Researchers have used new ultra-precise data to map the hidden ground beneath Antarctica’s ice sheet, revealing a chaotic terrain of sharp hills, steep ridges and an immense buried valley that may control how quickly the ice can slide into the ocean.
A secret landscape beneath two kilometres of ice
Antarctica looks flat from space, a smooth white dome stretching across a frozen continent. Underneath, the story is completely different. In many places, nearly two kilometres of solid ice cover a landscape that had never been mapped in real detail.
Scientists have now produced a new high‑resolution map of this hidden bedrock. The work draws on radar data from aircraft, satellite measurements and complex computer modelling. Where older maps showed soft curves and broad basins, the new one reveals sharp relief: twice as many hills as previously identified and a sprawling valley that rivals the great canyons on other continents.
The ground beneath East and West Antarctica looks less like a flat plain and more like a frozen version of the Scottish Highlands, cut by a canyon on the scale of the Grand Canyon.
This rugged terrain matters. The shape of the rock beneath the ice controls how the ice flows, where it sticks, and where it may accelerate towards the sea.
Why hills and valleys change the fate of ice
Ice behaves a bit like very slow, thick syrup. When it lies on a rough surface dotted with hills, it tends to snag and slow down. Where it reaches a downhill slope or a deep trough, it can pick up speed.
The new Antarctic map shows many more small hills than earlier surveys. These bumps and ridges may act as “speed bumps” for glaciers. They can hold ice in place for centuries, especially where the hills are high enough and close together.
The giant buried valley, on the other hand, creates a potential fast track to the coast. It forms a long corridor where relatively thin ice could move far more quickly if warming ocean water or rising air temperatures weaken nearby ice shelves.
Hidden ridges can anchor the ice sheet, while deep troughs can turn into sliding lanes that funnel ice into the sea.
➡️ Winter Storm Warning Issued as 70 mph Winds, 3 Feet of Snow Approach rapidly
➡️ The day I built a self-watering system from trash I never thought I’d keep
➡️ Get ready: in 2026, generative AI shifts into high gear
➡️ When were boats invented? | Live Science
➡️ Thousands of passengers stranded in USA as Delta, American, JetBlue, Spirit and others cancel 470 and delay 4,946 flights, disrupting Atlanta, Chicago, New York, Los Angeles, Dallas, Miami, Orlando, Boston, Detroit, Fort Lauderdale and more
➡️ If you want beautiful apples, this step is indispensable starting today
➡️ The Colorado River’s largest tributary flows ‘uphill’ for over 100 miles — and geologists may finally have an explanation for it
➡️ A robot can now build a 200 m² house in just 24 hours, a major technological breakthrough that could reshape construction and ease the housing crisis
Climate models rely on accurate information about this sub‑ice landscape. If the models underestimate how easily ice can move along valleys, they might predict slower sea level rise than reality. If they ignore stabilising hills, they might exaggerate how quickly some regions will collapse.
How scientists mapped a place no one can see
Listening to the ice from the air
Researchers cannot simply dig through kilometres of ice. Instead, they send radar waves from aircraft down to the bedrock and measure the echoes. These signals reveal how far the rock lies beneath the surface and where the ice thickness changes.
Over decades, planes have flown thousands of lines across Antarctica, building up an enormous archive of radar tracks. The new map pulls together these scattered measurements, fills gaps with advanced modelling and cross‑checks them with satellite gravity data, which reacts subtly to mountains and valleys below the ice.
- Radar from aircraft measures ice thickness and bedrock depth.
- Satellites track tiny changes in gravity over mountains and basins.
- Computer models combine these inputs to reconstruct continuous terrain.
- Older maps are updated where fresh data show sharper relief.
The result is a digital reconstruction of the Antarctic underworld at far higher resolution than before. Features just a few hundred metres across now appear where only blurry shapes were visible.
