Scientists have good estimates of the place the retreating grounding line is, due to satellites looking ahead to tiny adjustments within the ice’s elevation. However they haven’t had image of what the glacier’s stomach appears like on the grounding line, as a result of it’s underneath hundreds of toes of ice. “These knowledge are actually thrilling as a result of we’re getting a glance right into a hidden system,” says College of Waterloo glaciologist Christine Dow, who research Antarctic glaciers however wasn’t concerned within the analysis.
Video: ITGC/Schmidt/Washam
With Icefin, the researchers may remotely pilot a digital camera whereas measuring the salinity, temperature, and oxygen content material of the water. “We noticed that the ice base itself was very complicated in its topography, so there’s a lot of staircases, terraces, rifts, and crevasses,” says British Antarctic Survey bodily oceanographer Peter Davis, the lead creator of one of many papers and coauthor on the opposite. “The speed of melting on completely different surfaces was very completely different.”
The place the glacier’s underside (or basal ice, within the scientific parlance) is smoother, melting is certainly occurring, however at a a lot slower price than the place the topography is jagged. That’s as a result of a layer of chilly water rests the place the ice is flat, insulating it from hotter ocean water like a liquid blanket. However the place the topography is sloped and irregular, there are extra vertical surfaces the place heat water can assault the ice, together with making incursions from the facet. This melting creates a peculiar “scalloped” look, just like the floor of a golf ball.
These complicated, increasing basal options may then affect the remainder of the ice. “When you open up options beneath the ice, you additionally get related reflections of them on the floor, due to the way in which that the ice is floating,” says Davis. “So there is a worry that when you’re widening these rifts and crevices underneath the ice, you may destabilize the ice shelf, which may result in better disintegration over time.”
