Buried large block revealed by gravity anomalies in the Tonankai and Nankai earthquakes regions, southwestern Japan

• Honda Ryo

  Graduate School of Natural Science and Technology, Kanazawa University

• Kono Yoshiteru

  Graduate School of Natural Science and Technology, Kanazawa University

抄録

We confirmed existence of a buried large block beneath seafloor off Cape Shionomisaki, Kii Peninsula, southwestern Japan, by improving marine gravity data. We found that the 1944 Tonankai and 1946 Nankai earthquakes occurred close to this block. The block is characterized by high gravity anomalies of 80 mGal larger than surrounding area with a diameter of about 40 km. Center of the anomaly is located 30 km off Cape Shionomisaki, southern end of the Kii Peninsula. This high gravity anomaly can be explained by existence of a higher density body with approximate thickness of 8 km just beneath the seafloor. This block coincides with the reported high velocity zone from recent seismic refraction survey in this area. Judging from seismic velocity, density, and geologic evidences, the block presumably consists of intruded acidic rocks, not seamount.

収録刊行物

• Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ

  Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ 57 (1), e1-e4, 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

• Gravity anomaly
• Cape Shionomisaki
• Nankai earthquake
• Tonankai earthquake

詳細情報

• CRID: 1390001206512454528
• NII論文ID: 130003781069
• NII書誌ID: AA11211921
• DOI: 10.1186/bf03351799
• ISSN: 18805981
• ISSN: 13438832
• NDL書誌ID: 7757433
• Web Site: http://hdl.handle.net/2297/41840
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7757433
• Web Site: https://link.springer.com/content/pdf/10.1186/BF03351799.pdf
• Web Site: https://link.springer.com/article/10.1186/BF03351799/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1186/BF03351799
• 本文言語コード: en
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