[DLS] Rob DeConto (UMass Amherst)

“Rethinking ice-cliff calving on a warming Antarctica”

Most of the Antarctic Ice Sheet margin terminates in the ocean, where seaward-flowing glaciers coalesce to form floating ice shelves. When confined or pinned on submarine bedrock, ice shelves buttress seaward ice flow and provide structural support at grounding zones where the grounded ice sheet transitions to floating ice shelf. Many Antarctic ice shelves are currently thinning in response to elevated sub-ice ocean temperatures making them more vulnerable to surface warming and meltwater. It is widely accepted that the loss or thinning of buttressing ice shelves allows faster seaward ice flow, resulting in sea level rise. The onset of rapid calving and brittle failure at thick, marine-terminating ice fronts has also been proposed as a possible consequence of ice shelf loss. However, this latter process and its impact on sea level rise remains heavily contested, complicating coastal planning efforts and policy decisions. Here, I’ll introduce a new approach to modeling calving at thick, unbuttressed ice fronts accounting for multi-mode ice failure, preexisting damage and meltwater-enhanced crevassing. Calving rates in the new model are in close agreement with observations in Greenland and support the notion that the onset of rapid and sustained ice-cliff calving is indeed possible in some Antarctic settings.

EAPS Department Lecture Series
Weekly talks aimed to bring together the entire EAPS community, given by leading thinkers in the areas of geology, geophysics, geobiology, geochemistry, atmospheric science, oceanography, climatology, and planetary science. Runs concurrently with class 12.S501.

Contact: eapsinfo@mit.edu