库车坳陷中强地震发震规律打破成因初步分析

PRELIMINARY STUDY ON BREAKING SEISMIC LAW REASONS OF MEDIUM-STRONG EARTHQUAKES IN KUCHE DEPRESSION

库车地区自1970~2000年中强地震发震有着成准周期性和丛性特征,该地区后续中强地震打破这种规律。库车坳陷区中强地震与塔里木地块周边MS≥7.0地震发生有密切关联,两者都有一定的准周期性,但是两者的准周期性在后续都被打破。经研究发现库车坳陷的中强地震规律被打破与库车地区的3个小震群活动有一定的相关性,时间对应很明显;而有2个小震群活动又与库车-轮台地区采油气活动又有高度的相关性,另一个小震群活动则可能与克孜尔水库落成导致该地区的降雨量增加有关。

The occurrence of medium-strong earthquakes in Kuche area from 1970 to 2000 has characteristics of quasi periodicity and clustering, and the following medium-strong earthquakes in this area break this law. Medium-strong earthquakes in Kuche depression are closely related to MS≥7.0 earthquakes around Tarim block. Both of them have certain quasi periodicity, but their quasi periodicity is broken in the following. It is found that the regularity of medium-strong earthquakes in Kuche depression is broken, which has a certain correlation with the activities of three small earthquake swarms in Kuche area, and the corresponding time is obvious;the activities of two small earthquake swarms are highly correlated with the activities of oil and gas production in Kuche-Luntai area, and the activity of the other small earthquake swarm may be related to precipitation increase caused by Kizil reservoir.