青海省共和7.0级地震形成机制再研究

RESTUDY ON THE GENESIS FOR THE 1990 GONGHE MS7.0 EARTHQUAKE,QINGHAI PROVINCE

分析了龙羊峡水库区的地质、水文条件 ,研究了 1 990年共和MS7.0地震与龙羊峡水库蓄水过程的关系 .结果表明 ,龙羊峡水库的蓄水过程和水位变化与共和地震序列主震和强余震的时间分布、前兆场变化、形变场变化和测震学指标的变化呈对应关系 ,与国内外典型水库震例相似 ,说明共和 7.0级地震为龙羊峡水库诱发作用所致 。

Geological and hydrological conditions of Longyangxia reservoir region are analysed.Relationship between the Gonghe M S7.0 earthquake,1990 and water storage process of the reservoir is studied.The results show that distribution of main shock and strong aftershocks in Gonghe M S7.0 earthquake sequence with time,changes of precursory field, deformation field and some seismometry indexes are related to the water storage process and change of water level of the reservoir,being similar to typical reservoir earthquakes.It is proved that the Gonghe M S7.0 earthquake is induced by the Longyangxia reservoir and is an induced tectonic earthquake.