How often does Mount Shasta erupt?
On average, Mount Shasta has erupted at least once every 800 years during the last 10,000 years, and about once every 600 years during the last 4,500 years. The last known eruption occurred about 200 years ago, possibly in 1786.
Eruptions during the last 10,000 years produced lava flows and domes on and around the flanks of Mount Shasta. Pyroclastic flows from summit and flank vents extended as far as 20 km (12.4 mi) from the summit. Most of these eruptions also produced large mudflows, many of which travelled several tens of kilometers from Mount Shasta.
Learn more at the website for the USGS California Volcano Observatory.
Related Content
Can earthquakes trigger volcanic eruptions?
How many eruptions have there been in the Cascades during the last 4,000 years?
How much ash was there from the May 18, 1980 eruption of Mount St. Helens?
How far did the ash from Mount St. Helens travel?
How dangerous are pyroclastic flows?
When did Lassen Peak last erupt?
What was the largest volcanic eruption in the 20th century?
Which volcanoes in the conterminous United States have erupted since the Nation was founded?
Where does the United States rank in the number of volcanoes?
What was the most destructive volcanic eruption in the history of the United States?
What is the "Ring of Fire"?
What are some benefits of volcanic eruptions?
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.
California’s exposure to volcanic hazards
The potential for damaging earthquakes, landslides, floods, tsunamis, and wildfires is widely recognized in California. The same cannot be said for volcanic eruptions, despite the fact that they occur in the state about as frequently as the largest earthquakes on the San Andreas Fault. At least ten eruptions have taken place in the past 1,000...
Mangan, Margaret; Ball, Jessica; Wood, Nathan; Jones, Jamie L.; Peters, Jeff; Abdollahian, Nina; Dinitz, Laura; Blankenheim, Sharon; Fenton, Johanna; Pridmore, Cynthia
2018 update to the U.S. Geological Survey national volcanic threat assessment
When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U....
Ewert, John W.; Diefenbach, Angela K.; Ramsey, David W.
Geologic field-trip guide to Mount Shasta Volcano, northern California
The southern part of the Cascades Arc formed in two distinct, extended periods of activity: “High Cascades” volcanoes erupted during about the past 6 million years and were built on a wider platform of Tertiary volcanoes and shallow plutons as old as about 30 Ma, generally called the “Western Cascades.” For the most part, the Shasta segment (for...
Christiansen, Robert L.; Calvert, Andrew T.; Grove, Timothy L.
Late Holocene volcanism at Medicine Lake Volcano, northern California Cascades
Late Holocene volcanism at Medicine Lake volcano in the southern Cascades arc exhibited widespread and compositionally diverse magmatism ranging from basalt to rhyolite. Nine well-characterized eruptions have taken place at this very large rear-arc volcano since 5,200 years ago, an eruptive frequency greater than nearly all other Cascade volcanoes...
Donnelly-Nolan, Julie M.; Champion, Duane E.; Grove, Timothy L.
A sight "fearfully grand": eruptions of Lassen Peak, California, 1914 to 1917
On May 22, 1915, a large explosive eruption at the summit of Lassen Peak, California, the southernmost active volcano in the Cascade Range, devastated nearby areas and rained volcanic ash as far away as 280 miles to the east. This explosion was the most powerful in a series of eruptions during 1914–17 that were the last to occur in the...
Clynne, Michael A.; Christiansen, Robert L.; Stauffer, Peter H.; Hendley, James W.; Bleick, Heather A.
The California Volcano Observatory: Monitoring the state's restless volcanoes
Volcanic eruptions happen in the State of California about as frequently as the largest earthquakes on the San Andreas Fault Zone. At least 10 eruptions have taken place in California in the past 1,000 years—most recently at Lassen Peak in Lassen Volcanic National Park (1914 to 1917) in the northern part of the State—and future...
Stovall, Wendy K.; Marcaida, Mae; Mangan, Margaret T.
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.
This dynamic planet: World map of volcanoes, earthquakes, impact craters and plate tectonics
Our Earth is a dynamic planet, as clearly illustrated on the main map by its topography, over 1500 volcanoes, 44,000 earthquakes, and 170 impact craters. These features largely reflect the movements of Earth's major tectonic plates and many smaller plates or fragments of plates (including microplates). Volcanic eruptions and earthquakes are awe-...
Simkin, Tom; Tilling, Robert I.; Vogt, Peter R.; Kirby, Stephen H.; Kimberly, Paul; Stewart, David B.
What are volcano hazards?
No abstract available.
Myers, Bobbie; Brantley, Steven R.; Stauffer, Peter; Hendley, James W.
This dynamic earth: the story of plate tectonics
In the early 1960s, the emergence of the theory of plate tectonics started a revolution in the earth sciences. Since then, scientists have verified and refined this theory, and now have a much better understanding of how our planet has been shaped by plate-tectonic processes. We now know that, directly or indirectly, plate tectonics...
Kious, W. Jacquelyne; Tilling, Robert I.
Gigantic debris avalanche of Pleistocene age from ancestral Mount Shasta Volcano, California, and debris-avalanche hazard zonation
Crandell, Dwight Raymond
Which U.S. volcanoes pose a threat?
USGS Volcanic Threat Assessment updates the 2005 rankings.
Say Hello to CalVO: USGS California Volcano Observatory Opens
The U.S. Geological Survey announces the establishment of the USGS California Volcano Observatory, or CalVO, headquartered within existing USGS facilities in Menlo Park, Calif. Establishing CalVO will increase awareness of and resiliency to the volcano threats in California, many of which pose significant threats to the economy and well being of the state and its inhabitants.
July Public Lecture — USGS CalVO: It's not just earthquake country!
Volcanic eruptions occur int he State about as frequently as the large San Andreas Fault Zone earthquakes. California's "watch list" volcanoes are dispersed throughout the State and future eruptions are inevitable—the likelihood of renewed volcanism is on the order of one in a few hundred to one in a few thousand annually.
With Margaret Mangan, Scientist-in-Charge,
...
Mount Shasta with city lights
Twilight image of snow-covered Mount Shasta. Lights from the town of Weed, California are visible at the mountain's base.