No latest activity reported for Shasta.

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

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.

Christiansen R L, Miller C D, 1976. Volcanic evolution of Mt. Shasta, California (abs). {Geol Soc Amer Abs Prog}, 8: 360-361

Coombs H A, Howard A D, 1960. United States of America. {Catalog of Active Volcanoes of the World and Solfatara Fields}, Rome: IAVCEI, 9: 1-68

Crandell D R, Miller C D, Glicken H X, Christiansen R L, Newhall C G, 1984. Catastrophic debris avalanche from ancestral Mount Shasta volcano, California. {Geology}, 12: 143-146

Hildreth W E, 2007. Quaternary magmatism in the Cascades--geologic perpectives. {U S Geol Surv Prof Pap}, 1744: 1-125

Miller C D, 1980. Potential hazards from future eruptions in the vicinity of Mount Shasta volcano, northern California. {U S Geol Surv Bull}, 1503: 1-43

Sherrod D R, Smith J G, 1990. Quaternary extrusion rates of the Cascade Range, northwestern United States and southern British Columbia. {J Geophys Res}, 95: 19,465-19,474

Ui T, Glicken H, 1986. Internal structural variations in a debris-avalanche deposit from ancestral Mount Shasta, California, USA. {Bull Volc}, 48: 189-194

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

The most voluminous of the Cascade volcanoes, northern California's Mount Shasta is a massive compound stratovolcano composed of at least four main edifices constructed over a period of at least 590,000 years. An ancestral Shasta volcano was destroyed by one of Earth's largest known Quaternary subaerial debris avalanches, which filled the Shasta River valley NW of the volcano. The Hotlum cone, forming the present summit, and the Shastina lava dome complex were constructed during the early Holocene, as was the SW flank Black Butte lava dome. Eruptions from these vents have produced pyroclastic flows and mudflows that affected areas as far as 20 km from the summit. Eruptions from Hotlum cone continued throughout the Holocene.