Calvin University's official student newspaper since 1907

Calvin University Chimes

Since 1907
Calvin University's official student newspaper since 1907

Calvin University Chimes

Calvin University's official student newspaper since 1907

Calvin University Chimes

Warmer oceans threaten Antarctica’s Totten Glacier

Late last year, scientists discovered that the West Antarctic ice sheet is collapsing, which is predicted to lead to a global sea level rise of roughly 11 feet.

Last week, scientists from the United States, Britain, France and Australia published a paper in Nature Geoscience predicting that number could double (reaching 22 feet) as a large glacier on the east side of the continent is melting as well.

According to Ph. D. candidate and lead study author Jamin Greenbaum of the University of Texas at Austin, this is “a conservative lower limit.”

The scientists conducted a number of research flights over Antarctica’s Totten Glacier, the world’s fastest shrinking ice sheet, to find the cause for its retreat. They discovered that, like the western ice sheet, increasingly warm waters are getting under the glacier.

These warm waters cause the 90 mile by 22 mile glacier to lose an amount of ice “equivalent to 100 times the volume of Sydney Harbor every year,” according to the Australian Antarctic Division.

If such a vast amount of ice were to flow into the ocean and melt, we could see a rise in sea level of 11 feet.  Combined with the melting of the West Antarctic ice sheet, ocean levels could rise by 22 feet.

By taking gravitational, radar and laser altimetry measurements, the researchers discovered two large undersea valleys beneath the Totten Glacier. In these areas, due to the salt content, warmer water slips beneath the cold water which increases the warm water’s density.

The combination of warm water availability and the observed melting of the Totten Glacier “supports the idea that the behaviour of Totten Glacier is an East Antarctic analogue to ocean-driven retreat underway in the West Antarctic Ice Sheet (WAIS),” the study stated. “The global sea level potential of 3.5 m flowing through Totten Glacier alone is of similar magnitude to the entire probable contribution of the WAIS.”

Unfortunately, this study did not include direct temperature measurements of the ocean water that is reaching the glacier itself. The equipment necessary to complete that task was not part of the study.

According to Antarctica expert Eric Rignot of the University of California, Irvine, however, “other research efforts are underway to get critical oceanographic information near Totten.”

Major ice loss from Antarctica could lead to dire consequences for countries in the Northern Hemisphere.  Antarctica currently has a large enough mass to pull the ocean toward itself through gravitational forces. As it melts, it will lose that mass and the water will be more free to move towards the Northern Hemisphere, creating serious trouble for many coastal cities.

This process could take place over the course of hundreds of years, affecting future generations. Once the massive melting begins, however, it is difficult to see how it could stop.

“With warming oceans,” says Martin Siegert, a co-author of the study based at the Grantham Institute at Imperial College London, “it’s difficult to see how a process that starts now would be reversed, or reversible, in a warming world.”

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