中国大陆强震孕育深处的变形模式构建

Deep Deformation Pattern of Strong Earthquakes in China's Mainland

针对地震预测所面临的地球内部“不可入”和大地震“非频发”问题,对重复地震探测获得的孕震深处滑动速率与浅表观测的结果进行对比分析,采用空间换时间的方式初步构建了中国大陆强震孕育深处的变形模式;还通过一些强震事例展示了利用重复地震进行陆内断裂带深部变形的原位探测的优势,并提出应对断裂闭锁段和深浅构造变形差异显著地区的强震危险性加以深入研究。

In view of problems of the "inaccessible" deep Earth and "non-frequent" strong earthquakes in the earthquake prediction,this paper finalizes a deep deformation pattern of strong earthquake cycles in China's Mainland based on the comparative analysis of the slip rates inferred from repeating earthquakes and from surface GPS and geological data by piecing together slip rate‘snapshots’ from different stages of the earthquake cycle.Slip rate increases with depth and accelerated slip were thought to have preceded a number of recent large subduction zone earthquakes and the 2008 Wenchuan earthquake,and repeating earthquakes may document short-term precursory slip at depth.We suggest that slip rates at seismogenic depths are of critical importance in seismic hazard analysis.Repeating earthquakes can be regarded as "deep creepmeters" that measure the in-situ deep slip rate of active faults.The potential earthquake hazard of locked faults with unusually high inferred deep slip rates should be paid more attention.