EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Could the Laurentide Ice Sheet have exhibited internal oscillations?

Daniel Moreno1,2, Jorge Alvarez-Solas1,2, Marisa Montoya1,2, Javier Blasco1,2, and Alexander Robinson1,2,3
Daniel Moreno et al.
  • 1Universidad Complutense de Madrid, Faculty of Physics, Earth Physics and Astrophysics, Spain (
  • 2Geosciences Institute CSIC-UCM, Madrid, Spain
  • 3Potsdam Institute for Climate Impact Research, Potsdam, Germany

It is well known that the climate during the last glacial period was far from stable. The presence of layers of ice-rafted debris (IRD) in deep-sea sediments has been interpreted to reflect quasi-periodic episodes of massive iceberg calving from the Laurentide Ice Sheet (LIS). Several mechanisms have been proposed, yet the ultimate cause of these events is still under debate. From the point of view of ice dynamics, one of the main sources of uncertainty and diversity in model response is the choice of the basal friction law. Therefore, it is essential to determine the impact of basal friction on ice-stream surges. Here we study the effect of a wide range of basal friction parameters and laws for the LIS under constant LGM boundary conditions by running ensembles of simulations using a higher-order ice-sheet model. The potential feedbacks among till mechanics, basal hydrology and thermodynamics are also considered to shed light on the behaviour of the ice flow. Our aim is to determine under what conditions, if any, physically-based internal oscillations are possible in the LIS. Increasing our understanding of both basal friction laws and basal hydrology will improve not only reconstructions of paleo ice dynamics but also help to constrain the potential future evolution of current ice sheets.

How to cite: Moreno, D., Alvarez-Solas, J., Montoya, M., Blasco, J., and Robinson, A.: Could the Laurentide Ice Sheet have exhibited internal oscillations?, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3080,, 2022.