Age-Depth Stratigraphy of Pine Island Glacier Inferred From Airborne Radar and Ice-Core Chronology



Bodart, JA, Bingham, RG, Ashmore, DW ORCID: 0000-0003-4829-7854, Karlsson, NB, Hein, AS and Vaughan, DG
(2021) Age-Depth Stratigraphy of Pine Island Glacier Inferred From Airborne Radar and Ice-Core Chronology. JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE, 126 (4).

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Abstract

<jats:title>Abstract</jats:title><jats:p>Understanding the contribution of the West Antarctic Ice Sheet (WAIS) to past and future sea level has been a major scientific priority over the last three decades. In recent years, observed thinning and ice‐flow acceleration of the marine‐based Pine Island Glacier has highlighted that understanding dynamic changes is critical to predicting the long‐term stability of the WAIS. However, relatively little is known about the evolution of the catchment during the Holocene. Internal reflecting horizons (IRHs) provide a cumulative record of accumulation, basal melt, and ice dynamics that, if dated, can be used to constrain ice‐flow models. Here, we use airborne radars to trace four spatially extensive IRHs deposited in the late Quaternary across the Pine Island Glacier catchment. We use the WAIS Divide ice‐core chronology to assign ages to three IRHs: 4.72 ± 0.28, 6.94 ± 0.31, and 16.50 ± 0.79 ka. We use a 1‐D model, constrained by observational and modeled accumulation rates, to produce an independent validation of our ice‐core‐derived ages and provide an age estimate for our shallowest IRH (2.31–2.92 ka). We find that our upper three IRHs correspond to three large peaks in sulfate concentrations in the WAIS Divide ice‐core record and hypothesize that the origin of these spatially extensive IRHs is from past volcanic activity. The clear correspondence between our IRHs and the ones previously identified over the Weddell Sea Sector, altogether representing ∼20% of the WAIS, indicates that a unique set of stratigraphic markers spanning the Holocene exists over a large part of West Antarctica.</jats:p>

Item Type: Article
Uncontrolled Keywords: Englacial stratigraphy, Holocene, ice&#8208, penetrating radar, Pine Island Glacier, Thwaites Glacier, West Antarctica
Divisions: Faculty of Science and Engineering > School of Environmental Sciences
Depositing User: Symplectic Admin
Date Deposited: 11 May 2021 07:58
Last Modified: 04 Sep 2023 02:33
DOI: 10.1029/2020JF005927
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3121503