摘要
本文使用简化的能流模型（Ｆｒａｎｋｅｌ，Ａ．ｅｔａｌ，１９８７）研究了海城地震震源区的地震尾波衰减及介质Ｑ值的时空分布特征。结果表明，使用该方法求得的尾波Ｑ值基本上是介质非弹性吸收的度量；海城７．３级地震前震的Ｑ值较高，约为５００，震后显著降低至３８０，但５．９级最大余震震源区的Ｑ值仍与大震前相同。这可能说明大震发生时该处介质并未破裂。最大余震发生后，整个震源区的平均Ｑ值降至３４４。但地震前后介质Ｑ值发生明显变化的范围并不大，直径约为２０ｋｍ。
The authors studied seimie coda attenuation and time-space distribution of Q-values in the source region of the Haicheng earthquake (M=7. 3) by using simplified energy-flux model, and it is showed that the Q-values obtained by using the method actually is a measure of intrinsic attenuation of the crust media. The average Q-values were higher(500)and lower (380) for foreshocks and aftershocks of the event respectively, but the average Q-value in source region of the M=5. 9 maximum aftershock still is identical with one of the foreshocks and it probably showed that the media in source region of the maximum aftershock un faulted when the mainshock occurred. The average Q-value of whole source region of the Haicheng earthquake dropped to 344 after the maximum aftershock occurred. However the space range of the Q-value variation before and after the mainshock is not large, and its major axis of the range is about 20km only.
出处
《中国地震》
CSCD
北大核心
1995年第1期62-71,共10页
Earthquake Research in China
基金
地震科学联合基金
关键词
地震震源
地震波衰减
尾波
Q值
海域
Seismic wave attenuation, Coda, Q-vaule, Haicheng, Model
