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First exposure ages from the Amundsen Sea Embayment, West Antarctica: The Late Quaternary context for recent thinning of Pine Island, Smith, and Pope Glaciers

2008; Geological Society of America; Volume: 36; Issue: 3 Linguagem: Inglês

10.1130/g24207a.1

1943-2682

Joanne S. Johnson, Michael J. Bentley, Karsten Gohl,

Polar Research and Ecology

Research Article| March 01, 2008 First exposure ages from the Amundsen Sea Embayment, West Antarctica: The Late Quaternary context for recent thinning of Pine Island, Smith, and Pope Glaciers Joanne S. Johnson; Joanne S. Johnson 1British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK Search for other works by this author on: GSW Google Scholar Michael J. Bentley; Michael J. Bentley 2Department of Geography, Durham University, South Road, Durham DH1 3LE, UK and British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK Search for other works by this author on: GSW Google Scholar Karsten Gohl Karsten Gohl 3Alfred-Wegener-Institut für Polar- und Meeresforschung, Postfach 120161, D-27515 Bremerhaven, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information Joanne S. Johnson 1British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK Michael J. Bentley 2Department of Geography, Durham University, South Road, Durham DH1 3LE, UK and British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK Karsten Gohl 3Alfred-Wegener-Institut für Polar- und Meeresforschung, Postfach 120161, D-27515 Bremerhaven, Germany Publisher: Geological Society of America Received: 22 Jun 2007 Revision Received: 15 Nov 2007 Accepted: 25 Nov 2007 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 The Geological Society of America, Inc. Geology (2008) 36 (3): 223–226. https://doi.org/10.1130/G24207A.1 Article history Received: 22 Jun 2007 Revision Received: 15 Nov 2007 Accepted: 25 Nov 2007 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Joanne S. Johnson, Michael J. Bentley, Karsten Gohl; First exposure ages from the Amundsen Sea Embayment, West Antarctica: The Late Quaternary context for recent thinning of Pine Island, Smith, and Pope Glaciers. Geology 2008;; 36 (3): 223–226. doi: https://doi.org/10.1130/G24207A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Dramatic changes (acceleration, thinning, and grounding-line retreat of major ice streams) in the Amundsen Sea sector of the West Antarctic Ice Sheet (WAIS) have been observed during the past two decades, but the millennial-scale context for these changes is not yet known. We present the first surface exposure ages recording thinning of Pine Island, Smith, and Pope Glaciers, which all drain into the Amundsen Sea. From these we infer progressive thinning of Pine Island Glacier at an average rate of 3.8 ± 0.3 cm yr−1 for at least the past 4.7 k.y., and of Smith and Pope Glaciers at 2.3 ± 0.2 cm yr−1 over the past 14.5 k.y. These rates are more than an order of magnitude lower than the ∼1.6 m yr−1 recorded by satellite altimetry for Pine Island Glacier in the period 1992–1996. Similarly low long-term rates (2.5–9 cm yr−1 since 10 ka) have been reported farther west in the Ford Ranges, Marie Byrd Land, but in that area, the same rates of thinning continue to the present day. Our data provide the first evidence that puts into context recent rates of thinning of the WAIS in the Amundsen Sea Embayment and demonstrates that these are unusually rapid. The data also provide much-needed constraints for ice sheet models, which are the primary tool for predicting the future behavior of the WAIS and its likely contribution to sea-level rise. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.