EGU2020-13504
https://doi.org/10.5194/egusphere-egu2020-13504
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Limited Retreat of the Wilkes Basin Ice Sheet during the Last Interglacial.

Johannes Sutter1, Olaf Eisen2, Martin Werner2, Klaus Grosfeld2, Thomas Kleiner2, and Hubertus Fischer1
Johannes Sutter et al.
  • 1University of Bern, Climate and Environmental Physics (CEP), Switzerland (johannes.sutter@awi.de)
  • 2Alfred Wegener Institute Helmholtz-Centre for Polar and Marine Research, Bremerhaven, Germany

The response of the marine sectors of the East Antarctic Ice Sheet to future global warming represents a major source of uncertainty in sea level projections. If greenhouse gas emissions continue unbridled, ice loss in these areas may contribute up to several meters to long-term global sea level rise. In East Antarctica, thinning of the ice cover of the George V and Sabrina Coast is currently taking place, and its destabilization in past warm climate periods has been implied. The extent of such past interglacial retreat episodes cannot yet be quantitatively derived from paleo proxy records alone. Ice sheet modelling constrained by paleo observations is therefore critical to assess the stability of the East Antarctic Ice Sheet during warmer climates. We propose that a runaway retreat during the Last Interglacial of the George V Coast grounding line into the Wilkes Subglacial Basin would either leave a clear imprint on the water isotope composition in the neighbouring Talos Dome ice-core record or prohibit the preservation of an ice core record from the Last Interglacial alltogether. We test this hypothesis using a dynamic ice sheet model and infer that the marine Wilkes Basin ice sheet remained stable throughout the Last Interglacial (130,000-120,000 years ago). Our analysis provides the first constraint on Last Interglacial East Antarctic grounding line stability by benchmarking ice sheet model simulations with ice core records. Our findings also imply that ambitious mitigation efforts keeping global temperature rise in check could safeguard this region from irreversible ice loss in the long term.

How to cite: Sutter, J., Eisen, O., Werner, M., Grosfeld, K., Kleiner, T., and Fischer, H.: Limited Retreat of the Wilkes Basin Ice Sheet during the Last Interglacial., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13504, https://doi.org/10.5194/egusphere-egu2020-13504, 2020

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