Map reveals whole of Antarctica’s subglacial world in intricate detail

Scientists have combined a new mapping technique with satellite data to provide the most detailed view to date of the terrain underneath Antarctica – crucial for understanding the continent’s response to climate change, researchers say.

Their findings include specific geographical details of large mountain ranges, deep canyons and wide valleys, as well as some 30 thousand smaller hills and valleys.

Previous research has shown that rough areas of subglacial land - such as jagged hillsides and sharp mountain ridges - can slow the retreat of Antarctica’s glacial sheet by providing frictional resistance against the ice flowing towards the sea.

An international team, led by researchers from the University of Edinburgh, used a mapping technique called Ice Flow Perturbation Analysis (IFPA), which identifies characteristic shapes in the glacial surface generated by the ice flowing over hills and valleys.

The team combined IFPA data with the latest satellite observations to reveal the landscape across the whole continent, including previously unchartered regions.

The latest map serves as an important guide to inform scientists where future surveys should be focused, and will help develop more accurate projections of where and how much sea levels could rise in the future, the team says.

The research, published in the journal Science, was funded by the UK’s Natural Environment Research Council (NERC) and the Evans Family Foundation in the United States.

Dr Helen Ockenden, researcher at L'Institut des Géosciences de l'Environnement in Grenoble, France, who led the research during her PhD at the University of Edinburgh, said: “Because making scientific observations through ice is difficult, we know less about the landscape hidden beneath Antarctica than we do about the surface of Mars or Venus. So it’s really exciting that this new method allows us to use satellite measurements of the ice surface to fill all of the gaps in our maps, revealing new details about mountain ranges, canyons and geological boundaries.”

Co-author, Professor Robert Bingham from the University of Edinburgh’s School of GeoSciences, said: “Over millions of years Antarctica’s ice sheet has sculpted a landscape consisting variously of flat plains, dissected plateaus and sharp mountains, all hidden under the present miles-thick ice cover. With this technique we are able to observe for the first time the relative distributions of these highly variable landscapes over the whole continent.”

Co-author, Professor Andrew Curtis from the University of Edinburgh, said: "This method to project ice surface information from satellites down to the base of the ice provides a completely new way to see through ice sheets. Over several years we have proven that it works well in detailed tests and this application across all of Antarctica demonstrates its power."

 Co-author, Professor Mathieu Morlighem from Dartmouth College, US, said: “Understanding the landscape beneath Antarctica is really important for ice-sheet models. In particular, rougher areas with more hills can really slow down the retreat of the ice sheet, and so this new map will help our models to produce better projections of where and how much sea levels will rise in the future.”

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