09 Nov 2022
 | 09 Nov 2022
Status: a revised version of this preprint is currently under review for the journal TC.

Simulating the Laurentide ice sheet of the Last Glacial Maximum

Daniel Moreno, Jorge Alvarez-Solas, Javier Blasco, Marisa Montoya, and Alexander Robinson

Abstract. In the last decades, great effort has been made to reconstruct the Laurentide Ice Sheet (LIS) during the Last Glacial Maximum (LGM, ca. 21,000 years before present, 21 kyr ago). Uncertainties underlying its modelling have led to large differences in fundamental features such as its maximum elevation, extension and total volume. However, the uncertainty in ice dynamics and thus in ice extension, volume and ice-stream stability remains large. We herein use a higher-order three-dimensional ice-sheet model to simulate the LIS under LGM boundary conditions for a number of basal friction formulations of varying complexity. Their consequences on the Laurentide ice streams, configuration, extension and volume are explicitly quantified. Total volume and ice extent generally reach a constant equilibrium value that falls close to prior LIS reconstructions. Simulations exhibit high sensitivity to the dependency of the basal shear stress on the sliding velocity. In particular, a regularized-Coulomb formulation appears to be the best choice in terms of ice volume and ice-stream realism. Notable differences are found when the stress balance is thermomechanically coupled: the LIS volume is lower than for a purely mechanical friction scenario and the base remains colder. Thermomechanical coupling is fundamental for producing rapid ice streaming, yet it leads to a similar distribution of ice overall.

Daniel Moreno et al.

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on tc-2022-215', Julien Seguinot, 21 Dec 2022
    • AC1: 'Reply on RC1', Daniel Moreno-Parada, 13 Feb 2023
  • RC2: 'Comment on tc-2022-215', Niall Gandy, 21 Dec 2022
    • AC2: 'Reply on RC2', Daniel Moreno-Parada, 13 Feb 2023

Daniel Moreno et al.

Daniel Moreno et al.


Total article views: 542 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
347 183 12 542 3 4
  • HTML: 347
  • PDF: 183
  • XML: 12
  • Total: 542
  • BibTeX: 3
  • EndNote: 4
Views and downloads (calculated since 09 Nov 2022)
Cumulative views and downloads (calculated since 09 Nov 2022)

Viewed (geographical distribution)

Total article views: 532 (including HTML, PDF, and XML) Thereof 532 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 19 Mar 2023
Short summary
We have reconstructed the Laurentide Ice Sheet, placed in North America during the Last Glacial Maximum (21,000 years ago). The absence of direct measurements raises a number of uncertainties. Here we study the impact of different physical laws that describe the friction as the ice slides over its base. We found that the Laurentide Ice Sheet is closest to prior reconstructions when the basal friction takes into account whether the base is frozen or thawed during its motion.