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Hundreds of square miles were reduced to wasteland, causing over $1 billion in damage (equivalent to $3.4 billion in 2023), thousands of animals were killed, and Mount St. Helens was left with a crater on its north side.
Learn about the 1980 eruption of Mount Saint Helens, one of the greatest volcanic explosions in North America, and its effects on the environment and people. Explore the volcano's history, features, and national monument with Britannica.
- The Editors of Encyclopaedia Britannica
Learn how the devastating eruption of Mount St. Helens in 1980 sparked the development of modern volcano science and monitoring. Discover how the eruption changed the way scientists cooperate, forecast and communicate volcanic hazards.
Nov 7, 2023 · Learn how a magnitude-5+ earthquake triggered a debris avalanche that removed the northern flank of Mount St. Helens and unleashed a powerful eruption on May 18, 1980. See photos, maps, and seismograms of the precursory activity and the aftermath of the catastrophic event.
- Ring of Fire
- A Volcanic Giant Rouses
- Earthquakes and Landslides
- Mount St. Helens Erupts
- Ash Cloud Circles The Globe
- Death and Destruction
- National Volcanic Monument
- Mount St. Helens Today
- Sources
Mount St. Helens and the Cascade Range are a small part of the Ring of Fire, a zone of intense volcanic and seismic activity that surrounds the Pacific Ocean, stretching from the west coast of South America, northward through Central and North America to Alaskaand the Aleutian Islands. The Ring of Fire continues over to the east coast of Asia (incl...
Modern-day scientists and geologists were concerned about Mount St. Helens years before 1980. Some felt it was the most likely volcano to become active before the end of the twentieth century. They were right. Beginning on March 16, 1980, a series of thousands of earthquakes and hundreds of steam explosions (known as phreatic explosions) began at M...
Early in the morning on Sunday, May 18, 1980, volcanologist David Johnston took measurements of Mount St. Helens from a nearby observation post. There were no red flags to predict the catastrophe about to happen. At 8:32 Pacific Daylight Time, a magnitude 5.1 earthquake struck one mile under Mount St. Helens, triggering the largest debris landslide...
The debris landslide took the pressure off the volcano’s magma structure, which caused massive lateral explosions and spewed tons of ash, rock, volcanic gas and steam. As the lateral blast accelerated, it reached a velocity of up to 670 miles per hour and covered a 230-square-mile area north of the volcano with searing debris. It’s estimated the bl...
After the lateral blast, a massive ash cloud mushroomed vertically into the air at least 12 miles, producing lightning and sparking forest fires. The cloud traveled 60 miles per hour and darkened the daylight skies in Spokane, Washington. Intense ash emissions continued until about 5:30 p.m. and began to weaken by the next day. Over the course of t...
The events that took place at Mount St. Helens in 1980 turned the immediate surrounding area into a wasteland, destroying plants, trees and entire ecosystems. Fifty-seven people were killed including volcanologists, loggers, campers and reporters. Autopsy reports showed most died of thermal burns or from inhaling hot ash. Some people estimate the d...
In 1982, Congress set aside 110,000 acres of land around Mount St. Helens and within the Gifford Pinchot National Forestfor the National Volcanic Monument. The Monument was established for research, recreation and education. The environment within the Monument has been largely left alone to naturally revive itself. Visitors can view Mount St. Helen...
Mount St. Helens experienced several more blasts in the summer and autumn following the May 1980 eruption. The blasts caused lava to form in the new crater and create new lava domes; however, later blasts obliterated two of those domes. Over the next several years, 17 additional blasts took place and by 1986 had formed a new lava dome over 820 feet...
1980 Cataclysmic Eruption. USGS. 2004-2008 Renewed Volcanic Activity. USGS. About the Forest. USDA Forest Service: Gifford Pinchot National Forest. Decades After Catastrophic 1980 Eruption, Mount St. Helens is ‘Recharging.” ABC News. Eruptions of Mount St. Helens: Past, Present, and Future. USGS. Life Returns: Frequently Asked Questions About Plant...
- Mount St. Helens
Learn how the 1980 eruption of Mount St. Helens affected people, communities, and ecosystems in the Pacific Northwest and beyond. Discover how scientists, officials, and volunteers responded and adapted to the volcanic hazards and impacts.
May 18, 2020 · A boiling plume of ash rising 15 miles high. The top 1,300 feet of the mountain gone. The north slope blown out with an avalanche of mud, rock and ice burying valleys and racing downstream. A...
