Deglacial grounding-line retreat in the Ross Embayment, Antarctica, controlled by ocean and atmosphere forcing

Lowry, Daniel P.; Golledge, Nicholas R.; Bertler, Nancy A.N.; Jones, R. Selwyn; McKay, Robert

doi:10.1126/sciadv.aav8754

Deglacial grounding-line retreat in the Ross Embayment, Antarctica, controlled by ocean and atmosphere forcing

Lowry, Daniel P.; Golledge, Nicholas R.; Bertler, Nancy A.N.; Jones, R. Selwyn; McKay, Robert

Authors

Daniel P. Lowry

Nicholas R. Golledge

Nancy A.N. Bertler

R. Selwyn Jones

Robert McKay

Abstract

Modern observations appear to link warming oceanic conditions with Antarctic ice sheet grounding-line retreat. Yet, interpretations of past ice sheet retreat over the last deglaciation in the Ross Embayment, Antarctica’s largest catchment, differ considerably and imply either extremely high or very low sensitivity to environmental forcing. To investigate this, we perform regional ice sheet simulations using a wide range of atmosphere and ocean forcings. Constrained by marine and terrestrial geological data, these models predict earliest retreat in the central embayment and rapid terrestrial ice sheet thinning during the Early Holocene. We find that atmospheric conditions early in the deglacial period can enhance or diminish ice sheet sensitivity to rising ocean temperatures, thereby controlling the initial timing and spatial pattern of grounding-line retreat. Through the Holocene, however, grounding-line position is much more sensitive to subshelf melt rates, implicating ocean thermal forcing as the key driver of past ice sheet retreat.

Citation

Lowry, D. P., Golledge, N. R., Bertler, N. A., Jones, R. S., & McKay, R. (2019). Deglacial grounding-line retreat in the Ross Embayment, Antarctica, controlled by ocean and atmosphere forcing. Science Advances, 5(8), Article eaav8754. https://doi.org/10.1126/sciadv.aav8754

Journal Article Type	Article
Acceptance Date	Jul 9, 2019
Online Publication Date	Aug 14, 2019
Publication Date	Aug 31, 2019
Deposit Date	Sep 4, 2019
Publicly Available Date	Sep 4, 2019
Journal	Science Advances
Publisher	American Association for the Advancement of Science
Peer Reviewed	Peer Reviewed
Volume	5
Issue	8
Article Number	eaav8754
DOI	https://doi.org/10.1126/sciadv.aav8754

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Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).
This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.