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A year ago, the Antarctic Peninsula experienced a particularly pronounced ice melt in summer, which corresponds to our December to February.

A study on the George VI Ice Shelf - the second largest ice shelf in this region - gives an impression of this.

Ice shelves are areas that float on seawater and do not belong directly to the mainland ice.

Almost a quarter of the area - 23 percent - was covered by water about knee-deep last January.

This is what a team led by Alison Banwell from the University of Colorado in Boulder reports after evaluating decades of measurement data in the journal "The Cryosphere".

“In summer 2019/2020 we observed the most extensive melt and the highest total number of melting days for the north of the George VI Ice Shelf,” says the scientist.

Accordingly, from the end of November, the temperatures were at least 0 degrees Celsius on a third of the days - in one case even continuously over a period of 90 hours.

That summer, on February 6th, the Argentinian research station Esperanza at the tip of the peninsula also measured the previous Antarctic heat record of 18.4 degrees Celsius.

In general, the Antarctic Peninsula, which extends far north towards South America, is the fastest melting part of the continent's ice sheet.

In the current study, the researchers focused on the George VI Ice Shelf.

With an area of ​​23,500 square kilometers, the ice shelf is slightly larger than Mecklenburg-Western Pomerania.

The ice is around 100 meters thick at the edges and up to 600 meters in the center.

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For the north of the ice shelf, the researchers combined analyzes of satellite images with weather data over a period of 41 years.

Accordingly, the melt in the previous summer was significantly more pronounced than in the rest of the study period - the researchers only exclude the summer of 1987/88 due to a lack of data.

The satellite images show that at the height of summer on January 19, 2020, around 23 percent of the 7850 square kilometer study area was covered by water - with an average depth of half a meter.

Mild air flowing in from the northeast was responsible for the melting of the ice.

The main concern of the researchers is that the meltwater seeping down into the ice is causing cracks in the ice and could encourage the ice shelf to break up.

"The George VI Ice Shelf supports the ice that lies on land," explains Banwell.

This makes up the bulk of the Antarctic ice.

“If it were to break up, the ice on land would flow into the ocean faster and contribute more to sea level rise than any other ice shelf on the peninsula.” Most of the ice is on the mainland.

The researchers estimate the increase caused by this alone to be up to eight millimeters by 2100 and up to 22 millimeters by 2300.