江西九江-瑞昌地震序列震源位置和发震构造再研究  

RESTUDY ON HYPOCENTRAL LOCATION AND SEISMOGENIC TECTONIC OF THE JIUJIANG-RUICHANG M_S5.7 EARTHQUAKE SEQUENCE,JIANGXI PROVINCE

作　　者：罗丽 吕坚 曾文敬 汤兰荣 

机构地区：[1]江西省地震局,南昌330039

出　　处：《地震地质》2016年第2期342-351,共10页Seismology and Geology

基　　金：中国地震局地震科技星火计划项目(XH12027)资助

摘　　要：选取江西九江-瑞昌MS5.7地震序列2005年11月26日至2006年6月30日228次ML≥1.0的地震,利用基于波形互相关技术的Hypodd定位方法进行了重新定位,最终获得224次地震的精确震源参数。统计定位误差（2倍标准偏差）在水平方向上为0.5km左右,垂直方向上〈2km。重定位后地震序列的震源深度主要集中在8~14km,震中在NW和NE 2个方向展布,其中又以NW向条带地震居多。结合几个主要地震的震源机制解、地震序列展布方向和震区的构造背景,我们推断NW向断裂错动产生了MS5.7主震,在右旋兼逆推过程中触发NE向断裂,产生了MS4.8最大余震。NE向断裂的地震活动经过短时间应力调整后进入相对平静期,之后则是NW向断裂在长时间的应力释放过程中引发了一系列余震。MS5.7主震的发震构造可能是NW向的洋鸡山-武山-通江岭隐伏断裂,而MS4.8最大余震的发震构造可能是NE向的刘家-范家铺-城门山断裂。We collected seismic records of 228 ML≥1.0 Jiujiang-Ruichang MS5.7 earthquake sequence from Dec.26,2005 to Jun. 30,2006. By using double-difference method combined with waveform crosscorrelation,those earthquakes were relocated and finally the accurate source parameters of 224 earthquakes were obtained. The errors are about 0.5km in horizontal and less than 2km in vertical direction,respectively. It was found that the depth of earthquake sequence concentrates in 8 ~ 14 km range,and the epicenters are distributed along both NW and NE direction,and dominantly along NW direction. Combined with the focal mechanism,the distribution direction and the tectonic setting,we infer that the rupture of the NW-trending fault caused the MS5.7 main shock,and then the rupture probably encountered an asperity and triggered the MS4.8 strong aftershock. The NE- trending fault came into a seismically quiet period by stress adjustment in a short time,while the NW-trending fault released stress for a long time which caused a series of aftershocks. The MS5.7 main shock is caused by the NW striking Yangjisshan-Wushan-Tongjiangling Fault and the MS4.8 aftershock occurred on the NE striking Liujia-Fanjiapu-Chengmenshan Fault.

关 键 词：九江-瑞昌地震 Hypodd方法 波形互相关 发震构造 

分 类 号：P315.2[天文地球—地震学]