2011 年東北地方太平洋沖地震の震源のモデル化  [in Japanese] Source Modeling of the 2011 Off the Pacific Coast of Tohoku Earthquake  [in Japanese]

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Abstract

2011年東北地方太平洋沖地震(Mw9.0)に対し、経験的グリーン関数法を用いたフォワードモデリングにより工学的に重要な0.1~10秒の周期帯を対象とした震源のモデル化を行った。結果として、宮城県沖から茨城県沖にかけて、5つの強震動生成域からなる震源モデルを提案した。得られた震源モデルにおける5つの強震動生成域は、これらの地域における地震調査研究推進本部による想定震源域内にほぼ含まれていること、強震動生成域のみの地震モーメントは総地震モーメントの5%程度であり、より周期の長い地震動、巨大津波及び地殻変動を説明する震源モデル(海溝軸側に大すべり領域)とは相補的であるとの結果が得られた。

The 2011 off the Pacific coast of Tohoku earthquake of 11 March 2011 occurred along the subduction zone plate boundary between the Pacific and North American plates along the Japan Trench. This earthquake caused the Great East Japan Earthquake Disaster. In this study, we try to estimate the source model by a forward-modeling approach based on the characterized source model using the empirical Green's function method. Based on the results, we proposed a source model composed of five strong motion generation areas (SMGAs) along the subduction zone plate boundary. The SMGAs were located in the sea off Miyagi Prefecture, south Iwate, Fukushima and Ibaraki Prefectures. Comparing synthetic waveforms calculated by the empirical Green's function method and the observed waveforms, it can be seen that the observed waveforms are well reproduced at each observation station. The total seismic moment of SMGAs is 5% of the seismic moment determined by the Japan Meteorological Agency.

Journal

  • Journal of Japan Association for Earthquake Engineering

    Journal of Japan Association for Earthquake Engineering 13(2), 2_75-2_87, 2013

    JAPAN ASSOCIATION FOR EARTHQUAKE ENGINEERING

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