Oblique aerial view of Mount St. Helens as viewed from the north. Skamania County, Washington. 1980.

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.