New map shows Antarctica in more detail than ever before

What does it look like under the ice? Under the direction of the British Antarctic Survey (BAS), scientists have created the most accurate map of Antarctica to date. Among other things, the map is intended to provide insights into how global warming is affecting the Antarctic.

Bedmap3 is, as the name suggests, the third version of the map, which shows what Antarctica looks like under the ice sheet. On average, it is 2,148 meters thick (excluding the ice shelf, which is included in the calculation, it is 1,948 meters). The map contains 82 million data points – - more than twice as many as in previous versions.

One of the interesting new findings is the location with the thickest overlying ice. Previously, this was located in the Astrolabe Basin in Adélie Land. According to the new data, however, this is an unnamed canyon in Wilkes Land. The ice here is 4,757 meters thick. It also shows the contours of the deep valleys, for example, more accurately than before.

Satellites, airplanes and dogsleds collected data

Bedmap3 incorporates survey data collected over a period of more than six decades. It was collected from satellites, airplanes, ships and even dog sleds. Various methods were used, including radar, seismic reflection (sound waves) and gravity measurements (gravimetry). The project, in which the Alfred Wegener Institute (AWI) in Bremerhaven was also involved, is described in the journal Scientific Data.

The map is an important tool for understanding how the Antarctic could react to global warming. It makes it possible to investigate the interactions between the ice sheet and the subsurface. "This is the fundamental information that underpins the computer models we use to study how the ice will flow across the continent as temperatures rise," said Hamish Pritchard, glaciologist at BAS and lead author of the study.

The total area of Antarctic ice, including ice shelves, is 13.63 million square kilometers. The volume, including the ice shelf, is 27.17 million cubic kilometers. If all the ice melts, the global sea level would rise by around 58 meters.

"In general, it has become clear that the Antarctic ice sheet is thicker than previously assumed and has a larger volume of ice resting on a rock bed below sea level," said AWI glaciologist Olaf Eisen. "This is particularly important at the edge of the continent, where the ice is in contact with the ocean. This increases the risk of more ice melting due to the intrusion of warmer ocean water. Bedmap3 shows us that Antarctica is somewhat more vulnerable than we previously thought."

(wpl)