How was mount st helens formed

Mount St. Helens, located in southwestern Washington about 50 miles northeast of Portland, Oregon, is one of several
lofty volcanic peaks that dominate the Cascade Range of the Pacific Northwest; the range extends from Mount
Garibaldi in British Columbia, Canada, to Lassen Peak in northern California. Geologists call Mount St. Helens a
composite volcano (or stratovolcano), a term for steepsided, often symmetrical cones constructed of alternating layers
of lava flows, ash, and other volcanic debris. Composite volcanoes tend to erupt explosively and pose considerable
danger to nearby life and property. In contrast, the gently sloping shield volcanoes, such as those in Hawaii, typically
erupt nonexplosively, producing fluid lavas that can flow great distances from the active vents. Although Hawaiian-type
eruptions may destroy property, they rarely cause death or injury. Before 1980, snow-capped, gracefully symmetrical
Mount St. Helens was known as the "Fujiyama of America." Mount St. Helens, other active Cascade volcanoes, and
those of Alaska form the North Ameri

Mount St. Helens

Mount St. Helens

3,000-foot (910 m) steam"plume" on May 19, 1982, two years after its major eruption

Elevation8,365 ft (2,550 m)
Prominence4,605 ft (1,404 m)
Coordinates46°11′28″N122°11′40″W / 46.1912000°N 122.1944000°W / 46.1912000; -122.1944000[1]
LocationSkamania County, Washington, U.S.
Parent rangeCascade Range
Topo mapUSGS Mount St. Helens
Age of rock< 40,000 yrs
Mountain typeActive stratovolcano
Volcanic arcCascade Volcanic Arc
Last eruption2004 – July 10, 2008
First ascent1853 by Thomas J. Dryer
Easiest routeHike via south slope of volcano (closest area near eruption site)

Mount St. Helens is a volcano in the U.S. state of Washington. It is 96 miles (154 km) south of Seattle and 53 miles (85 km) northeast of Portland, Oregon. The volcano is in Cascade Range of mountains. It is part of the Cascade Volcanic Arc in the Pacific Ring of Fire that includes over 160 active volcanos. This is a deadly volcano.

Moun

Mount St. Helens

Volcano in Washington, U.S.

This article is about the volcano in Washington state. For the mountain in California, see Mount Saint Helena. For more information about the volcano's 1980 eruption, see 1980 eruption of Mount St. Helens.

Mount St. Helens

3,000 ft (0.9 km) high steam plume on May 19, 1982, two years after the 1980 major eruption

Elevation8,363 ft (2,549 m)
Prominence4,605 ft (1,404 m)
Listing
Coordinates46°11′28″N122°11′40″W / 46.1912000°N 122.1944000°W / 46.1912000; -122.1944000[1]
EtymologyAlleyne FitzHerbert, 1st Baron St Helens
Native name

Mount St. Helens

Location in Washington state

Parent rangeCascade Range
Topo mapUSGS Mount St. Helens
Rock ageLess than 40,000 years old
Mountain typeActive stratovolcano (Subduction zone)
Volcanic arcCascade Volcanic Arc
Last eruption2004–2008
First ascent1853 by Thomas J. Dryer
Easiest routeHike via south slope of volcano (closest area near eruption

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