An updated seabed bathymetry beneath Larsen C Ice Shelf, Antarctic Peninsula

Authors Organisations
  • Alex Brisbourne(Author)
    British Antarctic Survey
  • Bernd Kulessa(Author)
    Prifysgol Abertawe | Swansea University
  • Thomas Hudson(Author)
    British Antarctic Survey
  • Lianne Harrison(Author)
    British Antarctic Survey
  • Paul Holland(Author)
    British Antarctic Survey
  • Adrian Luckman(Author)
    Prifysgol Abertawe | Swansea University
  • Suzanne Bevan(Author)
    Prifysgol Abertawe | Swansea University
  • David Ashmore(Author)
    University of Liverpool
  • Bryn Hubbard(Author)
  • Emma Pearce(Author)
    University of Leeds
  • James White(Author)
    British Geological Survey
  • Adam Booth(Author)
    University of Leeds
  • Keith Nicholls(Author)
    British Antarctic Survey
  • Andrew Smith(Author)
    British Antarctic Survey
Type Article
Original languageEnglish
Pages (from-to)887-896
JournalEarth System Science Data
Volume12
Issue number2
DOI
Publication statusPublished - 20 Apr 2020
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Abstract

In recent decades, rapid ice shelf disintegration along the Antarctic Peninsula has had a global impact through enhancing outlet glacier flow and hence sea level rise and the freshening of Antarctic Bottom Water. Ice shelf thinning due to basal melting results from the circulation of relatively warm water in the underlying ocean cavity. However, the effect of sub-shelf circulation on future ice shelf stability cannot be predicted accurately with computer simulations if the geometry of the ice shelf cavity is unknown. To address this deficit for Larsen C Ice Shelf, West Antarctica, we integrate new water column thickness measurements from recent seismic campaigns with existing observations. We present these new data here along with an updated bathymetry grid of the ocean cavity. Key findings include a relatively deep seabed to the southeast of the Kenyon Peninsula, along the grounding line and around the key ice shelf pinning-point of Bawden Ice Rise. In addition, we can confirm that the cavity's southern trough stretches from Mobiloil Inlet to the open ocean. These areas of deep seabed will influence ocean circulation and tidal mixing and will therefore affect the basal-melt distribution. These results will help constrain models of ice shelf cavity circulation with the aim of improving our understanding of sub-shelf processes and their potential influence on ice shelf stability.

The datasets are comprised of all the new point measurements of seabed depth. We present the new depth measurements here, as well as a compilation of previously published measurements. To demonstrate the improvements to the sub-shelf bathymetry map that these new data provide we include a gridded data product in the Supplement of this paper, derived using the additional measurements of both offshore seabed depth and the thickness of grounded ice.

The underlying seismic datasets that were used to determine bed depth and ice thickness are available at https://doi.org/10.5285/315740B1-A7B9-4CF0-9521-86F046E33E9A (Brisbourne et al., 2019), https://doi.org/10.5285/5D63777D-B375-4791-918F-9A5527093298 (Booth, 2019), https://doi.org/10.5285/FFF8AFEE-4978-495E-9210-120872983A8D (Kulessa and Bevan, 2019) and https://doi.org/10.5285/147BAF64-B9AF-4A97-8091-26AEC0D3C0BB (Booth et al., 2019).

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