Feedbacks of lithosphere dynamics and environmental change of the Cenozoic West Antarctic Rift System.

This special issue of Global and Planetary Change contains 11 contributions dealing with various aspects of the Cenozoic West Antarctic Rift System. During the last two decades, investigations of the interplay of tectonics and climate greatly improved understanding of Cenozoic global change. Major p...

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Bibliographic Details
Published in:Global and Planetary Change
Main Authors: van der Wateren, F.M., Cloetingh, S.A.P.L.
Format: Article in Journal/Newspaper
Language:English
Published: 1999
Subjects:
Online Access:https://research.vu.nl/en/publications/47fc4762-a25e-4917-893a-e9e1d84ac107
https://doi.org/10.1016/S0921-8181(99)00048-X
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Summary:This special issue of Global and Planetary Change contains 11 contributions dealing with various aspects of the Cenozoic West Antarctic Rift System. During the last two decades, investigations of the interplay of tectonics and climate greatly improved understanding of Cenozoic global change. Major plate reorganizations in the Southern Hemisphere, starting with the breakup of Gondwana in the Mesozoic, were a key factor in the thermal isolation of Antarctica and the initiation of the East and West Antarctic Ice Sheets, which, in their turn, influenced lower latitude and Northern Hemisphere climates with the oceans as intermediaries. Recent studies are increasingly drawing attention to the tectonic effects in glaciated rifts and rifted margins. During the Pleistocene, the rifted margins around the North Atlantic repeatedly were the core regions for continental ice sheet expansions. However, as demonstrated by recent work, Cenozoic uplift of the Norwegian margin started as early as 30 Ma. Similarly, from the early Oligocene onwards, topographic uplift of the Transantarctic Mountains, the western flank of the Cenozoic West Antarctic Rift System, triggered the formation of local ice centres which merged to form large ice sheets. This process was repeated a number of times until, in the late Pliocene, the present-day East and West Antarctic Ice Sheets were established. Throughout the evolution of the Antarctic Ice Sheet, lithosphere dynamic processes and environmental change have been strongly linked, as indicated by: (1) the great variation in landscape evolution histories along the Transantarctic Mountains rift flank, as a result of differential topographic uplift of fault blocks under late Neogene transtension in the western Ross Embayment; (2) the influence of the rising rift flank on ice sheet dynamics which differs for regions in the central Transantarctic Mountains and more peripheral regions; (3) the routing of major ice streams draining the West Antarctic Ice Sheet along the Cenozoic rift, which, by its high geothermal heat flux, directly influences the dynamics of these ice streams; and (4) the late Neogene evolution of the continental shelves of the Ross Sea and Weddell Sea, from shallow seaward sloping to overdeepened landward sloping shelves, influencing the production and dynamics of the oceans' abyssal currents. To unravel the interplay of tectonics and environmental change requires data constraining the rates of both surface processes and underlying lithospheric processes. The parallel evolutions of one of the world's largest riff systems and the world's largest ice sheets make the West Antarctic Rift System a key region for studies quantifying the effects of these processes on regional and global environmental change. An integrated approach is required to elucidate the fine structure of the interaction of tectonics, surface processes and climate in glaciated rift systems. (C) 1999 Elsevier Science B.V.