Work

Direct Geologic Constraints on the Timing of Late Holocene Ice Thickening in the Amundsen Sea Embayment, Antarctica

Year: 2024

Type: article

Abstract: Constraining past West Antarctic Ice Sheet (WAIS) change helps validate numerical models simulating future ice sheet dynamics. Following rapid deglaciation during the mid‐Holocene, ice near Thwaites Glacier was ∼35 m thinner than present; however, the timing of ice regrowth to its present configuration remains unknown. To fill this knowledge gap, we present cosmogenic nuclide exposure ages of cobbles from the surface of a moraine situated between Thwaites and Pope glaciers. We infer that the moraine formed and stabilized in the Late Holocene (∼1.4 ka) when a small glacier thickened. We also present a novel reconstruction of WAIS volume constrained by sea‐level data, which demonstrates that moraine formation coincided with a large‐scale WAIS readvance. Our new geologic constraints will help inform models of the solid Earth response to surface mass loading, improving our understanding of ice sheet dynamics in a vulnerable part of WAIS.

Source: Geophysical Research Letters

DOI: 10.1029/2024gl110350

Authors: Keir A. Nichols, Jonathan R. Adams, Katie Brown, Roger C. Creel, Marion A. McKenzie, Ryan A. Venturelli, Joanne S. Johnson, Dylan H. Rood, Klaus Wilcken, John Woodward, Stephen J. Roberts

Institutions: Imperial College London, British Antarctic Survey, University College London, Woods Hole Oceanographic Institution, Colorado School of Mines, Australian Nuclear Science and Technology Organisation, Northumbria University

Language: English

Topic: Cryospheric studies and observations

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDG: Climate action

Open Access status: gold

Estimated APC paid: $2,900

Funders: National Science Foundation, National Aeronautics and Space Administration, Australian Nuclear Science and Technology Organisation, Sight Research UK, Office of Nuclear Energy, Natural Environment Research Council, Office of Polar Programs, British Antarctic Survey

Awards: G1104663396, G1173262082, G2143310323, G2810269120, G3061010496, Postdoctoral Fellowship: EAR-PF: Pairing on-and-offshore observations of paleo-ice streams to constrain and elucidate dynamics of the Cordilleran Ice Sheet (PISCES), G4399130109, Reconstructing millennial-scale ice sheet change in the western AmundsSea Embaymenten , Antarctica, using high-precision exposure dating., G4861057680, G5957514831, NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System, G6253087171, G6283662192, NSFPLR-NERC: Geological history constraints on the magnitude of grounding line retreat in the Thwaites Glacier system, G672490221, G7106786466, Reconstructing millennial-scale ice sheet change in the western Amundsen Sea Embayment, Antarctica, using high-precision exposure dating., NSFPLR-NERC: Geological history constraints on the magnitude of grounding line retreat in the Thwaites Glacier system, G8989489056, G9000205966, G9000239457

OpenAlex ID: W4405577218

FWCI: 0.555

Cites: 89

Cited by: 2

Related to: 10