Glacier Hazards From Space

(Before image) Meltwater lakes can form on top of glaciers, threatening potentially disastrous floods if they burst forth. Careful monitoring of the Belvedere Glacier in the Italian Alps began in the mid-1980s following an outburst of the moraine lake Lago delle Locce in 1979 (dark blue lake to right of glacier). This monitoring was fortunate, because in June 2002, authorities discovered that a tiny lake that had developed the previous summer atop the Belvedere Glacier had grown to an exceptionally large lake with a volume of some three million cubic yards (see aquamarine lake in center of both images). When discovered, the lake level was rising at up to a yard a day and had only a few yards of freeboard remaining. The Italian Civil Defense Department and the scientists involved initiated emergency actions. These actions, together with natural drainage and a cold spell in early July, helped return the lake size to that seen in the first image by October 2002. When the lake grew to a similar huge size in spring 2003, the authorities were prepared and were able to avert a damaging flood.