【摘要】 北京时间1999年11月1日21时25分在山西省大同县的堡村、西团堡村一带,即39°57′N,113°52′E发生了MS5.6的地震,随后发生一系列余震。本文使用近场观测资料对这次地震的部分余震进行了精确定位和震源机制解的测定。野外观测时间是从1999年11月7日到11月18日,精确定位结果显示此次余震活动分布于近东西走向的六棱山北麓断裂和北东走向的大王隐伏断裂及北西走向团堡断裂交汇带上,地理位置在六棱山东段的秋林村至大王村段约10km处。震源机制解的结果表明此部分余震的运动形态主要为倾滑断层。但是断层走向并不完全一致,余震的震源机制解反映了处于多个断层交汇处的复杂的构造应力状态。更多还原

【Abstract】 An earthquake with magnitude M_S 5.6 hit the place between Pucun to Xituanpu,Datong county,Shanxi province in the first of November,1999.The aftershock sequence followed the main event.The location and mechanism of a part of the aftershocks were illustrated in this paper.The records of the aftershock sequence were from the eleventh of November to eighteenth.We have located 31 events which were well recorded and 18 of them which have clear waveform and were chosen to calculate the mechanism.The software of "Seismic Handler" and HYPO71 program was used for location.The moment tensor inversion program was used to calculated mechanism.The process of Moment Inversion is in frequency domain.The results of the location show that the aftershock sequence is at an intersection of almost EW strike Liulengshang fault,NE Dawang fault and NW TuanBao fault.The geographical position is between Quilin to Dawang about 10 kilometers.The mechanism shows that the movement of aftershock is on strike-slip fault.But the strikes are not at same orientation.Source mechanism come from aftershocks shows that the aftershocks occurred at the fault intersection and the stress field was complicated.更多还原