Lost Limbs Foundation

Thursday, August 15, 2013

Mt. Shasta

This active 4322 metre stratovolcano towers over the northern California landscape, and is popular with hiker, climbers and skiers. It is the largest volcano by volume in the Cascade arc, a chain of smokers which results from subduction at the edge of the north American plate. Known as Uytaahkoo or white mountain to the original inhabitants, due to its coating of glaciers and snow. Unlike the classic perfect cone, Shasta is a complex compound of at least four cones, with a satellite cone called Shastina. It erupts every six centuries or so, with the last blowout being two centuries back. Lava domes and flows were squeezed out and pyroclastic flows travelled up to 20Km from the mountain. Lahars, muddy rivers thickened by volcanic ash roared through the landscape following the river valleys. 

Image credit: Mike Doukas, USGS.