[Fleuves de glace : toujours plus vite ?]
L'écoulement rapide des fleuves de glace est causé soit par leur grande épaisseur, soit par une lubrification efficace à la base, en particulier due aux sédiments sous-glaciaires déformés. Les différents processus thermiques en compétition peuvent stabiliser ou déstabiliser ces fleuves de glace lubrifiés, ce qui pourrait contribuer à leur variabilité à court terme comme à leur persistance à long terme. Les évidences s'accumulent en faveur d'une accélération des fleuves de glace en réponse au réchauffement climatique global, par un amincissement ou un retrait des plate-formes glaciaires, et peut-être par la pénétration d'eau de fonte vers le lit glaciaire.
Rapid flow of ice streams is caused either by great thickness, or by effective basal lubrication especially from deforming tills. Competing thermal processes act to stabilize and to destabilize the well-lubricated ice streams, and may contribute to their observed short-term variability yet long-term persistence. Increasing evidence indicates that ice streams are subject to speed-up in response to warming, through thinning or loss of ice shelves, and possibly in response to meltwater penetration to ice-stream beds.
Mot clés : Fleuves de glace, Calottes polaires, Antarctique, Groenland, Sédiments sous glaciaires, Niveau des mers, Plate-forme glaciaire
Richard B. Alley 1 ; Sridhar Anandakrishnan 1 ; Todd K. Dupont 1 ; Byron R. Parizek 1
@article{CRPHYS_2004__5_7_723_0, author = {Richard B. Alley and Sridhar Anandakrishnan and Todd K. Dupont and Byron R. Parizek}, title = {Ice streams{\textemdash}fast, and faster?}, journal = {Comptes Rendus. Physique}, pages = {723--734}, publisher = {Elsevier}, volume = {5}, number = {7}, year = {2004}, doi = {10.1016/j.crhy.2004.08.002}, language = {en}, }
Richard B. Alley; Sridhar Anandakrishnan; Todd K. Dupont; Byron R. Parizek. Ice streams—fast, and faster?. Comptes Rendus. Physique, Volume 5 (2004) no. 7, pp. 723-734. doi : 10.1016/j.crhy.2004.08.002. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/j.crhy.2004.08.002/
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