconsistent with the slipped fault plane, thus indicating that slipping was unfavorable. The regional differences are consistent with the volcano distribution and thus, the fluid supply from volcanic activity may have helped the fault slip under difficult stress conditions. Graphical Abstract: (Figure presented.)

    DOI： 10.1186/s40623-024-01986-w

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  • Miyamachi H., Yakiwara H., Kobayashi R., Hirano S., Kubo T., Souda M., Sakao K., Unno N., Matsushima T., Uchida K., Miyamachi R., Isoda K., Teguri Y., Kamiya Y., Triahadini A., Shimizu H., Katao H., Shibutani T., Tameguri T., Yamashita Y., Miura T., Nakagawa J., Yoneda I., Kato S., Takishita K., Nakai K., Maeda Y., Watanabe T., Horikawa S., Matsushiro K., Okuda T., Tsuji S., Sogawa N., Hasegawa D., Nakahigashi K., Kurashimo E., Yamada T., Abe H., Ando M., Tanaka S., Ikezawa S., Iwasaki T., Shinohara M., Sato T., Yamamoto M., Azuma R., Hirahara S., Nakayama T., Suzuki S., Otomo S., Hino R., Tsutsui T., Inoue Y., Takei R., Tada Y., Takahashi H., Murai Y., Aoyama H., Ohzono M., Shiina T., Takada M., Ichiyanagi M., Yamaguchi T., Ono N., Saito K., Ito C., Susukida Y., Nakagaki T., Tanaka Y., Akinaga Y. .  Solidified magma reservoir derived from active source seismic experiments in the Aira caldera, southern Kyushu, Japan .  Earth, Planets and Space75 ( 1 )   2023.12

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    Language：Japanese   Publisher：Earth, Planets and Space  

    The Aira caldera, located in southern Kyushu, Japan, originally formed 100 ka, and its current shape reflects the more recent 30 ka caldera-forming eruptions (hereafter, called the AT eruptions). This study aimed to delineate the detailed two-dimensional (2D) seismic velocity structure of the Aira caldera down to approximately 15 km, by means of the travel-time tomography analysis of the seismic profile across the caldera acquired in 2017 and 2018. A substantial structural difference in thickness in the subsurface low-velocity areas in the Aira caldera between the eastern and western sides, suggest that the Aira caldera comprises at least two calderas, identified as the AT and Wakamiko calderas. The most interesting feature of the caldera structure is the existence of a substantial high-velocity zone (HVZ) with a velocity of more than 6.8 km/s at depths of about 6–11 km beneath the central area of the AT caldera. Because no high ratio of P- to S-wave velocity zones in the depth range were detected from the previous three-dimensional velocity model beneath the AT caldera region, we infer that the HVZ is not an active magma reservoir but comprises a solidified and cool remnant. In addition, a poorly resolved low-velocity zone around 15 km in depth suggests the existence of a deep active magma reservoir. By superimposing the distribution of the known pressure sources derived from the observed ground inflation and the volcanic earthquake distribution onto the 2D velocity model, the magma transportation path in the crust was imaged. This image suggested that the HVZ plays an important role in magma transportation in the upper crust. Moreover, we estimated that the AT magma reservoir in the 30 ka Aira caldera-forming eruptions has the total volume of 490 km3 DRE and is distributed in a depth range of 4–11 km. Graphical Abstract: [Figure not available: see fulltext.]

    DOI： 10.1186/s40623-023-01919-z

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  • Tameguri Takeshi, Yakiwara Hiroshi, Tsutsui Tomoki, Iguchi Masato .  Seismic velocity imaging below Aira caldera .  PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN2022 ( 0 ) 69 - 69   2022Seismic velocity imaging below Aira caldera

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    Language：Japanese   Publisher：The Volcanological Society of Japan  

    DOI： 10.18940/vsj.2022.0_69

  • Tashiro Haruna, Yakiwara Hiroshi .  Peak frequencies of harmonic tremor accompanied with volcanic activity at the Showa Crater of the Sakurajima volcano .  PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN2022 ( 0 ) 65 - 65   2022Peak frequencies of harmonic tremor accompanied with volcanic activity at the Showa Crater of the Sakurajima volcano

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    Language：Japanese   Publisher：The Volcanological Society of Japan  

