远震反演中新的地壳异常体改正方法

近年来,远震走时层析成像方法有了长足的发展,在地下结构反演的研究中获得了众多成果。针对射线在台站下方覆盖率较差而导致远震反演方法对地壳速度约束不足的问题,本文提出了一种新的地壳异常体改正方法--对同一台站的相对走时残差进行求和平均去均值,消除了地壳中复杂的速度异常体对上地幔速度结构反演的干扰,反演结果具有更优的相对走时残差分布,同时反演得到的速度模型具有更小的数据方差。

A New Method of Crustal Anomaly Correction for Teleseismic Inversion

Teleseismic travel-time tomography has made great progress in recent decades,and many achievements have been obtained in the study of inversion of underground structures. Due to the poor coverage of rays under the stations,the remote seismic inversion method has the problem of insufficient restriction on crustal velocity. In this paper a new crustal anomaly correction method is proposed,in which the relative travel time residuals of the same station are summed up and averaged,and the complex velocity anomaly bodies in the crust are eliminated for the inversion of upper mantle velocity structure. Our results are of relatively better relative travel time residuals,as well as the smaller data error.