The first detailed map of the Unterstant of an ice skating shows melted areas in unexpected form: tears. Researchers could help the new data published today in science advances Data-label = "https://www.nature.com/articles/d41586-02168-Y" Data-Track-Category = "Body Text Link"> How ice is influenced by sea currents and more precisely of the marine level lead.

While Remote-controlled diving vehicles have already penetrated under ice skirts, none previously created a finely dissolved ice card. "It is a little like the Holy Grail in Antarctic Oceanography," said Anna Wåhlin, Oceanographer at the University of Gothenburg in Sweden and first author of the study. "We had to completely revise our mental picture of the ice cream when we received this data."

pings draw an image

ice rink swimming on sea water that is fed by glaciers in the country that flow to the ocean. The new study describes the belly of Detson-Ice Schelfs , part of the West Antarctic ice sheet . In the current scenario, the ice shield could cause an average increase in sea level by 3.2 meters if it suddenly collapsed. If Dotson broke away, the land -based glaciers could be destabilized and accelerating their river to the sea, say Wåhlin and others.

In 2022, Wåhlin and her colleagues sent an underwater vehicle equipped with a sonar to map about 20 % of the ice shelf. The vehicle repeatedly fired pings of 450 sonar rays, which bounced off the Schelf and returned to the underwater vehicle, while it drove under the ice in a lawnmower pattern for 27 days. The team also measured the sea currents as well as the temperature and salinity of the water.

The researchers discovered more than 75 previously unknown tear forms that were engraved into the bottom of the ice shelf, with lengths of 20 to 300 meters and an average depth of 14 meters. The tears were only observed on the west side of the Schelf. This part of the shelf is thinner and is plagued by faster currents than the east side of the Schelf.

An orange diving vehicle sits just below the surface of icy water on a cloudy day

The authors suspect that the friction between ice and ocean surface and the circulation of the water could create a whirlpool that accelerates melting and produces these tears of tears, which the researchers called "enigmatically". But repeated observations are necessary to confirm this idea, says Wåhlin.

"These results are really important because the antarctic ice shield is changing rapidly," said Hélène Seroussi, a glaciologist at Dartmouth College in Hanover, New Hampshire, who was not involved in the study. Changes in the ocean conditions can accelerate melt, but most of the studies that quantify the melting rate are limited by indirect observations such as distant sensation, she says.

dangerous kingdom

Further direct observations of the soil of the ice skate are crucial for more precise predictions of the sea level an increase, says Seroussi. "We can't even start without such observations."

The team used the underwater vehicle again this year to repeat the mapping at Detson and the nearby Thwaites-Gletscher to map this data. But they lost contact with the $ 3.8 million underwater vehicle during the last part of their mission.

"We know that there is a great risk of sending expensive equipment under hundreds of meters of ice cream," says Wåhlin. "That is the reason why we don't have this data so far."