Mount St. Helens erupted catastrophically on May 18, 1980 beginning at 8:32 a.m. USGS geologist Don Swanson photographed and filmed the eruption from about 9:30 a.m. to 12:30 p.m., documenting the rising ash column and ground-hugging pyroclastic density currents. Swanson filmed the eruption from a fixed-wing surveillance aircraft using a Bell & Howell hand-wound 16mm movie camera. The films were digitized and compiled into this video.
Video: www.usgs.gov/media/videos/mou...