    DOI： 10.18940/vsj.2022.0_65

  • Susukida Y., Katsumata K., Ichiyanagi M., Ohzono M., Aoyama H., Tanaka R., Takada M., Yamaguchi T., Okada K., Takahashi H., Sakai S., Matsumoto S., Okada T., Matsuzawa T., Miyamachi H., Hirano S., Yamanaka Y., Horikawa S., Kosuga M., Katao H., Iio Y., Nagaoka A., Tsumura N., Ueno T., Katsumata K., Ohzono M., Aoyama H., Tanaka R., Takada M., Yamaguchi T., Okada K., Takahashi H., Sakai S., Miyakawa K., Tanaka S., Ando M., Okada T., Matsuzawa T., Uchida N., Azuma R., Takagi R., Yoshida K., Nakayama T., Hirahara S., Terakawa T., Yamanaka Y., Maeda Y., Hirano S., Yakiwara H., Maeda T., Iio Y., Nagaoka A., Shimazaki M., Ueno T., Asano Y. .  Focal mechanisms and the stress field in the aftershock area of the 2018 Hokkaido Eastern Iburi earthquake (MJMA = 6.7) .  Earth, Planets and Space73 ( 1 )   2021.12Reviewed

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    Language：Japanese   Publisher：Earth, Planets and Space  

    The tectonic stress field was investigated in and around the aftershock area of the Hokkaido Eastern Iburi earthquake (MJMA = 6.7) occurred on 6 September 2018. We deployed 26 temporary seismic stations in the aftershock area for approximately 2 months and located 1785 aftershocks precisely. Among these aftershocks, 894 focal mechanism solutions were determined using the first-motion polarity of P wave from the temporary observation and the permanent seismic networks of Hokkaido University, Japan Meteorological Agency (JMA), and High Sensitivity Seismograph Network Japan (Hi-net). We found that (1) the reverse faulting and the strike-slip faulting are dominant in the aftershock area, (2) the average trend of P- and T-axes is 78° ± 33° and 352° ± 51°, respectively, and (3) the average plunge of P- and T-axes is 25° ± 16° and 44° ± 20°, respectively: the P-axis is close to be horizontal and the T-axis is more vertical than the average of the P-axes. We applied a stress inversion method to the focal mechanism solutions to estimate a stress field in the aftershock area. As a result, we found that the reverse fault type stress field is dominant in the aftershock area. An axis of the maximum principal stress (σ1) has the trend of 72° ± 7° and the dipping eastward of 19° ± 4° and an axis of the intermediate principal stress (σ2) has the trend of 131° ± 73° and the dipping southward of 10° ± 9°, indicating that both of σ1- and σ2-axes are close to be horizontal. An axis of the minimum principal stress (σ3) has the dipping westward of 67° ± 6° that is close to be vertical. The results strongly suggest that the reverse-fault-type stress field is predominant as an average over the aftershock area which is in the western boundary of the Hidaka Collision Zone. The average of the stress ratio R = (σ1 − σ2)/(σ1 − σ3) is 0.61 ± 0.13 in the whole aftershock area. Although not statistically significant, we suggest that R decreases systematically as the depth is getting deep, which is modeled by a quadratic polynomial of depth.[Figure not available: see fulltext.]

    DOI： 10.1186/s40623-020-01323-x

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  • Shito A. .  3-D Intrinsic and Scattering Seismic Attenuation Structures Beneath Kyushu, Japan .  Journal of Geophysical Research: Solid Earth125 ( 8 )   2020.8

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    Publisher：Journal of Geophysical Research: Solid Earth  

