海城-岫岩地区较大地震前震源机制的比较

摘要

海城-岫岩地区是辽宁省小震、震群多发地区。本文选用1975年以来具有一定发震规模,且仪器记录相对较完整的3个显著震群（1975年海城7.3级,1999年岫岩5.4级和2008年海城ML4.8级地震）,将其较大地震前ML≥4.0级地震震源机制结果进行比较,发现海城7.3级和岫岩5.4级地震前ML≥4.0级地震震源机制解与主震有较好的一致性,而2008年11月海城4.8级地震前ML≥4.0级地震震源机制一致性较差。我们对能否借鉴前震震源机制一致性的差异快速判断中强震发展的趋势,进行了探讨和研究。%Haicheng-Xiuyan area is an earthquake fluently-happened region in Liaoning Province.We selected 3 large scale earthquake swarms with complete instrumental records since 1975,which are Haicheng 7.3 magnitude earthquake in 1975,Xiuyan 5.4 magnitude earthquake in 1999 and Haicheng ML4.8 earthquake in 2008.We compared the focal mechanism of ML≥4.0 earthquakes before each main shock and found that the consistency between them is significant in Haicheng 7.3 magnitude earthquake and Xiuyan 5.4 magnitude earthquake but not in Haicheng ML4.8 earthquake.Then we researched the rapid determination of development of earthquakes by means of former earthquake focal mechanism consistency.