Details

Autor(en) / Beteiligte

• Larter, Robert D.

Titel

Basal Melting, Roughness and Structural Integrity of Ice Shelves

Ist Teil von

• Geophysical research letters, 2022-02, Vol.49 (4), p.n/a

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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. Plain Language Summary In many places around Antarctica, and some around Greenland, glaciers flowing on beds that are hundreds of meters below sea level continue out over the sea for some distance, forming “ice shelves”. Over the past 40 years, break‐up of several ice shelves has been observed and shown to result from melting on their surface and/or at their base. Subsequent increases in the flow speed of glaciers that flowed into them confirmed that ice shelves restrict outflow of glaciers and thus limit their contribution to sea‐level rise. Furthermore, changes resulting from removal of ice shelves could lead to runaway retreat of glaciers flowing on beds that get deeper upstream, and lack of knowledge about whether and how quickly this will happen is the largest uncertainty in predicting future sea‐level rise. Basal melting weakens ice shelves in several ways. Results from analyses of variations in thickness, or “roughness”, of ice shelves by Watkins et al. (2021; https://doi.org/10.1029/2021GL094743) suggest that they may provide a measure of the extent to which basal melting has weakened an ice shelf. Conducting similar analyses on additional ice shelves would help show the extent to which other processes contribute to roughness. Key Points Ice shelves restrict glacier flow but are vulnerable to environmental change Basal melting can impact the structural integrity of ice shelves in several ways A new study suggests that ice‐shelf roughness may provide a measure of the extent to which basal melting has impacted structural integrity