Mount Shasta
Find U.S. Volcano
Mt. Shasta is a majestic, steep-sided stratovolcano located about 97 km (60 mi) north of Redding along the I-5 corridor in Northern California. It is the most voluminous of all the Cascade Range volcanoes, and the towns of Weed, Mt Shasta City, and McCloud lie in the shadow of its 4,317 m (14,163 ft) high snow- and ice-clad edifice.
Quick Facts
Location: California, Siskiyou County
Latitude: 41.409° N
Longitude: 122.193° W
Elevation: 4,317 (m) 14,163 (f)
Volcano type: Stratovolcano
Composition: andesite, dacite
Most recent eruption: ~3,200 years ago
Nearby towns: Weed, Mount Shasta, Edgewood, Dunsmuir
Threat Potential: Very High*
*based on the National Volcano Early Warning System
Summary
Mount Shasta began forming on the remnants of an older, similar volcano that collapsed 300,000 to 500,000 years ago. The collapse spawned one of the largest landslides known on Earth, covering more than 440 km2 (170 mi2) of Shasta Valley to the northeast. Activity over the last 300,000 years includes long intervals of quiet interrupted by shorter spans of frequent eruptions. Eruptions at about 11,000 years ago built Black Butte and Shastina on the western flanks of Mount Shasta. In the last few millennia, smaller eruptions have broken out at the volcano’s summit and from vents on its upper east flank. The youngest dated eruption occurred about 3,200 years ago, producing block and ash flows on the volcano's north flank. Hot springs and volcanic gases seep from the summit indicating a relatively young and still-hot system. Non-volcanic shedding of young volcanic rock and ash from Mount Shasta’s steep slopes occurs during heavy rainfall or glacial floods. In the last 1,000 years, more than 70 mudflows have inundated stream channels. The record of eruptions over the last 10,000 years suggests that, on average, at least one eruption occurs every 800 to 600 years at Mt Shasta. USGS and UNAVCO seismic and geodetic networks provide real-time volcano monitoring data. Earthquake activity has been low for the last few decades and ground deformation is negligible.
News
How tall are you really? Establishing Mount Shasta's summit elevation in the 20th century
The curious case of Mount Shasta's 1905 "Spasm"
Stratovolcano flank vents and the origin of Black Butte
Publications
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 years, and future volcanic eruptions are inevitable.The
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.S. Geological Survey and its partners. This update
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 volcanic eruptions are inevitable. The U.S. Geological Survey Californ
