California Volcano Observatory

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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. 


News

Date published: May 6, 2019

The National Volcano Early Warning System (NVEWS) will help USGS better monitor nation’s most dangerous volcanoes

In September 2004, USGS scientists detected sudden, but unmistakable, signs that Mount St. Helens was waking up. Volcano monitors had picked up the occurrence of hundreds of small earthquakes and other signals that the volcano’s crater floor had begun to rise. Within a week, several eruptions blasted clouds of ash into the atmosphere, and soon after, a new lava dome emerged in the crater.

Date published: July 31, 2017

Subsurface Magma Triggers Earth’s Most Severe Extinction

Subsurface magma intrusions (sills), rather than surface lava flows, may have triggered the Earth’s most catastrophic extinction event approximately 252 million years ago.

Date published: July 13, 2016

Young and Old Volcanoes East of the Sierra Nevada: New Map, Report and Public Events

A new geologic map of the Long Valley Caldera, Mammoth Mountain, and the Middle Fork canyon of the San Joaquin River including Devils Postpile National Monument, recounts the geologic and volcanic history of the area east of the Sierra Nevada in far greater detail than any previously published report.

Volcanoes Hazards Program Links