A glacier the size of Florida could melt at a faster rate than previously anticipated. The Thwaites Glacier, located in Antarctica, has been dubbed the “doomsday” glacier because of its potential to markedly raise already rising sea levels.
The glacier could raise sea levels by 2 feet or more if melted. Its precarious location in contact with warm ocean currents makes it even more susceptible to collapse.
Scientists made the discovery after a team of researchers from the U.S., Sweden, and the United Kingdom conducted a study to determine the fastest rates the glacier has retreated in the past. Dr. Robert Larter, one of the study’s co-authors, noted the significance of the findings in the study’s release.
“Thwaites is really holding on today by its fingernails, and we should expect to see big changes over small timescales in the future — even from one year to the next — once the glacier retreats beyond a shallow ridge in its bed.”
The glacier is the widest on earth, sitting at 80 miles wide. It protects the West Antarctic Ice Sheet, acting as a buffer between the sheet and warming waters. The entire West Antarctic Ice Sheet could raise sea levels by up to 16 feet.
For the study, the researchers sent an autonomous vehicle to the glacier’s former grounding zone. The grounding zone of a glacier is where an attached ice shelf transitions into a floating ice shelf. The autonomous vehicle, named Rán, was equipped with two geophysical sensors and used to produce 3D scans of the underwater surface.
These scans allowed scientists to map the glacier’s movements throughout the last 200 years. Previously, scientists could only see its movements within the past 30 years because of satellite imagery limitations.
The study aimed to learn about the glacier’s past retreat rates to more accurately predict the rate at which it may continue to retreat. The scientists found that the glacier is capable of retreating more rapidly than previously thought. Sometime in the last 200 years, it had retreated at twice the rate it did between 2011 and 2019.
The leader of the mission, University of Florida’s Dr. Alastair Graham, warned that while the slower rate is seemingly positive, the findings confirm that the glacier is highly perceptible to changes in climate. Since the rate of the glacier retreating has pulsated, it is likely to happen again.
“Our results suggest that sustained pulses of rapid retreat have occurred at Thwaites Glacier in the past two centuries. Similar rapid retreat pulses are likely to occur in the near future when the grounding zone migrates back off stabilizing high points on the sea floor.”
Dr. Graham said that once the glacier retreats beyond a certain point, it has the potential to shrink at an even greater rate. In fact, “just a small kick to Thwaites could lead to a big response,” Dr. Graham predicted.
These findings rebut the hope once held by scientists that the Antarctic ice sheets would be more resilient to climate change.