    DOI： 10.1029/2019JB018742

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  • SHITO Azusa, NAKAMOTO Manami, MIYAMACHI Rintaro, ICHIYANAGI Masayoshi, OHZONO Mako, OKADA Kazumi, KATSUMATA Kei, TAKADA Masamitsu, TAKAHASHI Hiroaki, TANIOKA Yuichiro, YAMAGUCHI Teruhiro, MITSUOKA Ayaho, KOSUGA Masahiro, AZUMA Ryosuke, UCHIDA Naoki, EMOTO Kentaro, OHTA Yusaku, OKADA Tomomi, KAIDA Toshiki, KOZONO Tomofumi, SUZUKI Syuichi, TAKAGI Ryota, MATSUMOTO Satoshi, DEMACHI Tomotsugu, NAKAHARA Hisashi, NAKAYAMA Takashi, HIRAHARA Satoshi, MATSUZAWA Toru, MIURA Satoshi, YAMAMOTO Mare, IMANISHI Kazutoshi, UCHIDE Takahiko, YOSHIMI Masayuki, MATSUSHIMA Takeshi, AOI Shin, ASANO Youichi, UENO Tomotake, FUJITA Eisuke, ABE Eiji, IIDAKA Takashi, IWASAKI Takaya, KATO Aitaro, KURASHIMO Eiji, SAKAI Shin'ichi, AIZAWA Koki, SHIINA Takahiro, SERIZAWA Masato, TANAKA Shinichi, NAKAGAWA Shigeki, HIRATA Naoshi, MASUDA Masataka, MIYAKAWA Koji, YAGI Takeo, WATANABE Atsushi, GOTO Kazuhiko, SHIMIZU Hiroshi, ITO Takeo, OKUDA Takashi, TERAKAWA Toshiko, HORIKAWA Shinichiro, MAEDA Yuta, MATSUHIRO Kenjiro, YAMANAKA Yoshiko, WATANABE Toshiki, IIO Yoshihisa, KATAO Hiroshi, UCHIDA Kazunari, KANO Yasuyuki, TSUDA Hiroo, MIURA Tsutomu, MURAMOTO Tomoya, YAMASHITA Yusuke, OKUBO Makoto, YAMASHINA Tadashi, OHKURA Takahiro, NAKAO Shigeru, HIRANO Shuichiro, KAMIZONO Megumi, MIYAMACHI Hiroki, YAKIWARA Hiroshi, TEGURI Yoshiko .  Urgent Joint Seismic Observation Data of the 2016 Kumamoto Earthquakes .  Zisin (Journal of the Seismological Society of Japan. 2nd ser.)73 ( 0 ) 149 - 157   2020Reviewed

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    Publisher：SEISMOLOGICAL SOCIETY OF JAPAN  

    DOI： 10.4294/zisin.2019-11

  • Katsumata K. .  The 2018 Hokkaido Eastern Iburi earthquake (MJMA = 6.7) was triggered by a strike-slip faulting in a stepover segment: insights from the aftershock distribution and the focal mechanism solution of the main shock .  Earth, Planets and Space71 ( 1 )   2019.12Reviewed

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    Publisher：Earth, Planets and Space  

    DOI： 10.1186/s40623-019-1032-8

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  • Katakami, S., Yamashita, Y., Yakihara, H., Shimizu, H., Ito, Y., and Ohta,K .  Tidal response in shallow tectonic tremors. .  Geophysical Research Letters44   9699 - 9706   2017.10Tidal response in shallow tectonic tremors.Reviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • Hiroshi Yakiwara, Shuichiro Hirano, Yusuke Yamashita, Hiroshi Shimizu, Kazunari Uchida,Kodo Umakoshi, Kazuo Nakahigashi, Hiroki Miyamachi, Mitsuharu Yagi, Hisao Kanehara, Shigeru Nakao .  Seismic Observations using Ocean Bottom Seismometers around Kuchierabujima Volcano .  Journal of Natural Disaster Science38 ( 1 ) 119 - 131   2017.7Seismic Observations using Ocean Bottom Seismometers around Kuchierabujima VolcanoReviewed

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    Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

  • Taishi Yamada, Hiroshi Aoyama, Takeshi Nishimura, Hiroshi Yakiwara, Haruhisa Nakamichi, Jun Oikawa, Masato Iguchi, Muhamad Hendrasto, Yasa Suparman .  Initial phases of explosion earthquakes accompanying Vulcanian eruptions at Lokon-Empung volcano, Indonesia .  Journal Volcanology and Geothermal Research327   310 - 321   2016.8Initial phases of explosion earthquakes accompanying Vulcanian eruptions at Lokon-Empung volcano, IndonesiaReviewed

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    Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier  

  • Yuta Maeda, Koshun Yamaoka, Hiroki Miyamachi, Toshiki Watanabe,Takahiro Kunitomo, Ryoya Ikuta, Hiroshi Yakiwara, and Masato Iguchi .  A subsurface structure change associated with the eruptive activity at Sakurajima Volcano, Japan, inferred froman accurately controlled source .  Geophysical Reseach Letters42   5179 - 5186   2015.7A subsurface structure change associated with the eruptive activity at Sakurajima Volcano, Japan, inferred froman accurately controlled sourceReviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • Y. Yamashita, H. Yakiwara, Y. Asano,et al. .  Migrating tremor off southern Kyushu as evidence for slow slip of a shallow subduction interface .  Science348   676 - 679   2015.5Migrating tremor off southern Kyushu as evidence for slow slip of a shallow subduction interfaceReviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

