It’s been a longtime coming, but the Pine Island Glacier in Antarctica has finally given birth to what’s now called Iceberg B-31 — a chunk of ice about the size of the Hawaiian island of Molokai. I mention Molokai because this is an island many people have actually seen as they fly between Honolulu and Maui.
The satellite images above show the 250-square-mile (750-square-kilometer) iceberg both before (Oct. 28) and after (Nov. 13). The massive calving event started way back in October 2011, when NASA’s Operation IceBridge caught sight of the crack. Last summer infrared and radar images showed the crack to have cut all the way across the ice shelf.
The Operational Land Imager on the Landsat 8 satellite acquired these images, which are now available in natural color, higher resolution at the NASA Earth Observatory. An additional view of the iceberg on Nov. 10, just after the Nov. 9 detachment is also available.
Scientists have been watching and studying this event for some time, as it has been a real world laboratory for how these huge pieces of ice manage to break free of not only the glacier, but from the ocean bottom, and then start a slow journey into the ocean and probably around Antarctica in the counterclockwise current that encircles the continent. There is also evidence that warming waters helped this particular iceberg to calve, which is a trend that could be connected to anthropogenic global warming.
Some of the latest science will be presented by researchers at the coming meeting of the American Geophysical Union (AGU) in San Francisco, on Dec 9-13 (full disclosure, I also work part-time for AGU).
IMAGE: NASA Earth Observatory images by Holli Riebeek, using Landsat 8 data from the USGS Earth Explorer.