2013年四川芦山MS7.0地震近断层强地面运动模拟及烈度分布估计

2013年4月20日在我国四川省发生了芦山M_S7.0地震，地震给当地群众的生命财产安全带来了巨大的损失，其中最严重的破坏发生在震中附近的芦山、宝兴等地区.根据地震发生的快速反演结果，及发震断层面上滑动位移的分布情况，构建有限断层模型，对近断层区域的强地面运动进行初步计算，并基于强地面运动的模拟结果给出震区烈度分布的初步估计.模拟结果显示：模拟烈度图显示极震区的烈度在IX级左右，VI级烈度影响范围大致为16000 km²，该结果与中国地震局于4月27日给出的震区实测烈度图一致程度较高.强烈地震发生后，基于近断层强地面运动模拟计算的结果，可以给出相对合理的地震烈度分布情况估计，对震区震情判定及救灾工作具备较高的现实意义.

Estimation of the near-fault strong ground motion and intensity distribution of the 2013 Lushan,Sichuan, MS7.0 earthquake

The April 20, 2013 M_S7.0 earthquake in Lushan city, Sichuan province of China occurred as the result of east-west oriented reverse-type motion on a north-south striking fault. The source location suggests the event occurred on the Southern part of Longmenshan fault at a depth of 13 km. The Lushan earthquake resulted in a great loss of property and caused 196 deaths, and the Lushan city, nearby the epicenter was most seriously damaged. Considering the effect of slip distribution on the fault plane to near-fault strong ground motion, one finite fault source model was constructed based the comprehensive influence of three rupture processes and slip distributions of fault, respectively. We calculate the strong ground motion, including acceleration and velocity, near causative fault using the finite fault source model. Based on the simulated results of the near-fault strong ground motion, we described the intensity distribution of the Lushan earthquake field. The simulated intensity indicated that the maximum intensity value is IX, and the region of intensity VⅡ and above is almost 16000 km², which is consistent with observation intensity published online by China earthquake administration on April 25. In fact, the numerical modeling developed in this study has great application in the strong ground motion prediction and intensity estimation for the earthquake rescue purpose.