1978年5月18日海城6级地震前兆及区域地震活动特征

PRECURSORS AND REGIONAL SEISMICITY BEFORE THE HAICHENG EARTHQUAKE OF MAGNITUDE 6.0(MAY.18,1978)

摘要:

1978年5月18日海城6级强震发生在1975年2月4日海城7.3级大震的余震区内。和7.3级大震相比较,在6级地震前,也观测到地壳形变,重力和区域地震活动等中期异常变化。但是,临震异常现象少,没有记录到前震活动。

Abstract:

The Haicheng earthquake of magnitude 6.0(May.18,1978) took place in the aftershock region of the great earthquake (Feb.4,1975,M_s=7.3).In comparison with the anomalous changes before the great earthquake,the middle-term anomalous change in crustal deformation,gravity and region-al seismicity were observed,but there was a litter shor-term anomaly and no foreshock before the occurrence of Haicheng earthquake of 6.0.