New research by British and American scientists reveals that tidal action on the underside of Antarctica’s Thwaites Glacier will “inexorably” accelerate melting this century, potentially destabilizing the entire West Antarctic Ice Sheet and leading to its collapse.
Thwaites Glacier, roughly the size of Florida, is a focal point for scientists due to its rapid changes and significant implications for sea levels, earning it the nickname “Doomsday Glacier.” At over 2 kilometers (1,2 miles) thick in some areas, it acts as a barrier for the West Antarctic Ice Sheet. If it were to collapse, sea levels could rise by 65 centimeters (26 inches), with the potential loss of the entire ice sheet leading to a rise of 3,3 meters.
Source: NSF photo
While some models suggest that reducing greenhouse gas emissions might help slow the glacier’s retreat, the situation remains dire. Thwaites has been retreating for over 80 years, with accelerated changes in the past 30 years. New findings indicate that it will continue to retreat faster, influenced by dynamics not currently included in large-scale models.
Researchers used a torpedo-shaped robot to study the glacier’s underside, discovering that a thin layer of cold water insulates it. However, in areas where the glacier lifts off the seabed, tidal action is introducing warmer seawater under the ice, disrupting this insulating layer and likely speeding up the retreat of the grounding zone.
A concerning worst-case scenario involves the formation of 100-meter-high ice cliffs that could rapidly calve off icebergs, causing a runaway retreat that might raise sea levels by several centimeters this century. However, it’s still uncertain how likely such outcomes are.
A crucial question remains whether the loss of Thwaites Glacier is already irreversible. Although heavy snowfalls in Antarctica can replenish some ice loss, the current situation shows an imbalance where ice loss exceeds snowfall. Global warming may initially lead to increased moisture and more snowfall, but eventually, this could shift to rain and surface melting, further accelerating the glacier’s decline. The speed of these changes will depend on the progress made by nations in addressing climate change.
