2007年苏门答腊8．5级、8．3级地震强余震库仑破裂应力触发研究

Large aftershocks triggering by coulomb failure stress following the 2007 M_S8.5 and 8.3 Sumatra great earthquakes

2007年9月12日印尼苏门答腊发生了8.5级地震,9月13日其西北边又发生了8.3级地震,震后在附近还发生了一系列6级以上强震。该文依次计算了苏门答腊8.5级地震后各次地震前其所在主破裂面的库仑破裂应力变化。结果表明,2007年苏门答腊8.5级地震的后续强震都发生在库仑破裂应力显著增加区,其应力变化值均大于0.01 MPa,即后续强震可能都是被触发的。

A series of large aftershocks with magnitude larger than 6.0 occurred after the Sumatra Ms8.5 earthquake （Sep. 12, 2007）. The change of Coulomb failure stress on aftershock focal depth produced by all the earthquakes before each aftershock is calculated. The results show that the large aftershocks of the 2007 Ms8. 5 Sumatra earthquake occurred in areas of increscent stress, which is more than 0.01 MPa. Therefore, the aftershocks were probably triggered by the Coulomb failure stress change.