紫坪铺水库区小地震震源机制研究  

RESEARCH ON FOCAL MECHANISM OF SMALL EARTHQUAKES IN ZIPINGPU RESERVOIR AREA

作　　者：胡先明[1] 张永久[1] 谢蓉华[1] 韩进[1] 邵玉平[1] 

机构地区：[1]四川省地震局,成都610041

出　　处：《地震地质》2009年第4期676-685,共10页Seismology and Geology

基　　金："十一五"国家科技支撑计划项目(2006BAC01B040201);国家科技支撑计划项目(2008BAC38B030202)共同资助

摘　　要：用紫坪铺水库专用台网的地震记录测定紫坪铺水库区262次小震震源机制参数,结果表明:节面I的优势方向与断裂走向展布一致性很好;库区地震断层有逆断层、正断层、左旋和右旋走滑断层,走滑断层占45%;库区断层66%陡峻,35%几近直立;受水库蓄水的影响,2006年7月1日后以走滑断层活动方式明显增多,水库地震群时段走滑断层活动方式表现突出。The focal mechanism parameters of 262 small earthquakes recorded by Zipingpu reservoir earth- quake monitoring network are calculated. The results show that the dominant strike of nodal plane I and rupture are in good consistency. There are reverse fault, normal fault, left-lateral and right-lateral strike-slip fault in the reservoir area and the percentage of strike-slip fault amounts to 45%. Of all the faults,66% are steep and 35% are almost vertical. As a result of the impact of reservoir impoundment, the strike-slip type faulting has obviously increased since 1 July 2006,and this type of faulting became dominant during the period of the reservoir earthquake swarm. Key words Zipingpu reservoir,small earthquake,focal mechanism solution,fault activity

关 键 词：紫坪铺水库 小地震 震源机制解 断层活动 

分 类 号：P315.9[天文地球—地震学]