Arctic Terns feeding around an area of 'upwelling' (a surge of melt water rising up from under a glacier) at the edge of Humboldt glacier which calves into Kane Basin in northern Greenland. Upwelling introduces iron and other nutrients into the food chain which provide food for small fish that the terns feed on. Terns live in Greenland during the summer period before leaving for the Austral summer in the Southern Ocean.