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California Volcano Observatory (CalVO)

Overlay represents area within CalVO's jurisdiction.
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Monthly Update
Monday, November 02, 2015 12:31 PM
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN
California Volcano Observatory's mission
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   (archive)
Young Volcanoes in California & Nevada1

Field-trip guide for Lassen Volcanic Center published
November 16, 2015
USGS geologists Patrick Muffler and Michael Clynne published a new geologic field-trip guide for areas in and around Lassen Volcanic National Park in northern California. The guide begins with a comprehensive overview of the geologic framework and the stratigraphic terminology of the Lassen region, based primarily on the "Geologic map of Lassen Volcanic National Park and vicinity". The geologic overview is followed by detailed road logs describing the volcanic features that can easily be seen in the park and its periphery. Twenty-one designated stops provide detailed explanations of important volcanic features. The guide also includes mileage logs along the highways leading into the park from the major nearby communities. The field-trip guide is intended to be a flexible document that can be adapted to the needs of a visitor approaching the park from any direction. Try it out on your next vacation!

3D Images of Magma Below Mono Craters Area
November 04, 2015

USGS CalVO scientists have developed a new 3D conceptual model of the magma system below Mono Lake and Mono Craters in eastern California to give scientists a more detailed understanding of volcanic processes at depth. The technology used, magnetotellurics, measures slight electrical currents naturally created by the movement of ions in the Earth's magnetic field (like the Aurora Borealis, or Northern Lights). Magma chambers with liquid, melted rock, or a partially crystallized "mush," have a very low resistivity to electrical current flow.

The Mono Craters volcanic area is ranked among the nation's high threat volcanoes. Recent eruptions at Mono Craters occurred about 600 years ago at Panum Crater, and about 350 years ago on Paoha Island in the middle of Mono Lake. The accuracy and high resolution of the new three-dimensional images of the magma chambers and volcanic "plumbing" below Mono Basin give scientists a better understanding of their size, shape and where the next eruption might occur.

Read the press release or the full research study.
Bi-national Exchange provides opportunity for Chile and US officials to work together on volcano hazard risk reduction.
September 03, 2015

Scientists, civil authorities, and emergency managers from Chile and the U.S. met in California to discuss the challenges of effective volcanic hazard education, response planning, hazard mitigation, and risk reduction, as part of the second Bi-national Exchange program for Volcanic Risk Reduction in the Americas.

The program focused on the Long Valley volcanic region (California, USA) and Chaitén Volcano (Región de los Lagos, Chile). Both of these restless volcanic systems have erupted rhyolite lava. Eruptions of rhyolite lava exhibit extremely diverse behavior, from sluggish lava flows to catastrophic explosions. The similarities in the nature of the hazards posed at Long Valley and Chaitén and the challenges of communicating with at-risk communities provide opportunities for scientists and civil authorities to learn from one another and strengthen risk reduction in their home countries. In the U.S. and Chile, participants inspected volcano monitoring networks, learned about the geologic history of volcanoes, volcanic hazards, eruption forecasting, disaster preparedness, and communications with affected communities.

The principle coordinators of the Chile-USA exchange are Dr. Margaret Mangan, Scientist-in-Charge of the USGS-California Volcano Observatory in Menlo Park, California, and Dr. Luis Lara, the Head of the Volcano Hazards Program at Servicio Nacional de Geología y Minería in Santiago, Chile. The program is funded by the U.S. Agency for International Development/Office of Foreign Disaster Assistance with cooperation from the USGS' Volcano Disaster Assistance Program.

CalVO and Lassen Fact Sheets Published
December 10, 2014
We are pleased to announce the publication of two new Fact Sheets relevant to CalVO.