HUSCAP logo Hokkaido Univ. logo

Hokkaido University Collection of Scholarly and Academic Papers >
理学院・理学研究院  >
雑誌発表論文等  >

Strain anomalies induced by the 2011 Tohoku Earthquake (Mw 9.0) as observed by a dense GPS network in northeastern Japan

EPS64-12_1231-1238.pdf6.35 MBPDF見る/開く

タイトル: Strain anomalies induced by the 2011 Tohoku Earthquake (Mw 9.0) as observed by a dense GPS network in northeastern Japan
著者: Ohzono, Mako 著作を一覧する
Yabe, Yasuo 著作を一覧する
Iinuma, Takeshi 著作を一覧する
Ohta, Yusaku 著作を一覧する
Miura, Satoshi 著作を一覧する
Tachibana, Kenji 著作を一覧する
Sato, Toshiya 著作を一覧する
Demachi, Tomotsugu 著作を一覧する
キーワード: Coseismic strain anomaly
2011 Tohoku Earthquake
structural heterogeneity
strain concentration zone
発行日: 2012年
出版者: Terra Scientific Publishing Company
誌名: Earth, Planets and Space
巻: 64
号: 12
開始ページ: 1231
終了ページ: 1238
出版社 DOI: 10.5047/eps.2012.05.015
抄録: We have evaluated an anomalous crustal strain in the Tohoku region, northeastern Japan associated with a step-like stress change induced by the 2011 off the Pacific coast of Tohoku Earthquake (Mw 9.0). Because the source area of the event was extremely large, the gradient of the observed eastward coseismic displacements that accompanied uniform stress change had a relatively uniform EW extension in northeastern Japan. Accordingly, the deformation anomaly, which is determined by subtracting the predicted displacement in a half-space elastic media from the observed displacement, should reflect the inhomogeneity of the rheology, or stiffness, of the crust. The difference of the EW extension anomaly between the forearc and backarc regions possibly indicates a dissimilarity of stiffness, depending on the crustal structure of the Tohoku region. The Ou-backbone range - a strain concentration zone in the interseismic period - shows an extension deficit compared with predictions. A low viscosity in the lower crust probably induced a relatively small extension. Meanwhile, the northern part of the Niigata-Kobe tectonic zone, another strain concentration zone, indicates an excess of extensional field. This is probably caused by a low elastic moduli of the thick sedimentation layer. The detection of strain anomalies in the coseismic period enables a new interpretation of the deformation process at strain concentration zones.
資料タイプ: article
出現コレクション:雑誌発表論文等 (Peer-reviewed Journal Articles, etc)

提供者: 大園 真子


本サイトに関するご意見・お問い合わせは repo at へお願いします。 - 北海道大学