EGU2020-15477
https://doi.org/10.5194/egusphere-egu2020-15477
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Basal melting of Dronning Maud Land ice shelves twice as high as previously estimated

Sophie Berger1,2, Veit Helm2, Tore Hattermann3, Niklas Neckel2, Quentin Glaude4,5, Ole Zeising2, Sainan Sun4, Frank Pattyn4, and Olaf Eisen2,6
Sophie Berger et al.
  • 1Université Paris Saclay, IIPCC WG1 Technical Suppport Unit, Saint-Aubin , France (sophie.berger@universite-paris-saclay.fr)
  • 2Alfred Wegener Institute, Helmholtz-Centre for Polar and Marine Research , Bremerhaven, Germany
  • 3Norwegian Polar Institute, Tromsø, Norway
  • 4Laboratoire de Glaciologie, Université libre de Bruxelles, Brussels, Belgium,
  • 5Centre Spatial de Liège, Université de Liège, Angleur, Belgium,
  • 6Department of geosciences, University of Bremen, Bremen, Germany

Basal melting of floating ice shelves is the main process by which  the Antarctic ice sheet is currently losing ice and is responsible for the accelerating Antarctic contribution to sea-level rise. Moreover, basal melting can strongly vary both spatially and temporally. Detailed observations on high  spatio-temporal scales remain however challenging, not to mention accounting for them in ice-sheet models. 

In this study, we combine CryoSat-2 and TanDEM-X elevation changes to capture in unprecedented detail the spatial (and temporal) variability of ice-shelf basal melting in the entire region of Dronning Maud Land, East Antarctica. The high spatial resolution of TanDEM-X elevations provide us with great  details on the spatial variability of the basal mass balance, whereas CryoSat-2 elevations inform us about temporal changes.

We find sub-shelf melt rates that average 1 m/a for the whole of Dronning Maud Land. Those relatively low melt rates conceal however a significant spatial variability on a wide range of scales (from sub-kilometers to ice-shelf wide scales). Spatially integrated, this basal melting represent  an annual basal loss ~140 Gt/a. This revised estimate corresponds to a two-fold increase compared to previous estimates, which could question the relative stability of ice shelves in this region. 

This study highlights different regimes in sub-shelf melting in Dronning Maud Land and  sheds new light on ice-ocean interactions in a region of Antarctica that has long been considered as very stable and which is therfore regularly overlooked.

How to cite: Berger, S., Helm, V., Hattermann, T., Neckel, N., Glaude, Q., Zeising, O., Sun, S., Pattyn, F., and Eisen, O.: Basal melting of Dronning Maud Land ice shelves twice as high as previously estimated , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15477, https://doi.org/10.5194/egusphere-egu2020-15477, 2020

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