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Antarctica’s subglacial world revealed in unprecedented detail

Undated handout map showing Antarctica’s subglacial landscape, revealing buried mountain ranges, deep canyons, broad valleys, and thousands of smaller hills, with comparative landscape examples inset. Source: Cyprus Mail (image by Robert Bingham, University of Edinburgh/Handout via REUTERS)

For decades, Antarctica’s ice surface has been mapped in remarkable detail, yet the terrain beneath remained one of Earth’s least understood landscapes. That gap has now narrowed significantly. Using satellite observations and physics-based ice-flow modelling, researchers have produced the most detailed map yet of Antarctica’s subglacial topography, revealing thousands of previously unknown hills, ridges, valleys and channels hidden beneath ice sheets up to 4.8 km thick.

The approach moves beyond traditional radar surveys, which often leave large gaps between flight lines. By analysing subtle changes in ice surface elevation and flow velocity, scientists inferred the shape of the bedrock below, much like reading surface currents to identify rocks beneath a river. The result is a continent-scale reconstruction that exposes entire mountain ranges, deep basins and long channels with far greater clarity than before.

Comparison between older and new subglacial maps, illustrating the dramatic increase in resolved terrain detail. Source: BBC (image by Science)

The newly mapped features are not just geological curiosities. Subglacial topography directly controls how glaciers move, accelerate and retreat. Many areas of West Antarctica sit below sea level, making them especially sensitive to ocean-driven melting and unstable retreat. The new map highlights deep channels and sharp transitions between highlands and lowlands that can act as fast-flow corridors for ice, increasing the risk of rapid mass loss.

One striking example is a channel in the Maud Subglacial Basin, averaging 50 m deep, around 6 km wide and extending nearly 400 km. Features of this scale can strongly influence how ice responds to warming, yet were poorly resolved in earlier datasets. By clarifying where ice is grounded, where it is vulnerable, and how it interacts with the bed, the map provides essential constraints for ice-sheet and sea-level models.

Improved knowledge of Antarctica’s bedrock is critical because ice-sheet behaviour remains one of the largest uncertainties in climate science. Small differences in basal geometry can lead to large differences in predicted ice retreat and global sea-level rise. The new dataset allows modellers to better simulate ice dynamics, grounding-line stability and long-term responses to atmospheric and ocean warming.

While uncertainties remain and further ground and airborne surveys are needed, the map represents a major step forward. It transforms Antarctica’s hidden landscape from a patchwork of assumptions into a coherent framework, strengthening projections of how the world’s largest ice sheet may evolve in a warming climate.

Sources: science.org, bbc.com, livescience.com, cyprus-mail.com