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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
北海道大学地球物理学研究報告 = Geophysical bulletin of Hokkaido University >
第70号 >
臨時稠密地震観測で見えてきた有珠山の微小地震活動
| Title: | 臨時稠密地震観測で見えてきた有珠山の微小地震活動 |
| Other Titles: | Micro-earthquake activity at Usu volcano revealed by temporary dense observation |
| Authors: | 青山, 裕1 Browse this author →KAKEN DB | | 鬼澤, 真也2 Browse this author | | 為栗, 健3 Browse this author | | 鈴木, 敦生4 Browse this author | | 前川, 徳光5 Browse this author | | 大島, 弘光6 Browse this author | | 森, 濟7 Browse this author | | 橋本, 武志8 Browse this author | | 志賀, 透9 Browse this author | | 小山, 寛10 Browse this author | | 中橋, 正樹11 Browse this author | | 吉川, 章文12 Browse this author | | 福山, 由朗13 Browse this author |
| Authors(alt): | AOYAMA, Hiroshi1 | | ONIZAWA, Shin'ya2 | | TAMEGURI, Takeshi3 | | SUZUKI, Atsuo4 | | MAEKAWA, Tokumitsu5 | | OSHIMA, Hiromitsu6 | | MORI, Hitoshi7 | | HASHIMOTO, Takeshi8 | | SHIGA, Toru9 | | KOYAMA, Hiroshi10 | | NAKAHASHI, Masaki11 | | YOSHIKAWA, Akifumi12 | | FUKUYAMA, Yoshirou13 |
| Issue Date: | 15-Mar-2007 |
| Publisher: | 北海道大学大学院理学研究院自然史科学部門（地球物理学） |
| Journal Title: | 北海道大学地球物理学研究報告 |
| Journal Title(alt): | Geophysical bulletin of Hokkaido University |
| Volume: | 70 |
| Start Page: | 107 |
| End Page: | 121 |
| Abstract: | We performed temporary dense observation at Usu volcano in summer 2006, aiming to reveal micro-earthquake activity under the summit crater during dormant period of the volcanic activity. During about 80 days of temporary observation, more than 330 volcanic earthquakes were observed. Of these earthquakes, well-recorded 142 events are selected for relocation analysis assuming the 3D-velocity structure model which is a result of the explosion seismic experiment at Usu volcano in 2001. Following the result of relocation, we estimated focal mechanism of 7 earthquakes whose magnitudes are more than 1.0. The temporal observation and analyses gave us three new insights about seismic activity; 1) Continuous activity of volcanic earthquake is seen at the shallow part under the southern crater floor, 2) Hypocentral regions are distributed along the SW end of the U-shaped fault which was built in the 1977-1982 eruption associated with the uplift of Usu-Shinzan crypt dome, 3) Strike direction of the 7 major earthquakes are almost parallel to the U-shaped fault, and dominant mechanism is dip-slip type which suggests subsidence of summit domes relative to the southern crater floor. |
| Type: | bulletin (article) |
| URI: | http://hdl.handle.net/2115/20427 |
| Appears in Collections: | 北海道大学地球物理学研究報告 = Geophysical bulletin of Hokkaido University > 第70号
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