Uplift of the central transantarctic mountains

• Published in: Nature Communications
• Main Authors: Wannamaker, Phil, Hill, Graham, Stodt, John, Maris, Virginie, Ogawa, Yasuo, Selway, Kate, Boren, Goran, Bertrand, Edward, Uhlmann, Daniel, Ayling, Bridget, Green, A. Marie, Feucht, Daniel
• Format: Text
• Language: English
• Published: Nature Publishing Group UK 2017
• Subjects: Article; Transantarctic Mountains; West Antarctica; Antarc*; Antarctica
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5693935/; http://www.ncbi.nlm.nih.gov/pubmed/29150611; https://doi.org/10.1038/s41467-017-01577-2

The Transantarctic Mountains (TAM) are the world’s longest rift shoulder but the source of their high elevation is enigmatic. To discriminate the importance of mechanical vs. thermal sources of support, a 550 km-long transect of magnetotelluric geophysical soundings spanning the central TAM was acquired. These data reveal a lithosphere of high electrical resistivity to at least 150 km depth, implying a cold stable state well into the upper mantle. Here we find that the central TAM most likely are elevated by a non-thermal, flexural cantilever mechanism which is perhaps the most clearly expressed example anywhere. West Antarctica in this region exhibits a low resistivity, moderately hydrated asthenosphere, and concentrated extension (rift necking) near the central TAM range front but with negligible thermal encroachment into the TAM. Broader scale heat flow of east-central West Antarctica appears moderate, on the order of 60–70 mW m−2, lower than that of the U.S. Great Basin.