What was the extent of ash deposition from the largest Yellowstone eruptions?

During the three giant, caldera-forming eruptions that occurred between 2.1 million and 640,000 years ago, tiny particles of volcanic debris (volcanic ash) covered much of the western half of North America. That ash was likely a third of a meter deep several hundred kilometers from Yellowstone and several centimeters thick farther away (see this map). Wind carried sulfur aerosol and the lightest ash particles around the planet and likely caused a notable decrease in temperatures around the globe.

Learn more:

Related Content

Filter Total Items: 10

What would happen if a "supervolcano" eruption occurred again at Yellowstone?

Such a giant eruption would have regional effects such as falling ash and short-term (years to decades) changes to global climate. Those parts of the surrounding states of Montana, Idaho, and Wyoming that are closest to Yellowstone would be affected by pyroclastic flows, while other places in the United States would be impacted by falling ash (the...

What type of eruption will occur if Yellowstone erupts again?

The most likely explosive event to occur at Yellowstone is actually a hydrothermal explosion —a rock-hurling geyser eruption—or a lava flow . Hydrothermal explosions are very small; they take place every few years and form a crater a few meters across. Every few thousand years, a hydrothermal explosion will form a crater as much as a few hundred...

How much volcanic activity has there been at Yellowstone since the most recent giant eruption?

Since the most recent giant ( caldera-forming ) eruption 631,000 years ago, approximately 80 relatively nonexplosive eruptions have occurred. Of these eruptions, at least 27 were rhyolite lava flows in the caldera, 13 were rhyolite lava flows outside the caldera, and 40 were basalt vents outside the caldera. The most recent volcanic eruption at...

What is the chance of another catastrophic volcanic eruption at Yellowstone?

Although another catastrophic eruption at Yellowstone is possible, scientists are not convinced that one will ever happen. The rhyolite magma chamber beneath Yellowstone is only 5-15% molten (the rest is solidified but still hot), so it is unclear if there is even enough magma beneath the caldera to feed an eruption. If Yellowstone does erupt...

How far in advance could scientists predict an eruption of the Yellowstone volcano?

The science of forecasting a volcanic eruption has significantly advanced over the past 25 years. Most scientists think that the buildup preceding a catastrophic eruption would be detectable for weeks and perhaps months to years. Precursors to volcanic eruptions include strong earthquake swarms and rapid ground deformation and typically take place...

Could a large Yellowstone eruption significantly change weather patterns?

If another catastrophic caldera-forming Yellowstone eruption were to occur, it would probably alter global weather patterns and have enormous impacts on human activity (especially agricultural production) for many years. At this time, however, scientists do not have the ability to predict specific consequences or durations of possible global...

Can you release some of the pressure at Yellowstone by drilling into the volcano?

Scientists agree that drilling into a volcano would be of questionable usefulness. In addition to the enormous expense and technological difficulties in drilling through hot, mushy rock, drilling is unlikely to have much effect. At near magmatic temperatures and pressures, any hole would rapidly become sealed by minerals crystallizing from the...

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. The total volume of the ash before its compaction by rainfall was about 0.3 cubic mile, equivalent to an area the size of a football field piled about 150 miles high with fluffy...

How far did the ash from Mount St. Helens travel?

The May 18, 1980 eruptive column at Mount St. Helens fluctuated in height through the day, but the eruption subsided by late afternoon. By early May 19th, the eruption had stopped. By that time the ash cloud had spread to the central United States. Two days later, even though the ash cloud had become more diffuse, fine ash was detected by systems...

Do volcanoes affect weather?

