摘要
对2008年8月19日内蒙古喀喇沁旗震群和随后在该地区发生的地震进行重定位,并计算震源机制,以此来研究震群的发震构造背景。双差法重定位的深度剖面显示,震源分布与八里罕断裂倾斜方向基本一致,震源机制类型与断裂活动性质相近。震群中震源机制解类型比较离散,没有出现趋于一致的现象。历史上该区发生过强震,震源体岩石比较破碎,不利于应力应变的集中,但对整个区域应力场的增强比较敏感,可作为华北块体应力背景增强的敏感窗口。
Based on the relocation of the earthquake swarm occurred in Nalaqln, Inner Nlongolia on August 19, 2008 and the subsequent earthquake in the region and calculation of focal mechanism, we study the seismogenic structure of the earthquake swarm. According to the depth profile of the double-difference relocation, hypocentral distribution is basically consistent with the dip direction of the Balihan fault. The focal mechanism type is similar to the nature of the fault activity. The focal mechanism solutions of the earthquake swarm is discrete, do not appear consistent phenomenon. The rock body beneath this region where a strong historical earthquake occurred is broken and not conducive to concentration of stress and strain. But it is sensitive to the enhance of entire regional stress field. This region can be considered as a sensitive window of enhanced stress background of the North China block.
出处
《地震地磁观测与研究》
2013年第1期10-14,共5页
Seismological and Geomagnetic Observation and Research
基金
地震科技星火计划项目(XH1032)
关键词
震群
双差法重定位
震源机制
八里罕断裂
earthquake swarm
HypoDD relocation
focal mechanism
balihan fault
