2003年青海德令哈M6.6地震序列的活动特征
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摘要
分析了2003年4月17日青海省德令哈6.6级地震序列活动的空间和时间变化特征及其发震构造,得到以下结果:①主震发生在地震活跃区与相对平静区的分界带上;②主震后半个多月内余震快速衰减,初期余震持续到7月底,以后平静了4个多月,接着震源区东部又发生第2期余震活动,连续发生5次5.0级以上地震,最大余震震级5.9;③震源区西侧的初期余震以逆断层活动为主,东侧的后期余震以走滑断层活动为主;④德令哈地震的发震构造是NWW—SEE走向、向南倾的大柴旦—宗务隆山逆断层带。
Delingha M6.6 earthquake occurred on Apr.17,2003,in Qinghai Province,followed by a series of aftershocks.This paper studied the spatial and temporal characteristics of the earthquake sequence activity.The result showed:① the main shock occurred in a boundary zone between seismic active and inactive region.② the aftershocks within the first 16 days after the main shock attenuated quickly till the end of July.There was a relatively inactive period more than 4 months after the first period aftershocks.Afterwards the aftershocks of the second period occurred in the eastern part of focal area,with successive 5 M≥5.0 aftershocks and the largest being M5.9.③ The most aftershocks of first period are reverse faults in the western part of focal area;while the aftershocks of second period expanded toward east and most of them show strike-slip faults.④ The seismogenic structure of the Delingha earthquake sequence is the NWW—SEE striking and south dipping Da Qaidam-Zongwulongshan fault,which is a boundary fault between southern Qaidam fault depression and northern Qilian fold uplift.
Delingha M6.6 earthquake occurred on Apr.17,2003,in Qinghai Province,followed by a series of aftershocks.This paper studied the spatial and temporal characteristics of the earthquake sequence activity.The result showed:① the main shock occurred in a boundary zone between seismic active and inactive region.② the aftershocks within the first 16 days after the main shock attenuated quickly till the end of July.There was a relatively inactive period more than 4 months after the first period aftershocks.Afterwards the aftershocks of the second period occurred in the eastern part of focal area,with successive 5 M≥5.0 aftershocks and the largest being M5.9.③ The most aftershocks of first period are reverse faults in the western part of focal area;while the aftershocks of second period expanded toward east and most of them show strike-slip faults.④ The seismogenic structure of the Delingha earthquake sequence is the NWW—SEE striking and south dipping Da Qaidam-Zongwulongshan fault,which is a boundary fault between southern Qaidam fault depression and northern Qilian fold uplift.
引文
[1]W aldhause F,E11 sworth W L.A doub le d ifference earthquake location algorithm:M ethod and application to the Northern Hay-ward Fau lt,Californ ia[J].Bu ll.Seism.Soc.Am er,2000,90(6):1 353-1 368.
[2]孙长虹,钱荣毅,肖国林,等.2003年青海德令哈6.7级地震序列的重新定位和发震构造[J].物探与化探,2006,30(1):79-82.
[3]Ratchkovsk i N A,W iem er S,Hansen R A.Seismotecton ics of the Central D enali Fau lt,A laska,and the 2002 D enali Fau ltearthquake sequence[J].Bu ll.Seism.Soc.Am er,2004,94(6B):S156-S174.
[4]蒋海昆,曲延军,李永莉,等.中国大陆中强地震余震序列的部分统计特征[J].地球物理学报,2006,49(4):1 110-1 117.
[5]高国英,聂晓红,夏爱国.2003年伽师6.8级地震序列特征和震源机制的初步研究[J].中国地震,2004,20(4):179-186.
[6]焦远碧.地震序列类型、地震序列b值与地震大形势关系初探[J].地震,1998,18(1):33-39.
[7]刘瑞丰,陈运泰,任枭,等.中国地震台网震级的对比[J].地震学报,2007,29(5):467-476.
[8]国家地震局震害防御司.地震工作手册[M].北京:地震出版社,1990:258.
[9]曾秋生.青海地震综合研究[M].北京:地震出版社,1999.
[2]孙长虹,钱荣毅,肖国林,等.2003年青海德令哈6.7级地震序列的重新定位和发震构造[J].物探与化探,2006,30(1):79-82.
[3]Ratchkovsk i N A,W iem er S,Hansen R A.Seismotecton ics of the Central D enali Fau lt,A laska,and the 2002 D enali Fau ltearthquake sequence[J].Bu ll.Seism.Soc.Am er,2004,94(6B):S156-S174.
[4]蒋海昆,曲延军,李永莉,等.中国大陆中强地震余震序列的部分统计特征[J].地球物理学报,2006,49(4):1 110-1 117.
[5]高国英,聂晓红,夏爱国.2003年伽师6.8级地震序列特征和震源机制的初步研究[J].中国地震,2004,20(4):179-186.
[6]焦远碧.地震序列类型、地震序列b值与地震大形势关系初探[J].地震,1998,18(1):33-39.
[7]刘瑞丰,陈运泰,任枭,等.中国地震台网震级的对比[J].地震学报,2007,29(5):467-476.
[8]国家地震局震害防御司.地震工作手册[M].北京:地震出版社,1990:258.
[9]曾秋生.青海地震综合研究[M].北京:地震出版社,1999.
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