Pine Island Glacier is one of the main glaciers responsible for moving ice from the interior of the West Antarctic Ice Sheet to the ocean and it has just experienced yet another calving event.
Ian Howat a glaciologist at Ohio State University noted that this particular calving event is much smaller than recent calving events on Pine Island Glacier. “I think this event is the calving equivalent of an ‘aftershock’ following the much bigger event,” Howat said. “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.”
x YouTube VideoDuring August of 2015 a large block of ice broke off from the floating section of Antarctica’s massive Pine Island Glacier. These events are natural occurrences, but this one was precipitated by an unusual rift in the middle of the ice pointing to a new mechanism for the collapse of West Antarctica Ice Sheets. American Geophysical Union noted that it wasn't until they started testing for new image processing software recently “that they noticed a crack had formed at the very base of the ice shelf nearly 20 miles inland in 2013. The rift propagated upward over two years, until it broke through the ice surface and set the iceberg adrift over 12 days in late July and early August 2015.”
NASA reports and shares images on the 2017 Glacial Aftershock:
Although not visible in these images, more small rifts persist on Pine Island about 10 kilometers (6 miles) from the ice front. One such rift was photographed on November 4, 2016, during a flight of NASA’s Operation IceBridge—an airborne science mission that makes annual flights over this area. Other rifts are less visible at the surface because they are growing upward from the basal (bottom) side of the shelf. Scientists expect that these rifts will result in more calving in the near future.
“Such ‘rapid fire’ calving does appear to be unusual for this glacier,” Howat said. But the phenomenon “fits into the larger picture of basal crevasses in the center of the ice shelf being eroded by warm ocean water, causing the ice shelf to break from the inside
Large rift near the Pine Island Glacier tongue, West Antarctica, as seen during an IceBridge flight on Nov. 4, 2016.The West Antarctic Ice Sheet is particularly vulnerable to global warming caused by our burning of fossil fuels. It’s collapse will be catastrophic. Pine Island and Thwaites glaciers have 10 feet of sea level rise currently locked up in ice, the rapid flow of that ice into the ocean would submerge most coastal cities throughout the world.