79 Bradley.pdf (3.16 MB)
Low post-glacial rebound rates in the Weddell Sea due to Late Holocene ice-sheet readvance
journal contribution
posted on 2023-05-18, 10:40 authored by Bradley, SL, Hindmarsh, RCA, Whitehouse, PL, Bentley, MJ, Matt KingMatt KingMany ice-sheet reconstructions assume monotonic Holocene retreat for the West Antarctic Ice Sheet, but an increasing number of glaciological observations infer that some portions of the ice sheet may be readvancing, following retreat behind the present-day margin. A readvance in the Weddell Sea region can reconcile two outstanding problems: (i) the present-day widespread occurrence of seemingly stable ice streams grounded on beds that deepen inland; and (ii) the inability of models of glacial isostatic adjustment to match present-day uplift rates. By combining a suite of ice loading histories that include a readvance with a model of glacial isostatic adjustment we report substantial improvements to predictions of present-day uplift rates, including reconciling one problematic observation of land sinking. We suggest retreat behind present grounding lines occurred when the bed was lower, and isostatic recovery has since led to shallowing, ice sheet re-grounding and readvance. The paradoxical existence of grounding lines in apparently unstable configurations on reverse bed slopes may be resolved by invoking the process of unstable advance, in accordance with our load modelling.
Funding
Australian Research Council
History
Publication title
Earth and Planetary Science LettersVolume
413Pagination
79-89ISSN
0012-821XDepartment/School
School of Geography, Planning and Spatial SciencesPublisher
Elsevier Science BvPlace of publication
Po Box 211, Amsterdam, Netherlands, 1000 AeRights statement
Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) https://creativecommons.org/licenses/by-nc-nd/4.0/Repository Status
- Open