【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。更多还原

【Abstract】 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.更多还原