Local Geology
College of the Siskiyous is located at the western base of Mount Shasta, a 14,162-foot high stratovolcano that has been built by eruptions during the past 200,000 years. The campus is also set close against the eastern flank of the Eddy Range, part of the Klamath Mountain system that stretches 150 km westward to the coast. Volcanism in the High Cascades and earthquakes beneath both the Klamaths and the Cascades are occurring in response to subduction of oceanic lithosphere beneath northern California. To learn more about regional volcanism and seismicity visit one or more of the following sites:
- Geologic Provinces of the United States—Cascade Volcanoes: Brief, non-technical introduction to subduction in the Pacific Northwest and the origin of the Cascade volcanic chain. [US Geological Survey and National Park Service]
- Assessment of Volcanic Threat and Monitoring Capabilities in the United States: A report that evaluates the threats posed by169 volcanoes and volcanic fields in the conterminous United States, Alaska, Hawaii, and the Marianas Islands. The report ranks Mount Shasta as the nation's fifth highest risk volcano. [United States Geological Survey]
- California Volcano Information: Discussions of the eruptive histories and potential hazards of California's volcanoes. [USGS Cascade Volcano Observatory]
- Mount Shasta Companion—Geology: General introduction to the geologic setting and processes of the Mount Shasta region, as well as to the mountain's eruptive history and hazards. Part of the more comprehensive "Mount Shasta Companion" project. [Bill Hirt, College of the Siskiyous]
- California Earthquake Information: Interactive map and database for earthquakes that have occurred in California during the past week. [USGS, CDMG, and seismological programs at several regional universities]
- California Earthquake Forecast: Real-time forecast of the likelihood of an earthquake with a Modified Mercalli Intensity VI or above during the next 24 hours California. [USGS, ETH Zurich, and SCEC]
- Pacific Northwest Earthquake Information: Interactive map and database for earthquakes that have occurred in the Pacific Northwest during the past week. [USGS and University of Washington Department of Earth and Space Sciences]
- College of the Siskiyous Seismic Station: Near real-time records from the US Geological Survey's seismic station operating on the College of the Siskiyous campus west of Mount Shasta. [USGS Earthquake Hazards Program]
- Mount Shasta Area Seismicity: Maps that show the locations of earthquakes (M>2) in the California Cascades during the past week, month, and year. [U.C. Berkeley Seismological Laboratory]
