报告地点：教学行政楼1004会议室 腾讯会议(会议ID：411 4788 6096）
报告时间：2020-10-30 从 15:00 到 16:30
报告人：王丽凤
报告人简介：
2010年获德国鲁尔大学固体地球物理学博士学位，现为中国地震局地质研究所/地震动力学国家重点实验室研究员，构造物理实验室副主任。以第一作者发表的文章包括，Science Advances、J. Geophys. Res.、Geophys. J. Int.等，并评审J.Geophys. Res. Geophys. J. Int.、Tectonophysics等期刊论文。近年研究主要集中在，以GPS/InSAR等形变观测为基础的区域构造、断层运动学与动力学建模；以室内岩石实验为基础的地震物理建模；基于前二者的地震危险性研究。
报告题目：Exploring frictional property of San Andreas fault and the implication for seismic hazard
报告内容简介
Understanding the physical control along the fault is important from the perspective of both seismic hazard evaluation and fault zone rheology. Parkfield segment as a transition from creeping to locking along the San Andreas fault is marked by, besides the periodic M6 earthquakes, abundant deep low frequency earthquakes and deep slow slip event. In the framework of rate-and-state friction law, we use the long-term GPS data measured before, during and after the 2004 M6 earthquake to determine the frictional parameter. The data resolve apparent along-strike variation of friction parameter in the brittle upper crust [1]. On the other hand, the concurrent deep low frequency earthquake and slow slip event in Parkfield challenge our classical understanding of fault zone rheology, in which the middle crust is associated with stable creep preventing stress accumulation. However, taking shear heating during fault sliding into account, temperature-weakening effect in friction strength may lead to fault instability. Therefore, we consider rate-state-temperature dependent friction to model the deep fault behaviors in Parkfield. The results well explain the behavior of deep fault instabilities. The simulated deep faulting could locally rise the temperature by hundreds of degree, reaching the condition for partial melting of granite, which provides an alternative physical understanding for pseudotachylite observed below the seismogenic zone.