    DOI： 10.1126/science.aaa4242

  • 及川輝樹, 八木原 寛, 高美喜男, 平野舟一郎, 中野 俊, 中尾 茂, 小林哲夫 .  トカラ列島南部，横当島，上ノ根島の噴気活動 .  火山58 ( 4 ) 563 - 567   2013.12トカラ列島南部，横当島，上ノ根島の噴気活動 Reviewed

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    Language：Japanese   Publishing type：Research paper (scientific journal)  

  • Takeshi Nishimura, Masato Iguchi, Hiroshi Yakiwara, Jun Oikawa, Ryohei Kawaguchi, Hiroshi Aoyama, Haruhisa Nakamichi, Yusaku Ohta, Takeshi Tameguri .  Mechanism of small vulcanian eruptions at Suwanosejima volcano, Japan, as inferred from precursor inflations and tremor signals .  Bulletin of Volcanology, Springer75   32.45902777777778 - 32.46666666666667   2013.11Mechanism of small vulcanian eruptions at Suwanosejima volcano, Japan, as inferred from precursor inflations and tremor signalsReviewed

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  • Hiroshi Yakiwara, Shuichiro Hirano, Hiroki Miyamachi, Tetsuro Takayama, Tomoya Yamazaki, Takeshi Tameguri, Masato Iguchi .  Semi-diurnal tidal periodicity observed by an ocean bottom seismometer deployed at a location very close to seafloor fumaroles in Wakamiko Caldera, northeast of Sakurajima Volcano .  Bull. Volcanol. Soc. Japan58   269 - 279   2013.3Semi-diurnal tidal periodicity observed by an ocean bottom seismometer deployed at a location very close to seafloor fumaroles in Wakamiko Caldera, northeast of Sakurajima VolcanoReviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • Hiroki Miyamachi, Chisato Tomari, Hiroshi Yakiawra, Masato Iguchi, Takeshi Tameguri, Keigo Yamamoto, Takahiro Ohkura, Takashi Ando,Kyosuke Onishi, Hiroshi Shimizu, Yusuke Yamashita, Haruhisa Nakamichi, Teruo Yamawaki, Jun Oikawa, Sadato Ueki, Tomoki Tsutsui, Hitoshi Mori, Makoto Nishida, Hideyuki Hiramatsu, Tomoyuki Koeda,Yoshirou Masuda, Kouji Katou, Kengo Hatakeyama, Tetsuo Kobayashi .  Shallow velocity structure beneath the Aira caldera and Sakurajima volcano as inferred from refraction analysis of the seismic experiment in 2008 .  Bull. Volcanol. Soc. Japan58   227 - 237   2013.3Shallow velocity structure beneath the Aira caldera and Sakurajima volcano as inferred from refraction analysis of the seismic experiment in 2008Reviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • Shigeru Nakao, Yuichi Morita, Hiroshi Yakiwara, Jun Oikawa, Hideki Ueda, Hiroaki Takahashi .  Volume change of the magma reservoir relating to the 2011 Kirishima Shinmoe-dake eruption—Charging, discharging and recharging process inferred from GPS measurements .  Earth, Planets, and Space65   505 - 515   2013Volume change of the magma reservoir relating to the 2011 Kirishima Shinmoe-dake eruption—Charging, discharging and recharging process inferred from GPS measurementsReviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • Masanao Shinohara, Yuya Machida, Tomoaki Yamada, Kazuo Nakahigashi, Takashi Shinbo, Kimihiro Mochizuki, Yoshio Murai, Ryota Hino, Yoshihiro Ito, Toshinori Sato, Hajime Shiobara, Kenji Uehira, Hiroshi Yakiwara, Koichiro Obana, Narumi Takahashi, Shuichi Kodaira, Kenji Hirata, Hiroaki Tsushima, Takaya Iwasaki .  Precise aftershock distribution of the 2011 off the Pacific coast of Tohoku Earthquake revealed by an ocean-bottom seismometer network .  Earth Planets Space64 ( 12 ) 1137 - 1148   2012.12Precise aftershock distribution of the 2011 off the Pacific coast of Tohoku Earthquake revealed by an ocean-bottom seismometer networkReviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • Paul Karson Alanis, Hiroki Miyamachi, Hiroshi Yakiwara, Kazuhiko Goto, Reiji Kobayashi, Takeshi Tameguri, Masato Iguchi .  Seismic velocity structre of the crust beneath the Aira caldera in southern Kyushu by tomography of travel times of local earthquake data .  Bull. Volcanol. Soc. Japan57   227 - 234   2012.12Seismic velocity structre of the crust beneath the Aira caldera in southern Kyushu by tomography of travel times of local earthquake dataReviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • Masanao Shinohara, Tomoaki Yamada, Kazuo Nakahigashi, Shin'ichi Sakai, Kimihiro Mochizuki, Kenji Uehira, Yoshihiro Ito, Ryusuke Azuma, Yuka Kaiho, Tetsuo No, Hajime Shiobara, Ryota Hino, Yoshio Murai, Hiroshi Yakiwara, Toshinori Sato, Yuya Machida, Takashi Shinbo, Takehi Isse, Hiroki Miyamachi, Koichiro Obana, Narumi Takahashi, Shuichi Kodaira, Yoshiyuki Kaneda, Kenji Hirata, Sumio Yoshikawa, Kazushige Obara, Takaya Iwasaki, Naoshi Hirata .  Aftershock observation of the 2011 off the Pacific coast of Tohoku Earthquake by using ocean bottom seismometer network .  Earth, Planets and Space63 ( 7 ) 841 - 845   2011.7Aftershock observation of the 2011 off the Pacific coast of Tohoku Earthquake by using ocean bottom seismometer network Reviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • Koki Aizawa, Wataru Kanda, Yasuo Ogawa, Masato Iguchi, Akihiko Yokoo, Hiroshi Yakiwara, Takayuki Sugano .  Temporal Changes in Electrical Resistivity at Sakurajima Volcano from Continuous Magnetotelluric Observations .  Journal of Volcanology and Geothermal Research199   165 - 175   2011.1Temporal Changes in Electrical Resistivity at Sakurajima Volcano from Continuous Magnetotelluric ObservationsReviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

