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| Cascades Volcano Observatory, Vancouver, Washington |
| Mount St. Helens, Washington, Precursors to the May 18, 1980 Eruption |
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Mount St. Helens Precursory Activity
Images Scroll to bottom for Graphics and Maps |
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1964:
Mount St. Helens from the northeast, 1964, image by D.R. Mullineaux, USGS 
May 1965: Mount St. Helens from the southeast, May 1965, image by D.R. Mullineaux, USGS 
1970: Mount St. Helens from the southeast, 1970, image by D.R. Mullineaux, USGS 
August 1973: Mount St. Helens and Spirit Lake, as seen from Bear Cove. Image courtesy U.S. Forest Service. 
1977: Mount St. Helens from West Linn, 1977, image Ken Cameron, USGS 
1979: Mount St. Helens from the southwest, 1979, image by Rick Hoblitt, USGS 
September 28, 1979: Aerial view Mount St. Helens, as seen from the northwest, with Mount Jefferson, Oregon, in the background, September 28, 1979, image by Rick Hoblitt, USGS 
September 28, 1979: Aerial view of the summit of Mount St. Helens, looking at Shoestring Glacier, September 28, 1979, image by Rick Hoblitt, USGS 
1970-1980: Mount St. Helens and Spirit Lake, pre-1980, image courtesy Jim Nieland, U.S. Forest Service Mount St. Helens was quiet. In 1972 seismometers had been installed around the volcano, and, between 1975 and early 1980, these seismometers recorded only 44 earthquakes within 22 miles of the peak. This all would soon change as a new period of unrest was about to begin. 
March 24, 1980: Aerial view, Mount St. Helens, March 24, 1980, as seen from the north, showing one of the historic thermal areas (red circle). Scientists determine everything appears normal. Image by David Frank, USGS 
March 24, 1980: Aerial view, Mount St. Helens, March 24, 1980, image by David Frank, USGS 
March 27, 1980: First crater at the summit, March 27, 1980, image by David Frank, USGS 
March 27, 1980: First views of Mount St. Helens in eruption, March 27, 1980, image by David Frank, USGS 
March 28, 1980: Phreatic eruption of Mount St. Helens, March 28, 1980, as seen from the north. Image by C.Dan Miller, USGS 
March 30, 1980: Mount St. Helens, phreatic eruption, view from the northwest, March 30, 1980, image by C.Dan Miller, USGS 
March 30, 1980: Two-tone effect, Mount St. Helens summit, with Mount Rainier in the background, March 30, 1980, image by Robert Krimmel, USGS 
March 30, 1980: Mount St. Helens summit, showing two craters, view looking west, March 30, 1980, image by Robert Krimmel, USGS 
April 2, 1980: Aerial view of north flank of Mount St. Helens with sharp lobate ash margin from flow-emplaced ash (right), April 2, 1980, image by Richard Waitt, USGS 
April 4, 1980: USGS geologist David A. Johnston, with gas-detection equipment, April 4, 1980, USGS 
April 4, 1980: USGS geologist David Johnston standing by aircraft outfitted with COSPEC, to sample gases from Mount St. Helens, April 4, 1980, image by Tom Cascadevall, USGS 
April 4, 1980: Summit of Mount St. Helens, April 4, 1980, image by Tom Cascadevall, USGS 
April 6, 1980: "Mount St. Helens Alive and Well" sign in Cowlitz County, April 6, 1980, image by Pete Lipman, USGS 
April 6, 1980: Steam blast from the summit of Mount St. Helens, April 6, 1980, image by James G. Moore, USGS 
April 7, 1980: Graben at St. Helens' summit, April 7, 1980, image by Pete Lipman, USGS 
April 8, 1980: Small eruption of Mount St. Helens, April 8, 1980, USGS 
April 9, 1980: View from Timberline, April 9, 1980, image by Pete Lipman, USGS 
