Warming Seawater Is Making Ice Shelves More Vulnerable

This week, NASA reported that an iceberg roughly twice the size of New York City is expected to break off an ice shelf in Antarctica. Researchers say the iceberg could be the largest to break from the Brunt Ice Shelf in more than a hundred years.

Linda Ivany is a professor of Earth Sciences at Syracuse University’s College of Arts and Sciences.

Ivany says:

“There are suggestions that ice shelves are particularly vulnerable right now because of warming seawater. Warmer waters will melt them from below, and if that happens back underneath where the ice is still in contact with land, it can destabilize them and make them flow and/or break up faster. That will cause sea level to rise faster.

“So, is this particular one a catastrophe? No. But is it potentially a harbinger of more things to come? Perhaps. Time will tell.

“Calving of ice at the front of ice shelves is normal, and it happens as the ice pouring off the continent advances out over water and breaks off.  The piece they’re talking about is big, but not giant by Antarctic standards – it’s about half the size of the famous Larsen B ice shelf that disintegrated in 2002, drawing global attention to the phenomenon.

“The Larsen ice shelves were evidently stable for thousands of years before breaking up, suggesting that something unusual might be happening. Losing part or all of an ice shelf won’t affect sea level, because the ice is already floating. But they do seem to have a buttressing effect on the flow of ground-based glacier ice, which does have an impact on sea level.  If there is a broad ice shelf, ice doesn’t flow out as fast. It sounds like the Brunt ice shelf is in a bit of a precarious position now because a corner of it is grounded, hung up on a bump in the sea floor, and that is likely slowing its progress. If the impending crack breaks off the shelf landward of that, then there is the potential that ice could start flowing off the continent in that area faster.”

To request interviews or get more information:

Daryl Lovell
Media Relations Manager
Division of Marketing and Communications

T 315.443.1184   M 315.380.0206
dalovell@syr.edu | @DarylLovell

The Nancy Cantor Warehouse, 350 West Fayette Street, 2^nd Fl., Syracuse, NY 13202
news.syr.edu | syracuse.edu

Syracuse University