  • 八木原 寛・井口正人・為栗 健・筒井智樹・及川 純・大倉敬宏・宮町宏樹 .  諏訪之瀬島の火山体浅部3次元P波速度構造と爆発発生場 .  火山55 ( 2 ) 75 - 87   2010.4諏訪之瀬島の火山体浅部3次元P波速度構造と爆発発生場Reviewed

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    Language：Japanese   Publishing type：Research paper (scientific journal)  

  • Masato Iguchi, Hiroshi Yakiwara, Takeshi Tameguri, Muhamad Hedrasto, Jun-ichi Hirabayashi .  Mechanism of explosive eruption revealed by geophysical observation at the Sakurajima, Suwanosejima and Semeru volcanoes .  Journal of Volcanology and Geothermal Research178   1 - 9   2008.1Mechanism of explosive eruption revealed by geophysical observation at the Sakurajima, Suwanosejima and Semeru volcanoesReviewed

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    Language：English   Publishing type：Research paper (scientific journal)  

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Books

  • 鹿児島湾奥部海域の繰り返し海底地震観測による桜島火山周辺の地震活動と上部地殻3次元地震波速度モデルとの比較

    八木原 寛, 平野舟一郎, 宮町宏樹, 高山鐵朗, 市川信夫, 為栗 健, 井口正人（ Role： Joint author）

    桜 島火山における多項目観測に基づく火山噴火準備過程解明のための研究（課題番号1809） 2012年   2014.2 

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    Language：Japanese Book type：Report

  • 海底地震観測からわかった2011 年東北地方太平洋沖地震の余震分布と応力変化

    村井芳夫，東 龍介，篠原雅直，町田,祐弥，山田知朗，中東和夫，真保 敬，望月公廣，日野亮太，伊藤喜宏，佐藤利典，塩原 肇，植平賢司，八木原 寛，尾鼻浩一郎，高橋成実，小平秀一，平田賢治，対馬弘晃，岩崎貴哉（ Role： Joint author）

    北海道大学地球物理学研究報告・北海道大学  2013.3 

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    Language：Japanese Book type：Report

