Unstable Antarctic Ice Sheet Could Raise Sea Levels Dramatically With Global Warming

As Earth’s climate changes, several scientists across the world debate the possible changes that could arise from the significant warming of our home planet that is already causing a huge change in landscapes all over.

Of the many types of natural terrain on Earth, ice shelves in the two poles are the least inhabited, the most unforgiving and the least explored. There are many ice shelves here that form intricate glacial systems that feed off one and other, growing and shrinking constantly.

Now, researchers have found out that the East Antarctic Ice Sheet, which was considered a very unaffected-by-climate-change ice mass might not be as stable as it looks. Scientists have found portions of the huge block of ice are very susceptible to our warming oceans and atmosphere which could in turn raise sea levels across the globe by 53 meters. This would spell disaster to most coastal cities that would certainly go underwater if that were to happen.

This ice sheet holds more water than any other ice sheet on the planet. Up until now, scientists studying the change in these ice shelves had found minimal or no change in the East Antarctic Ice Sheet. Even as other ice masses around the shelf was melting, this ice shelf was considered to be the most stable, not gaining or losing mass over a long period of time.

However, a team of researchers from the University of Texas at Austin and the University of South Florida published a paper in the journal Nature on Dec. 14, which found that the East Antarctic Ice Sheet may not be as stable as it seems.

In fact, the team found that the ice sheet has a long history of expanding and shrinking — a finding that indicates the ice sheet may contribute substantially to the global sea level rise as Earth's climate warms in the very near future.

"It turns out that for much of the East Antarctic Ice Sheet's history, it was not the commonly perceived large stable ice sheet with only minor changes in size over millions of years," said co-lead author of the study, Sean Gulick, a research professor at the University of Texas Institute for Geophysics in a press release.

The team says in the study that the results were derived from geophysical and geological data collected during the first-ever oceanographic survey of East Antarctica's Sabrina Coast. An area on this glacier known as the Aurora basin lies below the sea level, making it highly prone to melting as sea temperatures around Greenland, the Arctic and Antarctic continue to grow.

The Sabrina Coast, and nearby Aurora Basin, were identified by the study as regions in the ice shelf that were under immediate risk of heavy melting. The team estimates that if just the ice in the Aurora Basin melted, global sea levels would rise more than 3-5 meters (10-15 feet) in the next century, causing a devastating impact on low-lying coasts and potentially changing the coastlines across the world that would cause several hundred million people to move to higher regions.

Channels under the ice shelf caused by flowing melt-water an estimated 11 million years ago left behind formations known as "tunnel valleys," which caused severe shrinking and growing. These structures also provide clues to an unstable past.

"A lot of what we are seeing right now in the coastal regions is that warming ocean waters are melting Antarctica's glaciers and ice shelves, but this process may just be the beginning," Shevenell said. "Once you have that combination of ocean heat and atmospheric heat — which are related — that's when the ice sheet could really experience dramatic ice mass loss."