The Karakoram Anomaly: Is it real?

In recent years with sharp summer sea ice decline, the Arctic seems more sensitive to climate warming than elsewhere on Earth. But are other frozen features of Earth changing too? Notably, most of the world’s glaciers are also getting smaller—except for a few stubborn ones, such as in the Karakoram area of the Himalaya. Why are these glaciers not retreating? 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

Core of climate history

Lou and the Ice Core Drill

Scientists take ice core samples in cold, windy, and forbidding environments. After drilling through solid ice to retrieve a core, initial measurements are taken before it is sent away for more in-depth analysis and storage. Photo credit: NSIDC courtesy Ted Scambos and Rob Bauer

People have asked how scientists know that today’s climate situation is unusual. Hasn’t the Earth undergone many cold and warm cycles before? Could this just be another? Buried in the world’s ice sheets is a long story of climate on Earth–and the contribution of atmospheric CO2 to warming or cooling. Scientists can access a unique and detailed look at the history of the Earth’s atmosphere through ice cores and start to understand the recent climate in context of past ones. Continue reading

Are Greenland’s galloping glaciers slowing down?

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One of the three major ice streams studied, the outlet of the Jakobshavn-Isbræ glacier produces about 10 percent of Greenland’s icebergs due to calving. Located in West Greenland, its icebergs float down the fjord, sometimes getting stuck in shallower waters for years. Though the glacier’s acceleration rate has fluctuated through the years, it is still a major contributor to Greenland’s ice loss. Courtesy Spencer Weart, flickr (http://www.flickr.com/photos/weartpix/4077525679/)

For the past decade, Greenland’s ice sheet has been losing its ice more rapidly, raising concerns about its contribution to sea level rise. A recent study, published in Nature, proposes that Greenland could slow its shedding of ice from its massive ice sheet into the ocean. “This doesn’t mean glacial recession and melting will slow,” said Faezeh M. Nick, a glaciologist from the University Centre in Svalbard in Norway. Nick’s study points out that the problem is not so straightforward. Continue reading