Total Pageviews

Wednesday, May 18, 2016

May 18, 1980: Where were you when Mt St Helens Exploded?

     May 18, 1980, was a remarkable day for me and almost every geologist I know.  We identified with David A Johnston, the geologist killed in the volcanic event. The explosion and subsequent landslide of the north face of Mt. St. Helens in Washington state, USA, was top news throughout that day and ensuing weeks and months.



      The USGS put together still photos to create this video of one of the largest (if not the largest) landslides ever on earth.




     An earthquake at 8:32 a.m. local time on Sunday, May 18, 1980, caused the entire weakened north face to slide away. This suddenly exposed the partly molten gas- and steam-rich rock in the volcano to lower pressures. The rock responded by exploding a hot mix of lava and pulverized older rock toward Spirit Lake so fast that it overtook the avalanching north face.



         An eruption column rose 80,000 feet into the atmosphere and deposited ash in 11 U.S. states. A USGS friend brought back vials of varying sized ash collected after the explosion.




        At the same time, snow, ice and several entire glaciers on the volcano melted, forming a series of large lahars (volcanic mudslides) that reached as far as the Columbia River, nearly 50 miles to the southwest. 


       Individual trees in the direct path of the blast were charred. . .


and trees were caught up in the mudflows.


      Downed logs still remain as in this 2012 photograph:
     


What are your memories of that day? Were you nearby, perchance?

Steph


24 comments:

  1. I was in Wisconsin that day, taking a day-of-rest off from my job at our local YMCA. Being a non-geologist, the Mt. St. Helen's tragedy/eruption did not affect me as much as it probably should have. Indeed, I had forgotten completely about the loss of life.

    I do recall, however, thinking that the name of the volcano and the name of my mother (both Helen) did not jibe. The Helen I knew was gentle, kind and patient -- never one to erupt and spew hateful heat. Both were saints, however, I guess.

    LegoWhoseMotherWasNotALavaLampSpewingRageButRatherALovingLampSheddingWisdomAndJoy,WarmthAndLight

    ReplyDelete
    Replies
    1. Yes, I imagine your mom never blew her top, Lego.

      And, yes, 57 people lost their lives in the explosion. David Johnston hit closest to home for our new geology team that day. We had been working together just 3 1/2 months. . .

      Delete
  2. I don't remember the day at all. Not like the JFK assassination, or 9/11, or the Challenger explosion, or TMI ...
    What does that say about me as a person?

    ReplyDelete
    Replies
    1. No judgments, Paul. I was just curious if it was as memorable a day to non-geologists. . .

      Delete
    2. I'm with Paul. JFK, RFK, MLK, Apollo 11, Challenger, Columbia -- I remember where I was when I heard of those. Not St. Helens, or Pinatubo, or Elvis.

      Delete
    3. So maybe it is more of a geologist thing. Pinatubo and Elvis did not stick with me either. . .

      Delete
  3. I remember it. We were living in Japan at the time, but had friends who lived somewhat close to the St. Helen's area. We were worried about them, and they said the ash deposits were awful. Then, we traveled home to the U.S. in September, and flew over St. Helens, and the pilot pointed out the crater...it was still smoking!

    ReplyDelete
    Replies
    1. Yes, it was still steaming for decades! Glad your friends were safe. And welcome, ghostmmnc.

      Delete
  4. Replies
    1. What's your best theory?

      Zoë is now in the village of K'unzila, on the southwest shore of Lake Tana. And she's seen some of those crocs in their native environment!

      Delete
    2. There are lots of reptile fans in South Florida. Probably, one of them let some Nile crocodiles go. Same thing that happened to the Burmese pythons years ago. If 3 were caught, I'm sure there are plenty more out there.

      Delete
    3. Never understood the appeal. ..

      Delete
  5. OK, I have no idea what I would do with this knowledge, and I couldn't possibly justify acquiring more crap to fill up my basement, but this just looks like so much fun: How to Build Stuff.

    ReplyDelete
    Replies
    1. But why isn't there a section on 3-D printing?

      Delete
  6. FYI:

    The "Dessert Puzzle" on this week's edition of Joseph Young's Puzzleria! is very solvable by science lovers. People start posting answers at 2 p.m. Mountain Time tomorrow (Wednesday).

    LegoWhoLikesStrunkAndWhite'sStyle

    ReplyDelete
    Replies
    1. Sorry, That is 1 p.m. Mountain Time, not 2 p.m.

      LegoNoWonderI'mAlwaysADollarShortAndAnHourLate

      Delete
    2. Thanks, Lego. I hope folks here will wander over to Puzzleria!

      Delete
  7. New post on "The Cat is Big and Smart: A Second Box for Schrödinger's Cat?" is now up.

    ReplyDelete
  8. Tacoma, Washington. I won't ever forget walking to a nearby hill and seeing a black column of ash in the distance

    ReplyDelete
    Replies
    1. Wow, brewbooks, I imagine it was quite amazing. Did you collect any ash?

      Delete