Photo courtesy of USGSBefore the eruption of May 18, 1980, Mount St. Helens' elevation was 2,950 m (9,677 ft). View from the west, Mount Adams in distance. S. Fork Toutle River is valley in center of photo.
Denver Post fileVolcano crater appears at the top of Mount St. Helens March 27, 1980 after the volcano belched steam and mud in a thunderous explosion. It is the first volcanic eruption in the contiguous United States in 66 years.- Denver Post fileThe north side of Mount St. Helens, continued to bulge May 7, 1980. Geologists said that the 320-foot bulge near the top of volcano, definitely was caused by molten rock rushing into the cone from deep underground. The bulging is just outside of the 2000 foot wide crater on the top of the mountain.
- Denver Post fileThis is an aerial view of Mount St. Helens volcano erupting May 18, 1980. Scientists were still unsure whether the eruptive cycle that began March 27, 1980, has run it course or whether the volcano could explode again.
- The Associated PressThis is an aerial view of the eruption of Mount St. Helens Volcano May 18, 1980 and obtained by the Associated Press from the Geological Survey. The plume venting from the crater at the mountain's summit reached to more than 60,000 feet into the atmosphere.
- The Associated PressHarry Truman, on the steps of his lodge the day before the eruption. Mount St. Helens buried his lodge under tons of mud and ash and he's been written off as dead.
- Denver Post fileA plume of smoke, ash and rock debris spews skyward as Mount St. Helens erupts on May 18, 1980. The eruption killed at least 57 people. Mount St. Helens is located 45 miles northeast of Portland in Washington.
- Photo courtesy of USGSAsh plume (close up) from May 18, 1980 Mount St. Helens. Plume moved eastward at an average speed of 60 mi per hour , with ash reaching Idaho by noon. For more than nine hours a vigorous plume of ash erupted, eventually reaching 20-25 km (12-15 mi) above sea level. By early May 19, the devastating eruption was over.
- Photo by Vern HodgsonPhoto of the May 18 eruption of Mount St. Helens in southwest Washington. The cloud, filled with ash, hot rocks and steam, is about 20 miles across and moving fast. Lightning later rippled from the cloud, and there was a dull, low, ominous roar, said photographer Vern Hodgson of Lynnwood, Wash.
- United Press InternationalPlume of smoke and ash rises for miles from Mount St. Helens as the volcano erupted with vengeance.
- The Associated PressMount St. Helens erupts with Its most violent display Sending Ash, Smoke and Debris Nearly 9 Miles into the air. Westerly winds spread the ash eastward across Washington and Idaho and into Montana, about 500 miles away.
- Denver Post fileWashington national Maj. Robert Williams tends to the burns of a man picked up by helicopter from the end of a log in the middle of the Green River, May 19, 1980.
- The Associated PressMike Fitzpatrick, Right, and Bob Muller wear handkerchiefs for protection from ash. They were heading home in Missoula, Mont, May 19, 1980 while volcanic residue filtered down into the streets.
- Denver Post fileOn May 18, 1980, Mount St. Helens blew its top in a cataclysmic eruption that left 60 people dead or missing. The volcanic debris spread by the eruption caused problems for the residents of Washington and Oregon that will continue for at least the next half-century.
- The Associated PressA Washington Army National Guard helicopter crewman wades through ashes just North of sprit lake about 8 miles from the erupting Mount St. Helens to check for survivors. Two occupants inside the camper were found dead and officials speculated they were campers trying to watch the eruption, but were overcome by the poisonous gases.
- George Wedding, San Jose Mercury NewsUnidentified body lies in back of ash covered pickup May 19, 1980 on Mount St. Helens near Toutle River, Basin. Officials believe the victim was killed by heat and the gas from volcanic eruption May 18 when Mt. St. Helens spewed plume of steam and hot ash 60,000 feet in air.
- The Associated PressSoldier looks over remains of camp near volcano The army assisted in the search for survivors around Mount St. Helens.
- United Press InternationalMount St. Helens, still a simmering menace in spite of being shorn of 100 million tons of rock, wrecked more bridges May 20, 1980 and threatened another flood of steaming mud and water. The Cowlitz river at Longview, Wash., is jammed with millions of logs. A lone boat is caught up in the debris.
- The Associated PressMike Clinton shovels volcanic ash from a sidewalk in downtown Yakima, Wash. The ash from the Mount St. Helens volcano was piled up to seven inches deep in some Northwest communities.
- Denver Post fileA burn victim is wheeled into Portland's Emanuel hospital May 19, 1980 after he was exposed to hot gases from St. Helens eruption.
- The Associated PressResidents of Moses lake, Wash., dig out after large deposits of volcanic ash were dumped on the city from the volcano Mount St. Helens on May 24, 1980. Moses lake is about 150 miles from Mount St. Helens in central Washington.
- Denver Post fileDanny Balsch, 20, Longview, Wash., lies in a bed in Longview's St. John's hospital, where he is being treated for burns of the arms and legs received when the Mount St. Helens volcano exploded May 18. He and a friend, Brian Thomas were camping on the Green river, 14 miles north of the volcano when it exploded. Thomas was buried under logs, tree branches and debris. Balsch, along with four friends, rescued him. The four friends are missing as the search for bodies and survivors continues in the volcano area.
- The Associated PressJust as 100-foot snags left standing in the Green river valley after the eruption of Mount St. Helens have their nickname, standing dead, so does the timber that was blown down by the eruption. It is called dead and down.
- Denver Post fileJohn Brown is covered with mud and is exhausted following unsuccessful rescue attempt of three from Toutle river flood at Kid Valley, Wash., May 19, 1908.
- The Associated PressSuppression crewmen inspect ravaged timberland September 21, 1980 ashot spots may be smoldering beneath ash deposited in "Red Zone."
