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| This aerial view shows the dramatic effect on the headwaters of the Muddy River of a fast- moving lahar that swept from the east flank of Mount St. Helens during the first minutes of the 18 May 1980 eruption. The lahar flowed as a broad sheet 1.3 km wide and least 5 m deep in places, as estimated from abraded trees on the sides of the lahar. Nearly all of the trees were toppled, buried, or carried downstream. The momentum of the lahar carried it 47 m up and over a ridge just to the right of the photograph (out of view)! |
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URL of this document:
http://volcanoes.usgs.gov/Hazards/Effects/MuddyPost_caption.html
Last modified: October 19, 1998
