华北地区震前断层异常活动方式

分析了华北地区跨断层形变资料, 研究了唐山、 大同及张北地震前断层异常活动方式。 结果表明, 震前存在显著的断层异常活动; 断层异常活动方式具有构造控制特征,并与孕震机理有关; 地震孕育过程中有可能出现多次应力集中; 从断层不可逆异常活动地区的分布推测, 唐山地震缓解了延怀地区的地震危险性, 大同地震缓解了紫荆关-狼山断层一线的地震危险性; 张北地震断层异常活动呈松弛变化, 首都圈及邻近地区地震活动将趋于缓解。

Pattern of the fault movement before earthquakes in North China Region

In this paper, the authors have analyzed the cross-fault mobile geodetic deformation data and studied the pattern of the fault movement before the Tangshan, Datong and Zhangbei earthquakes. It is considered that faults have remarkable anomalous movement before earthquakes. It is considered that faults have remarkable anomalous movement before earthquakes. The anomalous pattern of the fault movement is of the tectonically controlled feature and also related to seismogenic mechanism. In the process of earthquake preparation, multiple stress concentration may occur. From the distribution of fault irreversible anomalous movement, we have inferred that the Tangshan earthquake has eased up the seismic risk in Yanqing-Huailai area, and the Datong earthquake eased off the seismic risk along Zijingguan-Langshan fault zone. The anomalous fault movement of the Zhangbei earthquake offered relaxation variation. The tendency of seismic risk in the Capital circle and its neighboring area will be relaxed.