This paper calculates the static Coulomb stress changes generated by four earthquakes in the Yutian area during 2008 ~ 2014 separately,then discusses the triggering influence,their accumulated Coulomb stress changes a...This paper calculates the static Coulomb stress changes generated by four earthquakes in the Yutian area during 2008 ~ 2014 separately,then discusses the triggering influence,their accumulated Coulomb stress changes and their influence on nearby faults.The results indicate that the M S5.5 earthquake in 2011 and the M_S7.3 earthquake in 2014 are both in the regions where the Coulomb stress change is positive,the stress changes are 0.004 MPa and 0.021 MPa, respectively, meaning they are triggered by prior earthquakes.The M S6.2 earthquake in 2012 occurred in the place where Coulomb stress change was negative,so it is postponed by the prior earthquakes.The image of Coulomb stress changes of the M S7.3 earthquake in 2014 is in accord with aftershocks( M L≥ 3.0)distribution,but some regions on the fault where the Coulomb stress change is positive have few aftershocks,and strong aftershocks may occur at these districts in future.In addition,this paper calculates the Coulomb stress change on nearby faults,and finds that the Coulomb stress changes of different elements in the GGC fault are very different,and must receive strong triggered-influence,though the result may be influenced by the input finite fault model,so there is still a large earthquake-risk.The GGN,PLC,PLW and LBW faults were also triggered by the four earthquakes occurring between 2008 ~ 2014.Their maximum Coulomb stress changes all exceed 0.002 MPa,so they also have a strong earthquake hazard.展开更多
基金funded by the National Key Technology R&D Program of China(2012BAK19B02)
文摘This paper calculates the static Coulomb stress changes generated by four earthquakes in the Yutian area during 2008 ~ 2014 separately,then discusses the triggering influence,their accumulated Coulomb stress changes and their influence on nearby faults.The results indicate that the M S5.5 earthquake in 2011 and the M_S7.3 earthquake in 2014 are both in the regions where the Coulomb stress change is positive,the stress changes are 0.004 MPa and 0.021 MPa, respectively, meaning they are triggered by prior earthquakes.The M S6.2 earthquake in 2012 occurred in the place where Coulomb stress change was negative,so it is postponed by the prior earthquakes.The image of Coulomb stress changes of the M S7.3 earthquake in 2014 is in accord with aftershocks( M L≥ 3.0)distribution,but some regions on the fault where the Coulomb stress change is positive have few aftershocks,and strong aftershocks may occur at these districts in future.In addition,this paper calculates the Coulomb stress change on nearby faults,and finds that the Coulomb stress changes of different elements in the GGC fault are very different,and must receive strong triggered-influence,though the result may be influenced by the input finite fault model,so there is still a large earthquake-risk.The GGN,PLC,PLW and LBW faults were also triggered by the four earthquakes occurring between 2008 ~ 2014.Their maximum Coulomb stress changes all exceed 0.002 MPa,so they also have a strong earthquake hazard.