by Valerie Wong (’24) | October 7, 2022

Thwaites Glacier, one of the world’s biggest glaciers, is on the verge of collapse. Some call it the “doomsday glacier” because of the catastrophic effects of its potential melting. If left unchecked, its collapse could result in a global sea level rise of up to eleven feet. 

Thwaites Glacier is a part of the West Antarctic Ice Sheet. Part of the glacier is anchored on land, but much of it protrudes into the Amundsen Sea. However, unlike typical glaciers, it is grounded to the seabed instead of land, making it especially susceptible to melting from underneath. The glacier rests on a piece of land with a “retrograde slope”—this means that the land slopes downwards, creating a “bowl” that the glacier sits in where the rim, or grounding line, represents the place where the glacier first meets the sea floor. 

Currently, this grounding line is stable because the glacier is grounded on a “pinning point,” or ridge, that grabs onto the glacier’s base, effectively stabilizing its melting rate. However, the glacier will soon become detached from its current pinning point, allowing water to flow underneath it and accelerate melting. 

In 2019, scientists were able to map the ocean floor near Thwaites Glacier due to the unprecedented melting of sea ice. They found a pattern of ridges along the ocean floor, which served as a physical record of the glacier’s retreat as the ice melted and reformed on the seabed through the seasons. By using these ridges, scientists were able to determine that the melting rate of Thwaites has increased to approximately 1.3 miles per year. 

Once the glacier melts enough, the remaining ice shelf will become structurally unstable and could collapse upon itself. For over 60% of the world’s population, this collapse would be disastrous. Islands like Kiribati and the Maldives would become completely submerged as a result of global flooding.

The United States National Climate Assessment predicts between one to four feet of sea level rise by 2100. Similarly, the Intergovernmental Panel on Climate Change predicts 1.5 to three feet of sea level rise if the current trend of carbon emissions continues. However, neither of these projections accounts for the potential eleven foot sea level rise if the West Antarctic Ice Sheet is lost. Cities worldwide would be entirely unprepared for such a catastrophe. 

Thwaites may be nicknamed the “Doomsday Glacier,” but that does not mean the situation is hopeless. Although the Thwaites Glacier will eventually melt, we can help alleviate this pressing environmental issue by lowering carbon emissions to keep the melting crisis from intensifying.