A record‑breaking deep point on Earth
Among the most striking features is an ultra‑deep canyon beneath the Denman Glacier in East Antarctica. Earlier work, such as the BedMachine project, already hinted at this. The new mapping confirms that this land canyon reaches more than 3.5 kilometres below sea level, making it the deepest point on Earth’s continental crust that is not filled with ocean water.
This trench is so deep that, if it were suddenly drained of ice and flooded, it could host a sea deeper than many parts of the Pacific. At the moment, thick, cold ice blocks that possibility. Future warming could change the balance, though, by altering how much ice flows out of Denman and similar glaciers.
The Denman trough is deeper than any ocean floor outside the trenches, yet today it holds ice, not seawater.
Implications for sea level and future planning
The Antarctic ice sheet contains enough frozen water to raise global sea level by about 58 metres if it melted completely. No one expects that to happen in this century, but even small losses make a difference. Just a few centimetres of extra sea level can worsen storm surges and high tides along low‑lying coasts.
The new map helps scientists pinpoint “weak spots” where warm ocean currents may reach the base of the ice. Deep valleys that slope from inland basins towards the sea are of particular concern. They can allow relatively warm water to creep underneath the ice edges, thinning them from below and removing the friction that slows glaciers.
Regions where the bedrock rises inland, by contrast, act as natural barriers. Ice there tends to remain grounded and stable, unless warming becomes extreme. Knowing where these stabilising ridges sit helps coastal planners and insurers assess long‑term flood risks.
| Feature | Effect on ice flow | Potential impact on sea level |
|---|---|---|
| Subglacial hills and ridges | Increase friction, slow glacier movement | Can delay rapid ice loss in some regions |
| Deep inland valleys | Provide channels for fast‑flowing ice | May speed up sea level rise if ice retreats |
| Canyons below sea level | Allow ocean water penetration under ice shelves | Can trigger thinning and retreat of major glaciers |
Key terms behind the new Antarctic map
Several technical terms keep coming up in discussions of this new mapping effort. A few are worth unpacking.
“Ice sheet” refers to the vast body of ice covering Antarctica, not just individual glaciers. It spreads over about 98% of the continent and holds one of the largest freshwater reserves on the planet.
“Subglacial topography” means the shape of the land beneath the ice: hills, valleys, ridges, and basins. This is what the new map targets. Even small changes in that topography can alter the direction and speed of ice flow.
“Grounding line” describes the point where a glacier stops resting on rock and begins to float as an ice shelf. This line often sits over deep channels. When it retreats inland along a downward‑sloping bed, the ice sheet can become unstable and lose mass more rapidly.
What the new map allows scientists to test
With a sharper picture of Antarctica’s buried landscape, teams can now run more realistic simulations of how the continent might respond to different warming pathways. For instance, they can model what happens if ocean waters around West Antarctica warm by 1 or 2 °C, tracking how quickly grounding lines pull back along deep troughs.
They can also test scenarios where snowfall increases in some regions, adding weight and thickening the ice, while warming oceans carve away at ice shelves elsewhere. The balance of these competing processes decides whether Antarctica gains mass, stays steady or contributes more strongly to sea level rise.
These simulations feed into global climate assessments used by governments, city planners and industries such as shipping and insurance. Better terrain data reduces one of the largest uncertainties in long‑term sea level projections.
From satellite images to everyday consequences
For people living far from the polar circles, the idea of a hidden Antarctic landscape can feel abstract. Yet the consequences reach straight into daily life. Higher sea levels mean more frequent saltwater flooding, damaged roads and railways, and higher costs for flood defences in cities such as New York, Miami, London and Shanghai.
The new map also matters for scientific fieldwork. Knowing where valleys and ridges lie helps teams choose safe routes for over‑ice traverses and select drilling sites where they can sample ancient ice without risking sudden crevasses or unstable ground.
In coming years, researchers expect to refine the Antarctic map even further with new radar flights and satellite missions. Each improvement adds detail to the picture of this buried terrain, tightening projections of how the frozen continent will shape coastlines over the coming centuries.