Aerial view of Mount St. Helens volcano erupting. Skamania County, Washington. 1980.
Dates
Date Taken
1980-05-18
Summary
Caption: Mount St. Helens in Action. Aerial view of the erupting Mount St. Helens volcano, Wahington, Taken about 6:00p.m., May 18, 1980, from the northwest. View shows, in part, the new vent-valley (second blow out area) whic was formed during the initial blast which occurred about 9 hours earlier. Mount Hood can be seen in background to the right of Mount St. Helens. Photo by Austin Post, U.S. Geological Survey, Tacoma, Washington. The initial plume of the May 18 eruption reached more than 60,000 feet into the atmosphere. USGS scientists estimate that the minimum volume of ash and rock ejected during the May 18 eruption amounted to about 1 cubic kilometer (1.3 billion curbin yeards) of material. The estimate is based on an assumption [...]
Summary
Caption: Mount St. Helens in Action. Aerial view of the erupting Mount St. Helens volcano, Wahington, Taken about 6:00p.m., May 18, 1980, from the northwest. View shows, in part, the new vent-valley (second blow out area) whic was formed during the initial blast which occurred about 9 hours earlier. Mount Hood can be seen in background to the right of Mount St. Helens. Photo by Austin Post, U.S. Geological Survey, Tacoma, Washington.
The initial plume of the May 18 eruption reached more than 60,000 feet into the atmosphere.
USGS scientists estimate that the minimum volume of ash and rock ejected during the May 18 eruption amounted to about 1 cubic kilometer (1.3 billion curbin yeards) of material. The estimate is based on an assumption that the new crater formed by the blast at Mount St. Helens measures about 1 kilometer wide, 2 kilometers long, and at least 0.3 kilometers deep.
If the May 18 eruption did produce as much as estimated, USGS scientists say, the volume would be about equal to the estimate volume of volcanic materials ejected by Mount St. Helens in in 1500 A.D., and about one-third the volume of the volcano's 1900 B.C. eruption. By comparison, the eruption of Mount Vesuvius that buried Pompeii in 79 A.D. produced slightly more than 1 cubic kilometer of ash; the deadly eruption of Indonesia's Krakataua in 1883 produced about 20 cublic kilometers of ash; and one of the largest eruptions in history, Tamora in Indonesia, in 1815, produced nearly 80 cubic kilometers of ash and other ejected material.
The May 18 eruption was the biggest of the series of eruptions that began on March 27, 1980. Its eruptive plume reached over 60,000 feet into the atmosphere, and its initial burst released the energy equivalent of about 10 to 50 megatons of TNT. As a comparison, the largest nuclear bomb test, conducted in the Soviet Union in October 1961, released the energy equivalent of about 50 megatons of TNT.
PIO No. 80-126b (2d)
Note stamped information on duplicate photograph: 80 S 3 303 May 18 '80
Available in the U.S. Geological Survey Denver Library Photographic Collection, 2010 DENPH0011, PIO Collection.
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