The pillars that prevent floating Antarctic ice sheets from entering the ocean are rapidly disappearing – scientists

The number of underwater anchor points for ice, which prevent the spread of floating icebergs from Antarctica into the ocean, is shrinking at half the rate of 50 years ago. Since the beginning of the century, more than a third of them have decreased in size.

In the study, published in the journal Nature, scientists warn that further decline in anchor points that hold floating ice sheets will accelerate sea-level rise, writes Phys.

Researchers at the University of Edinburgh used satellite images from a 50-year archive of the NASA/USGS Landsat program to track changes in the appearance of anchor points on the ice surface.

The obtained results are part of the first-ever study of changes in the thickness of the Antarctic ice shelf – ice extensions floating in the ocean. The study of the trend began back in 1973.

Floating ice sheets cover 75% of the coastline of Antarctica and occupy an area equivalent to the size of Greenland.

The so-called barriers are points that form when part of the floating ice sheet is fixed on the uplift on the ocean floor, creating a visible bump on the smooth surface of the ice shelf.

For the study, the team used changes in reference points. They are considered a reliable indicator of variations in the thickness of the ice shelf. Changes in their characteristics were recorded during three periods: from 1973 to 1989, from 1990 to 2000, and from 2000 to 2022.

The scientists found that only 15% of anchor points decreased in size between 1973 and 1989, resulting in small, localized pockets of thinner ice shelves.

However, in the 1990s, widespread acceleration and detachment of the ice shelf from anchorage points began in the western Antarctic Peninsula and in the Amundsen Sea.

The number of such points that disappeared increased to 25% from 1990 to 2000, and to 37% from 2000 to 2022.

“The transition over the last 50 years from a relatively limited and regionally concentrated melting of the ice shelf to a much more widespread breakup is striking,” says Dr. Bertie Miles.

“What we’re seeing around Antarctica is the long-term effects of a warming climate on the supports that slow global sea level rise. This reinforces the need to reduce global carbon emissions.” – says Professor Robert Bingham.

We will remind, scientists determined how much ice has melted in Antarctica for 25 years. Also global warming accelerated the rate of melting of glaciers in Greenland five times compared to the situation 20 years ago.

Snowy mountains of Nepal lost almost a third of their ice over 30 years due to global warming. And the glaciers in the Himalayas until the end of the century can lose up to 75% of its volume due to global warming.