中国大陆中强地震余震序列的部分统计特征  

Some statistic features of aftershock sequences in Chinese mainland

作　　者：蒋海昆[1] 曲延军[2] 李永莉[3] 郑建常[1] 华爱军[1] 代磊[1] 侯海峰[1] 

机构地区：[1]山东省地震局,济南250014 [2]新疆维吾尔自治区地震局,乌鲁木齐830011 [3]云南省地震局,昆明650041

出　　处：《地球物理学报》2006年第4期1110-1117,共8页Chinese Journal of Geophysics

基　　金：国家"十五"科技攻关计划延续项目子专题"余震序列统计特征及强余震预测研究(2004BA601B01-04-02)";地震联合基金项目(105076)共同资助

摘　　要：依据1970年以来记录相对完整的294次5.0级以上地震序列资料,研究中国大陆中强地震余震序列统计特征,探讨序列类型、最大余震震级、强余震活动持续时间等与主震震级及主震断层性质之间的关系.中国大陆孤立型、主余型及多震型地震余震序列分别约占23%、59%及18%.其中走滑型、具有倾滑分量的走滑型、具有走滑分量的倾滑型及逆冲型分别占48%、24%、17%及11%.余震序列1年内最大余震震级与主震震级正相关,但主震震级较低时相对离散,孤立型序列离散程度较高,主余型及多震型序列线性相关性较好.绝大多数序列最大余震均发生在震后200天内,少数具有晚期强余震的序列主要属主余型序列,孤立型及多震型序列通常没有晚期强余震发生.68%的序列1年内最大余震发生在震后10天内,77%发生在震后30天之内,95%发生在震后120天之内.序列最大余震发生时间及5、6级强余震活动持续时间与序列类型及主震震级大小有关,多震型序列最大余震发生最快,孤立型次之、主余型最长.若仅就主余型序列而言,当主震震级较高时最大余震与主震间时间间隔相对较短,主震震级较低时最大余震与主震间时间间隔相对较长.Based on 294 earthquake sequences with magnitude greater than or equal to 5.0 occurred in Chinese mainland from 1970 to 2003, some statistic features of aftershock sequences, such as sequence types, magnitude of maximum aftershock, duration of aftershock activity and the relationships between these parameters with the magnitude or fault property of the mainshock, have been studied. For sequence types in Chinese mainland, about 23% is isolated earthquake, 59% is mainshoek-aftershoek sequence and 18% belongs to the multiple mainshoek type. For fault property of the mainshoek, about 48 % is strike-slip, 24% is strike-slip with some dip-slip component, 17% is dip-slip with some strike-slip component and about 11% is reverse-slip. The magnitude of the maximum aftershoek in 1 year after the mainshoek is proportional to the magnitude of the mainshoek, but the data are relatively scattered when the mainshoek is small. The degree of data scatter is high for isolated earthquake sequences, and the linear relation between the magnitude of maximum aftershoek and the mainshock is good for mainshock-aftershock and multiple mainshock sequences. The maximum aftershock for most sequences occurred in 200 days since the mainshock, a few sequences with later large aftershocks mainly belong to the mainshock-aftershock type and generally there is no later large aftershock occurred for isolated or multiple mainshock sequences. About 68% maximum aftershocks occurred in 10 days since the mainshock, 77% in 30 days and 95% in 120 days. The occurrence time of the maximum aftershock and the duration of the aftershock activity with M ≥ 5.0 or M ≥ 6.0 are related to the sequence type and the magnitude of the mainshock. The time interval from the mainshock to the maximum aftershock is shortest for multiple mainshock sequences and is longest for mainshock-aftershock sequences, the time interval of isolated earthquake sequences is shorter than that of mainshock-aftershock sequences and longer than that of multiple mainshock sequences. If only

关 键 词：中国大陆 序列类型 最大余震震级 强余震活动持续时间 主震震级 主震断层类型 

分 类 号：P315[天文地球—地震学]