A huge Antarctic ice hole reopens for the first time in 40 years

A huge Antarctic ice hole almost the size of South Carolina has opened up in winter sea ice cover, leaving scientists with a bunch of unanswered questions.

Antarctic hole

The hole, known as a polynya, was found about a month back in Antarctica’s Weddell Sea as a group of Scientists from the University of Toronto and the Southern Ocean Carbon and Climate Observations and Modeling project used satellite technology to screen a comparative, much smaller, hole that opened a year ago.

It is the first time a hole of this size has been observed in the Weddell Sea in over 40 years. It has fluctuated in size up to a maximum of nearly 80,000 square kilometres, according to the scientists.

There was a bigger hole in 1971 with 250,000 square kilometres in the same location. Presently analysts are endeavouring to make sense of why it repeated. It’s like an enigma on many levels, said Kent Moore, professor of physics at the University of Toronto.

It is learned that there are two sorts of polynyas such as coastal and open-ocean. Coastal polynyas form right at the coast, mainly due to strong winds which blow ice out of the area.

Moor said “these coastal polynyas occur all the time. They’re always there. Polynyas that form deep in the ice pack are a lot rarer. It’s a different mechanism.”

Antarctic hole2

Open-ocean polynas, similar to the one found in the Weddell Sea a month ago, are caused by the rising of hotter and saltier water from below.  There’s a submerged ocean mountain situated around where the polynya formed, Moore clarified.

In this manner, sea streams around that region bring further warm water toward the surface, where it can liquefy the ice away to make a polynya.

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This resembles opening a pressure relief valve — the sea at that point discharges an excess of warmth to the environment, said Prof. Dr Mojib Latif, leader of the exploration division at GEOMAR, a German marine research foundation.

The overflow of heat makes it troublesome for new layers to form. In the long run, the hotter water begins to cool, however but with exposure to the frigid atmosphere, some water can get sufficiently icy to sink.

“That can enable this open convection to proceed with,” Moore said.

This may clarify why polynyas can expand so quickly, however analysts are as yet attempting to comprehend the wonder, Moore said. In seven days, the newfound hole developed from 10,000 square kilometres to about 80,000.

The cooling of the water that is caused by polynyas can affect the sea’s temperature, however, Moore says it’s still unclear how much of an impact a polynya such as this one could have on Antarctica’s oceans and climate.

“I think it’s a bit premature to talk about a change in climate,” Moore said.

Researchers may not realize what the long haul impacts the polynya will have on nature, yet marine mammals appear to appreciate the break in the ice.

“It truly is a hotspot. There are seals utilizing it, predators, leopard seals — they’ll be exploiting this region. It’s like an oasis to them,” Moore said.

Moore predicts the hole will remain open for the rest of the Southern Hemisphere’s winter, however, what occurs beyond that is a riddle.

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