Crustal Structure of Northern Victoria Land from Receiver Function Analysis

N. Piana Agostinetti*, A. Amato, M. Cattaneo & M. Di Bona

Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 603, 00143 Roma – Italy

Received 13 January 2003; accepted in revised form 18 May 2004
 

Abstract - As a part of the joint German-Italian Antarctic expedition 1999-2000, a passive seismological campaign was carried out, aimed at the reconstruction of crustal structure using source-equalized teleseismic P waveforms, or  Receiver Functions. Seismic stations were deployed along two profiles across the main known structural features of Northern Victoria Land, as the Leap Year and the Lanterman faults. Over 150 teleseismic events at 7 digital seismic stations were recorded and 52 high signal/noise ratio records have been selected for use in this study. Receiver Functions were computed through frequency-domain deconvolution technique, developed by Di Bona (1998). For each station, Receiver Functions data-set was analysed and  best waveforms were inverted for shear-wave velocity structure using  a Neighbourhood Algorithm scheme (Sambridge, 1999a,b). The first goal of this study is to gain information on crustal geometry in Northern Victoria Land, particularly in Robertson Bay area, where no results from other work are available. The results show a crustal thickness of 24 km in Robertson Bay area. Under TransAntarctic Mountains, two interfaces between 26 and 48 km depth are present, while crustal thickness keeps a value around 31 km along Oates Land, west of the Transantarctic Mountains.



*Corresponding author (piana@ingv.it)