April 10, 1980: Early eruption of Mount St. Helens, as seen from the northeast, April 10, 1980, image by Don Swanson, USGS 
April 10, 1980: Mount St. Helens summit crater during degassing (no plumes visible), April 10, 1980, image by Tom Cascadevall, USGS 
April 10, 1980: Mount St. Helens, as seen from the west, with Mount Adams in the background, April 10, 1980, image by Don Swanson, USGS 
April 10, 1980: Aerial view of Spirit Lake, April 10, 1980, image by Pete Lipman, USGS 
April 10, 1980: Gas-sampling COSPEC setup at Timberline parking lot, April 10, 1980, with USGS geologist David Johnston (kneeling) and Larry Malinconico (standing). Image by Tom Cascadevall, USGS 
April 11, 1980: Ash and Snow layers at Timberline parking lot, north side of Mount St. Helens, April 11, 1980, image Richard Waitt, USGS 
April 11, 1980: Aerial view of Coldwater observation site, April 11, 1980, located 8.4 miles northwest of Mount St. Helens. This site would later be called "Coldwater I" after "Coldwater II" - located 4 miles northwest of the volcano - was established. Image by C.Dan Miller, April 11, 1980, USGS 
April 12, 1980: Mount St. Helens as seen from Chehelis, Washington, April 12, 1980, image by Lyn Topinka, USGS 
April 12, 1980: Aerial view Mount St. Helens' summit, as seen from the northeast, April 12, 1980, image by R.L. Christiansen, USGS 
April 12, 1980: Aerial view of phreatic eruption, closeup, April 12, 1980, as seen from the west. Image by C.Dan Miller, USGS 
April 13, 1980: Bulge from the northeast, April 13, 1980, image by Austin Post, USGS 
Spring 1980: Small eruption of Mount St. Helens, Spring 1980, USGS 
April 23, 1980: Establishing unmanned target on Sugar Bowl, northeast flank of Mount St. Helens, April 23, 1980, image by Pete Lipman, USGS 
April 25, 1980: Aerial view, Mount St. Helens looking west-southwest, April 25, 1980, image by Austin Post, USGS 
April 25, 1980: Geodimeter Station from Smith Creek Butte, east of Mount St. Helens, April 25, 1980, image by Pete Lipman, USGS 
April 27, 1980: Bulge from the north, April 27, 1980, image by Pete Lipman, USGS 
April 27, 1980: View of Mount St. Helens as seen from the YMCA camp, April 27, 1980, image by Pete Lipman, USGS 
April 30, 1980: USGS geologist, David Johnston, enters crater of Mount St. Helens, April 30, 1980, image by Rick Hoblitt, USGS 
April 30, 1980: USGS geologist, David Johnston, samples waters of Mount St. Helens crater lake, April 30, 1980, image by Rick Hoblitt, USGS 
May 2, 1980: USGS geologists with geodimeter, Timberline parking lot, north side of Mount St. Helens, May 2, 1980, image by Pete Lipman, USGS 
May 2, 1980: West side of Mount St. Helens as seen from geodimeter station Toutle Canyon, May 2, 1980, image by Pete Lipman, USGS 
May 2, 1980: Aerial view of surveying target on the saddle of Goat Rocks, May 2, 1980, image by C.Dan Miller, USGS 
May 2, 1980: Aerial view of Mount St. Helens' summit crater as seen from the west, May 2, 1980, image by C.Dan Miller, USGS 
May 3, 1980: Locked gate on Highway 504, leading to Mount St. Helens, May 3, 1980, image by C.Dan Miller, USGS 
May 3, 1980: Mount St. Helens summit, with bulge, as seen from the north, May 3, 1980, image by Robert Tilling, USGS 
May 4, 1980: Aerial view of the "bulge" on the north side of Mount St. Helens, May 4, 1980, image by C.Dan Miller, USGS 
May 4, 1980: USGS Scientists take geodimeter measurements to Mount St. Helens' north flank, May 4, 1980, image by C.Dan Miller, USGS 
May 4, 1980: Coldwater II observation post, May 4, 1980, USGS photographer unknown. 
