Basal freeze-on generates complex ice-sheet stratigraphy.
Journal article

Basal freeze-on generates complex ice-sheet stratigraphy.

  • Leysinger Vieli GJC Glaciology and Geomorphodynamics Group, Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. gwendolyn.leysinger@geo.uzh.ch.
  • Martín C British Antarctic Survey, Natural Environment Research Council, Madingley Road, Cambridge, CB3 0ET, UK.
  • Hindmarsh RCA British Antarctic Survey, Natural Environment Research Council, Madingley Road, Cambridge, CB3 0ET, UK.
  • Lüthi MP Glaciology and Geomorphodynamics Group, Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
  • 2018-11-09
Published in:
  • Nature communications. - 2018
English Large, plume-like internal ice-layer-structures have been observed in radar images from both Antarctica and Greenland, rising from the ice-sheet base to up to half of the ice thickness. Their origins are not yet understood. Here, we simulate their genesis by basal freeze-on using numerical ice-flow modelling and analyse the transient evolution of the emerging ice-plume and the surrounding ice-layer structure as a function of both freeze-on rate and ice flux. We find good agreement between radar observations, modelled ice-plume geometry and internal layer structure, and further show that plume height relates primarily to ice-flux and only secondarily to freeze-on. An in-depth analysis, performed for Northern Greenland of observed spatial plume distribution related to ice flow, basal topography and water availability supports our findings regarding ice flux and suggests freeze-on is controlled by ascending subglacial water flow. Our results imply that widespread basal freeze-on strongly affects ice stratigraphy and consequently ice-core interpretations.
Language
  • English
Open access status
gold
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Persistent URL
https://sonar.ch/global/documents/47454
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