Evaluation of recent activity at Satsuma-Iwojima —Felt earthquake on June 8, 1996—

• Iguchi Masato

  Sakurajima Volcano Research Center, Disaster Prevention Research Institute of Kyoto University

• Saito Eiji

  Geological Survey of Japan

• Nishi Yuji

  Geological Survey of Japan

• Tameguri Takeshi

  Sakurajima Volcano Research Center, Disaster Prevention Research Institute of Kyoto University

書誌事項

タイトル別名

• Evaluation of recent activity at Satsuma-Iwojima -Felt earthquake on June 8, 1996-
• Evaluation of recent activity at Satsuma-Iwojima—Felt earthquake on June 8, 1996

抄録

Emission of large amount of volcanic gas occurs at the summit crater of Satsuma-Iwojima volcano located south of Kyushu, Japan. Sakurajima Volcanological Observatory (SVO), DPRI, Kyoto University has conducted seismic observation at a permanent station 1.5 km WNW of the summit crater since June 1995. Volcanic earthquakes at the volcano are classified into A-type (high frequency), B-type (low frequency), C-type (monochromatic) and tremor. A-type earthquake generated by shear fracture and B-type earthquake with volumetric source are dominant at the volcano. Volcanic activity of Satsuma-Iwojima was evaluated from seismicity of the volcanic earthquakes. During the period of 1995-1998, the seismicity has remained at a constant level with seismic energy release rate of 7×10¹⁴ erg/year. The seismicity was as high as that during 1975-1977. The energy release rate of volcanic earthquakes at the volcano has been stable at least for recent 20 years. Within the stable activity, a minor increase in activity occurred in mid-1990's, as shown by a felt earthquake (M2.9) on June 8, 1996. The earthquake on June 8, 1996 may be related to topographic changes and ground deformation around the summit crater, because a crack with length of 100 m was found at southeast rim of the summit crater in October 1996 and the benchmark near the crack moved eastward by 6 cm during the period from June 1995 to April 1997. The stable activity for 20 years and minor inflation of activity estimated from seismic observation coincides with those from SO₂ flux, highest fumarolic temperatures and gas equilibrium temperatures. Although daily number of B-type earthquakes with smaller amplitude increased almost 10 times in September 1998, this increase in the seismicity did not accompany any change of eruptive activity. Unstable seismicity of B-type earthquake may reflect fluctuations of condition in the gas conduit.

収録刊行物

• Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ

  Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ 54 (3), 187-195, 2002

  地球電磁気・地球惑星圏学会 、公益社団法人 日本地震学会、特定非営利活動法人 日本火山学会、日本測地学会、日本惑星科学会

キーワード

• Space and Planetary Science
• Geology

詳細情報

• CRID: 1390001206513526528
• NII論文ID: 10008634545
• NII論文ID: 130003956290
• NII書誌ID: AA11211921
• DOI: 10.1186/bf03353018
• ISSN: 18805981
• ISSN: 13438832
• NDL書誌ID: 6262930
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I6262930
• Web Site: https://link.springer.com/content/pdf/10.1186/BF03353018.pdf
• Web Site: https://link.springer.com/article/10.1186/BF03353018/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1186/BF03353018
• 本文言語コード: en
• データソース種別:
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