Pyroclastic flow deposits from the third eruptive pulse of the Mount St. Helens July 22 eruption. Skamania County, Washington. 1980.

Typed caption accompanying slides: 19:18:25 new pyroclastic flow deposits from third eruptive pulse cover crater floor. Skamania County, Washington. (Photo by R. Hoblitt). Index card (nos. 1ct-98ct): Series of essentially time lapse photographs recording the three major eruptive pulses that began at 17:14 hours, 18:30 hours, and 19:02 hours Pacific Daylight Savings Time, July 22, 1980. Photographs were taken by Jim Vallance in a fixed wing aircraft, Michael P. "Mike" Doukas, Harry Glicken, and Richard P. "Rick" Hoblitt in a helicopter. Skamania County, Washington. (Complete captions on file). Note: Mount St. Helens - List of color transparencies (slides) of the July 22, 1980 eruption. The following slides (1-114) of the July 22, [...]