May 6, 1980: Mount St. Helens on an overcast day, May 6, 1980, as seen from Coldwater II observation post, image by Norm Banks, USGS 
May 7, 1980: Aerial view of Mount St. Helens' summit crater, as seen from the north, May 7, 1980, image by C.Dan Miller, USGS 
May 7, 1980: Aerial view of Mount St. Helens' summit crater with the beginning of a second series of phreatic eruptions, May 7, 1980, image by C.Dan Miller, USGS 
May 7, 1980: Phreatic eruption from summit crater of Mount St. Helens, May 7, 1980, as seen from the southwest, image by C.Dan Miller, USGS 
May 7, 1980: Aerial view new fumarole southeast of the crater on upper Shoestring Glacier, May 7, 1980, image by C.Dan Miller, USGS 
May 13, 1980: Aerial view of Mount St. Helens' summit and crater with new ash fall, as seen from the northeast, May 13, 1980, image by C.Dan Miller, USGS 
May 16, 1980: Aerial view of Mount St. Helens, as seen from the west, showing the bulge on the north flank (on left). Mount Adams, Washington, is in the distance. May 16, 1980, image by R.L. Christiansen, USGS 
May 16, 1980: Aerial view of summit crater of Mount St. Helens, as seen from the east. Note Shoestring Glacier fumarole on the left. Image by C.Dan Miller, USGS 
May 17, 1980: Aerial view of Mount St. Helens' summit and crater, as seen from the north-northeast, May 17, 1980, image by C.Dan Miller, USGS 
May 17, 1980: Aerial side view of the "bulge" on the north flank of Mount St. Helens. Unknown USGS photographer. 
May 17, 1980: USGS geologist David Johnston (red circle) sampling fumarole at crest of the "bulge", May 17, 1980. Image taken from hovering helicopter. Unknown USGS photographer. 
May 17, 1980: Mount St. Helens as seen from the northwest, May 17, 1980, image by Harry Glicken, USGS 
May 17, 1980: David A. Johnston sitting on Johnston Ridge, May 17, 1980, image by Harry Glicken, USGS 
May 18, 1980:" May 18, 1980, image by Austin Post, USGS 
1919: USGS topo map detail of the summit of Mount St. Helens from 1919 
August 5, 1972: Computer-generated vertical view of Mount St. Helens, from photos taken August 5, 1972. Data were filtered by averaging pixel values over areas. 
1975 to March 1980: Plot of earthquakes in the Mount St. Helens vicinity, from 1975 through March 1980. Figure from USGS Professional Paper 1250. 
March 1980: Daily earthquake counts for mid-March, 1980. Figure modified from USGS Professional Paper 1250, p.100. 
March 20, 1980: Seismogram of moderate earthquake recorded on the afternoon of March 20, 1980, at station SHW. At approximately 3:45 PM a magnitude 4.1 earthquake occurred just northwest of the summit of Mount St. Helens at shallow depth. It was unlike any that had been previously detected in the area. 
March 21-23, 1980: Seismogram from stations SHW, for March 21 to 23, 1980, USGS 
March 24-25, 1980: Seismogram from stations SHW and CPW, for March 24 to 25, 1980, USGS 
April 2, 1980: Seismogram showing harmonic tremor, April 2, 1980, USGS 
April 12 to May 1, 1980: Topographic map showing increases in elevation (blue) and decreases in elevation (red) from April 12 to May 1, 1980. Contour interval is 40 feet. Solid black line indicates outline of the "bulge". Dashed black line is outline of the crater following the May 18 eruption. Modified from USGS Professional Paper 1250. 
"before and after May 18, 1980": Sketches showing Mount St. Helens before and after the May 18, 1980 eruption, by Dee Molenaar, USGS. 
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