A Centuries-Long Delay between a Paleo-Ice-Shelf Collapse and Grounding-Line Retreat in the Whales Deep Basin, Eastern Ross Sea, Antarctica

Authors

Philip J. Bart, Louisiana State University
Matthew DeCesare, Auburn University
Brad E. Rosenheim, University of South FloridaFollow
Wojceich Majewski, Polish Academy of Sciences
Austin McGlannan, The University of Oklahoma

Document Type

Article

Publication Date

2018

Digital Object Identifier (DOI)

https://doi.org/10.1038/s41598-018-29911-8

Abstract

Recent thinning and loss of Antarctic ice shelves has been followed by near synchronous acceleration of ice flow that may eventually lead to sustained deflation and significant contraction in the extent of grounded and floating ice. Here, we present radiocarbon dates from foraminifera that constrain the time elapsed between a previously described paleo-ice-shelf collapse and the subsequent major grounding-line retreat in the Whales Deep Basin (WDB) of eastern Ross Sea. The dates indicate that West Antarctic Ice Sheet (WAIS) grounding-line retreat from the continental shelf edge was underway prior to 14.7 ± 0.4 cal kyr BP. A paleo-ice-shelf collapse occurred at 12.3 ± 0.2 cal kyr BP. The grounding position was maintained on the outer-continental shelf until at least 11.5 ± 0.3 cal kyr BP before experiencing a 200-km retreat. Given the age uncertainties, the major grounding-line retreat lagged ice-shelf collapse by at least two centuries and by as much as fourteen centuries. In the WDB, the centuries-long delay in the retreat of grounded ice was partly due to rapid aggradational stacking of an unusually large volume of grounding-zone-wedge sediment as ice-stream discharge accelerated following ice-shelf collapse. This new deglacial reconstruction shows that ongoing changes to ice shelves may trigger complex dynamics whose consequences are realized only after a significant lag.

Rights Information

This work is licensed under a Creative Commons Attribution 4.0 License.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Scientific Reports, v. 8, art. 12392

Scholar Commons Citation

Bart, Philip J.; DeCesare, Matthew; Rosenheim, Brad E.; Majewski, Wojceich; and McGlannan, Austin, "A Centuries-Long Delay between a Paleo-Ice-Shelf Collapse and Grounding-Line Retreat in the Whales Deep Basin, Eastern Ross Sea, Antarctica" (2018). Marine Science Faculty Publications. 1292.
https://digitalcommons.usf.edu/msc_facpub/1292