摘要
本文根据Ａｋｉ的尾波散射理论，利用澜沧—耿马７．６、７．２级大震前后近１２年的时间，对大震区域及外围的７个地震台３０００多张地震记录图的尾波进行了测量，计算出尾波Ｑ值随时间的变化。结果表明：澜沧、耿马大震前有３～５年左右的低Ｑ值异常；在大震前一年左右，Ｑ值处于回升阶段；大震后多数台Ｑ值明显增大。在对两次大震震中和两次强震震中的不同距离的台站测出的Ｑ值，确实存在主震前低Ｑ值或高Ｑ值，主震后高Ｑ值或低Ｑ值的两种相互矛盾的现象。并得出地震强度与Ｑ值异常幅度无关，与Ｑ值异常的持续时间成正比。
According to Aki's coda theory, utilising more than 3000 seismograms recorded in 7 stations within the period of 12 years before and after Lancang-Gengma M=7.6 and M=7.2 earthquakes, variations of Q value of coda wave with time have been calculated which demonstrate: There existed 3-5 year low Q anomalies before Lancang-Gengma earthquakes;Q value was increasing a year before the earthquakes; Q values in most of the stations were obviously increasing after the earthquakes. From Q values observed in different stations to different earthquakes, there do exist mutual contradiction, such as low Q value or high Q value before the main shocks, high Q value or low Q value after the main shocks. The earthquake strength has no relations with amplitude of Q value, hut has direct ratio with duration of Q value anomalies.
出处
《地震研究》
CSCD
北大核心
1994年第4期330-339,共10页
Journal of Seismological Research
基金
地震科学联合基金
关键词
地震预报
尾波
Q值
地震前兆
Earthquake Prediction
Coda wave
Q value
Lancang-Gengma earthquakes
