Multimedia

  • The midnight sun casts a golden glow on an iceberg and its reflection in Disko Bay, Greenland. Much of Greenland’s annual mass loss occurs through calving of icebergs such as this. (Photo courtesy Ian Joughin)
  • Each summer, streams channel much of the melt that is produced by the warmer temperatures along the Greenland Ice Sheet’s lower elevation margins. (Photo courtesy Ian Joughin)
  • Surface melt water rushes along the surface of the Greenland Ice Sheet through a supra-glacial stream channel. (Photo courtesy Ian Joughin)
  • Over the course of several years, turbulent water overflow from a large melt lake carved this 60-foot deep canyon. Note the people for scale. (Photo courtesy of Ian Joughin)
  • For several summers this deeply incised melt channel transported overflow from a large melt lake to a Moulin, a conduit that drains the water through many hundreds of feet to the ice sheet’s bed. (Photo courtesy Ian Joughin)
  • Large (~0.75 mile diameter) melt lake that is just one of the many supraglacial lakes that form on the ice sheet’s surface during the period of strong summer melt. (Photo courtesy Ian Joughin)
  • Moulin that drains surface meltwater through ice more than 3000 feet thick to reach base of the ice sheet, from where a subglacial drainage network ultimately routes it to the ocean. (Photo courtesy Ian Joughin)
  • Close-up of large crevasses produced by Pine Island Glacier’s rapidly stretching ice just above its grounding line (the transition from grounded to floating ice). (Photo courtesy of Ian Joughin)
  • Close-up of large crevasses produced by Pine Island Glacier’s rapidly stretching ice just above its grounding line (the transition from grounded to floating ice). (Photo courtesy Ian Joughin)
  • Curvi-linear crevasses in a region of complex ice flow on Pine Island Glacier, West Antarctica. (Photo courtesy Ian Joughin)
  • Seaward-looking view down Pine Island Glacier’s floating ice shelf, with a train of crevasses receding toward the horizon. (Photo courtesy Ian Joughin)
  • Summer clouds swirl in around the Staccato Peaks of Alexander Island, Antarctic Peninsula. High snowfall and strong weather gradients in this mountainous area make assessment of glacier mass balance particularly challenging. (Image courtesy of Hamish Pritchard, British Antarctic Survey)
  • A British Antarctic Survey two-man field camp next to The Obelisk on Alexander Island, Antarctic Peninsula. (Image courtesy of Hamish Pritchard, British Antarctic Survey)
  • The late summer sun sets over mountains and icebergs around Adelaide Island, Antarctic Peninsula, as twenty-four hour daylight gives way to the long polar night of winter. (Image courtesy of Hamish Pritchard, British Antarctic Survey)
  • Hamish Pritchard on a British Antarctic Survey expedition in the Herschel Heights, Alexander Island. Rock samples can tell us when these summits emerged from the retreating ice sheet. (Photo courtesy of Mike Brian)

Polar Melt

Published November 29, 2012