A new map shows hidden landscapes beneath Antarctica's ice sheets

Scientists have created the most detailed map of the terrain beneath the vast ice sheets covering Antarctica. They discovered an exuberant landscape with mountains, canyons valleys, and plains.

Researchers used high-resolution satellite images and a technique called ice flow perturbation analysis to map the entire continent, including parts that had never been explored before.

A better understanding of the subglacial landscape could help forecast the climate-related retreat in Antarctica's Ice Sheet. Research has shown that rough terrain, such as jagged mountaintops and hillsides, can slow the retreat.

The study, published in the journal Science, was led by Robert Bingham, a glaciologist at the University of Edinburgh, Scotland.

Researchers were able map subglacial terrains with unprecedented accuracy. They identified, for example, more than 30,000 previously unknown hills. These are defined as terrain protuberances that measure at least 50 meters (165 feet).

Antarctica is about 40 percent larger than Europe and 50 percent larger than the United States. It also covers roughly half of Africa.

In each case, these continents have a variety of landscapes, ranging from high mountain ranges to vast flat plains. Bingham stated that the hidden landscape of Antarctica contains these vast extremes. It isn't boring.

The Antarctic Ice Sheet, the largest mass of ice on Earth, holds 70% of the freshwater in the world. The average thickness of the Antarctic Ice Sheet is about 1.3 miles (2 km) with a maximum thickness around 3 miles (4 km).

Antarctica was not always covered in ice. The subglacial features were first sculpted by the continent before it acquired its icy cover more than 34 millions years ago, before they were further modified by the Dynamic Ice Sheet. Antarctica was once connected to South America, but it separated because of a plate tectonics process that involves the gradual movement on Earth's surface of continent-sized plates.

The map showed a landscape with a variety of topographical features.

"Perhaps the type of landscape many people may not be familiar with is 'plateaus divided by deep-carved valleys. This is a familiar landscape for Scots. It is also common in Scandinavia, northern Canada, and Greenland. The fact that our method has revealed a landscape across Antarctica that matches these landscapes so well gives us great confidence in the new map," Bingham explained.

Researchers noted that the surface of Mars had been better mapped until now than the subglacial terrain in Antarctica.

Scientists traditionally map the subglacial terrain using radar equipment mounted on planes or towed behind snowmobiles. According to Helen Ockenden, glaciologist and lead author at the Institut des Geosciences de l'Environnement, France.

Ockenden stated that "these surveys often have gaps of up to 150 miles (93 km) and as much as 5 km (3.1miles) between them."

Ockenden stated that the method used in the new study is "really exciting" because it allows us combine the mathematics behind how the ice moves with high-resolution observations of the surface of the ice. This allows us to determine what the landscape under the ice must look like across the entire continent, even in those survey gaps. We can now see how the various landscape features are connected.

Researchers hope that the map will inform models used to predict future sea level rise, as well as forecasts made by the IPCC (the U.N. Intergovernmental Panel on Climate Change), which provides data to governments to help shape climate-related policy.

Bingham said, "We now can also better identify where Antarctica requires more detailed field surveys and where it doesn't."

(source: Reuters)