A new map reveals the landscape under Antarctica: 30,000 hills you never knew existed

Beneath the vast white surface of Antarctica lies a landscape that until recently was only partially understood. New research published in Science has revealed an extraordinarily detailed map of the continent’s subglacial terrain, identifying more than 30,000 previously unmapped hills along with deep valleys, ridges, and mountain ranges buried under kilometres of ice. The findings are not merely geological curiosities. They fundamentally change how scientists model ice flow and project future sea level rise in a warming climate.

Seeing Through Nearly Three Miles of Ice

For decades, scientists relied on airborne ice-penetrating radar and ground-based surveys to probe what lies beneath Antarctica’s ice sheet. These techniques produced highly accurate local measurements but left large areas unmapped because flights and fieldwork across such a remote continent are expensive and logistically complex. As a result, researchers often possessed more continuous topographic data for parts of Mars than for large sections of Antarctica’s bedrock. The new breakthrough comes from a technique called Ice Flow Perturbation Analysis, or IFPA, developed and refined by researchers including Helen Ockenden and Robert Bingham at the University of Edinburgh. The method, described in detail in the Journal of Glaciology in 2023, uses satellite observations of the ice sheet’s surface motion to infer the shape of the bedrock below.

Satellite instruments measure subtle variations in surface elevation and ice velocity with remarkable precision. As ice flows over hidden hills and depressions, it accelerates, decelerates, or bends in ways that reflect the underlying terrain. By combining these surface measurements with known ice-thickness data and applying physical models of ice deformation, researchers invert the signals to reconstruct the buried topography. This approach extends mapping coverage across vast areas where radar data were previously sparse or absent.

A Rugged World Beneath the Ice

The resulting continent-wide map reveals terrain features ranging in scale from 2 to 30 km. It includes more than 30,000 hills that were not previously resolved in earlier bedrock models. Many of these features resemble alpine landscapes, complete with ridges and troughs that predate the formation of the Antarctic ice sheet. According to reporting summarised by the University of Edinburgh, the new map provides the most consistent high-resolution view yet of Antarctica’s subglacial world. The ability to resolve small-scale hills and valleys is critical because even modest variations in bedrock topography can strongly influence ice motion.

Glaciologist Robert Bingham has emphasised that the geometry of the bedrock is an important control on the frictional resistance to ice flow. He explains that incorporating accurate subglacial topography into numerical models is essential for projecting how rapidly Antarctica’s ice will flow toward the ocean and contribute to global sea-level rise.

Why Bedrock Shapes Ice Behaviour

Ice sheets are not static blocks of frozen water. They behave like very slow-moving rivers, flowing under their own weight. The rate at which ice advances toward the ocean depends partly on how easily it slides across the rock beneath it. Rough terrain increases friction and can slow ice flow, whereas smooth basins or deep channels may allow faster streaming.

These dynamics have direct implications for climate projections. Faster ice flow means more ice reaching the ocean and potentially higher rates of sea level rise. Climate models used by international scientific bodies, such as the Intergovernmental Panel on Climate Change, rely on detailed representations of ice-sheet behaviour to estimate future coastal impacts. Without accurate bedrock maps, modellers must approximate subglacial terrain, which increases uncertainty. The new dataset enables scientists to reduce uncertainty by explicitly incorporating the influence of thousands of hills and valleys into ice-sheet simulations.

Geological History Frozen in Time

The new map also reveals a geological story that stretches back tens of millions of years. Many of the buried features were carved long before Antarctica became permanently glaciated around 34 million years ago. River valleys, mountain ridges, and ancient erosion surfaces remain preserved beneath the ice, offering clues about the continent’s climate and tectonic history prior to its current frozen state.

In this sense, the map is not only a tool for future climate forecasting but also a record of Earth’s deep past. By comparing the shape of buried landscapes with known geological formations elsewhere, scientists can reconstruct how Antarctica evolved from a greener continent to the ice-covered landmass we know today.

Improving Future Surveys and Forecasts

The improved resolution does more than refine models. It also guides future research priorities. Regions identified by the new mapping method as having complex or uncertain terrain can now be targeted for focused radar surveys and field campaigns. This strategic approach reduces costs and improves the efficiency of scientific exploration in one of the most remote places on Earth.

By integrating satellite data, physical modelling, and existing geophysical surveys, researchers have effectively removed a major blind spot in polar science. The hidden landscape beneath Antarctica is no longer an abstract concept inferred from scattered measurements. It is now a mapped terrain that scientists can analyse in detail. The discovery of more than 30,000 subglacial hills underscores a broader lesson about Earth science. Even in the 21st century, entire continental landscapes can remain concealed until new techniques allow us to interpret subtle signals with greater clarity. With this new map in hand, researchers are better equipped to understand both the ancient geology of Antarctica and the future behaviour of its vast ice sheet in a changing climate.