Yes, volcanoes can affect weather and the Earth's climate . Following the 1991 eruption of Mount Pinatubo in the Philippines, cooler than normal temperatures were recorded worldwide and brilliant sunsets and sunrises were attributed to this eruption that sent fine ash and gases high into the stratosphere, forming a large volcanic cloud that...
Filter Total Items: 11
Image shows gray ash covering cars and a house
July 18, 2016

Ash Coating from Rabaul Volcanic Eruption

Ash buries cars and buildings after the 1984 eruption of Rabaul, Papua New Guinea. Credit: USGS

May 26, 2016

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
Satellite image of eruption cloud from Pavlof Volcano in November 2014
November 15, 2014

Satellite image of eruption cloud from Pavlof Volcano in November 2014

Satellite image from the USGS/NASA Landsat-8 satellite showing the eruption cloud at Pavlof Volcano on November 15 at 12:46 pm AKST (21:46 UTC). This is just a portion of the eruption cloud, which extended for more than 250 miles to the northwest at the time this image was collected. In this image, the distance from the erupting vent to the upper left corner of the image

Attribution: Natural Hazards, Alaska
January 22, 2014

The Yellowstone Volcano: Past, Present and Future

Public Lecture on Yellowstone Volcano by Jake Lowenstern at Menlo Park, CA on January 23, 2014. The Q&A at the end of the talk can be found on the original source video (Source URL).

September 28, 2010

Caldera Demonstration Model

A caldera is a large, usually circular volcanic depression formed when magma is withdrawn or erupted from a shallow underground magma reservoir. It is often difficult to visualize how calderas form. This simple experiment using flour, a balloon, tubing, and a bicycle pump, provides a helpful visualization for caldera formation.

December 8, 2009

Inside USGS, No. 2, Patrick Muffler, Yellowstone

USGS emeritus geologist Patrick Muffler describes his career working on Yellowstone geysers and hydrothermal systems from the 1960's through 2014. Patrick's work along with his USGS colleagues revealed the details of Yellowstone's explosive volcanic past and how its spectacular geysers and other hydrothermal features work.

December 8, 2009

Inside USGS No. 1, Robert Christiansen, Yellowstone

USGS emeritus geologist Robert Christiansen describes his career working on Yellowstone geology from the 1960's through 2014. Bob's work along with his USGS colleagues revealed the details of Yellowstone's explosive volcanic past including mapping and dating of past super eruptions 2.1 million years ago, 1.3 million years ago and 640,000 years ago.

video thumbnail: Yellowstone Eruptions (Part 3 of 3)
January 29, 2009

Yellowstone Eruptions (Part 3 of 3)

USGS Scientist-in-Charge of Yellowstone Volcano Observatory, Jake Lowenstern, answers
the following questions to explain volcanic eruptions at Yellowstone: When was the last supereruption at
Yellowstone?", "Have any eruptions occurred since the last supereruption?", "Is Yellowstone overdue for
an eruption?", "What does the magma below indicate about a

video thumbnail: Yellowstone Volcano Observatory (Part 2 of 3)
January 29, 2009

Yellowstone Volcano Observatory (Part 2 of 3)

USGS Scientist-in-Charge of Yellowstone Volcano Observatory, Jake Lowenstern, answers
the following questions to provide a tour of the Yellowstone Volcano Observatory: "What is YVO?", "How
do you monitor volcanic activity at Yellowstone?", "How are satellites used to study deformation?", "Do
you monitor geysers or any other aspect of the Park?", "Are

video thumbnail: Yes! Yellowstone is a Volcano (Part 1 of 3)
January 29, 2009

Yes! Yellowstone is a Volcano (Part 1 of 3)

USGS Scientist-in-Charge of Yellowstone Volcano Observatory, Jake Lowenstern, answers
the following questions to explain volcanic features at Yellowstone: "How do we know Yellowstone is a
volcano?", "What is a Supervolcano?", "What is a Caldera?","Why are there geysers at Yellowstone?",
and "What are the other geologic hazards in Yellowstone?"


Large umbrella shaped cloud of volcanic ash viewed from a distance
June 15, 1991

Giant ash cloud from the eruption of Mount Pinatubo, 1991

Giant ash cloud from the eruption of Mount Pinatubo, 1991 towering above farms and agricultural lands in the Philippines.