Devastator Peak

 volcano, summit

Volcanic plug
Summit elevation 7635 ft. asl..
British Columbia, Canada

On the southwest side of the Mount Meager complex lies Devastator Peak, a massive leaning tower of rock which actually partially overlies the ice of the Devastator Glacier. As the glacier retreats, the rock becomes unsupported, and collapses. Massive rock avalanches result, which land on the glacier and partially melt its surface (surface temperatures in the rockfall, the result of friction from fragments colliding and rubbing on each other during the collapse, are high enough that the surface layers melt and then form an obsidian crust when cooling). The resultant landslide blocks Meager Creek at its confluence with Devastator, forming a temporary lake. When the lake grows to a large enough size, it overtops the landslide dam and produces a huge flood wave which roars down Meager Creek and Lillooet River for 20 km (12 mi) or more before subsiding into a large flood. Scientists believe a wave large enough to reach Pemberton could be created by a large enough initial rockfall. Historically, such landslide-flood events occurred in 1930 and on July 22, 1975. The latter event buried and killed a party of 4 BC Hydro geologists exploring the geothermal potential of the area.