Icebergs, including one with a sapphire pool of meltwater, clutter Greenland's Jakobshavn Fjord near the village of Ilulissat. The glacier that produced this flotilla has receded some four miles (six kilometers) since the year 2000. Glaciers such as Jakobshavn are calving icebergs much faster than scientific models had predicted they would. The ongoing Extreme Ice Survey hopes to shed some light on why these so-called tidewater glaciers, which end in water instead of land, are being lost at such a rapid rate. Photograph by James Balog