AuthorsR. Nerlich, S. Clark and H. Bunge
TitleThe Scotia Sea Gateway: No Outlet for Pacific Mantle
AfilliationScientific Computing, Scientific Computing
StatusPublished
Publication TypeJournal Article
Year of Publication2012
JournalTectonophysics
Volume604
Number24 September
Pagination41-50
PublisherElsevier
Abstract

The Scotia Sea in the South Atlantic holds a prominent position in geodynamics, because it has been proposed as a potential outlet of asthenosphere from under the shrinking Pacific into the mantle beneath the opening Atlantic. Shear wave splitting and geochemical studies have previously tested this hypothesis. Here, we take a different approach by calculating present-day dynamic topography of the region in search for a systematic trend in dynamic topography decreasing from west to east in response to a flow-related pressure gradient in the sublithospheric mantle. To this end, we reconstruct the kinematic history of the Scotia Sea, which is characterized by complex back-arc spreading processes active on a range of time scales. Our plate reconstructions allow us to derive an oceanic age-grid and to calculate the associated residual (dynamically maintained) topography of the Scotia Sea by comparing present-day isostatically corrected topography with that predicted from our reconstruction. The results provide no indication for a systematic trend in dynamic topography and we conclude that the material needed to supply the growing subatlantic mantle must be derived from elsewhere.

Citation KeySimula.simula.1648

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