Clear Lake Volcanic Field | U.S. Geological Survey Official websites use .gov .gov website belongs to an official government organization in the United States. Secure .gov websites use HTTPS lock ( or means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. Clear Lake Volcanic Field Find U.S. Volcano Filters The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows. Get Help Earthquake Plots To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over. Map Layers Earthquake Colors Earthquake Depth Units Earthquake Time Units Results Filters The map displays volcanoes, earthquakes, monitoring instruments, and past lava flows. Get Help Earthquake Plots To view an earthquake cross-sectional plot, click "Draw Plot" to start drawing on the map. Once the plot area is selected, click on "View Plot" to view chart or "Clear Plot" to start over. Settings Map Layers Earthquake Colors Earthquake Depth Units Earthquake Time Units Map Legend Map Legend Results Clear Lake Volcanic Field Science Data Maps Multimedia Publications News Connect Clear Lake Volcanic Field is located about 90 miles north of San Francisco, California. Quick Facts Location: California, Lake County Latitude: 38.97° N Longitude: 122.77° W Elevation: 1,439 (m) 4,721 (f) Volcano type: volcanic field Composition: basalt to rhyolite Most recent eruption: about 10,000 years ago Nearby towns: Clearlake, Kelseyville, Lakeport, Lucerne Threat Potential: High* *based on the National Volcano Early Warning System Summary The town of Clearlake lies within the volcanic field, as does much of the 43,000-acre freshwater lake of its namesake. The Geysers steam field, which sits at the southwest margin of the volcanic region, is host to one of the world's most productive geothermal power plants, producing enough electricity for 850,000 homes. The heat driving the geothermal system emanates from a zone of partially molten rock (magma) deep below the greater Clear Lake volcanic system. The most prominent volcanic feature is 300,000 year-old Mount Konocti, rising about 975 m (3,200 ft) above the southwestern shore of the lake. The most recent activity in the Clear Lake Volcanic Field occurred between 8,500 and 13,500 years ago as explosive maar eruptions in and along the shores of the southeastern part of the lake. Although there have been no documented eruptions within the last few thousand years, sporadic volcanic-type earthquakes do occur, and the numerous springs and volcanic gas seeps in the field point to its potential for future eruptions. Monitoring in the Clear Lake region by the USGS, and a collaborative effort with Calpine Corporation in the Geysers Steam Field, provides real-time tracking of earthquake activity. In addition, the USGS periodically analyzes volcanic gases and hot springs in the region. When it comes to analyzing rocks, only the freshest samples will do! March 24, 2026 When it comes to analyzing rocks, only the freshest samples will do! The curious case of Kelseyville’s Gas Hill March 17, 2026 The curious case of Kelseyville’s Gas Hill New study reveals the deep roots of early eruptions in the Clear Lake Volcanic Field September 17, 2025 New study reveals the deep roots of early eruptions in the Clear Lake Volcanic Field View All February 25, 2019 California’s exposure to volcanic hazards 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... Authors Margaret Mangan, Jessica Ball, Nathan Wood, Jamie L. Jones, Jeff Peters, Nina Abdollahian, Laura Dinitz, Sharon Blankenheim, Johanna Fenton, Cynthia Pridmore By Volcano Hazards Program Volcano Science Center California Volcano Observatory Clear Lake Volcanic Field Coso Volcanic Field Lassen Volcanic Center Long Valley Caldera Mammoth Mountain Medicine Lake Mono Lake Volcanic Field Mono-Inyo Craters Mount Shasta Salton Buttes Soda Lakes Ubehebe Craters October 22, 2018 2018 update to the U.S. Geological Survey national volcanic threat assessment 2018 update to the U.S. Geological Survey national volcanic threat assessment When erupting, all volcanoes pose a degree of risk to people and infrastructure, however, the risks are not equivalent from one volcano to another because of differences in eruptive style and geographic location. Assessing the relative threats posed by U.S. volcanoes identifies which volcanoes warrant the greatest risk-mitigation efforts by the U.S. Geological Survey and its partners... Authors John W. Ewert, Angela K. 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At least 10 eruptions have taken place in California in the past 1,000 years—most recently at Lassen Peak in Lassen Volcanic National Park (1914 to 1917) in the northern part of the State—and future volcanic eruptions are inevitable. The U.S. Geological... Authors Wendy K. Stovall, Mae Marcaida, Margaret T. Mangan By Natural Hazards Mission Area Volcano Hazards Program Volcano Science Center Clear Lake Volcanic Field Coso Volcanic Field Lassen Volcanic Center Long Valley Caldera Mammoth Mountain Mono Lake Volcanic Field Mono-Inyo Craters Mount Shasta Salton Buttes Soda Lakes Ubehebe Craters View All November 29, 2023 Mining and mineralization of the Clear Lake region The Geysers-Clear Lake area has been one of the most productive in the United States for mercury, and gold was mined in the late 1800s. Many of the deposits are directly associated with outcrops of early Clear Lake volcanic rocks. By Volcano Science Center California Volcano Observatory Clear Lake Volcanic Field Mining and mineralization of the Clear Lake region November 29, 2023 Mining and mineralization of the Clear Lake region The Geysers-Clear Lake area has been one of the most productive in the United States for mercury, and gold was mined in the late 1800s. Many of the deposits are directly associated with outcrops of early Clear Lake volcanic rocks. October 3, 2023 Gas monitoring at Clear Lake Volcanic Field The USGS periodically analyzes volcanic gases and hot springs at Clear Lake volcanic field during ground-based campaigns. By Volcano Hazards Program Volcano Science Center California Volcano Observatory Clear Lake Volcanic Field Gas monitoring at Clear Lake Volcanic Field October 3, 2023 Gas monitoring at Clear Lake Volcanic Field The USGS periodically analyzes volcanic gases and hot springs at Clear Lake volcanic field during ground-based campaigns. October 3, 2023 Deformation monitoring at Clear Lake Volcanic Field When magma moves into a volcanic system, and closer to the surface of the earth, the area surrounding the volcano may move upward and outward. By Volcano Hazards Program Volcano Science Center California Volcano Observatory Clear Lake Volcanic Field Deformation monitoring at Clear Lake Volcanic Field October 3, 2023 Deformation monitoring at Clear Lake Volcanic Field When magma moves into a volcanic system, and closer to the surface of the earth, the area surrounding the volcano may move upward and outward. View All Quick Facts Location: California, Lake County Latitude: 38.97° N Longitude: 122.77° W Elevation: 1,439 (m) 4,721 (f) Volcano type: volcanic field Composition: basalt to rhyolite Most recent eruption: about 10,000 years ago Nearby towns: Clearlake, Kelseyville, Lakeport, Lucerne Threat Potential: High* *based on the National Volcano Early Warning System Volcanoes Hazards Program Links Assess Prepare Forecast Activity Products Observatories About Was this page helpful?