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Upper mantle anisotropy from teleseismic SKS splitting beneath Lützow-Holm Bay Region, East Antarctica

Open-File Report 2007-1047-SRP-013
By: , , , , and 
https://doi.org/10.3133/ofr20071047SRP013

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Abstract

Investigations of SKS wave splitting of teleseismic events from digital seismographs recorded at eight stations around the Lützow-Holm Bay Region have lead to understanding the evolution of the Antarctic Plate. The observed delay times of SKS splitting are up to 1.3 s, which are generally equal to the global average. A two-layer model reveals that the lower layer anisotropy is caused by the recent asthenospheric flow, as compared with the Absolute Plate Motion by the HS3-NUVEL1 model. The upper layer anisotropy corresponds well to polarization of NE–SW convergence direction between East and West Gondwana in Pan-African age. We suggest that the upper layer anisotropy was formed during Pan-African orogeny and was possibly influenced by the preexisting structure during Gondwana break-up. The origin of anisotropy is the Lattice Preferred Orientation of olivine which was caused by both paleo-tectonic events and the recent asthenospheric flow.

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Publication type Report
Publication Subtype USGS Numbered Series
Title Upper mantle anisotropy from teleseismic SKS splitting beneath Lützow-Holm Bay Region, East Antarctica
Series title Open-File Report
Series number 2007-1047-SRP-013
DOI 10.3133/ofr20071047SRP013
Year Published 2007
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Description 4 p.
Larger Work Type Report
Larger Work Subtype USGS Numbered Series
Larger Work Title Antarctica: A Keystone in a Changing World--Online Proceedings for the Tenth International Symposium on Antarctic Earth Sciences. Santa Barbara, California, U.S.A.--August 26 to September 1, 2007
Other Geospatial Antarctica
Additional Online Files (Y/N) N
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