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Mt. Shasta is a majestic, steep-sided stratovolcano located about 97 km (60 mi) north of Redding along the I-5 corridor in Northern California.


Summary

Mt. Shasta is a majestic, steep-sided stratovolcano located about 97 km (60 mi) north of Redding along the I-5 corridor in Northern California. It is the most voluminous of all the Cascade Range volcanoes, and the towns of Weed, Mt Shasta City, and McCloud lie in the shadow of its 4,317 m (14,163 ft) high snow- and ice-clad edifice, which also holds the headwaters of the Upper Sacramento River. Mount Shasta began forming on the remnants of an older, similar volcano that collapsed 300,000 to 500,000 years ago. The collapse spawned one of the largest landslides known on Earth, covering more than 440 km2 (170 mi2) of Shasta Valley to the northeast. Activity over the last 300,000 years includes long intervals of quiet interrupted by shorter spans of frequent eruptions. Eruptions at about 11,000 years ago built Black Butte and Shastina on the western flanks of Mount Shasta. In the last few millennia, smaller eruptions have broken out at the volcano’s summit and from vents on its upper east flank. USGS scientists are working on constraining the age of the most recent eruption. Preliminary work indicates the volcano erupted in the past 200-300 years. Hot springs and volcanic gases seep from the summit indicating a relatively young and still-hot system. Non-volcanic shedding of young volcanic rock and ash from Mount Shasta’s steep slopes occurs during heavy rainfall or glacial floods. In the last 1,000 years, more than 70 mudflows have inundated stream channels. The record of eruptions over the last 10,000 years suggests that, on average, at least one eruption occurs every 800 to 600 years at Mt Shasta. USGS and UNAVCO seismic and geodetic networks provide real-time volcano monitoring data. Earthquake activity has been low for the last few decades and ground deformation is negligible.

News

Date published: April 5, 2017

Explore California's volcanic legacy and future with new field trip guides

California is well-known for its frequent earthquakes, but less so for its volcanic history – despite the fact that the most recent eruption in the state occurred just 100 years ago.

Date published: June 27, 2016

Fieldwork "Fun" Has Begun

Summer has arrived, and for many CalVO scientists, so has the season of fieldwork. During the fall, winter and spring, many of California's volcanoes are covered with snow, and challenging weather conditions make fieldwork difficult and time consuming.

Date published: April 3, 2015

Mount Shasta earthquake series poses no immediate hazard

Since February 19, 2015 an ongoing series of small earthquakes has been occurring approximately 5 miles southeast of the summit of Mount Shasta, near the Clear Creek Trailhead on a regional, unnamed fault at about 3-5 miles depth.

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