How much ash was there from the May 18, 1980 eruption of Mount St. Helens?
During the 9 hours of vigorous eruptive activity on May 18, 1980, about 540 million tons of ash from Mount St. Helens fell over an area of more than 22,000 square miles (57,000 square kilometers). The total volume of the ash before its compaction by rainfall was about 0.3 cubic mile (1.3 cubic kilometers), equivalent to an area the size of a football field piled about 150 miles (240 kilometers) high with fluffy ash.
Learn more:
- Ash and Tephra Fall Hazards at Mount St. Helens
- Ash Cloud Simulations - What if Mount st. Helens produced an explosive eruption today?
Related Content
How far would ash travel if Yellowstone had a large explosive eruption?
Does ash ever erupt from Kīlauea Volcano??
How old is Mount St. Helens?
What is the origin of the name "Mount St. Helens"?
How many eruptions have there been in the Cascades during the last 4,000 years?
How far did the ash from Mount St. Helens travel?
How high was Mount St. Helens before the May 18, 1980 eruption? How high was it after?
Can volcanic eruptions endanger helicopters and other aircraft?
Why is it important to monitor volcanoes?
What was the largest volcanic eruption in the 20th century?
What was the most destructive volcanic eruption in the history of the United States?
What are some benefits of volcanic eruptions?
Ten ways Mount St. Helens changed our world—The enduring legacy of the 1980 eruption
Mount St. Helens was once enjoyed for its serene beauty and was considered one of America’s most majestic volcanoes because of its perfect cone shape, similar to Japan’s beloved Mount Fuji. Nearby residents assumed that the mountain was solid and enduring. That perception changed during the early spring of 1980. Then, on May 18, 1980,...
Driedger, Carolyn L.; Major, Jon J.; Pallister, John S.; Clynne, Michael A.; Moran, Seth C.; Westby, Elizabeth G.; Ewert, John W.
Field trip guide to Mount St. Helens, Washington—Recent and ancient volcaniclastic processes and deposits
This field guide explores volcanic effusions, sediments, and landforms at Mount St. Helens in Washington. A detailed synopsis outlines the eruptive history of Mount St. Helens from about 300,000 years ago through 1980 and beyond.The five days in the field include about 28 stops and 12 potential stops. Exposures in valleys surrounding Mount St....
Waitt, Richard B.; Major, Jon J.; Hoblitt, Richard P.; Van Eaton, Alexa R.; Clynne, Michael A.
When volcanoes fall down—Catastrophic collapse and debris avalanches
Despite their seeming permanence, volcanoes are prone to catastrophic collapse that can affect vast areas in a matter of minutes. Large collapses begin as gigantic landslides that quickly transform to debris avalanches—chaotically tumbling masses of rock debris that can sweep downslope at extremely high velocities, inundating areas far beyond the...
Siebert, Lee; Reid, Mark E.; Vallance, James W.; Pierson, Thomas C.
Field-trip guide to Mount St. Helens, Washington - An overview of the eruptive history and petrology, tephra deposits, 1980 pyroclastic density current deposits, and the crater
This field trip will provide an introduction to several fascinating features of Mount St. Helens. The trip begins with a rigorous hike of about 15 km from the Johnston Ridge Observatory (9 km north-northeast of the crater vent), across the 1980 Pumice Plain, to Windy Ridge (3.6 km northeast of the crater vent) to examine features that document the...
Pallister, John S.; Clynne, Michael A.; Wright, Heather M.; Van Eaton, Alexa R.; Vallance, James W.; Sherrod, David R.; Kokelaar, B. Peter
U.S. Geological Survey Volcano Hazards Program—Assess, forecast, prepare, engage
At least 170 volcanoes in 12 States and 2 territories have erupted in the past 12,000 years and have the potential to erupt again. Consequences of eruptions from U.S. volcanoes can extend far beyond the volcano’s immediate area. Many aspects of our daily life are vulnerable to volcano hazards, ...
