【摘要】 在对山西地区的非弹性衰减系数、场地响应和震源新参数各量关系初步研究之后,利用山西地区2008年8月—2012年5月间发生的ML2.0级以上地震612次,计算其中148次地震的震源新参数。着重研究该时间段内山西地震带连续发生的5次ML4.0级以上地震震源区的背景应力降,阳曲震区的平均应力降为2.586 MPa,其它4个震区都在1~2MPa间。分析发现山西中部的阳曲震源区、原平震源区、大同震源区震后应力降趋于平稳的低位,而山西中南部地区的洪洞、河津2震源区附近的地震应力降在震后仍处于不断积累、逐步增强的趋势,所以应密切关注山西中南部地区的震情形势。更多还原

【Abstract】 After primary research on relationship among quantities of inelastic attenuation coefficient,site response and new source parameters,using data of 612 ML ≥2.0 earthquakes occurred between August 2008 and May 2012 in Shanxi area,this paper calculates the new source parameters of 148 earthquakes.It focuses on the background stress drop in the source regions of continuously occurred 5 ML ≥4.0 earthquakes in Shanxi seismic zone during this period,obtaining that the average stress drop of Yangqu seismic region is 2.586MPa,and those of other 4 seismic regions are among 1~2MPa.While the stress drops after the earthquakes of Yangqu source region,Yuanping source region and Datong source region in central Shanxi trend towards steady low,analytically it finds the earthquake stress drops are still in the trend of continued accumulation and gradual strengthening after the earthquakes near Hongdong and Hejin source regions in the south-central region of Shanxi,so the south-central region of Shanxi should be paid close attention.更多还原