CalVO's Successful First Year of Operation
March 12, 2013

February 2013 marked the first year of successful volcano monitoring and preparing for possible volcanic eruption for the California Volcano Observatory (CalVO). At Long Valley Caldera, analysis of continuous GPS data over the first half of 2012 showed a modest inflationary pattern within the caldera; ground motion was directed upward and away from the caldera's center, with a maximum uplift rate between 2 and 3 cm/yr. In January of this year at Clear Lake Volcanic Field, a short-lived swarm of low-magnitude earthquakes was detected under the south flank of Mt Konocti.

CalVO also worked with other agencies this year to develop information to help people better understand and prepare for the potential for volcanic eruption. A statewide ash aviation plan was formulated in conjunction with the National Oceanic and Atmospheric Administration, Federal Aviation Administration, and the California Emergency Management Association. CalVO released the hazards assessment for Lassen Volcanic Center and helped to build an interactive exhibit at Lassen Volcanic National Park. The new exhibit, located at the Park's Loomis Museum, displays regional earthquake data and videos detailing the geologic processes that helped to form the volcanic landscape at Lassen.

Volcano Hazards Discussed at Joint State and Federal Meeting
February 21, 2013

Many of California’s young volcanoes pose a threat to people and property. Volcanic eruptions occur in the State about as frequently as our largest San Andreas Fault Zone earthquakes: ten eruptions have occurred in California in the last 1000 years.

To better prepare for volcanic events in the State, the California Emergency Management Agency (Cal EMA), the USGS California Volcano Observatory, and the California Geological Survey are working together to produce the first ever Volcano Hazard Annex to the State Emergency Plan.

On February 12, 2013, a diverse group of state and federal stakeholders assembled at Cal EMA headquarters to discuss volcano hazards and identify State and Federal assets potentially at risk. Cal EMA’s new Volcano Annex will integrate hazard and socio-economic information in a format readily accessible to decision-makers at all levels of government.

Aeromagnetic Survey of Long Valley and Mono Basin Volcanic Areas
October 12, 2012
In mid-October, U.S. Geological Survey volcanologists and geophysicists plan to conduct the first comprehensive, high-resolution airborne magnetic survey of the rock layers under Mono Basin and Long Valley, on the east side of the California Sierra Nevada mountains. The resulting 3D subsurface geologic map will improve assessment of both volcanic and earthquake hazards in the mapped region. For more information about the airborne survey and how the resulting data will be used, read the full press release.

Lassen Hazards Assessment Published
October 01, 2012
A hazards assessment for Lassen Volcanic Center, California, is now available for download from the USGS Publications Warehouse. The Lassen region of the southernmost Cascade Range is an active volcanic area and will erupt in the future. At least 70 eruptions have occurred in the past 100,000 years, including 3 in the past 1,000 years, most recently in 1915. Although the annual probability of an eruption is small, the consequences of some types of eruptions could be severe. The hazards assessment and report presents a discussion of volcanic and other geologic hazards in the Lassen area and delineates hazards zones for different types of volcanic activity. Visit the Pubs Warehouse to download the report.

Earthquake Swarm in the Brawley Seismic Zone
August 27, 2012
An energetic earthquake swarm (largest event magnitude 5.5) is ongoing in the Brawley Seismic Zone south of the Salton Sea in Southern California. The swarm started on Saturday August 25 with earthquake activity on a northeast striking fault zone located about 20 km (12.5 miles) south of the young volcanic center known as Salton Buttes. The most recent eruptions, which took place about 9,000 years ago, produced five rhyolite lava domes along the present-day shore of the southern Salton Sea. The Brawley Seismic Zone, located between the northern end of the Imperial Fault and the southern end of the San Andreas Fault is a tectonically active area, with numerous earthquake swarms occurring over the last several decades, most recently in 2005 and in 1981. There is no evidence to suggest the present swarm is volcanic in nature. More information on the Brawley swarm can be found on the website of the Southern California Seismic Network (a partnership of Caltech and the USGS) at http://www.scsn.org. Visit the Salton Buttes page to learn more about the Salton Buttes volcanic area.

Summer Field Work Underway
July 24, 2012
Summer is the time when most CalVO scientists get out into the field to conduct geologic and ground-based monitoring investigations of our regional volcanoes. GPS measurements have been taken around Long Valley Caldera, mapping of volcanic units has occurred at Lassen Volcanic Center, and work is scheduled for Mount Shasta. Some of the new data will be made available in the fall, and you will find updates about that work as new website articles.

May 22 marks Lassen Peak's 97th eruption anniversary
May 22, 2012
On May 22, 1915 an explosive volcanic eruption occurred at Lassen Peak, California. It was the most powerful single explosion from the series of eruptions that lasted from 1914-1917. It generated a high eruption column, pyroclastic flows, and lahars. Lassen Volcanic Center is still active today and the USGS California Volcano Observatory monitors its activity daily. For more information about this eruption, please read our fact sheet that details the events.

Hello CalVO
January 10, 2012

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 100^th anniversary this year.

California Volcano Observatory website released at AGU
November 30, 2011
During FY11, Long Valley Observatory's jurisdiction was expanded to encompass all California volcanoes and one volcanic center in Nevada. The Observatory's name will change to California Volcano Observatory (CalVO), which will correspond to a new website launch in early 2012. Background information about the new website is being presented right now at the American Geophysical Union's Fall Meeting. During this presentation, the new overall look and feel for the USGS Volcano Science Center and Observatory websites will be unveiled. For comments, please contact vscweb@usgs.gov.

California volcanoes web pages soft, internal launch
August 16, 2011
A new design for the USGS Volcano Science Center (VSC) web pages is now open for internal viewing. This site has not been fully developed yet, and there are still many holes to fill. The launch is meant to give VSC staff a preview into the new database-driven website design. To navigate to a volcano, either search or pick from the drop-down "Find a Volcano" list. Not all volcanoes have a complete suite of information, but each does have an entry page and monitoring information. Since the website content is not complete, please pay most attention to layout and errors that may exist within the text or figures. For feedback, please send an email to vscweb@usgs.gov.

A Geologic 'Event' at Lassen Volcanic National Park
August 12, 2011
The U.S. Geological Survey and Lassen Volcanic National Park are pleased to announce a special public presentation by USGS scientists to unveil, the "Geologic Map of Lassen Volcanic National Park and Vicinity," a map and booklet that interprets the detailed geology of the park. The event will be held at Loomis Museum in Lassen Volcanic National Park on Wednesday, August 17 from 10:30 a.m. to 11:30 a.m. Read more about the presentation from the USGS newsroom.

USGS rules out volcanic origin of plume-like feature seen in NEXRAD in Mojave Desert (California)
August 01, 2011
Inquiries have come to the USGS regarding a potential eruption in the vicinity of Lavic Lake Volcanic Field (LLVF) in Southern California. USGS volcanologists evaluating the situation find nothing to indicate that the observed NEXRAD feature results from volcanic activity. Read the full statement from the Long Valley Volcano Observatory.