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Vallance, James W.

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Album caption: Oblique aerial view of Mount St. Helens as viewed from the north, sequence (4A-J) showing about the first 30 seconds of the second eruptive pulse of July 22, 1980. Photographs 4A-J (photos nos. 3-12) taken at about 3-second intervals beginning at 1825:20±5 PDT; photograph 4J taken about 6 second after 4I. Arrow (4H) indicates projection from pyroclastic fountain. Dashed line (4H) indicates front of pyroclastic density flow. Skamania County, Washington. (Photos by J.W. Vallance; graphic on published photos only; see also MSH-July 22, 1980 nos. 5ct-15ct in USGS Photo Library) Published as figure 4-C in U.S. Geological Survey. Professional paper 1335. 1986. Index card unavailable.
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Album caption: Oblique aerial view of Mount St. Helens as viewed from the north sequence (4A-J) showing about the first 30 seconds of the second eruptive pulse of July 22, 1980. Photographer 4A-J (photos nos. 3-12) taken at about 3-second intervals beginning at 1825:20±5 PDT; photograph 4J taken about 6 seconds after 4I. Arrow (4H) indicates projection from pyroclastic fountain. Dashed line (4H) indicates front of pyroclastic density flow. Skamania County, Washington. (Photos by J.W. Vallance; graphics on published photos only; see also MSH-July 22, 1980 nos. 5ct-15ct in USGS Photo Library) Published as figure 4-B in U.S. Geological Survey. Professional paper 1335. 1986. Index card unavailable.
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Typed caption not available. Note: Slide numbers 43 - 50 were taken at 19:01 and show the pyroclastic flow as it advances northward. Skamania County, Washington. July 22, 1980. Slide number 51 was taken at 19:02. Slide numbers 52 - 55 were taken at 19:03. Slide numbers 56 - 57 were taken at 19:04. Slide numbers 58 and 59 were taken at 19:04 and 19:05. Slide numbers 60 - 62 are views of the eruption and were taken at 19:06. Slide no. 52, msh_vjw00052_ct, is highlighted in this photo record. Slide no. 52 typed caption: View of eruption at 19:03, the plume develops a mushroom-like head while the elutriate cloud from the pyroclastic flow billows up through the cloud layer. Skamania County, Washington. (Photo...
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These slides of the July 22, 1980 eruption of Mount St. Helens were taken by Jim Vallance, who was in a U.S. Forest Service fixed wing aircraft and by Mike Doukas, Harry Glicken, and Rick Hoblitt who were in a U.S. Geological Survey helicopter. There were three major eruptive pulses on July 22, 1980. They begin at 17:14, 18:30 and 19:02 PDT. Slides no. 5 through 25 were taken between 18:25:20 and 18:26:30 This sequence was taken while moving counter-clockwise from the north to the west flank of Mount St. Helens at a distance of about 7 miles and while changing elevation from about 10,000 to 12,000 feet. Approximate 3 seconds after slide no. 14. (Wing of aircraft visible). Skamania County, Washington. (Photo by J....
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Typed caption accompanying slide: Stereopair with slide no. 64 taken at 19:11. The plume encounters an atmospheric boundary and is planed off into an anvil shape at about 60,000 feet. Skamania County, Washington. (Photo by J. Vallance) Note: Slide numbers 43 - 50 were taken at 19:01 and show the pyroclastic flow as it advances northward. Skamania County, Washington. July 22, 1980. Slide number 51 was taken at 19:02. Slide numbers 52 - 55 were taken at 19:03. Slide numbers 56 - 57 were taken at 19:04. Slide numbers 58 and 59 were taken at 19:04 and 19:05. Slide numbers 60 - 62 are views of the eruption and were taken at 19:06. Slide no. 52, msh_vjw00052_ct, is highlighted in this photo record. Slide no....
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