[关键词]
[摘要]
2011 年3 月日本MW7. 3 地震51h 之后,发生了东日本MW9. 0 地震并引发巨大灾难。地震学家多角度、多方法探讨了两次地震之间的关系,结果判断日本MW 7. 3 地震是东日本9. 0级地震的前震。本文计算了MW7. 3 前震和2005 ~ 2011 年沿日本海沟一系列7 级左右地震对MW9. 0 地震的静态库仑应力,结果显示其并未直接触发MW9. 0 主震,但对主震震中位置及周边区域的应力加载效应是明确的。利用Suito 等(2011)基于GPS 数据计算的板间地震滑移速率,分析了一般地震与有广义前震的地震在震后和同震释放能量的不同来分析2005 年以来日本海沟发生的5 次7 级左右地震与MW 9. 0 地震的关系。总的来说,日本MW 7. 3 地震是东日本MW9. 0 地震的前震,从长时间尺度的GPS 时间序列分析来看,2005 ~ 2011 年日本海沟一系列7 级左右地震可能是东日本MW9. 0 地震的广义前震。
[Key word]
[Abstract]
51 hours after the MW7. 3 earthquake,the Tohoku MW9. 0 earthquake,Japan in March 2011 occurred and caused a huge disaster. Seismologists used many different data and methods to discuss the relationship between these two earthquakes and the results showed that the MW7. 3 earthquake was a foreshock of the Tohoku MW9. 0 earthquake of Japan. We calculated the static coulomb stress of the MW7. 3 earthquake and the M7. 0-class sequence events,and the result shows both the MW7. 3 and the M7. 0-class sequence events did not trigger the Tohoku MW9. 0 earthquake directly,but the stress load effect to the main shock and peripheral zone was clear. In general,the MW7. 3 earthquake triggered the Tohoku MW9. 0 earthquake,Japan. We use the results of Suitor et al. ,(2011) which analyses the difference of the general earthquakes and the earthquake with the generalized foreshocks based on the GPS data and geodetic inversion. In terms of the long-term GPS time series,the M7. 0-class earthquakes from 2005 to 2011 might be regarded as the generalized foreshocks of the Tohoku MW9. 0 earthquake.
[中图分类号]
[基金项目]
地震行业科研专项(201208009)资助