三分量地震记录的互相关分析

Cross-correlation analysis of three-component seismic recordings

地震波场本质上是三维矢量波场,单分量记录实际上是三维矢量震动在某一方向上的部分投影.本文基于单分量地震记录互相关公式,提出了一种新的适合三分量地震波形记录多元互相关运算的简易方法,并以2008年汶川MS8.0地震余震序列波形为例,对其进行了效果验证.结果表明,相对单分量互相关,该方法可以得到更为合理的全局最优结果,解决波形识别匹配工作中不同分量间的差异问题.该方法还可以利用不同分量间的"同源"信息,有效压制随机噪声,并从理论上说明其合理性.其原理及计算过程均较为简单,整体运算量较小,适用于目前"大数据"时代的地震数据处理.

Seismic wave is a three dimensional vector wavefield, the single com- ponent recordings are actually the projection of particle motion along certain directions. Based on the single component seismogram cross correlation formu- la, this paper presents a novel simple solution which is suitable for the calcula- tion of three-component seismogram cross-correlation, and the effectiveness of this new approach is verified via a practical case from the aftershock sequence of 2008 Wenchuan Ms8.0 earthquake. Compared with single component seismo gram cross-correlation, the new approach can obtain a global optimized result more reasonably and erase the discrepancy between different components in the work of template waveform matching. Also this new formula can take advan- tage of the congenerous between different components, suppress the ambient seismic noise effectively, and its rationality was demonstrated in theory. This new approach requires rather small computations as its simplicity in principles and procedures, which is suitable for the seismic data processing in the currentera of ＂big data＂.