SHOESTRING A

 

Event description

 

On May 18, 1980, after nearly 2 months of local earthquakes and steam eruptions, ice-clad Mount St. Helens in the Cascade Range, southwestern Washington, began a major explosive eruption, directed first northward and then upward. The lateral blast, occuring in only the first few minutes of a 9-hour continuous eruption, devastated more than 150 km2 of forest and recreation area and left 60 people dead. The huge debris avalanche that immediately preceded the eruption and the intermittent eruptions during the following three days removed about 2.9 km3; this comprised new magmatic material and material from the old upper and northern part of the mountain, including about 40 to 45 Mio m3 of glacial snow and ice.

 

Damage

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devastated more than 150 km2 of forest and recreation area and left 60 people dead

 

Data source

 

Haeberli, W., M�ller, P. (1988): Fluctuations of Glaciers 1980�1985, Vol. V International Association of Hydrological Science.

 

Remarks

 

Shoestring Glacier, which had already been investigated before the eruption, lost major parts of ist accumulation area.