Crustal correction in teleseismic tomography and its application

Teleseismic tomography is a powerful technique for determining the 3-D upper mantle structure under a region, but it cannot determine the 3-D crustal structure well because the teleseismic rays do not crisscross well in the crust. Hence it is crucial to make crustal corrections to remove the effect of lateral crustal heterogeneity from the observed travel-time data. In this work we describe a technique for conducting the crustal correction in teleseismic tomography, which includes the choice of 3-D crustal model, the calculations of the travel-time residual in the crust and the relative residual after the crustal correction. We choose the Kamchatka region as an experiment to analyze the validity of the crustal correction via the mean relative residuals at each station and the results of teleseismic tomography, and also to verify the applicability of the technique for making crustal correction.