Crustal Structure Along the Transantarctic Mountain Front Using Receiver Functions

This study investigates crustal thickness variation along the front range of the Transantarctic Mountains using teleseismic waveforms recorded by the Transantarctic Mountain Seismic Experiment (TAMSEIS). This experiment deployed 44 three-component broadband seismometers from 2000-2003 and was divided into three arrays: Coastal, East-West, and North-South. Receiver functions have been computed for stations that are on bedrock along the Coastal and East-West arrays to avoid complications caused by reverberations in the ice layer. Estimates of crustal thickness and bulk Vp/Vs ratio have been obtained through the H- κ stacking method of Zhu and Kanamori (2000). The P-to-S converted phase across the crust-mantle boundary (Ps) is clearly observed in all the stations, but the reverberations in the crustal layer (PpPs, PsPs+PpSs) are difficult to identify. The lack of multiples likely indicates that the crust-mantle boundary is gradational, and it makes it difficult to estimate bulk Vp/Vs ratios accurately. Variations in earth structure around the stations have also been investigated, but no dependence of crustal properties with back-azimuth has been found. Preliminary results indicate the crust beneath the crest of the Transantarctic Mountains is ~39 km thick, in contrast to thicknesses between 30 and 35 km along the mountain front.