Big picture: Pakistan's surging glaciers

[Cornered Tiger]

This satellite image show the flow of the Baltoro Glacier in the Karakoram mountain range in Pakistan. Snow is shown as cyan, ice is pale blue, the bare terrain is a muddy brown. The branching formation in the centre of each image is the glacier's ice tongue, brown with rocky debris.

The snapshots come from Nasa's Landsat satellite, which produces "false colour" images by measuring wavelengths of light invisible to the human eye. "For glacier analysts this is extremely useful," says Frank Paul, senior researcher at the University of Zurich, who put together the images. "These composites show clouds in a different colour to snow."

Unlike other glaciers around the world, these are not receding, a phenomenon known as the "Karakoram Anomaly". To observe this, Paul turned Landsat images from 1990 to 2013 into an animated gif, which revealed some glaciers retreating over short periods, others stationary and some surging.

"This confirms the anomaly in climatic terms," says Paul. "As for the surging -- we have no clue why they are doing it."

Source: http://www.wired.co.uk/news/archive/2016-02/29/pakistans-surging-glaciers