日本东部内陆地区2011年大地震前后的应力状态与诱发地震

英文篇名：Stress before and after the 2011 great Tohoku-oki earthquake and induced earthquakes in inland areas of eastern Japan
中文刊名：国际地震动态
英文刊名：Recent Developments in World Seismology
作者：Keisuke Yoshida ; Akira Hasegawa ; Tomomi Okada ; Takeshi Iinuma ; Yoshihiro Ito ; Youichi Asano ; 洪启宇
英文作者：Keisuke Yoshida1) ; Akira Hasegawa1) ; Tomomi Okada1) ; Takeshi Iinuma1) ; Yoshihiro Ito1) ; Youichi Asano2)1) Research Center for Prediction of Earthquakes and Volcanic Eruptions ; Graduate School of Science ; Tohoku University ; Sendai ; Japan2) National Research Institute for Earth Science and Disaster Prevention ; Tsukuba ; Japan
出版日期：2012-04-25
机构：Research Center for Prediction of Earthquakes and Volcanic Eruptions,Graduate School of Science,Tohoku University,Sendai,Japan;National Research Institute for Earth Science and Disaster Prevention,Tsukuba,Japan;中国地震局地球物理研究所;
年：2012
期：04
出版单位：国际地震动态

摘要

通过反演震源机制数据,得到了东日本大地震前后日本东部内陆地区的应力场。地震前,在东北部(Tohoku),σ1轴呈EW方向,但在关东-东部(Kanto-Chubu)地区则呈NW-SE方向。地震后,在Tohoku北部和靠近磐城市(Iwaki City)的Tohoku东南部,应力场发生了变化,主应力取向大致等同于与地震相关的静应力变化取向。这说明地震前这些地区的差应力值小于1MPa。在Tohoku中部,虽然地震后加载的应力取向几乎逆转,但其应力场没有发生变化,说明那里的差应力值大大超过1MPa。在Kanto-Chubu,地震后加载了与背景应力方向近乎相同的应力,且应力场没有发生预期的变化。这可能就是Kanto-Chubu地区高地震活动水平的诱因。

引文

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