Clear Lake

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 38.97°N
  • 122.77°W

  • 1439 m
    4720 ft

  • 323100
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

There are no activity reports for Clear Lake.



 Available Weekly Reports

There are no Weekly Reports available for Clear Lake.

There are no Holocene eruptions known for Clear Lake. If this volcano has had large eruptions prior to 10,000 years ago, information might be found in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Anderson C A, 1936. Volcanic history of the Clear Lake area, Calif. Geol Soc Amer Bull, 47: 629-664.

California Div. Mines and Geology, 1958-69. Geologic atlas of California, 1:250,0000 scale.. Calif Div Mines Geol.

Donnelly-Nolan J M, Hearn B C Jr, Curtis G H, Drake R E, 1981. Geochronology and evolution of the Clear Lake volcanics. In: McLaughlin R J, Donnelly-Nolan J M (eds) Research in the Geysers-Clear Lake geothermal area, northern California. {U S Geol Surv Prof Pap}, 1141: 47-60.

Garrison L E, 1972. Geothermal steam in the Geysers-Clear Lake region, California. Geol Soc Amer Bull, 83: 1449-1468.

Hammersley L, DePaolo D J, 2006. Isotopic and geophysical constraints on the structure and evolution of the Clear Lake volcanic system. J Volc Geotherm Res, 153: 331-356.

Hearn B C Jr, Donnelly-Nolan J M, Goff F E, 1981. The Clear Lake volcanics: tectonic setting and magma sources. In: McLaughlin R J, Donnelly-Nolan J M (eds) Research in the Geysers-Clear Lake geothermal area, northern California. {U S Geol Surv Prof Pap}, 1141: 25-45.

Hearn B C Jr, Donnelly-Nolan J M, Goff F E, 1995. Geologic map and structure sections of the Clear Lake volcanics, Northern California. U S Geol Surv Map, I-2362.

Luedke R G, Smith R L, 1981. Map showing distribution, composition, and age of late Cenozoic volcanic centers in California and Nevada. U S Geol Surv Map, I-1091-C.

Miller C D, 1989. Potential hazards from future volcanic eruptions in California. U S Geol Surv Bull, 1847: 1-17.

Wood C A, Kienle J (eds), 1990. Volcanoes of North America. Cambridge, England: Cambridge Univ Press, 354 p.

The late-Pliocene to early Holocene Clear Lake volcanic field in the northern Coast Ranges, contains lava dome complexes, cinder cones, and maars of basaltic-to-rhyolitic composition. The westernmost site of Quaternary volcanism in California, the Clear Lake field is located far to the west of the Cascade Range in a complex geologic setting within the San Andreas transform fault system. Mount Konocti, a composite dacitic lava dome on the south shore of Clear Lake, is the largest volcanic feature. Volcanism has been largely non-explosive, with only one major airfall tuff and no ash flows. The latest eruptive activity, forming maars and cinder cones along the shores of Clear Lake, continued until about 10,000 years ago. A large silicic magma chamber provides the heat source for the Geysers, the world's largest producing geothermal field.