High resolution 3-D velocity structure in the source region of the 2000 Western Tottori Earthquake in the southwestern Honshu, Japan using very dense aftershock observations

• Shibutani Takuo

  Disaster Prevention Research Institute, Kyoto University

• Katao Hiroshi

  Disaster Prevention Research Institute, Kyoto University

• Group of the 2000 Western Tottori Earthquake

  The members of the group are listed at the end of this paper.

書誌事項

タイトル別名

• High resolution 3-D velocity structure in the source region of the 2000 Western Tottori Earthquake in southwestern Honshu, Japan using very dense aftershock observations

抄録

We carried out high density aftershock observations a week after the 2000 Western Tottori Earthquake for 40 days. We deployed 72 seismic stations in and around the aftershock area. The average spacing of the stations in the aftershock area was 4-5 km. We determined accurate hypocenters and focal mechanisms for -1, 000 aftershocks and obtained a high resolution 3-D velocity structure in the source region. High P and S wave velocity anomalies (> 4%) near the southeasternmost aftershock area at 2 km depth correlated with Jurassic to Late Cretaceous plutonic and high pressure metamorphic rocks. The depth distribution of the P and S wave velocities along the mainshock fault showed that high velocity anomalies were located at the shallow southeastern edge and the deeper central part of the aftershock area. The ratio between P and S wave velocities in the high velocity anomalies was a little higher (-1.75) than the average value (-1.70) in the upper crust. These results indicate that the high velocity anomalies could correspond to the plutonic or metamorphic rocks. The distributions of the high velocity anomalies and large slips of the mainshock were complementary. These suggest that the high velocity anomalies could be stronger than the surrounding materials and might behave as barriers to the mainshock rupture.

収録刊行物

• Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ

  Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ 57 (9), 825-838, 2005

  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

• The 2000 Western Tottori Earthquake
• aftershock observation
• 3-D velocity structure
• aftershock distribution
• focal mechanisms

詳細情報

• CRID: 1390282681488306432
• NII論文ID: 10017470077
• NII論文ID: 130003781101
• NII書誌ID: AA11211921
• DOI: 10.1186/bf03351861
• ISSN: 18805981
• ISSN: 13438832
• NDL書誌ID: 7489924
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7489924
• Web Site: https://link.springer.com/content/pdf/10.1186/BF03351861.pdf
• Web Site: https://link.springer.com/article/10.1186/BF03351861/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1186/BF03351861
• 本文言語コード: en
• データソース種別:
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  • NDL
  • Crossref
  • CiNii Articles
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