Antarctica: Scientists have produced the most comprehensive map yet of the landscape concealed beneath Antarctica’s extensive ice sheet, exposing a vibrant terrain of mountains, canyons, valleys, and plains, and identifying for the first time tens of thousands of hills and other smaller features.
According to Emirates News Agency, the researchers employed the latest high-resolution satellite observations and a technique known as ice-flow perturbation analysis to estimate subglacial topography and conditions based on surface features. This enabled them to map the entire continent, including parts that were previously uncharted. The enhanced understanding of the subglacial bedrock landscape may assist in predictions regarding the climate-related retreat of Antarctica’s ice sheet. Past studies have suggested that rugged terrain, such as jagged hillsides and mountaintops, can decelerate this retreat.
“Having the most accurate map of Antarctica’s bed shape is crucial, because the shape of the bed is an important control on friction acting against ice flow, which in turn we need to include in numerical models that are used to project how rapidly Antarctica’s ice will flow towards the ocean, melt and contribute to global sea-level rise,” stated Robert Bingham, a glaciologist from the University of Edinburgh in Scotland, who co-led the study published in the journal Science.
The researchers achieved unprecedented precision in mapping the subglacial terrain, identifying over 30,000 previously uncharted hills defined as terrain protuberances of at least 165 feet (50 meters). The Antarctic Ice Sheet, as the largest ice mass on Earth, contains approximately 70 percent of the planet’s freshwater. It has an average thickness estimated at about 1.3 miles (2.1 km) and can reach a maximum thickness of about 3 miles (4.8 km).
Antarctica’s subglacial features were initially sculpted before the continent became ice-covered more than 34 million years ago and were later modified by the dynamic ice sheet. Antarctica was once part of South America but separated due to plate tectonics, a process involving the gradual movement of continent-sized plates on Earth’s surface.
The map reveals a landscape with numerous topographical features. Traditionally, scientists have mapped the subglacial landscape using radar equipment suspended on planes or towed by snowmobiles, explained Helen Ockenden, a glaciologist from the Institut des Geosciences de l’Environnement in France and the study’s lead author.
Ockenden noted, “But these surveys often have gaps of 5 km (3.1 miles) or 10 km (6.2 miles) between them, and sometimes up to 150 km (93 miles).” She added that the method used in the new study “is really exciting because it allows us to combine the mathematics of how the ice flows with high-resolution satellite observations of the ice surface, and say what the landscape beneath the ice must look like everywhere across the whole continent, including in all those survey gaps. So we really gain a much more complete idea of how all the landscape features connect together.”
The researchers anticipate that the map will aid in refining models used to project future sea-level rise and assist the forecasts issued by the UN Intergovernmental Panel on Climate Change (IPCC), which provides data for governments to shape climate-related policies.
