https://www.wired.com/story/antarctica-thwaites-glacier-breaking-point/
Anandakrishnan stood up and walked over to a whiteboard to draw me a picture of the glacier bed’s geometry. It was a line that began with a bump in the front, where the glacier met the sea, and sloped gently downward as it went inland. At the moment, he said, it’s unclear how long Thwaites has before it pulls off its bump—its grounding line—and starts a rapid decline. “It’s kind of hanging on by its fingernails right about there,” he explained, gesturing at the bump.