云南地区强震前波速比、震源深度及中小地震活动的特征  

Characteristics of Wave-velocity Ratio,Focal Depth and Medium-small Seismicity before Strong Earthquakes in Yunnan

作　　者：李永莉[1] 毛慧玲[1] 王世芹[1] 秦嘉政[1] 

机构地区：[1]云南省地震局,昆明650224

出　　处：《地震研究》2010年第3期259-264,共6页Journal of Seismological Research

基　　金：云南省人民政府十项重大措施"云南强震活动与板缘动力学机制研究";中国地震局震情跟踪合同制定向工作任务"云南东部地区强地震短临动态跟踪研究"(2009010204)联合资助

摘　　要：分析了云南地区第四强震跃期内波速比的变化规律,探讨了强震孕育过程与波速变化、震源深度变化、中小地震活动的关系,结果表明:波速比异常、震源深度变化异常与3、4级中小地震活动的异常,最早出现于云南7级地震前4年左右,大多数异常集中出现于震前2年左右,表现为波速比、震源深度异常增多,震前1年左右异常则逐步减少;伴随着云南第四强震活跃期的开始—结束的过程,云南地区的波速比也经历了下降—恢复的准同步过程。We study the variation regularity of wave-velocity ratio in the 4th active period of strong earthquakes inYunnan,and discuss the relation between strong earthquake genesis and variation of wave velocity,medium-small earthquakes,and variation of focal depth.The result shows that wave-velocity ratio,focal depth and anomaly of M3-4.9 earthquakes appeared as early as 4 years before the M≥7.0 earthquakes.Most of them appeared about 2 years before the strong earthquakes,and anomaly of wave-velocity ratio and focal depth increased and gradually reduced about one year before the strong earthquakes.Corresponding to the beginning and the ending of the 4th active period.Wave-velocity ratio in Yunnan experienced the quasi-synchronous declining and rising.

关 键 词：波速比 震源深度 中小地震 强震活跃期 云南 

分 类 号：P315.72[天文地球—地震学]