The effects of climate change are becoming increasingly visible around the world, but the polar regions are suffering the most. In Antarctica, glaciers are melting and retreating, and the most vulnerable is the massive Toits Glacier. Researchers mapped the land beneath the glacier for the first time to see how it will evolve in the future.
Also known as the “doomsday” glacier, Touates extends into the ice shelf, which goes into the ocean. Most of the ice shelf is below sea level simply because it is huge and heavy. The point where the glacier meets the seafloor is called the grounding zone, and it has receded 14 kilometers (about 9 miles) since the late 1990s due to melting. If the entire ice shelf melted, sea level would rise by about half a meter in a few centuries. If the entire glacier melted, it would add several meters to the same timeline.
Researchers used different methods to study the land beneath Tuites. They expected more rocks, but instead found a lot of sediment. “The sediments contribute to a faster flow, similar to sliding through mud,” lead author Dr. Tom Jordan, a geophysicist with the British Antarctic Survey (BAS), said in a statement. “We now have a map of where the slippery deposits are, and we can better predict how the glacier will behave in the future as it retreats.”
The work was done using an airplane equipped with ice-penetrating radar, a device that can look through hundreds or thousands of meters of ice to reach the rocks of the ground and seafloor, and sensors sensitive to small changes in both gravity and magnetism from the rocks below the glacier.
“The complex nature of the aerial survey was one of the keys to this study. Each sensor on the plane provided an important but incomplete part of the picture, but by combining them all together, we could make a detailed map of the underlying geology,” Jordan explained.
“The integrated approach used in this study has significant potential for successful application elsewhere in Antarctica, allowing us to explore other potentially vulnerable regions where current knowledge is scarce,” added glaciologist Dr. Sarah Thompson, co-author of the paper.
The team has not yet figured out how to translate this new map into estimates of ice flow and loss, but they are working on it, hoping to provide more accurate models of what will happen in the future.
“We hope that by showing the detailed geology and how it correlates with basal friction, future models of glacial retreat will have less uncertainty because control over basal processes will be better understood,” Jordan added.
The study was published in Science Advances.