直达Ps与接收函数Ps联合分析地壳各向异性  

Utilizing P-S converted waves on seismograms and receiver functions to estimate crustal anisotropy

作　　者：杨颖航 朱良保[1,2] 王清东[1] 陈浩朋[1] 张攀[1] 

机构地区：[1]武汉大学测绘学院固体地球物理系,武汉430079 [2]武汉大学地球空间环境和大地测量重点实验室,武汉4300791

出　　处：《地球物理学报》2014年第7期2065-2076,共12页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41374053);国家测绘地理信息局测绘基础研究基金资助项目(11-02-01;12-02-06)资助

摘　　要：本文尝试直接利用地震图记录中的Ps转换波,而非传统的接收函数方法,检测地壳介质的各向异性.虽然远震记录中的P波对Ps转换波会有干扰,但P波与Ps转换波具有不同的偏振特性,最小能量法可以将Ps转换波的各向异性参数检测出来,对时间窗的选择也很强壮.本文利用IC台网(New China Digital Seismograph Network,中国新数字地震台网)中的KMI,ENH,LSA,BJT,XAN,WMQ六个台站接收的宽频远震记录进行了测试,并且对比了接收函数方法的结果.研究表明,利用最小能量法直接测量与利用旋转相关法测量接收函数中Ps转换波的结果基本一致.两种方法测量所得的快波偏振方向与地壳运动方向,最大水平主压应力方向,震源机制解压缩轴方向,最大主压应变率方向以及已有的各向异性研究结果基本一致.Traditional method to study anisotropy of receiver functions. We try to measure the splitting crust utilizes Ps-converted waves from parameters of Ps converted waves on seismogram directly. Ps converted waves on teleseismic seismograms will be unclear due to the interference of P waves. But P waves and Ps converted waves have different polarization characteristics, the minimum energy method can measure the splitting parameters of Ps converted waves on seismograms and the time window is relatively easily chosen. We used teleseismic seismograms recorded at six seismic stations, KMI, ENH, LSA, BJT, XAN, and WMQ of IC seismic network to test this method. Comparing two methods, we found that the result of utilizing minimum energy method to measure Ps converted waves directly agrees with the result of cross correlation method to measure Ps converted waves from receiver functions. The fast polarization directions of Ps phases measured by two methods approximately agree with the directions of crust movement, maximum horizontal compression, the compression axes of focal mechanism, principal compressing strain rate and previous anisotropy results.

关 键 词：PS转换波 地壳各向异性 接收函数 最小能量法 旋转相关法 

分 类 号：P315[天文地球—地震学] P541[天文地球—固体地球物理学]