Ash/Tephra Fall

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.

Based on this recent behavior, it is not likely that Mount Shasta will erupt very catastrophic volumes of tephra and ash in the near future.

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.

Hotlum cone forms the summit and the north and northwestern slopes of Mount Shasta.