中原地区M≥6级地震后的减(增)震效应

An Earthquake-decreasing(increasing)Effect after the M≥6 Earthquakes in the area of Central Plains

通过对中原地区 15 0 0年～ 2 0 0 0年所有 19次M≥ 6级地震后空间图像的分析 ,初步认为M≥ 6级地震发生后平均 6 3年内 ,在距原震中平均 176km内无M≥ 5级地震发生 ,全部 19次震例均呈现出内部减震效应。而在其外围出现地震增强的活动图像特征 ,增震效应对应率为 72 %。这种强震后的减 (增 )震效应 ,不仅对地震危险性分析 ,而且对

It is considered that there is no M≥5 earthquake within a distance of 176km from the original epicenter in averaging 63 years after an M≥6 through a spatial pattern analysis of 19 M≥6 in 1500-2000 in Central Plains.An internal earthquake-decreasing effect appears for all 19 earthquakes.The corresponding ratio of the earthquake-increasing effect is 72% in the ambient active pattern.This kind of earthquake-decreasing(increasing)effect has a certain sense not only to the seismic risk analysis but ablso to the l-year or longer forecast of earthquake tendency.