Variations in crustal structure across the transition from West to East Antarctica, Southern Victoria Land

• Published in: Geophysical Journal International
• Main Authors: Bannister, S, Yu, J, Leitner, B, Kennett, Brian
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Blackwell Publishing Ltd
• Subjects: Keywords: crustal structure; crustal thickness; Moho; seismic velocity; velocity structure; Antarctica; East Antarctica; Ross Island; Transantarctic Mountains; Victoria Land Antarctica; Crustal structure; Inversion; Moho discotinuity; Shear wave; Waveform analysis; Ross Sea; Victoria Land; Antarc*
• Online Access: http://hdl.handle.net/1885/88432; https://doi.org/10.1111/j.1365-246X.2003.02094.x

The crustal structure beneath Ross Island and the Transantarctic Mountains (TAM) in Southern Victoria Land, Antarctica, is inferred using non-linear inversion of receiver functions, derived from teleseismic earthquake data. Intermediate-period waveforms from more than 160 teleseismic earthquakes recorded between January 1994 and January 2000 were used in the analysis. The inversion results confirm a crustal thickness of 19-21 km beneath Ross Island, consistent with previous multichannel seismic work. In addition we observe a crustal thickness of 18-20 km beneath the Ross Sea coastline immediately adjacent to the TAM. Further inland, beneath the TAM, the estimated Moho depths range from 30-33 km (∼30 km from the coast) to 36-40 km (∼85 km from the coast), deepening away from the coast beneath the TAM. These results are in broad agreement with previous seismic and gravity interpretations. Beneath the TAM a sharp mid-crustal discontinuity is present at 8-14 km depth beneath the eastern-most stations, but absent on the western side of the TAM, indicating a spatial change in the mid-crustal composition.