New Map Uncovers Antarctica’s Hidden Mountains and Valleys Beneath Ice

Scientists have created the most detailed map yet of the landscape under Antarctica's ice sheet. The map shows mountains, deep valleys, hills, and ancient river channels hidden beneath more than two kilometers of ice. This work, led by Helen Ockenden from the University of Edinburgh, used satellite data and ice flow physics to reveal these features across the entire continent. The findings appeared in the journal Science on January 15, 2026. The map helps explain how the bedrock guides the massive ice sheet and affects global sea levels as the climate warms.

Background

Antarctica's ice sheet covers 98 percent of the continent and holds enough ice to raise sea levels by 58 meters if it all melted. The sheet is up to three kilometers thick in places, hiding the ground below from view. For years, researchers knew little about this hidden world because surveys by plane or on foot are hard in such a remote and harsh place. Past maps relied on scattered data points, often missing key details like narrow valleys that steer ice toward the sea.

Earlier efforts, like the Bedmap projects from the British Antarctic Survey, combined decades of measurements from planes, satellites, and even old sled teams pulled by dogs. Those maps improved our view of ice thickness and grounding lines where ice meets the ocean. But gaps remained, especially for smaller features from two to 30 kilometers across. Ground surveys cover only tiny areas, and satellites see just the ice surface. To fill these gaps, Ockenden's team turned to a method called Ice Flow Perturbation Analysis, or IFPA. This approach studies how the ice surface bends as it flows over bumps and dips below.

The ice sheet acts like a lens, passing small changes in the bedrock up to the surface. A canyon 100 meters deep under three kilometers of ice might lower the surface by just a few meters. Satellites can detect these subtle shifts with high-resolution images. By combining this with spot measurements of ice thickness, the team built a full map of the bedrock. This is one of the least-mapped surfaces in the solar system, even less known than parts of Mars until now.

Key Details

The new map reveals 71,997 hills across Antarctica, more than double what older maps showed. Many areas look like rugged alpine terrain with jagged peaks, not smooth hills. These rough features create friction that slows ice flow toward the ocean.

Major Features Discovered

One standout find is a steep-sided valley nearly 400 kilometers long in the Maud Subglacial Basin. This trench, along with deep alpine valleys and scoured lowlands, was invisible before. The map also shows extensive river channels stretching hundreds of kilometers, likely carved before the ice sheet formed millions of years ago. Basins, lakes, and sharp edges between highlands and lowlands appear too, hinting at old tectonic boundaries.

In one area, past air surveys guessed at buried rivers, but the new map confirmed deep valleys there. Midsized features from two to 30 kilometers stand out clearly for the first time. These include eroded troughs and buried fluvial networks that span vast distances. The map covers the full 14 million square kilometers of the ice sheet, showing how geology shapes ice from below.

Robert Bingham, a co-author from the University of Edinburgh, described the surprise of seeing such detail:

It is perhaps most surprising that ultimately so much detail of the bed topography – features such as glacial valleys, hills and canyons – are captured at all in the shape of the ice surface so far above. So much change at the surface is extremely subtle – as 3 km-thick ice passes over a subglacial canyon maybe 100 meters deep, the ice surface elevation typically only falls a handful of meters, a change that is barely noticeable when travelling over the ice surface itself.

The team integrated satellite data from missions like CryoSat-2 and ICESat-2 with ice thickness from radar surveys. IFPA then modeled how ice deforms over the terrain, inverting surface patterns to reveal the bedrock.

What This Means

These hidden features act as gears and brakes for the ice sheet. Valleys channel fast-flowing ice streams to the sea, while hills and rough ground slow it down. Better knowledge of this landscape improves computer models of ice behavior. Past models missed narrow valleys, leading to uncertain predictions of melt rates.

With climate change warming the air and ocean, warm water reaches under ice shelves, speeding up flow. The map reduces guesswork in forecasts of ice loss and sea-level rise over coming decades. Areas with reverse-sloping beds, where bedrock dips toward the sea, are more at risk as they sit below sea level. Thicker ice in some spots means more potential water if it goes.

The findings guide where to send future surveys by plane or drill. They also help reconstruct how the ice sheet grew over millions of years, interacting with mountains and rivers from wetter times. Peter Fretwell, a mapping expert at the British Antarctic Survey not on the team, called it a useful tool:

This is a really useful product. It gives us an opportunity to fill in the gaps between those surveys.

Overall, the map paints Antarctica as more rugged and complex than thought. This detail sharpens our view of a key player in global climate. As models get better, projections for coastal cities and islands worldwide become more reliable. The work opens doors to study subglacial lakes and sediments that hold clues to Earth's past climates.