The Coseismic Coulomb Stress Changes Induced by the 2010 Mw 6.9 Yushu Earthquake,China and Its Implication to Earthquake Hazards

We here investigate the coseismic Coulomb stress change and seismicity rate induced by the 2010 Mw 6.9 Yushu earthquake in order to deepen our understanding of the behavior of stress triggering among its foreshock,mainshock and aftershocks and to further make an assessment of the occurrence of potential earthquakes in its surrounding region and on major active faults.Our results show that: 1) the pattern of aftershocks of the Mw 6.9 Yushu earthquake is consistent with the spatial distribution of coseismic Coulomb stress changes with an aftershock triggering rate of 76.47%;2)For this 2010 Yushu earthquake sequence of foreshock-mainshock-aftershock type,the Mw 4.9 foreshock has little contribution to the occurrence of the Mw 6.9 Yushu mainshock,whilst the triggering causality between the Mw 6.9 Yushu mainshock and the Mw 6.1 aftershock is well pronounced;3) the Coseismic Coulomb stress changes are loaded on the portions of Ganzi-Yushu fault such as the Dangjiang and Haxiu segments which have been ruptured by the 1738 M 7.5 earthquake and the Dengke segment of the 1896 M 7.3 earthquake as well as the southeastern unruptured extension from the end of the Mw 6.9 earthquake termination,and thus they all pose high earthquake hazards in the near future.