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California Volcano Observatory images.
Cinder cones (or scoria cones) are relatively small, steep-sided volcanoes that are constructed around a single vent when lava is ejected into the air, breaks into smaller pieces, and builds up around the sides of the vent. This photo is looking across the quarry which exposes the interior of a cinder cone east of Clearlake Oaks in the Clear Lake Volcanic Field.
Cinder cones (or scoria cones) are relatively small, steep-sided volcanoes that are constructed around a single vent when lava is ejected into the air, breaks into smaller pieces, and builds up around the sides of the vent. This photo is looking across the quarry which exposes the interior of a cinder cone east of Clearlake Oaks in the Clear Lake Volcanic Field.
Located at the midpoint of Clear Lake in Lake County, California, Buckingham Peninsula shows evidence of young explosive volcanism in the Clear Lake Volcanic Field. Little Borax Lake, enclosed within the Buckingham golf course, is a water-filled maar crater, as is Horseshoe Bay to its northeast. USGS photo by J. Ball.
Located at the midpoint of Clear Lake in Lake County, California, Buckingham Peninsula shows evidence of young explosive volcanism in the Clear Lake Volcanic Field. Little Borax Lake, enclosed within the Buckingham golf course, is a water-filled maar crater, as is Horseshoe Bay to its northeast. USGS photo by J. Ball.
Rhyolite lavas in the Yellowstone Caldera younger than 631,000 years
Rhyolite lavas in the Yellowstone Caldera younger than 631,000 years
Thurston Lake and Mount Konocti, Clear Lake Volcanic Field, California.
Thurston Lake and Mount Konocti, Clear Lake Volcanic Field, California.
Mount Konocti as seen from the town of Clear Lake.
Mount Konocti as seen from the town of Clear Lake.
View of the Mammoth Mountain lava dome complex overlooking Horseshoe Lake.
View of the Mammoth Mountain lava dome complex overlooking Horseshoe Lake.
Photograph of permanent eddy covariance station installed since 2014 in area of volcanic CO2 emissions on Mammoth Mountain, California. USGS photo by Jennifer Lewicki, August 2019.
Photograph of permanent eddy covariance station installed since 2014 in area of volcanic CO2 emissions on Mammoth Mountain, California. USGS photo by Jennifer Lewicki, August 2019.
Located 50 miles north-northwest of Sacramento, Sutter Buttes are the only volcano in the Central Valley. They consist of a central core of andesite, dacite, and rhyolite domes and flows. These are surrounded by a large apron of fragmental volcanic debris.
Located 50 miles north-northwest of Sacramento, Sutter Buttes are the only volcano in the Central Valley. They consist of a central core of andesite, dacite, and rhyolite domes and flows. These are surrounded by a large apron of fragmental volcanic debris.
A 3-4m (10-12 ft) high outcrop of basalt lava, part of a broader lava flow. These flows were erupted about 300,000 years ago following basalt dike intrusions in a rear-arc region of northern California. The eruptions of three of these flows are thought to have taken place within several hundred years of each other.
A 3-4m (10-12 ft) high outcrop of basalt lava, part of a broader lava flow. These flows were erupted about 300,000 years ago following basalt dike intrusions in a rear-arc region of northern California. The eruptions of three of these flows are thought to have taken place within several hundred years of each other.
High-resolution, bare-earth, airborne light detection and ranging (LiDAR) image, looking obliquely northwest into Rocky Ridge.
High-resolution, bare-earth, airborne light detection and ranging (LiDAR) image, looking obliquely northwest into Rocky Ridge.
Mount Shasta, a steep-sided Cascade Range stratovolcano in Northern California, looms above Little Glass Mountain, a thick obsidian flow erupted from the Medicine Lake shield volcano about 1,000 years ago. These are just two of the young volcanic areas monitored by the USGS California Volcano Observatory. USGS photo.
Mount Shasta, a steep-sided Cascade Range stratovolcano in Northern California, looms above Little Glass Mountain, a thick obsidian flow erupted from the Medicine Lake shield volcano about 1,000 years ago. These are just two of the young volcanic areas monitored by the USGS California Volcano Observatory. USGS photo.
Simplified geologic map (left) and diagrammatic cross section (right) of Long Valley Caldera. The resurgent dome, Doe Ridge, Mammoth Mountain, and the Inyo Craters and Domes all reflect volcanic activity since 760,000 years ago, when a giant eruption formed the caldera.
Simplified geologic map (left) and diagrammatic cross section (right) of Long Valley Caldera. The resurgent dome, Doe Ridge, Mammoth Mountain, and the Inyo Craters and Domes all reflect volcanic activity since 760,000 years ago, when a giant eruption formed the caldera.
Argon geochronology lab in Menlo Park, California.
Argon geochronology lab in Menlo Park, California.
Microprobe laboratory in Menlo Park, California.
Example Hydrotherm output. Hydrotherm is a three-dimensional simulation of multiphase groundwater flow and heat transport in the temperature range of 0 to 1200 degrees Celsius and the pressure range of 1 to 1000 MPa.
Example Hydrotherm output. Hydrotherm is a three-dimensional simulation of multiphase groundwater flow and heat transport in the temperature range of 0 to 1200 degrees Celsius and the pressure range of 1 to 1000 MPa.
Medicine Lake, California simplified hazards map showing potential impact area for ground-based hazards during a volcanic event.
Medicine Lake, California simplified hazards map showing potential impact area for ground-based hazards during a volcanic event.
Map showing distribution of Long Valley postcaldera rhyolites. Abbreviations: CD, Casa Diablo geothermal plant; Ski area, Mammoth Mountain Ski Area; LVEW, Long Valley Exploratory Well, 3 km deep, located high on resurgent uplift; s, surficial deposits filling structural lows on resurgent uplift.
Map showing distribution of Long Valley postcaldera rhyolites. Abbreviations: CD, Casa Diablo geothermal plant; Ski area, Mammoth Mountain Ski Area; LVEW, Long Valley Exploratory Well, 3 km deep, located high on resurgent uplift; s, surficial deposits filling structural lows on resurgent uplift.
Inverted funnel connected to thermoplastic tubing used to collect gas from a hot spring pool near Lassen Peak, California.
Inverted funnel connected to thermoplastic tubing used to collect gas from a hot spring pool near Lassen Peak, California.
The photo shows several silica-rich lava domes in the Coso Volcanic Field, the closest of which erupted onto the desert floor around 80,000 years ago. USGS photo by Seth Burgess.
The photo shows several silica-rich lava domes in the Coso Volcanic Field, the closest of which erupted onto the desert floor around 80,000 years ago. USGS photo by Seth Burgess.
Flow banding of Panum pumice and obsidian of the same composition.
Flow banding of Panum pumice and obsidian of the same composition.
A mud pot releases a burst of gas in the Davis-Schrimpf Seep Field near the Salton Sea. The geothermal area here is related to the same faulting and volcanic system which created the Salton Buttes lava domes. USGS photo by Deb Bergfeld, 2016.
A mud pot releases a burst of gas in the Davis-Schrimpf Seep Field near the Salton Sea. The geothermal area here is related to the same faulting and volcanic system which created the Salton Buttes lava domes. USGS photo by Deb Bergfeld, 2016.