Abstract:

In order to analyse the Coulomb failure stress change on the most likely ruptured fault at four large earthquake concerned zone which is delimited by multidisciplinary research on northeastern Tibetan Plateau, we set up a regional rock model by combining the Coulomb failure stress change in a layered viscoelastic media, which is resulted from 18 times M_s≥7 earthquake between 1920 to 2010 and the accumulative Coulomb failure stress caused by secular tectonic loading. Our study shows that the stress change of Xiqinling fault and Liupanshan fault earthquake concerned zone are both in status of accelerated accumulation, but the other two earthquake concerned zone are in status of accelerated unloading if the secular tectonic loading is not considered. According to the average recurrence intervals and the elapsed time of large earthquake, we consider that Xiqinling fault is needed to pay most attention, Haiyuan fault is in second and Dongkunlun fault is followed as well as Liupanshan fault.

Key words: northeastern Tibetan Plateau, Coulomb failure stress change, earthquake risk analysis, earthquakes