Mount St. Helens: The Deadliest Volcano in US History
Approximately 50 miles northeast of Portland, Oregon you will come across the majestic Cascade Mountains and the wondrous, yet volatile, Mount St. Helens. Having been relatively dormant for over 100 years, it was Mount St. Helens’ devastating eruption on May 18th, 1980 that threw her into the limelight. It was early morning on Sunday, May 18th. An increasing number of earthquakes, over 170 measuring 2.6 or larger in a two day period, had been hitting the area during the previous months. Finally Mount St. Helens couldn’t hold out any longer.
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Her North face was already fractured and showing signs of eminent danger. In what appeared to be one massive explosion, or possibly even two concurrent blasts, Mount St. Helens blew her top.
Within seconds, a rock avalanche roared down the mountain at speeds between 70-150 mph, destroying everything in its path. Ash and pumice shot up at over 300 mph, reaching heights over 10 miles high in under 10 minutes. The eruption continued for more than nine hours.
The initial blast was so powerful that it is estimated to have destroyed everything in about 200 square miles. Thankfully Mount St. Helens had been closed, at the advice of the USGS. It was that one action alone that is credited at saving hundreds of lives. Unfortunately despite that action, 57 people and thousands of animals lost their lives that day.
Today Mount St. Helens stands at just 8363 feet tall, over 1300 feet shorter than she was prior to her May 18th eruption. And while she is quiet once again, scientists still consider Mount St. Helens to be an active volcano. They believe we haven’t heard the last from her.
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Comments
Mt. Saint Helens is 50 miles NE of Portland, yet apparently “The initial blast was so powerful that it is estimated to have destroyed everything in a 200-mile radius.” I don’t think so. Last time I checked, Portland was not wiped off the face of the earth in 1980. As short as this article is, it’s hard to believe there is such a glaring inconsistency.
Portland is 50mi away, but “the initial blast destroyed everything in a 200 mile radius”?
I’m not sure how this statement can be correct?
“The initial blast was so powerful that it is estimated to have destroyed everything in a 200-mile radius.”
I was well within a 200 mile radius in 1980 and although a bit of ash fell upon Hood River, it was definitely not destroyed. I’m pretty sure that Portland is still intact as well. According to the article Mt. St. Helens is “approximately 50 miles northeast of Portland, Oregon” which would fall within the 200 mile radius.
???
Nice article, but you need to check your math. Nobody — absolutely nobody — has estiamted that the blast destroyed everything in a 200-mile radius. that would include most of Washington State. See http://www.seattlepi.com/mountsthelens/laterblast.shtml for a more realistic estimate.
I was there, I remember my dad stumbling down our homes hall to make sure us kids were ok. He could not stand as the waves literally tossed the hallway from one of its sides to the other. To this day I have no idea how our home stayed standing. Still have the ash.
Thank you Gary for your comment. You are correct, it was a typo and the word “square” was mistakenly left out of the article. Thanks for letting us know
Please remove the last image as it is made with Terragen thus computer generated.
Thank you Chris for your comment. You are correct, it was a typo and the word “square” was mistakenly left out of the article. Thanks for letting us know
Thank you Laurence for your comment. You are correct. We made a typo and the word “square” was mistakenly left out of the article. Thanks for letting us know
Thank you Lester for your comment. You are right of course. There was a typo and the word “square” was left out of the article. Thanks for letting us know so that we could fix it
Glad you liked the article.
Ray,
My wife and I and our 2 kids were going to head down to see the volcano the morning of the eruption. I was awakened just after the eruption by my kids telling me it was too late.
“200 square mile radius” is still very, very strange measuring. Radius is measured in distance, not area. An 8 mile radius gives 200 square miles. Or you could say, “Everything was destroyed in the nearby 200 square mile area”. But I like the 8 mile radius–it is easier to understand.
um, what exactly is “a 200 square-mile radius”? Is it like when you are 5 square-feet tall?
Thanks again for the fine article, and the quick fix to the “200-mile radius.”
Now, not to be a natering nitpicker, but radii are not measured in ‘square’ anything. A radius in a linear quantity, and ‘square miles’ are a unit of area. You wouldn’t say, for example, “a 10 acre radius.”
You mean something like, “the blast destroyed everything in 200 square miles,” or “the blast destroyed everything in an 8 mile radius.”
200 is a more dramatic number, of course, but for the poor Easterners who are not graced with good math skills nor privileged to live in the Great Pacific Northwest, you should strive for accuracy in your units, lest they be misled into thinking that all of Seattle has been rebuilt since 1980.
But keep up the otherwise fine work.
Thank you for your comment and observation Cpt Obvious. We like the picture and will be keeping it in the story. It’s a representation of Mount St. Helens, even though it’s computer generated.
That last picture is a computer rendering, a very good one, but it is not a picture.
Thanks for you comment Brad. You are right, it’s a computer rendering of Mount St. Helens. We thought about not including it when we found it but decided to add it to the story anyhow. We think that he did a really good job and we liked it. We hope you enjoyed the story
The article is talking about square miles not radius. They are just refering to the amount of land actually damaged. Most of which was north and east though the Toutle and Cougar river valleys were also heavily damaged.