A new scientific study published Tuesday has found that warm ocean water is carving an enormous channel into the underside of one of the key floating ice shelves of West Antarctica, the most vulnerable sector of the enormous ice continent.

The Dotson ice shelf, which holds back two separate large glaciers, is about 1,350 square miles in area and between 1,000 and 1,600 feet thick. But on its western side, it is now only about half that thickness, said Noel Gourmelen, a researcher at the University of Edinburgh in Scotland and the lead author of the research, which was just published in Geophysical Research Letters.

The reason is the same one that is believed to be shrinking glaciers and pouring ice into the ocean across West Antarctica — warm ocean water located offshore is now reaching the ice from below.