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

Researchers in the School of GeoSciences have combined a new mapping technique with satellite data to provide the most detailed view to date of the terrain underneath Antarctica, which is crucial for understanding the continent’s response to climate change.

Image of ice sheet

Antarctica covers about 14.2 million square kilometres (roughly twice the size of Australia) and yet we know more about the surface of Mars than the landscape beneath Antarctica’s ice.

The Antarctic Ice Sheet is the largest ice mass on Earth and holds around 70% of the planet's freshwater. The ice thickness varies, averaging around 2 kilometres but reaching over 5 kilometres thick at its deepest.

Now, an international team, led by researchers from the School of GeoSciences have produced the most detailed map to date of the hidden landscapes beneath Antarctica’s ice sheet and have revealed previously unknown features, including thousands of subglacial hills and valleys.

The team used a mapping technique known as Ice Flow Perturbation Analysis (IFPA). This technique uses the physics of ice flow to infer the topography beneath the ice, identifying characteristic surface patterns created as ice moves over hills and valleys. They then combined IFPA data with the latest satellite observations to reveal the landscape across the whole continent.

Map of Antarctica showing geographical representations of what lies under the ice

Their findings have uncovered specific geographical details across previously uncharted regions, including large mountain ranges, deep canyons and wide valleys, as well as tens of thousands of previously undiscovered 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.

This 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. 

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.

Dr Helen Ockenden PhD researcher at the University of Edinburgh- currently based at L'Institut des Géosciences de l'Environnement, Grenoble.

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.

Professor Robert Bingham Co-author, Professor Robert Bingham, Personal Chair of Glaciology and Geophysics, School of GeoScienceds

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.

Professor Andrew Curtis Co-author, Personal Chair of Mathematical Geoscience, School of GeoSciences.

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.

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