Basal Melting, Roughness and Structural Integrity of Ice Shelves

Ice shelves restrict outflow from many of the largest glaciers in Antarctica, thus limiting the Antarctic contribution to sea-level rise. However, past ice-shelf collapse events show they are highly vulnerable to surface and basal melting. Collapse of ice shelves in front of glaciers flowing on retrograde slopes could initiate runaway retreat processes. Difficulty in projecting how quickly these could play out makes dynamic ice loss from Antarctica the largest uncertainty in predicting future sea-level rise. Basal melting can impact structural integrity of ice shelves in several ways. Results from analyses of variations in ice-shelf roughness by Watkins et al. (2021; https://doi.org/10.1029/2021GL094743) raise the tantalizing prospect that this may provide a simple quantitative measure of how the structural integrity of an ice shelf has been impacted by basal melting. Applying the method to additional ice shelves would be useful to examine how other factors may contribute to roughness.

Automated summary

Ice shelves in Antarctica restrict the outflow of glaciers and limit the contribution to sea-level rise. However, past events have shown their vulnerability to melting, making it the largest uncertainty in predicting future sea-level rise. An analysis of ice-shelf roughness variations suggests a potential measure of the impact of basal melting on the structural integrity of ice shelves. Further research is needed to explore other contributing factors.