【摘要】：近年來,太原盆地內(nèi)盡管沒有強(qiáng)震發(fā)生,小震卻異常活躍,而研究太原盆地構(gòu)造應(yīng)力場的分布和演化規(guī)律的工作比較少.采用有限元數(shù)值方法,綜合考慮區(qū)域地質(zhì)構(gòu)造差異、主要活動斷裂帶、地形起伏和巖石圈分層結(jié)構(gòu),引入深部速度結(jié)構(gòu),建立包含太原盆地在內(nèi)的山西地區(qū)三維粘彈性模型.以GPS觀測值和最大主壓應(yīng)力方向測量值為約束條件,重建研究區(qū)現(xiàn)今構(gòu)造背景應(yīng)力場.在此基礎(chǔ)上,依次模擬了自公元512年以來太原盆地6級以上和山西地震帶7級以上歷史強(qiáng)震序列.計(jì)算結(jié)果顯示,太原盆地內(nèi)的3次6級以上歷史地震均落在應(yīng)力場增加值大于0.01MPa的區(qū)域,盆地近年來小震空間分布與現(xiàn)今應(yīng)力增加值大于0.01MPa的區(qū)域有較好的對應(yīng)關(guān)系.研究表明:山西地震帶內(nèi)歷史強(qiáng)震序列和長期構(gòu)造加載對太原盆地內(nèi)3次歷史強(qiáng)震均有促進(jìn)作用,太原盆地的地震活動性明顯受區(qū)域當(dāng)前應(yīng)力水平的控制.
[Abstract]:In recent years, although there are no strong earthquakes in Taiyuan basin, small earthquakes are very active, but there is little work to study the distribution and evolution of tectonic stress field in Taiyuan basin. A 3-D viscoelastic model of Shanxi region including Taiyuan basin is established by introducing deep velocity structure into consideration of regional geological structure difference, main active fault zone, topographic fluctuation and lithospheric stratification structure by using finite element numerical method. Based on the GPS observations and the maximum principal compressive stress direction measurements, the present tectonic background stress field in the study area is reconstructed. On this basis, historical strong earthquake sequences of M 鈮，

本文編號：2259189