Stovall, Wendy K.; Wilkins, Aleeza M.; Mandeville, Charles W.; Driedger, Carolyn L.
Mount St. Helens, 1980 to now—what’s going on?
Mount St. Helens seized the world’s attention in 1980 when the largest historical landslide on Earth and a powerful explosive eruption reshaped the volcano, created its distinctive crater, and dramatically modified the surrounding landscape. An enormous lava dome grew episodically in the crater until 1986, when the volcano became relatively quiet...
Dzurisin, Daniel; Driedger, Carolyn L.; Faust, Lisa M.
Airborne volcanic ash; a global threat to aviation
The world's busy air traffic corridors pass over or downwind of hundreds of volcanoes capable of hazardous explosive eruptions. The risk to aviation from volcanic activity is significant - in the United States alone, aircraft carry about 300,000 passengers and hundreds of millions of dollars of cargo near active volcanoes each day. Costly...
Neal, Christina A.; Guffanti, Marianne C.
30 cool facts about Mount St. Helens
Commemorating the 30th anniversary of the 1980 eruptions of Mount St. Helens.
Driedger, Carolyn; Liz, Westby; Faust, Lisa; Frenzen, Peter; Bennett, Jeanne; Clynne, Michael
A New Perspective on Mount St. Helens - Dramatic Landform Change and Associated Hazards at the Most Active Volcano in the Cascade Range
Mount St. Helens has erupted more frequently than any other volcano in the Cascade Range during the past 4,000 years. The volcano has exhibited a variety of eruption styles?explosive eruptions of pumice and ash, slow but continuous extrusions of viscous lava, and eruptions of fluid lava. Evidence of the volcano?s older eruptions is recorded in the...
Ramsey, David W.; Driedger, Carolyn L.; Schilling, Steve P.
Eruptions in the Cascade Range during the past 4,000 years
Volcanoes have been erupting in the Cascade Range for over 500,000 years. During the past 4,000 years eruptions have occurred at an average rate of about 2 per century. This chart shows 13 volcanoes on a map of Washington, Oregon, and northern California and time lines for each showing the ages of their eruptions.
Myers, Bobbie; Driedger, Carolyn L.
The Pleistocene eruptive history of Mount St. Helens, Washington, from 300,000 to 12,800 years before present
We report the results of recent geologic mapping and radiometric dating that add considerable detail to our understanding of the eruptive history of Mount St. Helens before its latest, or Spirit Lake, stage. New data and reevaluation of earlier work indicate at least two eruptive periods during the earliest, or Ape Canyon, stage, possibly...
Sherrod, David R.; Scott, William E.; Stauffer, Peter H.; Clynne, Michael A.; Calvert, Andrew T.; Wolfe, Edward W.; Evarts, Russell C.; Fleck, Robert J.; Lanphere, Marvin A. Geologic map of Mount St. Helens, Washington prior to the 1980 eruption
It is rare that a geologic map exists for a volcano prior to such a catastrophic modification as that produced by the eruption of Mount St. Helens in 1980. As such, this map provides an important historical record of the volcano prior to that eruption. The map has not been reviewed or checked for conformity to USGS editorial standards or...
Hopson, Clifford A.
Ever Vigilant: USGS Marks the 37th Anniversary of Mount St. Helen's Eruption and the 35th Anniversary of the Cascades Volcano Observatory
Today, in 1980, Mount St. Helens unleashed the most devastating eruption in U.S. history. Two years later, USGS founded the Cascades Volcano Observatory to monitor Mount St. Helens and all the Cascades Volcanoes.
EarthWord–Phreatic Eruption
This EarthWord is straight up steampunk...
EarthWord–Lahar
Which sounds more dangerous, lava or mud? The answer may surprise you...
