Meltwater Waterfall, Kangerlussuaq, Greenland,National Geographic
Scientists in Kangerlussuaq on western edge of ice sheet film runoff from glacier washing out roads and taking out a tractor
The gust of warm air that caused the unprecedented thaw in Greenland's surface ice also appears to have caused unusually high runoff from a glacier, wiping out a crossing near a key research and transport hub.
Scientists who fly in Kangerlussuaq, near the western edge of the ice sheet, have been keeping an eye on the Watson river bridge for years.
The bridge dates from the 1950s, but wasn’t built for the magnitude of spring and summer melt of the last 12 years or so, said Jason Box, a glaciologist at Ohio State University who returned on Tuesday from a three-week stint in Greenland.
"The midsummer floods have been growing and threatening this bridge and finally took it out," he said. "It washed out roads and took out a tractor."