Pine Island Glacier is one of the main outlets for ice from the interior of the West Antarctic Ice Sheet to flow into the ocean.
The image above was taken on September 21, 2017 by the Landsat 8 satellite. It shows a clear rift visible across the centre of the glacier’s floating ice shelf.
Not long afterward, the rift resulted in the calving of a large iceberg, with an area of about 185 square kilometres, now floating in the Amundsen Sea.