Glacier Hazards From Space

Glaciers that become unstable and experience exceptionally high advance rates are called surging glaciers. Sometimes their surge history gets "stored" in so-called looped moraines. Here, the glacier in the middle shows deformed ("looped") moraines, in contrast to the "straight" moraines in the glacier to the left. These loops appeared when distinct surges in the tributary glacier (lower left in image) pushing into the main glacier deformed and transported its ice and debris cover, thereby storing the surge history. If a glacier surge leads to a rapid advance of the affected glacier, it may override and dam rivers too quickly to allow for slow drainage of the dammed river. A dangerous lake can develop and a corresponding flood hazard threaten people and infrastructure down-valley.