Crustal Structure From Receiver Functions Analysis in Northern Victoria Land

The Transantarctic Mountains (TAM) form one of the Earth's mayor interplate mountain belts. Evolution of TAM reflects regional- and global-scale processes. Understanding TAM uplift history and linkage to geophysical model requires the knowledge of crustal and upper mantle structure. Teleseismic body waveforms have often been used to infer crustal geometry beneath isolated seismic stations. In this study we model Receiver Functions (RFs) obtained from teleseismic P waveforms recorded at various antarctic broad-band seismic station deployed during four austral summer campaigns (1993-98,2000-01) in Terra Nova Bay (TNB) region and Rennick and Lillie Glaciers (RLG) area. We recorded several hundreds of teleseismic events (more than 200 for a single station) with magnitudes between 5.0 and 7.2 getting good azimuthal coverage. RFs are performed through frequency-domain deconvolution, following the approach developed by Di Bona (1998). This method is used in order to evaluate RFs variance and the actual noise level involved and allows to use small magnitude events (Mb=5.0) generally excluded from RFs analysis. RFs azimuthal characteristics, for each stations, were analyzed and best RFs from different azimuth were inverted for fine crustal structure following the inversion scheme of Sambridge (1998). Results show Moho-depth coherence with previous studies in TBN region. As no previous studies exist for RLG area, our results are original for RLG and of general interest for Antarctic.