【摘要】 利用张掖台网和天祝 -古浪台网的记录资料研究了 1988年 11月 2 2日肃南 5 .7级地震和 1996年 6月 1日天祝 -古浪 5 .4级地震前后震源区微震尾波 Qc值的变化特征 ,结果表明 :5 .7级地震前震源及邻近地区介质 1/ Qc值趋于一致 ,认为这是该次地震的一种前兆表现 ,结合该次地震的震源机制和构造情况进行了讨论。天祝 -古浪 5 .4级地震震源区附近地区微震尾波 Qc值与频率的关系表明 ,这一地区属于构造活动地区。更多还原

【Abstract】 The variation characteristics of the coda Q c values of micro earthquakes in the source areas before and after two earthquakes.The two events are Sunan earthquake(M5.7,Nov.22,1988)and Tianzhu Gulang earthquake(M5.4,June 1,1996).The results show that the 1/Q c values tend to identity in the source and its near area before the earthquake M5.7.It is considered that it is a precursor before the earthquake and discussed combining with the source mechanism of this earthquake and the tectonics in the area. The relation between the coda 1/Q c values near the source area of Tianzhu Gulang earthquake and the frequencies have been studied,it shows that the studied area belongs to active tectonic area.更多还原