Glacier Hazards From Space

(Before image) Ice collapses and the avalanches they can trigger are one of the gravest dangers that glaciers present. In the late evening of September 20, 2002, a rock-and-ice avalanche began on a peak high above the village of Karmadon in the Russian Caucasus. The avalanche fell onto the tongue of the Kolka glacier, shearing it off and triggering a massive landslide containing tens of millions of cubic yards of rock, mud, and ice. This rushed down the valley at speeds of over 60 miles per hour, burying the lower parts of Karmadon (center of images) and killing more than 120 people. The "before" image was taken on July 22, 2001, and the "after" image on September 27, 2002, a week following the disaster. By this date, lakes (visible in the center left of the landslide and in the lower right of the image) had begun to form as the landslide blocked rivers. Close to 10 million cubic yards in volume, these lakes posed a danger of outburst and catastrophic downstream flooding.