  • 鹿児島湾奥部海域における繰り返し海底地震観測，および陸上地震観測網による桜島火山周辺の広域地震活動

    八木原 寛，平野舟一郎，宮町宏樹，高山鐵朗，市川信夫，為栗 健，井口正人（ Role： Joint author）

    桜島火山における多項目観測に基づく火山噴火準備過程解明のための研究（課題番号1809） 2011年  2013.2 

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    Language：Japanese Book type：Report

  • 桜島火山の周辺海域における繰り返し海底地震観測

    八木原寛，平野舟一郎，宮町宏樹，高山鐡朗，市川信夫，為栗健，井口正人（ Role： Joint author）

    桜島火山における多項目観測に基づく火山噴火準備過程解明のための研究・京都大学防災研究所附属火山活動研究センター  2011.12 

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    Language：Japanese Book type：Report

  • 鹿児島湾の桜島火山周辺海域における海底地震観測

    八木原 寛・平野舟一郎・宮町宏樹・高山鐵朗・市川信夫・為栗 健・井口正人（ Role： Joint author）

    桜島火山における多項目観測に基づく火山噴火準備過程解明のための研究・京都大学防災研究所附属火山活動研究センター  2010.8 

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    Language：Japanese Book type：Report

  • 若尊カルデラおよび桜島南方海域における海底地震観測

    八木原 寛・平野舟一郎・宮町 宏樹・井口 正人・為栗 健・高山 鐵朗・山崎 友也（ Role： Joint author）

    第10回 桜島火山の集中総合観測 平成19年6月～平成20年3月  2008.4 

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    Language：Japanese Book type：Report

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Presentations

  • 久保武史，八木原寛   火山性深部低周波地震の自動検出及び波動エネル ギー推定の試み  

    日本火山学会2019年度秋季大会 

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    Event date： 2019.9

    Language：Japanese   Presentation type：Poster presentation  

  • 海野直弘，八木原寛，仲谷幸浩，平野舟一郎   阿多カルデラ周辺の地殻の3 次元地震波速度構造， 及び加久藤カルデラ下の速度構造との比較  

    日本火山学会2019年度秋季大会 

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    Event date： 2019.9

    Language：Japanese   Presentation type：Oral presentation (general)  

  • 仲谷幸浩、八木原 寛、平野舟一郎、小林励司、宮町宏樹、中尾 茂、内田和也、松島 健、清水 洋、山下裕亮、中東和夫、山田知朗、阿部英二、篠原雅尚   南西諸島北部域における海底地震観測と検出された相似地震の特徴  

    日本地震学会2019年度秋季大会 

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    Event date： 2019.9

    Language：Japanese   Presentation type：Poster presentation  

  • 宮町宏樹、小林励司、八木原 寛、他   人工地震探査による南九州横断測線下の速度構造（4）  

    日本地震学会2019年度大会 

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    Event date： 2019.9

    Language：Japanese   Presentation type：Oral presentation (general)  

  • 八木原 寛、仲谷幸浩、平野舟一郎、小林励司、宮町宏樹、中尾 茂、山下裕亮、内田和也、松島 健、清水 洋、中東和夫、馬越孝道、阿部英二、池澤賢志、諏訪祥士、山田知朗、篠原雅尚   南西諸島北部の海域及び島嶼域における地震観測によるプレート境界面形状の推定 （6）  

    日本地震学会2019年度秋季大会 

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    Event date： 2019.9

    Language：Japanese   Presentation type：Poster presentation  

  • Youichi Asano, Kazuhiko Goto, Hiroshi Yakiwara, Shuichiro Hirano   Spatiotemporal distribution of regular and very low-frequency earthquakes in the northern part of the Ryukyu subduction zone  

    日本地球惑星科学連合2019年大会 

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    Event date： 2019.5

    Language：English   Presentation type：Poster presentation  

  • Hiroki Miyamachi, et al.   Seismic refraction and wide-angle reflection experiment in southern Kyushu, Japan: (3) the 2018 exploration report  

    日本地球惑星科学連合2019年大会 

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    Event date： 2019.5

    Language：English   Presentation type：Poster presentation  

  • 陳 冠宇，佐藤 利典，佐藤 智治，寺田 麻美，篠原 雅尚，望月 公廣，山田 知朗，植平 賢司，眞保 敬，小平 秀一，町田 祐弥，日野 亮太，東 龍介，村井 芳夫，伊藤 喜宏，八木原 寛，平田 賢治，橋間 昭徳，Andrew Freed   房総沖太平洋プレート内二重深発地震の発震機構：2011年東北地震後の時間変化  

