California Volcano Observatory
Find U.S. Volcano
As a part of the U.S. Geological Survey's Volcano Hazards Program, the California Volcano Observatory aims to advance scientific understanding of volcanic processes and lessen the harmful impacts of volcanic activity in the volcanically active areas of California and Nevada.
Young Volcanoes in California & Nevada
Very High Threat Potential 1
Lassen Volcanic Center
Long Valley Caldera
Mount Shasta
High Threat Potential 1
Clear Lake Volcanic Field
Medicine Lake
Mono-Inyo Chain
Salton Buttes
Moderate Threat Potential 1
Coso Volcanic Field
Mammoth Mountain
Mono Lake Volcanic Field
Soda Lakes (NV)
Ubehebe Craters
1. View the threat rankings of US Volcanoes.
California's Volcanic Hazards Geonarrative
GIS-based interactive website guides you through the eight young volcanic areas within California that pose the highest threat.
Volcano Research Laboratories
CalVO hosts several laboratories for multidisciplinary research of geologic phenomena.
The U.S. Geological Survey California Volcano Observatory (USGS CalVO) was formed in 2012 and is headquartered in Menlo Park and Moffett Field, CA. It replaced the former Long Valley Observatory (LVO), which was established in 1982 to monitor the restless Long Valley Caldera and Mono-Inyo Craters region of Eastern California. CalVO now monitors these and other potentially hazardous volcanoes in California and Nevada to help communities and government authorities understand, prepare for, and respond to, volcanic activity.
Sixteen young volcanoes designated as Low Threat to Very High Threat are dispersed throughout the State. Partially molten rock (magma) resides beneath at least seven of these—Medicine Lake Volcano, Mount Shasta, Lassen Volcanic Center, Clear Lake Volcanic Field, the Long Valley Volcanic Region, Coso Volcanic Field, and Salton Buttes— producing volcanic earthquakes(seismicity), toxic gas emissions, hot springs, and (or) ground movement (deformation).
News
What's normal for a volcano? How CalVO scientists decide when to raise an alarm (or not)
How hot is hot when it comes to volcanoes?
USGS supercomputers help assess volcanic hazards in support of community resilience
Publications
Multidisciplinary constraints on magma compressibility, the pre-eruptive exsolved volatile fraction, and the H2O/CO2 molar ratio for the 2006 Augustine eruption, Alaska
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
