Thursday , April 9 2020
Home / unitedkingdom / The largest ice shelf melting 10 times faster in the world than was expected, as the water is heated

The largest ice shelf melting 10 times faster in the world than was expected, as the water is heated


The world's largest ice shelf is melting 10 times faster than expected, due to the solar heating of the surrounding Antarctica, scientists warn.

Ross ice shelf covers an area about the size of France, and has a thickness of several hundred meters, with 90 percent of the ice below sea level.

A study conducted by an international team of scientists carried out over four years, data were collected on how the north-west part of the shelf interacts with the ocean beneath.

He discovered that the ice is melting much faster than previously thought, due to the flowing warm water.

"The stability of the shelf is generally considered to be related to their exposure to warm deep ocean water, but we found that the solar heated water surface also plays an important role in the melting of ice shelves," said the study's lead author, Dr. Craig Stewart of the National Institute of Water and Atmospheric Research ( NIWA) in New Zealand, and who conducted the work while a graduate student at the University of Cambridge in the UK.

Interactions occurring between the ice and the ocean a hundred meters below the surface of the ice shelves have a direct impact on the long-term sea level.

Ross Ice Shelf to the & # 39 is a vital natural bar & # 39; EPAM ensure stability in the Western Antarctic shield, blocking the ice, which flows into it some of the largest glaciers in the world.

"Previous studies have shown that when ice shelves collapse, feeding glaciers can speed up by a factor or two or three," said co-author Dr. Poul Christoffersen from the Research Institute Scott Polar Cambridge.

"The difference is the sheer size of the Ross Ice Shelf, on the & # 39 is a hundred times more than the ice shelf we've seen disappear."

When all of the West Antarctic ice sheet melted, it was assessed on the huge & # 39; the amount of water releases will contribute to 4.8m (16ft) to global sea level.

The team collected data from oceanographic moorings, established under the Ross Ice Shelf team members from NIVA.

Using tools suppressed through 260m deep wells team measured temperature, salinity, melt rates and ocean currents in the cavity under the ice.

Devices on the dock showed solar heated surface water enters the cavity under the ice shelf near the Ross Island, causing the melt rates nearly three times over the summer months.

Immediately before the shelf is open water. The area known as the Ross Sea polynya, absorbs the sun's heat quickly in the summer, and that warmer water has the effect of melting ice shelves in the cavity, the researchers say.

The data indicate the conditions in the cavity ice shelves are more closely associated with the surface of the ocean and the atmosphere than previously. It also means that the level of the melt near the ice front will quickly respond to changes in the uppermost layer of warm water in the ocean.

"Climate change is likely to lead to a decrease in the sea ice and the high temperatures of the ocean surface in the Ross Sea, believing that the melt rate in this region will increase in the future," said Dr. Stewart.

Dr. Christoffersen added: "Seeing that we have done in front of the shelf has a direct impact on many large glaciers flowing down the ice shelf, some as far as 900 kilometers away."

Source link