Short Note Frequency-Dependent Crustal Correction for Finite-Frequency Seismic Tomography

Removing the crustal signature from teleseismic travel times is an important procedure to reduce the trade-off between crustal and mantle velocity heterogeneities in seismic tomography. Because reverberations of longand short-period body-wave arrivals in the crust affect the waveforms of the direct arrivals differently, the crustal effects on travel times measured by waveform cross correlation are frequency dependent. With synthetic responses of selected crustal models, this short note illustrates the significance of frequency-dependent crustal corrections to finitefrequency body-wave travel-time tomography. The differences in crustal correction between longand short-period body waves at the same station can be as large as 0.6 sec, depending on the crustal thickness, velocity contrast at the Moho, and layering within the crust.