菏泽5.9级地震震源力学过程和前兆表现形式

本文运用水准测量资料反演了一九八三年菏泽5.9级地震的断层参数。由垂直形变资料反演得到的地震断层力学性质的讨论,说明菏泽地震是受近东西向主压应力的作用,破裂面是北西方向左旋剪切正断层。震前,震区受左旋剪切作用,极震区完整块体处于闭锁状态,大小满城断裂首先反映出这种剪切作用,在作用平缓的前几年,断裂产生蠕动;而在震前作用力强化时产生突变式的预位移。

Journal of Seismology APPLICATION OF THE SHOCK-LACKING METHOD IN SOUTH SHANDONG

By using the shock-lacking method, the earthquake data from three small regions of south shandong were analyzed statistically and respectively. Results show that before the occurrence of the three earthquakes (M_L>4.5) in the western region, there is the phenomenon of "Shocklacking" there for a long time. Among them, the appearance of the "Shocklacking" phenomenon before the occurrence of Heze earthquake (M_L=6.2 Nov. 7, 1983) had lasted for 11 months. There is the same phenomenon for Ning-jin earthquake (ML=6.3, Nov. 9, 1981). In the middle region, a good correspondence relations between the earthquake (M_L=4.0) and the Shock-lacking is still in existence but no such a phenomenon could be seen in the adjacent area. As for the east region, such a relation is also evidently in existence. At the end of the paper, the availability of the earthquake predication by the method recommended has been discussed and examined.