    日本地球惑星科学連合2019年大会 

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    Event date： 2019.5

    Language：Japanese   Presentation type：Poster presentation  

  • Yukihiro Nakatani, Hiroshi Yakiwara, Shuichiro Hirano, Reiji Kobayashi, Hiroki Miyamachi Shigeru Nakao, Kazunari Uchida, Takeshi Matsushima, Hiroshi Shimizu, Kazuo Nakahigashi, Yusuke Yamashita, Hideji Abe, Tomoaki Yamada, Masanao Shinohara   Ocean bottom seismographic observation and similar earthquake detection in the northern part of the Nansei Islands  

    日本地球惑星科学連合2019年大会 

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    Event date： 2019.5

    Language：English   Presentation type：Poster presentation  

  • 八木原寛, 仲谷幸浩, 平野舟一郎, 小林励司, 宮町宏樹, 中尾茂, 馬越孝道, 内田和也, 松島健, 清水洋, 中東和夫, 山下裕亮, 阿部英二, 池澤賢志, 諏訪祥士, 山田知朗, 篠原雅尚   南西諸島北部の海域及び島嶼域における地震観測によるプレート境界面形状の推定（5）  

    日本地震学会　2018年秋季大会 

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    Event date： 2018.10

    Language：Japanese   Presentation type：Poster presentation  

    Venue：福島県郡山市  

  • 八木原寛, 平野舟一郎, 小林励司, 宮町宏樹, 中尾茂, 後藤和彦, 馬越孝道, 内田和也, 松島健, 清水洋, 中東和夫, 山下裕亮, 阿部英二, 池澤賢志, 諏訪祥士, 山田知朗, 篠原雅尚   南西諸島北部の海域及び島嶼域における地震観測によるプレート境界面形状の推定 (4)  

    日本地震学会2017秋季大会 

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    Event date： 2017.10

    Language：Japanese   Presentation type：Poster presentation  

  • 八木原寛，平野舟一郎，小林励司，宮町宏樹，中尾茂，後藤和彦，馬越孝道，内田和也，松島健，清水洋，中東和夫，山下裕亮，阿部英二，池澤賢志，諏訪祥士，山田知朗，篠原雅尚   南西諸島北部の海域及び島嶼域における地震観測によるプレート境界面形状の推定 (3)  

    日本地震学会2016秋季大会  （社）日本地震学会

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    Event date： 2016.10

    Language：Japanese   Presentation type：Poster presentation  

    Venue：名古屋国際会議場（名古屋市）  

  • 八木原寛，平野舟一郎，小林励司，宮町宏樹，馬越孝道，中東和夫，内田和也，清水洋，山下裕亮，阿部英二，山田知朗，篠原雅尚，中尾茂，後藤和彦   南西諸島北部の海域及び島嶼域における地震観測によるプレート境界面形状の推定 (2)  

    日本地震学会2015秋季大会  日本地震学会

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    Event date： 2015.10

    Language：Japanese   Presentation type：Poster presentation  

  • 八木原寛、平野舟一郎、中尾茂、小林励司、馬越孝道、中東和夫、内田和也、清水洋、山下裕亮、山田知朗、篠原雅尚、後藤和彦   南西諸島北部の海域及び島嶼域における地震観測によるプレート境界面形状の推定（１）  

    日本地震学会  日本地震学会

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    Event date： 2014.11

    Language：Japanese  

    Venue：新潟  

    国内学会

  • 八木原寛、平野舟一郎、宮町宏樹、高山鉄朗、市川信夫、為栗健   繰り返し海底地震観測による桜島火山周辺のVT 地震活動域と上部地殻3次元地震波速度モデルとの比較  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2014.5

    Language：Japanese  

    Venue：神奈川  

    国内学会

  • 八木原寛, 米良諒麻, 平野舟一郎, 後藤和彦, 中尾茂, 宮町宏樹   霧島火山周辺の上部地殻内３次元地震波速度構造（２）  

    日本火山学会  日本火山学会

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    Event date： 2013.9

    Language：Japanese  

    Venue：福島  

    国内学会

  • Hiroshi Yakiwara, Ryoma Mera, Syuichiro Hirano, Shigeru Nakao, Kazuhiko Goto, Hiroki Miyamachi   Three-dimensional seismic velocity structure of the upper crust beneath Kirishima Volcanoes derived from local earthquake data   International conference

