Back Mount Saint Helens Afrikaans جبل سانت هيلين Arabic Monte Santa Helena AST Сент-Хеленс Bashkir Сент-Хеленс Byelorussian Сейнт Хелънс (вулкан) Bulgarian সেন্ট হেলেনস পর্বত Bengali/Bangla Saint Helens Catalan Mount Saint Helens CEB Mount St. Helens Czech

Mount St. Helens

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
Highest point
Elevation8,363 ft (2,549 m)
Prominence4,605 ft (1,404 m)
Listing
Coordinates46°11′28″N 122°11′40″W / 46.1912000°N 122.1944000°W / 46.1912000; -122.1944000[1]
Naming
EtymologyAlleyne FitzHerbert, 1st Baron St Helens
Native name
Geography
Mount St. Helens is located in Washington (state)
Mount St. Helens
Mount St. Helens
Location in Washington state
Parent rangeCascade Range
Topo mapUSGS Mount St. Helens
Geology
Rock ageLess than 40,000 years old
Mountain typeActive stratovolcano (Subduction zone)
Volcanic arcCascade Volcanic Arc
Last eruption2004–2008
Climbing
First ascent1853 by Thomas J. Dryer
Easiest routeHike via south slope of volcano (closest area near eruption site)

Mount St. Helens (known as Lawetlat'la to the local Cowlitz people, and Loowit or Louwala-Clough to the Klickitat) is an active stratovolcano located in Skamania County, Washington,[1] in the Pacific Northwest region of the United States. It lies 52 miles (83 km) northeast of Portland, Oregon,[2] and 98 miles (158 km) south of Seattle.[3] Mount St. Helens takes its English name from that of the British diplomat Alleyne Fitzherbert, 1st Baron St Helens, a friend of explorer George Vancouver who surveyed the area in the late 18th century.[1] The volcano is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire.

The Mount St. Helens major eruption of May 18, 1980, remains the deadliest and most economically destructive volcanic event in U.S. history.[4] Fifty-seven people were killed; 200 homes, 47 bridges, 15 miles (24 km) of railways, and 185 miles (298 km) of highway were destroyed.[5] A massive debris avalanche, triggered by a magnitude 5.1 earthquake, caused a lateral eruption[6] that reduced the elevation of the mountain's summit from 9,677 to 8,363 ft (2,950 to 2,549 m), leaving a 1 mile (1.6 km) wide horseshoe-shaped crater.[7] The debris avalanche was 0.6 cubic miles (2.5 km3) in volume.[8] The 1980 eruption disrupted terrestrial ecosystems near the volcano. By contrast, aquatic ecosystems in the area greatly benefited from the amounts of ash, allowing life to multiply rapidly. Six years after the eruption, most lakes in the area had returned to their normal state.[9]

After its 1980 eruption, the volcano experienced continuous volcanic activity until 2008. Geologists predict that future eruptions will be more destructive, as the configuration of the lava domes requires more pressure to erupt.[10] However, Mount St. Helens is a popular hiking spot and it is climbed year-round. In 1982, the Mount St. Helens National Volcanic Monument was established by President Ronald Reagan and the U.S. Congress.

  1. ^ a b c "Mount Saint Helens". Geographic Names Information System. United States Geological Survey, United States Department of the Interior.
  2. ^ "Distance between Portland and Mount Saint Helens". distancefromto.net. Retrieved 27 March 2021.
  3. ^ "Distance between Seattle and Mount Saint Helens". distancefromto.net. Retrieved 27 March 2021.
  4. ^ "Mount St. Helens National Volcanic Monument". USDA Forest Service. Archived from the original on 23 November 2006.
  5. ^ Tilling, Robert I; Topinka, Lyn; Swanson, Donald A (1990). "Impact and Aftermath". Eruptions of Mount St. Helens: Past, Present, and Future. 1.01. USGS.
  6. ^ Cite error: The named reference USGSFrom1980 was invoked but never defined (see the help page).
  7. ^ "May 18, 1980 eruption of Mount St. Helens". USDA Forest Service. Archived from the original on 29 May 2009.
  8. ^ "1980 Cataclysmic Eruption". Mount St. Helens. USGS. Retrieved 27 March 2021.
  9. ^ "Mount St. Helens: A Living Laboratory for Ecological Research | Pacific Northwest Research Station | PNW - US Forest Service". www.fs.usda.gov. Retrieved 1 June 2021.
  10. ^ Haas, Maya (18 May 2020). "Mount St. Helens isn't where it should be. Scientists may finally know why". National Geographic. Archived from the original on 3 June 2021. Retrieved 20 June 2021.

Developed by StudentB