EuroWire, EDINBURGH: Researchers have produced the most detailed map yet of the landscape buried beneath Antarctica’s ice sheet, revealing a rugged terrain of mountains, valleys, canyons and plains that shapes how the continent’s ice moves. The map, described in a study published Jan. 15 in the journal Science, draws on satellite observations and existing measurements to fill major gaps in knowledge about the bedrock surface hidden under kilometers of ice.
Antarctica’s ice sheet covers about 98% of the continent and spans more than 14 million square kilometers. While scientists have long tracked changes on the ice surface, mapping the bed beneath has been harder because direct surveys are limited and expensive. The new work combines high resolution satellite data with ice thickness information collected over decades, then uses the physics of ice flow to infer the topography below.
The research team applied a method known as ice flow perturbation analysis, which estimates how the ice base must be shaped by examining subtle changes in ice motion and surface features. Where radar flights and ground campaigns have provided only patchy coverage, the technique expands detail across large regions that were previously poorly mapped. The resulting reconstruction identifies thousands of features that were indistinct or missing in earlier continent wide models.
Among the newly resolved landforms are more than 30,000 previously undetected hills, along with steep sided channels and deep troughs that cut across the buried landscape. The study describes a patchwork of rough highlands and smoother lowlands, with sharp transitions that can mark major geological boundaries. In places, the terrain resembles alpine landscapes, indicating substantial relief rather than the gentler contours suggested by older maps.
How the hidden bed controls ice movement
Scientists say the shape of the bedrock is a key factor controlling friction at the base of the ice sheet and influencing how quickly ice can flow toward the ocean. Rougher terrain can increase resistance, while smoother beds can allow faster movement, affecting the behavior of outlet glaciers that drain the interior. By improving knowledge of basal conditions, the map is designed to strengthen numerical models used to simulate Antarctic ice flow and quantify potential contributions to global sea level rise.
The map also highlights long subglacial channels and valleys that extend for hundreds of miles, features that can steer ice flow and guide meltwater beneath the ice. Researchers said such structures may preserve clues to Antarctica’s pre glacial past, when parts of the continent were not ice covered. The study notes that the new dataset captures landforms broadly in the 2 to 30 kilometer scale range, bringing finer detail to regions that previously appeared generalized.
More accurate bed topography is expected to reduce uncertainty in ice sheet simulations used in climate assessments, including work that informs coastal planning and adaptation. Scientists use these models to test how ice responds to changing temperatures and ocean conditions, but results can vary when the underlying terrain is poorly constrained. The researchers said the updated map offers a clearer baseline for comparing model outputs and targeting areas where additional measurements can most improve confidence.
Next steps for refining Antarctica’s subglacial map
The authors said the new approach does not replace direct observations, and smaller landforms remain unresolved where the satellite based inversion cannot retrieve fine scale detail. They expect the dataset to help prioritize future airborne radar and geophysical surveys, particularly in remote interior regions. The work also arrives as scientific institutions prepare for expanded polar research efforts later this decade, when coordinated campaigns could add new measurements of ice thickness and bed conditions.
Researchers described the mapping effort as a step toward closing one of Earth’s largest remaining data gaps, with practical implications for understanding the world’s biggest ice sheet. By revealing how complex the hidden terrain is across the continent, the study provides a sharper picture of the ground controlling Antarctic ice flow. The team said the dataset will be made available for broader scientific use, supporting continued refinement of ice sheet and sea level projections.