Regional changes in icescape impact shelf circulation and basal melting

• Published in: Geophysical Research Letters
• Main Authors: Cougnon, EA, Galton-Fenzi, BK, Rintoul, SR, Legresy, B, Williams, GD, Fraser, AD, Hunter, JR
• Format: Article in Journal/Newspaper
• Language: English
• Published: Amer Geophysical Union 2017
• Subjects: ocean-ice shelf interactions; Mertz Glacier; Antarctica; regional icescape changes; iceberg; calving; Antarctic; East Antarctica; Mertz Glacier Tongue; Antarc*; Ice Shelf; Ice Shelves; Iceberg*; Sea ice
• Online Access: https://eprints.utas.edu.au/25978/; https://eprints.utas.edu.au/25978/1/122422%20final.pdf; https://doi.org/10.1002/2017GL074943

Ice shelf basal melt is the dominant contribution to mass loss from Antarctic ice shelves. However, the sensitivity of basal melt to changes in icescape (grounded icebergs, ice shelves and sea ice) and related ocean circulation is poorly understood. Here, we simulate the impact of the major 2010 calving event of the Mertz Glacier Tongue (MGT), East Antarctica, and related redistribution of sea ice and icebergs on the basal melt rate of the local ice shelves. We find that the position of the grounded tabular iceberg B9B controls the water masses that reach the nearby ice shelf cavities. After the calving of the MGT and the removal of B9B, warmer water is present both within the MGT cavity and on the continental shelf driving a 57% increase of the deep MGT basal melting. Major changes in icescape influence the oceanic heat flux responsible for basal ice shelf melting.