Hello CalVO

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Welcome to the new USGS California Volcano Observatory website! The USGS Volcano Science Center recently restructured observatory operations to optimize volcano monitoring, eruption forecasting, and hazard mitigation efforts throughout California.

The new USGS California Volcano Observatory (CalVO), headquartered in Menlo Park CA, replaces 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.

Scientists at the five USGS volcano observatories research, monitor, and assess hazards at United States volcanoes and provide activity notifications and eruption warnings in the event of volcanic crises. The volcano monitoring responsibility of CalVO includes all potentially active volcanoes in California and Nevada. The Cascade Volcano Observatory (CVO), CalVO’s sister observatory in Vancouver, WA, oversees efforts at all potentially active volcanoes in Oregon, Washington, and Idaho. CalVO and CVO share scientific expertise, administrative staff, and equipment, ensuring a strategic and cost efficient program of volcanic hazard mitigation.

Note: The Yellowstone Volcano Observatory (YVO in Menlo Park, CA) monitors volcanoes in Montana, Wyoming, Colorado, Utah, New Mexico, and Arizona. The Alaska Volcano Observatory (AVO in Anchorage, AK) oversees Alaskan volcanoes and those within the Commonwealth of the Northern Mariana Islands. The oldest USGS volcano observatory, the Hawaiian Volcano Observatory (HVO in Hawaii National Park, HI), is responsible for the state of Hawaii and is celebrating its 100th anniversary this year.