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How much damage did Mount Saint Helens do?
— It was shortly after 8:30 a.m. on May 18, 1980 when Mount St. Helens erupted in Washington state. The eruption would quickly become the deadliest in U.S. history, killing 57 people. The destruction caused more than $1 billion in damage.
What is the effect of volcanic eruption on the environment?
Further effects are the deterioration of water quality, fewer periods of rain, crop damages, and the destruction of vegetation. During volcanic eruptions and their immediate aftermath, increased respiratory system morbidity has been observed as well as mortality among those affected by volcanic eruptions.
What is the activity of Mt St Helens?
Volcanic activity in Mount St. Helens is due to the Juan de Fuca Plate , an oceanic plate, subducting under the North American Plate , a continental plate. The weight of water on oceanic plates increases the density of oceanic crust to the point where it begins to slide under the continental plate.
What is the weather like in Mount St Helens?
The weather of Mount St. Helens is generally typical of the climate in Western Washington. This climate is characterized by warm and dry summers and wet winters. The best time to visit Mount St. Helens is during the warmer months from May through October.
What type of eruption does Mount St Helens have?
In volcanology , an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens. Such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such that expelled lava violently froths into volcanic ash when pressure is suddenly lowered at the vent.
How often does Mount St Helens erupt?
Research indicates that the volcano erupts episodically with ten or more eruptions occurring in short (500-2,000 year) time periods separated by long intervals (3,000-5,000 years) with few or no eruptions. Evidence suggests that magma most recently erupted at the surface about 3,200 years ago.