Propagation of Slow Slip Leading Up to the 2011 Mw 9.0 Tohoku-Oki Earthquake
Propagation of Slow Slip Leading Up to the 2011 Mw 9.0 Tohoku-Oki Earthquake
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DOI：
10.1126/science.1215141
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发表时间：
2012-02-10
期刊：
影响因子：
56.9
通讯作者：
Hirata, Naoshi
中科院分区：
文献类型：
--
作者：
Kato, Aitaro;Obara, Kazushige;Hirata, Naoshi
许多大地震之前都有一个或多个前震，但目前还不清楚这些前震与主震的成核过程有何关系。在使用波形相关技术创建的地震目录的基础上，我们确定了两个不同的前震序列，这些前震以每天2到10公里的速度沿着海沟轴向2011年日本东北冲地震矩震级（M-W）9.0的震中迁移。准静态滑动沿着板块界面的时间历史，基于小的重复地震的迁移地震活动的一部分，表明两个序列涉及缓慢滑动瞬变传播向初始破裂点。第二个序列，其中涉及大的滑移率，可能会造成大量的应力加载，促使主震的不稳定动态破裂。
Many large earthquakes are preceded by one or more foreshocks, but it is unclear how these foreshocks relate to the nucleation process of the mainshock. On the basis of an earthquake catalog created using a waveform correlation technique, we identified two distinct sequences of foreshocks migrating at rates of 2 to 10 kilometers per day along the trench axis toward the epicenter of the 2011 moment magnitude (M-w) 9.0 Tohoku-Oki earthquake in Japan. The time history of quasi-static slip along the plate interface, based on small repeating earthquakes that were part of the migrating seismicity, suggests that two sequences involved slow-slip transients propagating toward the initial rupture point. The second sequence, which involved large slip rates, may have caused substantial stress loading, prompting the unstable dynamic rupture of the mainshock.