Mount St. Helen's is an active stratovolcano in the Cascade Range in Skamania County, Washington and is part of the Ring of Fire centered around the Pacific Ocean. Mount St. Helen's was created when the oceanic Jean de Fuca plate subducted beneath the North American Plate and has a long history of eruptive periods followed lengthy dormancies. Her volcanic activity was marked by thousands of years of lava and pyroclastic flows only to fall silent and then reawaken to begin her destructive cycle again. In the 1800's, Louwala-Clough fell silent, all signs of volcanic activity blanketed beneath her snow capped peak for over one hundred years before she awakened with a deadly force in 1980.
Geologists Dwight R. Crandell and Donal R. Mullineux released …show more content…
Helen's. The initial earthquake gave rise to a swarm of earthquakes and volcanic activity for almost two months. The north side developed an ominous, silica rich-magma filled bulge as steam, ash and gas emissions signaled an impending disaster. On the morning of May 18, 1980 at 8:32 am, a 5.1 earthquake caused the north flank to slide away from the mountain, precipitating a deadly chain of events. The sudden drop in pressure created a lateral blast driven by the hydrothermal system and exposed the magma's gases under the north bulge to release a plinian eruption and sent pyroclastic debris into the air. The column of ash and gases rose thousands of feet into the air, turning the skies dark and carrying ashes across eleven states. The extreme heat from the steam and the magma melted snow and ice and lahars rushed down the mountain, completely destroying everything in its path.
When Washington's Governor, Dixie Lee Ray and President Carter surveyed the area, they both acknowledged the tragedy of the loss of lives however were quick to point out the that victims were in the red zone, an area where the public was not allowed because of the danger an eruption posed. There were only three victims in the red zone and each one had special permission to be
Geologists Dwight R. Crandell and Donal R. Mullineux released …show more content…
Helen's. The initial earthquake gave rise to a swarm of earthquakes and volcanic activity for almost two months. The north side developed an ominous, silica rich-magma filled bulge as steam, ash and gas emissions signaled an impending disaster. On the morning of May 18, 1980 at 8:32 am, a 5.1 earthquake caused the north flank to slide away from the mountain, precipitating a deadly chain of events. The sudden drop in pressure created a lateral blast driven by the hydrothermal system and exposed the magma's gases under the north bulge to release a plinian eruption and sent pyroclastic debris into the air. The column of ash and gases rose thousands of feet into the air, turning the skies dark and carrying ashes across eleven states. The extreme heat from the steam and the magma melted snow and ice and lahars rushed down the mountain, completely destroying everything in its path.
When Washington's Governor, Dixie Lee Ray and President Carter surveyed the area, they both acknowledged the tragedy of the loss of lives however were quick to point out the that victims were in the red zone, an area where the public was not allowed because of the danger an eruption posed. There were only three victims in the red zone and each one had special permission to be