close window AGU Fall Meeting 2009 /You may print by clicking on this button. To return to the previous page, close this browser window or click the 'X' button in the top right corner of the page./ ID# DI41B-1802 Location: Poster Hall (Moscone South) Time of Presentation: Dec 17 8:00 AM - 12:20 PM *SEISMIC ANISOTROPY ANALYSIS IN THE VICTORIA LAND REGION (ANTARCTICA)* /_S. Salimbeni_^1 ; S. Pondrelli^1 ; S. Danesi^1 ; A. Morelli^1 / 1. INGV Bologna, Bologna, Italy. We present here shear wave splitting results obtained from analysis of core refracted teleseismic phases in the Victoria Land region (Antarctica). We used data belonging to permanent and temporary stations in the area. The temporary stations are located around the David Glaciers and installation is part of two expeditions inside the Italian National Antarctic program (PNRA, Programma Nazionale di Ricerche in Antartide). The network was composed by 8 seismic stations, located on rocky outcrops around the glacier, and has been active from November 2003 to February 2004, and from November 2005 to February 2006. One of this (STAR) became permanent on 2004 and data until 2007 are analyzed. We use eigenvalue technique of Silver and Chan (1991) to linearize the rotated and shifted shear wave particle motions and determine the best splitting parameters. Scattered distribution of single shear-wave measurements is obtained. Null measurements follow the same distribution. Average measurements show clearly that the main anisotropy direction is NE-SW, accordingly with previous measurements obtained around this zone. Only two stations, OHG and STAR, have a different orientation and a N-S and NNW-SSE main directions are obtained respectively. The distribution of single shear-wave splitting measurements evidenced periodicity respect the back-azimuth of the events analyzed, therefore a possible two layers anisotropic structures could be supposed. To test this hypothesis we used the Menke and Levin (2003) code that allow to model waveforms using a cross convolution technique in one and two layer's cases. Significant improvements of the misfit in the double layer case allow choosing this more complex model. The one layer structure is the best for permanent stations TNV and VNDA with directions and delay time accordingly with average measurements. The double layer models fit better the data on stations STAR, located near the coast, and OHG located inland, and show in both cases the same contribution of the anisotropy. *Contact Information* Simone Salimbeni, Bologna, Italy, 40128, click here to send an email ScholarOne Abstracts® (patent #7,257,767 and #7,263,655). © ScholarOne , Inc., 2010. All Rights Reserved. ScholarOne Abstracts and ScholarOne are registered trademarks of ScholarOne, Inc. Terms and Conditions of Use