Ad blocker interference detected!
Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers
Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.
Contents (view all pages)
What's new on Volcanoes Wiki
- News text
- News text
To write a new article, just enter the article title in the box below.
- Not sure where to start?
- Find out more about the wiki on the About page.
- If you are new to wikis, check out the tutorial.
- Check out Help:Starting this wiki if you're setting up the wiki.
- Adding content
- Every wiki has two list of articles that need help called "Stubs" and "Wanted Articles". Don't be shy, get in there.
- Uploading images is another really easy way to help out - see the Special:Upload page!
- You can find a list of useful templates on Category:Templates, some of which are documented on the templates project page.
- Talk and more...
- Check out the community portal to see what the community is working on, to give feedback or just to say hi.
Mount St. Helens is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United States. It is 96 miles (154 km) south of Seattle and 53 miles (85 km) northeast of Portland, Oregon. Mount St. Helens takes its English name from the British diplomat Lord St Helens, a friend of explorer George Vancouver who made a survey of the area in the late 18th century. The volcano is located in the Cascade Range and is part of the Cascade Volcanic Arc, a segment of the Pacific Ring of Fire that includes over 160 active volcanoes. This volcano is well known for its ash explosions and pyroclastic flows.
Mount St. Helens is most famous for its catastrophic eruption on May 18, 1980, which was the deadliest and most economically destructive volcanic event in the history of the United States. Fifty-seven people were killed; 250 homes, 47 bridges, 15 miles (24 km) of railways, and 185 miles (300 km) of highway were destroyed. The eruption caused a massive debris avalanche, reducing the elevation of the mountain's summit from Template:Convert/ft to Template:Convert/ft and replacing it with a mile-wide (1.5 km-wide) horseshoe-shaped crater. The debris avalanche was up to 0.7 cubic miles (2.9 km³) in volume. The Mount St. Helens National Volcanic Monument was created to preserve the volcano and allow for its aftermath to be scientifically studied.
As with most other volcanoes in the Cascade Range, Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash, pumice, and other deposits. The mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted. The largest of the dacite domes formed the previous summit, and off its northern flank sat the smaller Goat Rocks dome. Both were destroyed in the 1980 eruption. read more...
<ref>tags exist, but no
<references/>tag was found