What about that hole in the sea ice?


There’s been discussion about a big opening in sea ice, called a polynya, and if it had anything to do with the Russian expedition ship, Akademik Shokalskiy, getting stuck near the Antarctic coast. The answer is not so straightforward. “In the winter, polynyas can close up really quickly,” said Kevin Arrigo, a professor at Stanford University. When they close, whatever is inside may be trapped. Continue reading

Why is there so much Antarctic sea ice?

Photograph from a ship traveling through Antarctic sea ice

Even during the Antarctic summer, heavy sea ice conditions are not uncommon. This photograph of sea ice was taken from the British icebreaker, HMS Protector, on its way to assist a Norwegian cruise ship that had become stuck in sea ice in January 2013.
–Credit: Royal Navy Media Archive (http://www.flickr.com/photos/rn_topten/8443836559/in/set-72157632684027667)

In late December 2013, the Russian research vessel, Akademik Shokalskiy, became trapped in thick sea ice off the coast of Antarctica. After several research vessels and icebreakers attempted rescue, the 52 passengers were evacuated. Soon after, one of the rescue ships also became stuck in the ice. However, conditions eased and both icebound ships safely churned out to open water.

Research in polar regions is inherently risky, and these events show how easily weather and ice conditions can disrupt research missions and travel during the already short Antarctic summer. But why was there so much sea ice around Antarctica to begin with, and why was it so thick? Antarctic sea ice is ruled by very different systems than Arctic sea ice. The reasons behind this increase are complex, and several recent studies show that scientists are still trying to understand them. Continue reading

What can stall a glacier?

Much talk surrounds the deterioration of glaciers and ice sheets—particularly, how they are thinning and losing mass with global warming; but the mechanisms are complicated and scientists want to know more about their flow. The Antarctic ice sheet, in particular, piques interest because it contains enough fresh water to raise sea levels 60 meters (200 feet), if it were to melt completely. So how does the ground beneath the ice influence mobility? When and how does the ice sheet stall? When does it accelerate? And how does this ebb and flow contribute to global sea level rise? Continue reading

Is an East Antarctic melt probable?

Does melting of the East Antarctic Ice Sheet (EAIS) pose a threat to sea level rise? Studies of the ice melt that fuels sea level rise often focus on the prominent warming and melting of glaciers in Greenland and western Antarctica. The massive East Antarctic Ice Sheet (EAIS) has been largely ignored, until recently. “It’s generally been assumed that it’s so big and so cold that it’s probably immune to some of the warming trends we’ve seen across the planet,” said Chris Stokes, a professor at Durham University. Two recent studies, however, paint a new picture of the world’s thickest, unwavering giant, suggesting the need to look deeper into eastern Antarctica. Continue reading

Arctic melt versus Antarctic freeze: Is Antarctica warming or not?

Photograph of a large tabular iceberg and sea ice near Antarctica

During the short austral summer, much of the sea ice surrounding Antarctica melts, often leaving only the large, tabular icebergs. Credit: NSIDC courtesy Andi Pfaffling

September 2012 was a record-setting month for both of Earth’s poles, but for different reasons: sea ice in the Arctic fell to a record low minimum extent after a summer of melting, while Antarctic sea ice froze to a record high extent during the South Pole winter. Is record Antarctic sea ice canceling out the losses in Arctic ice? And does the record in the south mean that Antarctica is not warming? Continue reading