The environment of Antarctica is unique in many ways, one being that the continent is covered almost entirely by a vast sheet of ice, stretching from the towering plateau of East Antarctica to the chain of mountainous islands (interconnected by ice) that form West Antarctica. This ice sheet comprises about 90% of the ice on Earth, not to mention the massive shelves of ice and icebergs that float just offshore.
If Earth’s oceans and atmosphere continue to warm at the rates projected by most climate models, over the next few hundred years, the Antarctic ice sheets could melt enough to cause a sea level rise of several meters. Most likely, the severity of ice loss will vary geographically because of physical differences across the continent, such as ice thickness and bedrock topography. Previous simulations have shown that most of the ice melt will occur in the West Antarctic Ice Sheet, yet less is known about how the East Antarctic Ice Sheet would respond to environmental warming.
The eastern side of the ice sheet is much larger and has slow-flowing glaciers, and its bedrock is a rocky terrain of deep basins and high mountain ranges buried beneath the ice. Recent studies have already shown warm ocean water flowing southward from areas of the East Antarctic Ice Sheet, suggesting that the region could be affected by further warming.
To find out more, Golledge et al. used an ice sheet model to simulate the flow of water from melting ice sheets, ice shelves, and ice streams over thousands of years. They also examined data on the average long-term rates of ice loss for each ice drainage basin, or catchment, to determine which catchments are most sensitive to various conditions associated with climate change.
Comparing the results of their models to other simulations and observations and given a projected ocean temperature rise of about 36°F, the researchers found that the majority of East Antarctica’s future ice loss will most likely come from a catchment in the eastern Weddell Sea called Recovery.
The researchers predict that how soon and how much the ice sheet in this region melts will determine the degree to which East Antarctica will contribute to future sea level rise. In turn, this could amplify surface temperatures, producing an even greater global impact. (Geophysical Research Letters, https://doi.org/10.1002/2016GL072422, 2017)
—Sarah Witman, Freelance Writer