摘要
利用天然重复地震观测地壳介质速度随时间的变化,其精度主要受地震定位精度、重复地震位置不一致以及震相读取误差等影响,这限制了其在实际中的应用。文中提出利用射线追踪方法对重复地震进行位置归一处理,并且采用波形互相关技术消除震相读取误差影响,从而达到提高精度的目的。根据上述方法原理,利用大姚地区重复地震观测该地区地壳介质随时间的变化。结果表明,该方法能够有效地提高测量的精度,并且显示在2003年大姚6.2级、6.1级地震前出现了短期的地壳介质速度明显升高的现象。
The accuracy of measuring crustal media variation by using repeating earthquakes is controlled by several factors, including the accuracy of earthquake location, dissimilar position of repeating earthquakes, and the error of phase reading, which restrict its application in practice. In this paper we present normalizing the position of repeating earthquakes by using ray tracing, and eliminating the effects of phase reading error by waveform cross-correlation methods that improve the precision in measuring media variation with time. According to the methods mentioned above, we measured the variations of Dayao crustal media with time by using repeating earthquakes. The results indicate that the measuring accuracy can be effectively improved by this method, showing that the short-term velocity variation of crustal media appears before Dayao M= 6.2 and M= 6.1 earthquakes in 2003.
出处
《地震》
CSCD
北大核心
2007年第3期1-9,共9页
Earthquake
基金
地震科学联合基金项目(106016)
关键词
重复地震
射线追踪
波形互相关
地壳介质变化
大姚地震
Repeating earthquakes
Ray tracing
Waveform cross-correlation
Variation of crustal media
Dayao earthquake
