Weakening of the pinning point buttressing Thwaites Glacier, West Antarctica ...

• Main Author: Unkn Unknown
• Format: Article in Journal/Newspaper
• Language: English
• Published: My University 2022
• Subjects: Thwaites Glacier; West Antarctica; Western Glacier; Antarc*; Antarctica; Ice Sheet; Ice Shelf
• Online Access: https://dx.doi.org/10.34944/dspace/9302; https://scholarshare.temple.edu/handle/20.500.12613/9340

The Thwaites Eastern Ice Shelf buttresses a significant portion of Thwaites Glacier through contact with a pinning point 40 km offshore of the present grounding line. Predicting future rates of Thwaites Glacier’s contribution to sea-level rise depends on the evolution of this pinning point and the resultant change in the ice-shelf stress field since the breakup of the Thwaites Western Glacier Tongue in 2009. Here we use Landsat-8 feature tracking of ice velocity in combination with ice-sheet model perturbation experiments to show how past changes in flow velocity have been governed in large part by changes in lateral shear and pinning point interactions with the Thwaites Western Glacier Tongue. We then use recent satellite altimetry data from ICESat-2 to show that Thwaites Glacier’s grounding line has continued to retreat rapidly; in particular, the grounded area of the pinning point is greatly reduced from earlier mappings in 2014, and grounded ice elevations are continuing to decrease. This loss has ...