The stability of present-day Antarctic grounding lines – Parts 1 & 2

8 September 2023

Part 1: The grounding lines of the Antarctic Ice Sheet could enter phases of irreversible retreat or advance. The authors use three ice sheet models to show that the present-day locations of Antarctic grounding lines are reversible with respect to a small perturbation away from their current position. This indicates that present-day retreat of the grounding lines is not yet irreversible or self-enhancing.

The stability of present-day Antarctic grounding lines – Part 1: No indication of marine ice sheet instability in the current geometry

Emily A. Hill, Benoît Urruty, Ronja Reese, Julius Garbe, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, Ricarda Winkelmann, Mondher Chekki, David Chandler, and Petra M. Langebroek

The Cryosphere, 17, 3739–3759, https://doi.org/10.5194/tc-17-3739-2023, 2023

Contact: Olivier Gagliardini (olivier.gagliardini@univ-grenoble-alpes.fr)

Part 2: The authors use an ice sheet model to test where current climate conditions in Antarctica might lead. They find that present-day ocean and atmosphere conditions might commit an irreversible collapse of parts of West Antarctica which evolves over centuries to millennia. Importantly, this collapse is not irreversible yet.

The stability of present-day Antarctic grounding lines – Part 2: Onset of irreversible retreat of Amundsen Sea glaciers under current climate on centennial timescales cannot be excluded

Ronja Reese, Julius Garbe, Emily A. Hill, Benoît Urruty, Kaitlin A. Naughten, Olivier Gagliardini, Gaël Durand, Fabien Gillet-Chaulet, G. Hilmar Gudmundsson, David Chandler, Petra M. Langebroek, and Ricarda Winkelmann

The Cryosphere, 17, 3761–3783, https://doi.org/10.5194/tc-17-3761-2023, 2023

Contact: Ronja Reese (ronja.reese@northumbria.ac.uk)

Youtube video: https://www.youtube.com/watch?v=wsSD_vuBz-s

Related press releases:
Northumbria University: https://newsroom.northumbria.ac.uk/pressreleases/west-antarctic-ice-sheet-has-not-reached-its-tipping-point-towards-irreversible-collapse-yet-new-research-finds-3271670
Potsdam Institute for Climate Impact Research: https://www.pik-potsdam.de/en/news/latest-news/stability-inspection-for-west-antarctica-shows-marine-ice-sheet-is-not-destabilized-yet-but-possibly-on-a-path-to-tipping (English)
https://www.pik-potsdam.de/de/aktuelles/nachrichten/stabilitaetspruefung-fuer-die-westantarktis-mariner-eisschild-bislang-nicht-destabilisiert-aber-moeglicherweise-auf-dem-weg-zum-kipppunkt?set_language=de (German)
Université Grenoble Alpes: https://www.univ-grenoble-alpes.fr/actualites/a-la-une/actualites-recherche/perte-de-glace-de-la-calotte-glaciaire-de-l-antarctique-son-futur-n-est-pas-encore-ecrit-1292104.kjsp