Johnston Ridge Observatory – Hit the Road in the Pacific Northwest

Mt St. Helens National Volcanic Monument, Washington

On the morning of May 18, 1980 a magnitude 5.1 earthquake triggered one of the world’s largest recorded landslides as the north face of Mt St. Helens collapsed to bury the valleys below, followed within seconds by one of the most powerful volcanic blasts in the history of North America. Within ten minutes the eruptionContinue reading “Mt St. Helens National Volcanic Monument, Washington”