Lahars

Future eruptions like those of the last 10,000 years will probably produce deposits of ash, lava flows, domes, and pyroclastic flows, and could endanger infrastructure that lie within several tens of kilometers of the volcano.

Mount Shasta is located in the Cascade Range in northern California about 65 km (40 mi) south of the Oregon-California border. One of the largest and highest (14,162 ft) of the Cascade volcanoes, the compound stratovolcano is located near the southern end of the range that terminates near Lassen Peak.

The next eruption at Mount Shasta would likely involve weeks to months of precursory earthquakes and ground deformation followed by a series of steam explosions blasting a deep crater at the summit of the volcano.

If they occur in the future, lahars may cover valley floors and other low areas as much as several tens of kilometers (10 km = 6.2 mi) from the volcano.