May is Volcano Preparedness Month in Washington State
May is Volcano Preparedness Month in Washington, providing residents an opportunity to become more familiar with volcano hazards in their communities and learn about steps they can take to reduce potential impacts.
EarthWord–Subduction
It’s not flirting for submarines, but this week’s EarthWord does feature the ocean...
EarthWord–Tephra
Look! In the sky! It’s a bird, it’s a plane! Wait, run, it’s this week’s EarthWord!
PubTalk 2/2018 — USGS Cascades Volcano Observatory
Title: The USGS Cascades Volcano Observatory - Research, monitoring, and the science of preparing society for low-probability, high-consequence events
- Volcanoes in the Cascade Range erupt twice per century on average, with eruptions often lasting for years.
- Although eruptions are generally not as high-consequence as large earthquakes, they are still
Forecasting Ashfall Impacts from a Yellowstone Supereruption
- Yellowstone is one of a few dozen volcanoes on earth capable of "supereruptions" that expel more than 1,000 cubic km of ash and debris.
- The plumes from such eruptions can rise 30 to 50 km into the atmosphere, three to five times as high as most jets fly.
- Yellowstone has produced three supereruptions in the past 2.1 million years. The most recent was
Mount St. Helens before and after 1980 eruption
Left: 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.
Right: Mount St. Helens soon after the May 18, 1980 eruption, as viewed from Johnston's Ridge.
Volcano Hazards
The United States has 169 active volcanoes. More than half of them could erupt explosively, sending ash up to 20,000 or 30,000 feet where commercial air traffic flies. USGS scientists are working to improve our understanding of volcano hazards to help protect communities and reduce the risks.
Video Sections:
- Volcanoes: Monitoring Volcanoes
Volcano Web Shorts 2: Debris Flows
Debris flows are hazardous flows of rock, sediment and water that surge down mountain slopes and into adjacent valleys. Hydrologist Richard Iverson describes the nature of debris-flow research and explains how debris flow experiments are conducted at the USGS Debris Flow Flume, west of Eugene, Oregon. Spectacular debris flow footage, recorded by Franck Lavigne of the
Volcano Web Shorts 4 - Instruments
USGS technologist Rick LaHusen describes how the development and deployment of instruments plays a crucial role in mitigating volcanic hazards.
Volcano Web Shorts 5 - Volcanic Ash Impacts
Volcanic ash is geographically the most widespread of all volcanic hazards. USGS geologist Larry Mastin describes how volcanic ash can disrupt lives many thousands of miles from an erupting volcano. The development of ash cloud models and ash cloud disruption to air traffic is highlighted.
Mount St. Helens: May 18, 1980
USGS scientists recount their experiences before, during and after the May 18, 1980 eruption of Mount St. Helens. Loss of their colleague David A. Johnston and 56 others in the eruption cast a pall over one of the most dramatic geologic moments in American history.
Mount St. Helens: A Catalyst for Change
The May 18, 1980 eruption of Mount St. Helens triggered a growth in volcano science and volcano monitoring. Five USGS volcano observatories have been established since the eruption. With new technologies and improved awareness of volcanic hazards USGS scientists are helping save lives and property across the planet.
Mount St. Helens 2004-2008 Eruption: A Volcano Reawakens
Mount St. Helens reawakened in late September 2004. Small magnitude earthquakes beneath the 1980-1986 lava dome increased in frequency and size, and a growing welt formed on the southeast margin of the previous lava dome and nearby portions of Crater Glacier. On October 1, 2004, the first of several explosions shot a plume of volcanic ash and gases from a vent on the
Mount St. Helens eruption highlights: September 2004 - May 2005
Compilation video of significant events from the dome-building eruption at Mount St. Helens, from October 1, 2004 to March 15, 2005, including steam and ash eruptions, growth of lava spines, helicopter deployment of monitoring equipment, collection of lava samples, and FLIR thermal imaging of rock collapse on lava dome.
- Eruption of Mount St. Helens, October 1
