Mount St Helens Earthquake
Impact
Approximately 57 deaths, about $1.1 billion in property damage; caused a partial collapse of the volcano's flank, deposited ash in eleven states and five Canadian provinces.
With no immediate precursors, a magnitude 5.1 earthquake occurred and was accompanied by a rapid series of events.
Mount St. Helens produces small to large explosive eruptions, which send varying quantities of ash and tephra into the atmosphere
Tephra (rock fragments and particles ejected by a volcanic eruption.)
• tephra plume lasted for about eight hours and the plume top ranged from 14–18 km (8.5–11 mi) high.
Ash falls
• Ash fallout caused major problems in communities up to 600 km (370 mi) away.
The major hazards associated with eruption of tephra result from suspension of the abrasive, fine particles in the air and water, burial of transportation routes and vegetation, and loading on roofs or other structures. While the volcanic ash may pose hazards hundreds of kilometers downwind from source, directly after accumulating at the surface and later, when particles are remobilized by wind or passing vehicles. …show more content…
The mountain had been known for its snow-capped peak, earning the nickname "the Fuji of America" for its resemblance to Japan's Mount Fuji.
• Fifty-seven people are killed. Damage caused by the blast costs $1.1 billion.
• Hot ash causes forest fires, and snow melt from the top of the mountain causes floods.
• Volcanic ash spreads across the Northwest. More than 900,000 tons of ash are cleaned up from areas around Washington state.
• The 1980 eruption is the first eruption in the continental United States outside of Alaska since
Approximately 57 deaths, about $1.1 billion in property damage; caused a partial collapse of the volcano's flank, deposited ash in eleven states and five Canadian provinces.
With no immediate precursors, a magnitude 5.1 earthquake occurred and was accompanied by a rapid series of events.
Mount St. Helens produces small to large explosive eruptions, which send varying quantities of ash and tephra into the atmosphere
Tephra (rock fragments and particles ejected by a volcanic eruption.)
• tephra plume lasted for about eight hours and the plume top ranged from 14–18 km (8.5–11 mi) high.
Ash falls
• Ash fallout caused major problems in communities up to 600 km (370 mi) away.
The major hazards associated with eruption of tephra result from suspension of the abrasive, fine particles in the air and water, burial of transportation routes and vegetation, and loading on roofs or other structures. While the volcanic ash may pose hazards hundreds of kilometers downwind from source, directly after accumulating at the surface and later, when particles are remobilized by wind or passing vehicles. …show more content…
The mountain had been known for its snow-capped peak, earning the nickname "the Fuji of America" for its resemblance to Japan's Mount Fuji.
• Fifty-seven people are killed. Damage caused by the blast costs $1.1 billion.
• Hot ash causes forest fires, and snow melt from the top of the mountain causes floods.
• Volcanic ash spreads across the Northwest. More than 900,000 tons of ash are cleaned up from areas around Washington state.
• The 1980 eruption is the first eruption in the continental United States outside of Alaska since