The evolution of the Patagonian Ice Sheet from 35 ka to the present day (PATICE)

Authors Organisations
  • Bethan J. Davies(Author)
    Royal Holloway University of London
  • Christopher M. Darvill(Author)
    The University of Manchester
  • Harold Lovell(Author)
    University of Portsmouth
  • Jacob M. Bendle(Author)
    Royal Holloway University of London
  • Julian A. Dowdeswell(Author)
    Scott Polar Research Institute
  • Derek Fabel(Author)
    Scottish Universities Environmental Research Centre
  • Juan Luis García(Author)
    Pontificia Universidad Católica de Chile
  • Alessa Geiger(Author)
    Pontificia Universidad Católica de Chile
    University of Glasgow
  • Neil Glasser(Author)
  • Delia M. Gheorghiu(Author)
    Scottish Universities Environmental Research Centre
  • Stephan Harrison(Author)
    University of Exeter
  • Andrew S. Hein(Author)
    University of Edinburgh
  • Michael R. Kaplan(Author)
    Lamont-Doherty Earth Observatory
  • Julian R.V. Martin(Author)
    Royal Holloway University of London
  • Monika Mendelova(Author)
    University of Edinburgh
  • Adrian Palmer(Author)
    Royal Holloway University of London
  • Mauri Pelto(Author)
    Nichols College
  • Ángel Rodés(Author)
    Scottish Universities Environmental Research Centre
  • Esteban A. Sagredo(Author)
    Pontificia Universidad Católica de Chile
    Millenium Nuclei Palaeoclimate
    INEE-CNRS
  • Rachel K. Smedley(Author)
    University of Liverpool
  • John L. Smellie(Author)
    University of Leicester
  • Varyl R. Thorndycraft(Author)
    Royal Holloway University of London
Type Review article
Original languageEnglish
Article number103152
Number of pages77
JournalEarth-Science Reviews
Volume204
Early online date18 Mar 2020
DOI
Publication statusPublished - 01 May 2020
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Abstract

We present PATICE, a GIS database of Patagonian glacial geomorphology and recalibrated chronological data. PATICE includes 58,823 landforms and 1,669 geochronological ages, and extends from 38°S to 55°S in southern South America. We use these data to generate new empirical reconstructions of the Patagonian Ice Sheet (PIS) and subsequent ice masses and ice-dammed palaeolakes at 35 ka, 30 ka, 25 ka, 20 ka, 15 ka, 13 ka (synchronous with the Antarctic Cold Reversal), 10 ka, 5 ka, 0.2 ka and 2011 AD. At 35 ka, the PIS covered of 492.6 x103 km2, had a sea level equivalent of ~1,496 mm, was 350 km wide and 2090 km long, and was grounded on the Pacific continental shelf edge. Outlet glacier lobes remained topographically confined and the largest generated the suites of subglacial streamlined bedforms characteristic of ice streams. The PIS reached its maximum extent by 33 – 28 ka from 38°S to 48°S, and earlier, around 47 ka from 48°S southwards. Net retreat from maximum positions began by 25 ka, with ice-marginal stabilisation then at 21 – 18 ka, which was then followed by rapid, irreversible deglaciation. By 15 ka, the PIS had separated into disparate ice masses, draining into large ice-dammed lakes along the eastern margin, which strongly influenced rates of recession. Glacial readvances or stabilisations occurred at least at 14 – 13 ka, 11 ka, 6 – 5 ka, 2 – 1 ka, and 0.5 – 0.2 ka. We suggest that 20th century glacial recession (% a-1) is occurring faster than at any time documented during the Holocene.

Keywords

  • Geochronology, Geomorphology, Glaciation, Ice Sheet, Patagonia, Quaternary

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