| 講演要旨(和文) | | 東海大学海洋学部では，海洋調査船望星丸を利用し，2009年から駿河湾で全磁力探査を継続的に実施している．駿河湾では，海上保安庁によって磁気探査が実施されているが2000年代になると磁気探査装置において技術革新が飛躍的に進みプロトン磁力計は，セシウム型磁力計，オーバーハウザー型磁力計と進化した．本研究データは，オーバーハウザー型磁力計を用いた東海地震震源域における精密な磁気的構造について紹介を行うものである． |
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| | 講演要旨(英文) | | In the year from 2009 to 2014, total geomagnetic and geological surveys by RV Bosei Maru, by School of Marine Science & Technology, Tokai University, were conducted in Suruga Bay located on the Pacific coast of central Japan. In the Suruga Bay area subducting Philippine Sea plate beneath SW Japan, we have some local magnetic anomalies in the overriding plate. A large thrust earthquake, referred to the Tokai earthquake, has been supposed soon to occur in this area (Ishibashi, 1981). The recent investigations of ship-borne survey conducted in this area are the geomagnetic anomaly data of the Hydrographic Department of the Maritime Safety Agency in 1997 and another data published by Honkura et al., 1999. The survey area in this study is 50 km x 35km in S-N and W-E directions, respectively. Total geomagnetic anomalies range from -200nT to +600nT. We carried out 2.5D inversion analyses for some positive high anomalies to reveal the dimensions of anomalous body, assuming uniform magnetization. As a result we present the features of those anomalous bodies in and around Suruga Bay. |
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