A Full-Stokes 3D Calving Model applied to a large Greenlandic Glacier

Authors Organisations
  • Joe Todd(Author)
    University of St Andrews
  • Poul Christoffersen(Author)
    Scott Polar Research Institute
  • Thomas Zwinger(Author)
  • Peter Råback(Author)
  • Nolwenn Chauché(Author)
  • Douglas Benn(Author)
    University of St Andrews
  • Adrian J. Luckman(Author)
    Prifysgol Abertawe | Swansea University
  • Johnny Ryan(Author)
  • Nick Toberg(Author)
    University of Cambridge
  • Donald Slater(Author)
    University of Edinburgh
  • Alun Hubbard(Author)
Type Article
Original languageEnglish
Pages (from-to)410-432
Number of pages22
JournalJournal of Geophysical Research: Earth Surface
Volume123
Issue number3
Early online date30 Jan 2018
DOI
Publication statusPublished - 01 Mar 2018
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Abstract

Iceberg calving accounts for around half of all mass loss from both the Greenland and Antarctic ice sheets. The diverse nature of calving and its complex links to both internal dynamics and climate make it challenging to incorporate into models of glaciers and ice sheets. Here, we present results from a new open-source 3D full-Stokes calving model developed in Elmer/Ice. The calving model implements the crevasse depth criterion, which states that calving occurs when surface and basal crevasses penetrate the full thickness of the glacier. The model also implements a new 3D rediscretization approach and a time-evolution scheme which allow the calving front to evolve realistically through time. We test the model in an application to Store Glacier, one of the largest outlet glaciers in West Greenland, and find that it realistically simulates the seasonal advance and retreat when two principal environmental forcings are applied. These forcings are 1) submarine melting in distributed and concentrated forms, and 2) ice mélange buttressing. We find that ice mélange buttressing is primarily responsible for Store Glacier's seasonal advance and retreat. Distributed submarine melting prevents the glacier from forming a permanent floating tongue, while concentrated plume melting has a disproportionately large and potentially destabilizing effect on the calving front position. Our results also highlight the importance of basal topography, which exerts a strong control on calving, explaining why Store Glacier has remained stable during a period when neighboring glaciers have undergone prolonged interannual retreat

Keywords

  • calving, Greenland, modelling