    IAVCEI 2013  IAVCEI 2013

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    Event date： 2013.7

    Language：English  

    Venue：鹿児島  

    国際学会

  • 米良諒麻, 八木原寛, 平野舟一郎, 中尾茂, 後藤和彦, 宮町宏樹   霧島火山周辺の上部地殻内3 次元地震波速度構造  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2013.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 八木原寛，平野舟一郎，後藤和彦，中尾茂，宮町宏樹，松本聡   霧島火山周辺領域の起震応力軸分布の時間空間的な特徴  

    日本火山学会  日本火山学会

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    Event date： 2012.10

    Language：Japanese  

    Venue：長野  

    国内学会

  • 八木原寛, 後藤和彦, 平野舟一郎, 宮町宏樹, 中尾茂   地盤の膨張と同期して活発化した霧島火山周辺の広域地殻内地震活動  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2012.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 八木原寛，平野舟一郎，宮町宏樹，高山鉄朗，市川信夫，為栗健，井口正人   海底地震観測による桜島火山周辺海域の微小地震活動  

    日本火山学会  日本火山学会

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    Event date： 2011.5

    Language：Japanese  

    Venue：北海道  

    国内学会

  • 八木原寛，後藤和彦，平野舟一郎，宮町宏樹，中尾茂   最近10年間の霧島火山群周辺領域の地震活動と臨時地震観測  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2011.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 小川莉佳，八木原寛，岩本健吾，福井海世，平野舟一郎，中尾茂，後藤和彦   長期間にわたって静穏な口之島燃岳溶岩ドーム下の浅部で発生する極微小地震  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2011.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 八木原寛，為栗健，井口正人   諏訪之瀬島火山の爆発地震の震源計算に対する浅部３次元Ｐ波速度モデルの適用  

    日本火山学会  日本火山学会

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    Event date： 2010.10

    Language：Japanese  

    Venue：京都  

    国内学会

  • 為栗 健・井口 正人・寺石眞弘・大倉 敬宏・八木原 寛・宮町 宏樹   マグマ溜り周辺における歪集中の解明  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2010.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 植平 賢司・八木原 寛・山田 知朗・馬越 孝道・中尾 茂・小林 励司・後藤 和彦・宮町 宏樹・望月 公廣・中東 和夫・篠原 雅尚・金沢 敏彦・日野 亮太・合田 政次・清水 洋   海陸地震観測データから求めた日向灘南部の応力場  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2010.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 後藤 和彦・八木原 寛・平野 舟一郎   相似地震活動から推定された日向灘・南西諸島北部プレート境界域における準静的すべり  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2010.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 神田 径・笠谷 貴史・市原 寛・八木原 寛・橋本 武志・小山 崇夫・タンク ブレント・カヤ チュライ・小川 康雄・宇津木 充・井上 寛之・園田忠臣   姶良カルデラおよび周辺における電磁気構造調査(序報)  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2010.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 西村 太志・井口 正人・太田 雄策・喜多村 陽・青山 裕・鈴木敦生・及川 純・中道 治久・八木原 寛・為栗 健   諏訪之瀬島火山火口近傍における傾斜観測  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2010.5

    Language：Japanese  

    Venue：千葉  

    国内学会

  • 八木原寛，井口正人   火山体浅部速度トモグラフィーにおけるグリッドの配置についての考察―2005年諏訪之瀬島火山体構造探査への適用―  

    日本火山学会  日本火山学会

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    Event date： 2009.10

    Language：Japanese  

    Venue：小田原市  

    国内学会

  • 八木原寛，平野舟一郎，宮町宏樹，井口正人，為栗健，高山鉄朗，山崎友也   起潮力に対応する海底噴気孔近傍の地動振幅の時間変化－鹿児島湾の若尊カルデラ底におけるOBS観測  

    日本地球惑星科学連合  日本地球惑星科学連合

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    Event date： 2009.5

    Language：Japanese  

    Venue：千葉  

    国内学会

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Research Projects

  • 霧島火山西山麓地域の微小地震活動

    2018.4

    民間企業 

  • 九州南部の地震活動性の調査・研究

    2017.11

    国内共同研究 

  • 災害の軽減に貢献するための地震火山観測研究計画

    2014.4