Plumes of sediment-laden meltwater from southwest Greenland’s glaciers are easily recognizable in this
NASA satellite image captured in early September. Meltwater at the top of the ice sheet starts out relatively clean, but as it flows through glacial channels down to the ground and out into the ocean, it picks up large amounts of sediment — a byproduct of the glacier scraping the bedrock. As a result, plumes like the ones that appear light-blue in this photograph, are good markers for estimating the amount of meltwater leaving the ice sheet, researchers say. Melting from the Greenland Ice Sheet could result in global sea level rise of 2 to 8 inches, according to the most recent assessment from the Intergovernmental Panel on Climate Change.