What It Looks Like When a Glacier Calves an Iceberg

There was nobody around to hear the crack when an iceberg around a mile long broke off from Antarctica's Pine Island Glacier, but a NASA satellite high above captured the dramatic event. The Landsat 8 satellite captured the iceberg's separation late last month in what was believed to be the sheet's biggest loss of ice since 2015, when a massive chunk of ice 20 miles long broke away, Live Science reports. This loss wasn't on the same scale, but NASA describes it as further evidence of the ice shelf’s "fragility," which is especially alarming because of the amount of ice the Pine Island sheet moves from the West Antarctic Ice Sheet to the ocean.

The new iceberg broke off from a floating ice sheet at the end of the glacier, meaning its loss won't contribute to rising sea levels, Mashable reports, explaining the floating sheet buttresses huge amounts of land-based ice behind it. Researchers expect more ice to break off from the glacier soon. The latest break was the "calving equivalent" of an "aftershock" from the 2015 event, Ohio State University glaciologist Ian Howat says in a NASA press release. "Apparently, there are weaknesses in the ice shelf—just inland of the rift that caused the 2015 calving—that are resulting in these smaller breaks." (Researchers fear the much larger West Antarctic Ice Sheet has already passed the point of no return.)