青藏高原东北缘4个强震重点监视区库仑破裂应力的近百年变化和危险性分析

针对青藏高原东北缘地区前人基于多学科研究资料圈定的4个未来强震重点监视区，构建了顾及到中下地壳黏弹性弛豫效应的区域岩石圈模型;考虑1920-2010年期间发生在本区域及其周边的18次Ｍ_s≥７级强震在这一区域的黏弹性静态库仑破裂应力变化，和长期构造背景加载下的应力积累情况，定量分析了每个重点监视区近百年来的库仑破裂应力变化，并在此基础上初步分析了各重点监视区的未来发震危险性程度。结果表明：西秦岭断裂带监视区和六盘山断裂带监视区均处于长期构造背景场和历史地震影响共同加载应力的状况；而海原断裂带监视区和东昆仑断裂带监视区，如果不考虑长期构造背景的应力加载，则处于地震影响的卸载状况。考虑到这4个重点监视区的大震平均复发周期及上次大震事件的离逝时间，认为西秦岭断裂带监视区的未来强震危险性程度最高，海原断裂带次之，然后是东昆仑断裂带和六盘山断裂带。

Coulomb Failure Stress and Earthquake Risk Analysis of Several Four Earthquake Concerned Zone on Northeastern Tibetan Plateau in Nearly Hundred Years

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.