THE MOMENT: Ian Bartholomew, a geoscience doctoral researcher at the University of Edinburgh, pours fluorescent dye into waters beside Russell Glacier in western Greenland. Downstream, he and his colleagues will test the water with a fluorometer, which can detect the dye even at weak concentrations. From those readings, researchers can calculate the volume of meltwater coming from the glacier. Bartholomew is using the data to determine whether seasonal meltwater is accelerating the movement of the Greenland ice sheet by seeping through cracks and lubricating its base. Until recently, scientists had believed Greenland’s ice was too thick for meltwater to penetrate.
THE SHOT: Photograph by Ashley Cooper using a Canon EOS 5D with a 21-mm lens, ISO 100, f/9, 1/60 second.