Because satellites are observing small changes in the height of the ice, scientists have a good estimate of where the receding grounding line will be.But they don’t yet have a good grasp of the glacier’s belly like On the grounding line because it’s under thousands of feet of ice. “These data are really exciting because we’re looking at a hidden system,” said Christine Dow, a glaciologist at the University of Waterloo who studies Antarctic glaciers but was not involved in the study.
Video: ITGC/Schmidt/Washam
With Icefin, researchers can remotely control cameras while measuring water salinity, temperature and oxygen levels. “We see that the topography of the ice base itself is very complex, so there are many steps, terraces, rifts and cracks,” said British Antarctic Survey physical oceanographer Peter Davies, lead author of one of the papers and co-author of the paper. Co-author of the paper. other. “The melting rates of different surfaces are very different.”
Where the underside of the glacier (or basal ice in scientific terms) is smooth, melting will definitely occur, but at a much slower rate than where the topography is jagged. That’s because a layer of cold water rests where the ice is flat, insulating it from the warmer seawater like a liquid blanket. But where the terrain is sloped and irregular, there are more vertical surfaces where warm water can attack the ice, including from the side. This melting creates a peculiar “scalloped” appearance, like the surface of a golf ball.
These complex, expanding base features may affect the rest of the ice. “If you turn on features under the ice, you’ll get similar reflections on the surface because of the way ice floats,” Davis said. “So there’s a concern that if you widen these cracks and fissures under the ice, you could destabilize the ice shelf, which could lead to greater disintegration over time.”