- Denver Post fileTrucks lie in piles after high water swept through a logging camp on the Toutle river following the eruption of Mount St. Helens.
- The Associated PressDave Amos slogs through the mud on the family farm with inner tubes strapped to his feet May 23, 1980. "We always get a lot of water here," said his father, Jesse." Hundreds of years ago this farm was right in the main river channel. When volcanic ash, logs and mud came down the Cowlitz River from Mount St. Helens Sunday, it buried all 118 acres of his grazing land in what looked like liquid concrete.
- The Associated PressCleanup crews begin a big job in the town of Toutle -- about 20 miles -- from the base of Mount St. Helens May 28, 1980. Homes and businesses in the area sustained heavy damage with the Toutle river over flowed its banks May 18 after violent eruptions on Mount St. Helens.
- Denver Post fileMount St. Helens, still a simmering menace in spite of being shorn of 100 million tons of rock by its mightiest eruption in over 30,000 years. The force of the gaseous eruption May 18, 1980, of mud, rocks and ash toppled these thousands of tall fir threes like toothpicks on north face of the mountain. The amount of timber lost equals the amount of lumber in about 200,000 single family homes.
- Denver Post fileWhite shows the path volcanic ash is taking across the U.S. Dotted lines indicate where edge of cloud will be at noon of each day.
- Denver Post fileClear weather on June 1, 1980 allowed one of the first unclouded views of the Mount St. Helens area since an explosive eruption of the southwestern Washington volcano May 18 devastated the area north of the mountain, upper left. The aerial photo taken from 10 miles northeast of the mountain toward the southwest shows a white ramp of steaming ash leading from the crater down to spirit Lake, which is covered with debris.
- Denver Post fileThis is the summit of Mount St. Helens before it erupted. It was a peaceful place where climbers could stroll after scaling the mountain. In the background Mount Adams, another mountain formed by a volcano.
- Denver Post fileA military helicopter sits on the devastated landscape while it helps in the massive search for survivors after Mount St. Helens erupted May 18, 1980 leaving a trail of death and destruction over a wide area.
- Denver Post fileThis is an aerial view of the north slope of Mount St. Helens volcano taken May 30, 1980 by the U.S. Geological Survey shows the gaping hole produced by the atom-bomb like eruption on May 18. Over 5,000 feet of the north slope was force as between 500-2,500 atomic bombs similar to that dropped on Hiroshima.
- Denver Post fileBlasted off tree stumps in the foreground offer stark testimony to the sheer energy that was unleashed when Mount St. Helens exploded on May 18, 1980. This view from Harry's Ridge, less than five miles from the steaming crater, taken October 1, 1980, shows a small portion of the devastation caused by the volcano.
- Denver Post fileTall fir trees lay toppled like toothpicks from the force of the gaseous eruption of Mount St. Helens. This is the north slope of the mountain. An estimated 100,000 acres of timber was destroyed by the volcano.
- Denver Post fileJohn Card makes his way through rain of ash May 19, 1980. He was in Spokane, where visibility was near zero because of volcano.
- The Associated PressTruck driver Sandy Jarvis finds himself mired down in a load of ash which has turned to mud as he unloads a truck in Sprauge May 28, 1980. Coming to his aid is waitress Shannon Smith, right. The ash, which Jarvis has been hauling from the streets of Sprauge since Mount St. Helens erupted, has turned to mud with the recent rains.
- Denver Post fileEpitaph on the back of a car in Kelso, Washington., says all. It was covered by ash from the eruption of Mount St. Helens.
- Photo courtesy of USGSMudline left on tree by May 18, 1980 from Mount St. Helens near the Old Highway 99 bridge across Toutle River.
- Photo courtesy of USGSAsh cloud from Mount St. Helens over Ephrata, Washington (230 km (145 mi) downwind), after the May 18, 1980.
- Photo courtesy of USGSBlowdown of trees from the shock-wave of the directed (lateral) blast from the May 18, 1980 eruption of Mount St. Helens. Elk Rock is the peak with a singed area on the left.
- Denver Post fileMount St. Helens souvenirs, December 1, 1980.
- Photo courtesy of USGSDebris avalanche deposit view from the northwest of Mount St. Helens after the May 18,1980 eruption. The landslide scarp, horseshoe-shaped crater top right, exposes the vent and opens to the north. After the May 18, 1980 eruption, Mount St. Helens' elevation was only 8,364 feet and the volcano had a one-mile-wide (1.5 kilometers) and approximately 600 m (2000 ft) deep horseshoe-shaped crater. View here is from the northwest.
Photo courtesy of USGS
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Before the eruption of May 18, 1980, Mount St. Helens' elevation was 2,950 m (9,677 ft). View from the west, Mount Adams in distance. S. Fork Toutle River is valley in center of photo.
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By Glen Barber | The Denver Post
PUBLISHED: | UPDATED:
Getting your player ready...
On May 18, 1980, Mount St Helens blew its top in a cataclysmic eruption that left 60 people dead or missing.
USGS – Magma began intruding into the Mount St. Helens edifice in the late winter and early spring of 1980. By May 18, the cryptodome (bulge) on the north flank had likely reached the point of instability, and was creeping more rapidly toward failure. A magnitude-5+ earthquake was accompanied by a debris avalanche, which in turn unloaded the confining pressure at the top of the volcano by removing the cryptodome.
This abrupt pressure release allowed hot water in the system to flash to steam, which expanded explosively, initiating a hydrothermal blast directed laterally through the landslide scar. Because the upper portion of the volcano was removed, the pressure decreased on the system of magma beneath the volcano. A wave of decreasing pressure down the volcanic conduit to the subsurface magma reservoir, which then began to rise, form bubbles (degas), and erupt explosively, driving a 9-hour long Plinian eruption.