When scientists tagged a curious seal, he led them to signs of a potential climate disaster - Boston.com

Given its salt content and the extreme depths and pressures involved — in some regions Denman Glacier rests on a seafloor that is over a mile deep — such warm water can destroy large amounts of ice.

The region of its “grounding line,” where the glacier touches both the seafloor and the ocean, had retreated backward more than three miles toward the center of Antarctica since 1996, bringing the sea to the edge of the newly discovered canyon.

“We dug out these data because we wanted to find out if warm water can indeed reach this glacier,” said Eric Rignot, an Antarctic expert at the University of California at Irvine and one of the authors of the paper.

A group of scientists based in Australia, led by Esmee Van Wijk of the Commonwealth Scientific and Industrial Research Organisation, were trying in 2020 to study Totten, a gigantic glacier hundreds of miles from Denman.

There is still a great deal of uncertainty about what Denman will do next, and scientists — hobbled by how little they know about this region — cannot predict it at this point, said Don Blankenship, an Antarctic expert at the University of Texas at Austin.

The precise details of what kind of bedrock the ice sits upon, and the exact contours of the ocean floor and the rock walls surrounding the wide glacier, will matter.