Scientists warn about the vulnerability of the Antarctic ice shelf



The researchers warn that unusual wind patterns could be driving the fourth largest ice shelf in Antarctica to destruction.

In an article published in the magazine. Geophysical research letters, a team led by Rajashree Tri Datta of the University of Maryland revealed that the Larsen C ice shelf experienced an unusual peak at the end of summer and the beginning of autumn in the melting of the surface in the years 2015 to 2017.

The finding fears that the platform, which is part of the Antarctic Peninsula, the northernmost part of the continent, can follow the fate of two other large ice platforms, Larsen A and B.

The snow and ice that melted on the surface of the land caused the rupture of Larsen A in 1995. In 2003, Larsen B gave birth to a section of approximately 3000 square kilometers.

The Antarctic Peninsula is particularly vulnerable to changing global conditions, and to badess the stability of Larsen C, which lies south of where Larsen B used to be, Datta and his colleagues studied data covering 1982 to 2017.

They discovered that in recent years there has been an increase in a particular type of wind, called the foehn wind, which originates in the high central mountain range of the peninsula and sends warm, dry air down near the surface.

The increase in enemy activity caused a higher than average melting point, which has begun to remodel Larsen C's snowpack, a development that, if maintained, could put the integrity of the platform at risk.

"Three years do not make a trend," says Datta, "but it's definitely unusual that we're seeing an increase in the winds of the enemies and the badociated fusion in late summer and early fall."

Data from previous years show that winds are shrinking much earlier in the season and that melt rates are reduced. The cool falls then fill the snow.

However, because this has not happened for three consecutive years, the topology of the platform is changing, a situation that could lead to increasingly adverse results.

"With greater densification, the ice enters the next warm season with a very different structure," explains Datta.

"Our modeling results show that with less open space for surface water to leak, runoff increases year after year. The dominant theory suggests that further densification led to the fracture of the Larsen A and B shelves. "

Because the ice shelf is floating, if the worst becomes the worst and Larsen C breaks and breaks, it will not on its own cause an increase in global sea levels. However, the image is not so simple.

"The ice shelf is supported by the flow of the glaciers that feed it," warns Datta.

"So, if Larsen C leaves, some of these glaciers will have the freedom to accelerate their rate of flow and fusion, which will cause an increase in the global level of the sea."


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