Is Mount St. Helens Ready to Erupt Again?

[matthyaouw]

Last time I checked, I thought it'd gone off & taken out /covered the camera... then i realized it was still dark in the U.S.A.
Man I'm having a stupid day today...

 

[Kerrie]

what i heard today is that the USGS said there is a 50/50 chance now that St Helens could erupt like it did in 80 because it is showing similar "behaviors" now as it did in 1980.

 

[Ivan Seeking]

So is now a good time to mention that something like 100,000 years ago, a volcano located in what's now known as the Blue Mountains in NE Oregon had such an energetic release of material that approximately 2/3 of the state was covered with an estimated 6 foot layer of lava and ash [on the average and I would think from a pyroclastic flow], in two hours! It's hard to even imagine such an event happening today, but I'm sure glad I live way, way south of Portland.

I picked this up in a filler class taken in college - A history of Oregon. We have a very rich geologic history around here. For example, look up the Great Missoula Floods.

http://192.211.16.13/curricular/energies/Aprojfolder/missoula/Five.htm

We have some large stones deposited from these around our place. Apparently we live where a large eddy would form and deposit flood debris.

Not to derail the thread but I find this stuff all very fascinating.

 

[thecolor11]

I'm glad the winds aren't blowing south as well. Sorry for all you suckers in SE Washington and NE Oregon.

 

[Ivan Seeking]

Vancouver! Vancouver! This is it!

I just heard the last words transmitted by David Johnston; a geologist who was on the north slope monitoring St. Helens when the 1980 eruption began...spooky...

Also, this is a nice site.
http://www.olywa.net/radu/valerie/StHelens.html?

The largest landslide in recorded history swept down the mountain at speeds of 70 to 150 miles per hour and buried the North Fork of the Toutle River under an average of 150 feet of debris. Some areas are covered by as much as 600 feet. I all, approximately 23 square miles of material was removed from the mountain.

Lateral Blast The lateral blast swept out of the north side of MSH at 300 miles per hour creating a 230 square mile fan shaped area of devastation reaching a distance of 17 miles from the crater. With temperatures as high as 660 degrees F and the power of 24 megatons of thermal energy, it snapped 100 year old trees like toothpicks and stripped them of their bark...

...As the north face of the mountain collapsed, expanding gases and steam from the molten rock hurtled rock and ash out across the land at speeds up to 670 miles per hour uprooting trees as far as 6 miles from the mountain. It was impossible to outrun and the searing heat too intense. Reid Blackburn, a photographer with The Columbian newspaper was one of the first victims of the eruption. Blackburn had tried to take shelter in his car but the lateral blast blew in the windows, letting in the hot, choking ash. He was found in his car 7 miles north of the mountain...

much more plus photos and links

 

[Kerrie]

Yes, the Johnston Observatory now stands where he yelled those famous words...

 

[matthyaouw]

Check the volcano cam- Methinks I see lava...

edit- although it now seems to have solidified. there are two lighter grey patches of rock- one immediately to the left of the smoking vent, and one further left & lower than the first. They were a distinct orange colour when first I spotted them.

 

[Ivan Seeking]

we sure do. Magma has hit the surface.

 

[arildno]

The mountain is grumbling again:
http://www.cnn.com/2004/US/11/06/mount.saint.helens/index.html

 

[Ivan Seeking]

SAN FRANCISCO -- An unusually smooth and swiftly growing lava dome within the crater of Washington state's Mount St. Helens volcano is an extraordinary and perplexing event with an unknown outcome, geologists said Tuesday. [continued]

http://www.livescience.com/forcesofnature/041215_msh_update.html

 

[wolram]

If this volcano erupts with any magnitude, how many people
are in the danger area, have evacuation plans been made,
how fast can every one evacuate the area.
How does it effect the day to day lives of people knowing
that one day an eruption from this volcano will happen.

 

[Integral]

Wolram,
The mountain is fairly isolated, the nearest major city, Portland (~600.000 population), is about 80km away. It would take a truly massive explosion to need an evacuation of Portland, though if the winds were right it could get a major coating of ash. The mountain is in the middle of a large wilderness area, it is about 20km to the closest town, and that is very small. I doubt that there are 50,000 living within 50km. Though for most of those towns there is just a single road connecting them to the major freeway. So it is conceivable that some could be isolated for extended periods of time if there is significant flow of material from the mountain.

I grew up in what would have been the shadow of Mt Mazama, 5000 yrs ago this was a 14,000ft peak which was one of the highest in the Cascade Mt Range. But, much like St Helens it blew itself up. What remains is called Crater Lake National Park. The road that leads up to the Park passes through several deep cuts where the banks are volcanic ash 20m to 20m deep. This is as much as 50km from the mountain!

 

[wolram]

Thank you Integral ,
I can see now why people are looking at a future event as a
curiosity rather than panicking.

 

[Ivan Seeking]

The first eruption pretty much took care of any immediate concerns.

 

[Ivan Seeking]

On a related note, in all likelihood Mt. Rainier will wipe out Seattle. She has been showing signs of activity for some years now but apparently nothing significant as yet.