EGU2020-15058, updated on 03 Dec 2020
https://doi.org/10.5194/egusphere-egu2020-15058
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Did a Beringian ice sheet once exist?

Zhongshi Zhang1,2,3, Qing Yan4, Ran Zhang5, Florence Colleoni6, Gilles Ramstein7, Gaowen Dai1, Martin Jakobsson8,9, Matt O’Regan8,9, Stefan Liess1,10, Denis-Didier Rousseau11,12, Naiqing Wu13,14, Elizabeth J. Farmer15, Camille Contoux7, Chuncheng Guo2, Ning Tan13, and Zhengtang Guo13,14
Zhongshi Zhang et al.
  • 1Department of Atmospheric Science, School of Environmental studies, China University of Geoscience, Wuhan, 430074, China
  • 2NORCE Norwegian Research Centre, Bjerknes Centre for Climate Research, 5007 Bergen, Norway
  • 3Center for Early Sapiens Behaviour, 5007 Bergen, Norway
  • 4Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Chinese Academy of Sciences, 100029, Beijing, China
  • 5Climate Change Research Center, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
  • 6Istituto Nazionale di Oceanografia e Geofisica Sperimentale, OGS, 34010 Sgonico (TS), Italy
  • 7Laboratoire des Sciences du Climat et de l’Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
  • 8Department of Geological Sciences, Stockholm University, 10691, Stockholm, Sweden
  • 9Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
  • 10Department of Soil, Water, and Climate, University of Minnesota, Saint Paul, MN 55108, USA
  • 11Laboratoire de Meteorologie Dynamique (CNRS and Institute Pierre Simon Laplace, IPSL), Ecole Normale Superieure, Paris Sciences & Lettres (PSL) Research University, 75005 Paris, France
  • 12Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
  • 13Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
  • 14College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
  • 15E. Farmer Science Editing and Writing, Bergen, Norway

Did a Beringian ice sheet once exist? This question was hotly debated decades ago until compelling evidence for an ice-free Wrangel Island excluded the possibility of an ice sheet forming over NE Siberia-Beringia during the Last Glacial Maximum (LGM). Today, it is widely believed that during most Northern Hemisphere glaciations only the Laurentide-Eurasian ice sheets across North America and Northwest Eurasia became expansive, while Northeast Siberia-Beringia remained ice-sheet-free. However, recent recognition of glacial landforms and deposits on Northeast Siberia-Beringia and off the Siberian continental shelf has triggered a new round of debate.These local glacial features, though often interpreted as local activities of ice domes on continental shelves and mountain glaciers on continents,   could be explained as an ice sheet over NE Siberia-Beringia. Only based on the direct glacial evidence, the debate can not be resolved. Here, we combine climate and ice sheet modelling with well-dated paleoclimate records from the mid-to-high latitude North Pacific to readdress the debate. Our simulations show that the paleoclimate records are not reconcilable with the established concept of Laurentide-Eurasia-only ice sheets. On the contrary, a Beringian ice sheet over Northeast Siberia-Beringia causes feedbacks between atmosphere and ocean, the result of which well explains the climate records from around the North Pacific during the past four glacial-interglacial cycles. Our ice-climate modelling and synthesis of paleoclimate records from around the North Pacific argue that the Beringian ice sheet waxed and waned rapidly in the past four glacial-interglacial cycles and accounted for ~10-25 m ice-equivalent sea-level change during its peak glacials. The simulated Beringian ice sheet agrees reasonably with the direct glacial and climate evidence from Northeast Siberia-Beringia, and reconciles the paleoclimate records from around the North Pacific. With the Beringian ice sheet involved, the pattern of past NH ice sheet evolution is more complex than previously thought, in particular prior to the LGM.

How to cite: Zhang, Z., Yan, Q., Zhang, R., Colleoni, F., Ramstein, G., Dai, G., Jakobsson, M., O’Regan, M., Liess, S., Rousseau, D.-D., Wu, N., Farmer, E. J., Contoux, C., Guo, C., Tan, N., and Guo, Z.: Did a Beringian ice sheet once exist?, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15058, https://doi.org/10.5194/egusphere-egu2020-15058, 2020

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Display material version 1 – uploaded on 23 Apr 2020
  • CC1: Comment on EGU2020-15058, Uta Krebs-Kanzow, 06 May 2020

    Thanks for your work! I asked in the chat about height constraints. I think why people overlook potential Siberian/Beringia ice sheets is, because there is not much postglacial rebound. Is that correct? And wouldn't this imply that any potential ice sheet was not very high? And just to throw in something: could it have been more like a frozen flood plain?  

    • CC2: Reply to CC1, Z.S. Zhang, 06 May 2020

      Hi, Uta. Thanks for the question. The Beringia ice sheet should be high, about 2000-3000 m during regional full glacials (in our simulations). If the ice sheet is low, it can not cause strong climate feedbacks.

      Unfortunately, there are no direct constraints for size of the ice sheet. We can only find a rough estimation from Simms et al., 2019. A comparison between estimations of Laurentide-Eurasian ice sheet volume and direct observations of sea level change during the LGM reveals a discrepancy of unexplained missing ice with a volume of ~6-25 m ice-equivalent sea-level change. However, the simulated extent of the ice sheet agree nicely with the distribution of direct evidence.

      In future, if the rebound evidence can be found in the NE Siberian-Beringian region, this will be  robust evidence to support the existence of the ice sheet.