1668年郯城大地震震源断层三维特征反演  

3-D characteristics inversion of hypocenter fault-plane of the 1668 Tancheng great earthquake

作　　者：周翠英[1] 刁桂苓[2] 耿杰[1] 李永红[1] 许萍[1] 胡新亮[2] 冯向东[2] 李冬梅[1] 

机构地区：[1]山东省地震局,济南250014 [2]河北省地震局,石家庄050021

出　　处：《地球物理学进展》2013年第6期2814-2824,共11页Progress in Geophysics

基　　金：山东省自然科学基金(Y2005E02)项目资助

摘　　要：1668年在山东郯城附近发生的8(1/2)级巨大地震,是有史料记载以来发生在中国东部的最大地震.该地震发生在郯庐断裂带山东区段,震源区现代小震依然频繁.本文以震源区附近重新定位的百余个现今中小地震基本参数,反演得到1668年郯城8(1/2)级大震震源断层产状:震源断层走向21.6°,倾角为89.5°,滑动角为148.9°,震源断层长度约180 km,下界深度约为32 km,上界埋深约为4 km左右,为北北东走向直立的右旋近走滑断层.震源断层在地壳浅表对应沂沭断裂带东地堑的安丘—莒县断裂(F5).根据8(1/2)级大震地表地震断层和烈度分布研究成果对反演结果进行了分析,并结合震源区地震深度分布、地震波速度剖面等对8(1/2)级地震的基本参数进行了讨论,认为各种结果之间能够相互验证,反演获得了理想结果.研究证明,对于震源区现代中小地震资料丰富的历史大地震,用该方法反演震源断层三维产状和错动性质是可行的.The Tancheng M 8 1/2 great earthquake in 1668 was the largest seismic event recorded in history in eastern of China, which occurred in Shandong section of Tanlu fault zone, meanwhile, the small earthquakes at the hypocentral region are still frequent now. This study inversed and calculated the source fault＇s fracture form of the 1668 Tancheng 8 1/2 earthquake based on the basic parameters of more than 100 small and medium re-positioning earthquakes occurred in nowadays around the hypocentral region. We get the results as follows： the strike of source fault is 21.6, the dip angle is 89.5, the slip angle is 148.9, the fault length is about 180 km, the lower-boundary depth is about 32 km and the buried depth of upper boundary is about 4 km. All the parameters show that the focal fault is a NNE-trending upright right-lateral strike-slip fault. And the surface projection of source fault is basically coincident with Anqiu-Juxian fault which is located at eastern-graben of Yishu fault belt （F5）. The inversion is analyzed according to the results of the surface seismic fault and intensity distribution of 8 1/2 earthquake, and the basic parameters are discussed combining earthquake-depth distribution and seismic-wave velocity profile in the focal area and so on. They showed that all kinds of results could be verified by each other, and the inversion has reached the ideal results. This study indicated that, for the great earthquake region with abundant present-day seismic data, it is feasible to invert its fault characteristics.

关 键 词：郯城8 1 2 级地震 现今中小地震 区域应力场 应力主轴参数 震源断层面反演 

分 类 号：P315[天文地球—地震学]