利用互相关函数求地震波衰减  

Estimating seismic attenuation using cross-correlation function

作　　者：徐平[1] 王宝善[2] 张尉[3] 林建民[4] 陈颙[2] 

机构地区：[1]中国科学院地质与地球物理研究所 [2]中国地震局地球物理研究所,北京100081 [3]浙江大学地球科学系,杭州310027 [4]中国科学技术大学地球和空间科学学院,合肥230026

出　　处：《地球物理学报》2006年第6期1738-1744,共7页Chinese Journal of Geophysics

基　　金：国家自然科学基金重点项目(NSFC40234038);地震联合基金(105108);北京市科技攻关项目(H030630090190)资助

摘　　要：与传统利用单事件波形求介质衰减的方法不同,我们提出一种以一系列事件为源,以源与远处记录波形的互相关函数为基础计算介质品质因子的方法.依据野外现场实验的数据,我们分别以单次和多次激发为源,讨论了事件波形和互相关函数波形的振幅变化及相应的介质品质因子,结果发现,与事件波形一样,互相关函数波形也可以用于计算介质的衰减系数.计算结果表明:(1)实验场地浅层介质在原场条件下的品质因子Q值在40左右;(2)互相关函数的最大幅度与事件波形的振幅随距离具有相同的衰减规律.Different from the traditional method of estimating seismic attenuation based on the waveform of single event, we regarded a series of events as an equivalent one, and obtained seismic attenuation on the basis of cross-correlation function between source and signal recorded at distance. We performed a field experiment by the end of 2004, and based on the data of this experiment, we studied the amplitude degression and corresponding seismic attenuation factor of both single event waveform and cross-correlation function. It is found that, same as single event waveform, cross-correlation function could be used to assess the seismic attenuation. The results show： （1） Q of in-situ medium is about 40; （2） Amplitude degressions with distance of single event waveform and cross-correlation functions are much similar.

关 键 词：地震波衰减 频谱比 互相关函数 Q值 

分 类 号：P631.315[天文地球—地质矿产勘探]