2011年東北地方太平洋沖地震(Mw 9.0)の本震記録と余震記録を用いた首都圏およびその周辺地域に於ける長周期地震動の特性  [in Japanese] Characteristics of Long-Period Ground Motions in the Tokyo Metropolitan Area and its Vicinity, by Recording Data of the 2011 Off the Pacific Coast of Tohoku Earthquake (Mw 9.0) and the Aftershocks  [in Japanese]

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Abstract

2011年東北地方太平洋沖地震の本震と余震の強震記録を用いて、首都圏および周辺地域に於ける周期2秒以上の地震動特性とサイト増幅特性を評価した。約650点の本震記録を用いたPGVとPGAから地震動が首都圏で複雑な分布を示すこと、擬似速度応答スペクトル分布から川崎~品川付近の東京湾沿岸部で周期2秒と3秒の速度応答が極めて大きいことが分かった。地表/地中の速度応答スペクトル比から算出したサイト増幅特性は、周期3秒以上の地震動に対して震源の位置に依存し、首都圏およびその周辺地域では東北地方の地震よりも長野県北部や静岡県東部の地震による地震動が大きく増幅されることが分かった。

We evaluated the characteristics of earthquake ground motions and site amplification factors for periods more than 2 seconds in the Tokyo Metropolitan Area and its vicinity, by the main shock and aftershocks of the 2011 off the Pacific coast of Tohoku Earthquake. The complex distribution of earthquake ground motions by PGV and PGA in the Tokyo Metropolitan Area were shown, using recording data of the main shock observed at seismic stations of about 650. Also, the pseudo velocity responses for periods of 2 and 3 seconds in Kawasaki to Shinagawa were extremely large. Site amplification factors, which were estimated by the ratio of velocity response spectra on surface to those in the seismic bed rock, have the azimuthal dependence to epicenter for periods more than 3 seconds. Long-period ground motions in the Tokyo Metropolitan Area were more largely amplified by earthquakes located in Northern Nagano Pref. and Eastern Shizuoka Pref. than those located in Tohoku Region.

Journal

  • Journal of Japan Association for Earthquake Engineering

    Journal of Japan Association for Earthquake Engineering 12(5), 5_102-5_116, 2012

    JAPAN ASSOCIATION FOR EARTHQUAKE ENGINEERING

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