West Antarctic Glaciers in Irreversible Decline: Sea Level Rise Warning

It turns out that there may be no going back when it comes to a section of the West Antarctic Ice Sheet. Scientists have discovered that this region is in irreversible decline, with nothing stopping the entire glacial basin from disappearing into the sea.

Melting glaciers contribute significantly to sea level rise. In fact, the glaciers in Antarctica release as much ice into the ocean each year as the entire Greenland Ice Sheet does. In total, these glaciers contain enough ice to raise sea levels by four feet.

Now, it looks as if some runaway melting may be occurring. After using 40 years of observations, scientists have concluded that six glaciers in the Amundsen Sea sector in Antarctica have essentially passed the point of no return. The researchers also used radar observations from the European Remote Sensing satellites between 1992 and 2011 in order to map ground lines' inland creep.

"This sector will be a major contributor to sea level rise in the decades and centuries to come," said Eric Rignot, one of the researchers, in a news release. "A conservative estimate is that it could take several centuries for all of the ice to flow into the sea."

In fact, the glaciers that the researchers looked like have melted so much that they're floating above places where they used to sit solidly on land. Glaciers have the ability to float over and area where it used to be grounded if it becomes lighter; this means that the grounding lines are retreating inland.

"The collapse of this sector of West Antarctica appears to be unstoppable," said Rignot in a news release. "The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating parts of the glaciers. At this point, the end appears to be inevitable."

The findings are published in the journal Geophysical Research Letters.