TORONTO -- In 2019, a lake on an ice sheet in East Antarctica vanished completely over the course of three days. The strange occurrence went unnoticed until the next summer, when Dr. Roland Warner, a glaciologist with the Australian Antarctic Program Partnership at the University of Tasmania, noticed discrepancies in satellite images of the Amery Ice Shelf. As he investigated further, he and other researchers concluded that something rare had happened: a hydrofracture. “We believe a large crack opened briefly in the floating ice shelf and drained the entire lake into the ocean within three days,” Warner said in a news release.