Effective Elastic Thickness Map Reveals Subglacial Structure of East Antarctica

• Published in: Geophysical research letters 2021-02, Vol.48 (4), p.n/a
• Main Authors: Swain, C. J., Kirby, J. F.
• Format: Article
• Language: English
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2020GL091576

East Antarctica is the least well‐exposed Precambrian shield on Earth. What is known, or surmised, of its geological structure comes from extrapolation over large distances and from geophysics. Here, we present a map of effective elastic thickness, Te, computed from Antarctic bedrock topography and both terrestrial and satellite gravity data. Te is directly related to lithospheric strength and can distinguish domains of differing tectonic history. Our map reveals a broad region of high Te in Wilkes Land, interpreted as a craton, while elsewhere a corridor of low Te meanders between areas of higher Te. The low‐Te belt follows the trend of prominent linear magnetic anomalies identified in the Gamburtsev and Dronning Maud Land provinces, two of which have previously been identified as possible Grenville or Pan‐African age sutures. Plain Language Summary This paper presents a new, high‐resolution map of the effective elastic thickness of the lithosphere of Antarctica. It is interpreted as indicating the tectonic structure of East Antarctica in the form of cratons and orogenic belts. Key Points New map of effective elastic thickness (Te) for Antarctica Known and suspected cratonic areas have high Te A low‐Te corridor meanders between these, joining the Lambert Rift, Gamburtsev Subglacial Mountains, and Dronning Maud Land passive margin escarpment