2010年山西地区M≥4.6主余型地震序列的视应力研究

Study on Apparent Stress of The Main-aftershockEarthquake Sequences with M≥4.6 in Shanxi in 2010

利用山西地区2010年3次M≥4.6地震序列及其50km范围内的背景地震波形资料,采用视应力方法获得3次序列的差视应力值。结果表明,河津—万荣地震序列的余震视应力均高于背景应力水平,反映其震源区应力水平较高,于2011年1月15日又发生河津ML4.1地震;大同—阳高序列和阳曲序列的余震视应力基本低于背景应力水平,且较短时间内恢复到背景应力水平。

By using the 3earthquake sequences with M≥4.6in Shanxi in 2010 and the background seismic waveform data in the range of 50 km,the differential apparent stress values of the 3sequences are obtained by the method of apparent stress.The results show that the apparent stresses of the aftershocks of Hejin-Wanrong earthquake sequence are all higher than the background stress level.It is indicated that the stress level of the source region is higher.And a ML4.1earthquakeoccurred in Hejin on January 15,201.Comparatively,the apparent stresses of aftershocks of Datong-yanggao sequence and Yangqu sequence are below the background stress level,and back to the background stress level in a short time.