Mount ST Helens Dome Splits

[edit on 2-12-2004 by mrsdudara]

Is there any kind of information about the blast radi of a large eruption from Rainier? This is a colossal volcanoe and I would not want to be within a thousand Km when it blows its trumpet. Also anyone traveling in airplanes around the area when this happens would most likely have to make emergency crash landings due to all the ash which would be sucked into the engines and disrupt the flow of power through the planes, not to mention the fallout and its clouding and sulpherous nature, planes would be falling out of the sky. Im glad I live in the Uk
Also if these two volcanoes blow (St Helens and Rainier) I would say that more eruptions from other active vlocanos would likey follow as these event are all connected and there is great disturbance underneath the earths crust at the moment due to the amount of interference with the earths geomagnetic fields which influence the tidal flow of molten rock in the earths flow.

Originally posted by radiant_obsidian
Is there any kind of information about the blast radi of a large eruption from Rainier?

Here is some bedtime reading for you...
Mount Rainier Could Blow -- Or Worse ...

Originally posted by Simcity4Rushour
I take it by eberyones post that rainer can have a larg ereption.
now Im dont know much about rainer but have read some on other super volcanios (talking cones here not yellow stone
and even the biggest would hardly destroy even the state its in let along the intire country .

The big concern with Rainer is not so much that it'll blow up and take out the state, but that if it goes the molten lava will be channeled right into Seattle due to the geography there.

Wonderful. I live right in the shadow of Rainier.

Surprisingly, hardly anything about Rainier in the local news, though some people in Enumclaw, Buckley, Yelm and out there, that I know, are thinking about leaving the area for a while until Rainier settles down.

It hasnt acted up THIS much for a while, but sometimes its prone to rumbling and making a fuss without blowing. So, more than likely, it will probably behave, being alot less tempermental and loud like St helens.

By the way, the Hopi Indians are from no where near this state. Local Indian tribes and nations include the Muckleshoot, Puyallup, Tahoma, Yakima, Makah, Tulalip, Salish, amongst others. Could have been one of their prophecies, Im trying to remeber which.

Originally posted by Hellmutt

Originally posted by radiant_obsidian
Is there any kind of information about the blast radi of a large eruption from Rainier?

Here is some bedtime reading for you...
Mount Rainier Could Blow -- Or Worse ...

The "hazard zones" map for lava flows and lahars is found at
vulcan.wr.usgs.gov...

Note, though, on the Hazard Zones, the areas that are marked as having volcanic sediment.

This is from one extremely powerful and deadly erruption in Rainier's past, where the lava/pyroclastic flow reached all the way to federal Way and up towards Renton (not shown on the map).

There is the danger of all the falling ash and cinders.

When St helens blew in 1980, the blast wave incinerated drivers 25 miles away from the crater. St helens is smaller than Rainier. And Seattle is only 45 miles from Rainier as the crow flies.

The lahars are the most clear and immediate danger, being a bit more common. If Rainier even starts heating up, that big glacier will start melting, might even flood the columbia river and do some damage to portland, some 150 miles south.

Originally posted by radiant_obsidian
Is there any kind of information about the blast radi of a large eruption from Rainier?

What you mean with this "blast"? Literally blast of explosion or pyroclastic flows?
If you mean directed lateral blast like St. Helens and Bezymianny they sweeped down trees to distance of 30 km. (I think one page of USGS said that energy released by directed blast of MSH was equal to 7 MT, with 14 MTs more from release of heat)
If you mean radius where there's major ashfalls then area is much bigger.


Here's very interesting page which has something about figuring what Mount Mazama might have looked before its eruption which was one the biggest bangs in last ten millennium... it propably was clearly smaller than Rainier.

Reconstructing Mount Mazama is inherently speculative. A number of geologists have speculated that the volcano had two summits since the drainages on the southeast side of the lake do not radiate from the same center as those on the west. The reconstruction above starts by reconstructing contours around the lake rim and then building upward using a typical slope for a stratovolcano. The reconstruction above shows a single, possibly dissected or landslide-collapsed peak, but it's not hard to picture a main cone to the west and a lower parasitic cone to the east. The reconstruction below shows a two-summit interpretation. The height is about 3400 meters or just over 11,150 feet, pretty close to the value estimated above. A slightly different slope could easily raise or lower that by 300 meters (1000 feet). Mazama was definitely no Shasta or Rainier but it could easily have been equal to Mount Lassen, Mount Hood or Mount Adams.

www.uwsp.edu...

In certain situation even pyroclastic flows can travel great distances... Like over water: one of them produced by Krakatau was felt in ship 80 km away from volcano as hurricane class wind, tephra and smell of sulfur. (estimated total energy release of eruption 150MT)
And eruption of Taupo few thousands years ago... well, it sweeped whole north island of NZ, maybe except peak of its highest mountain.

I'm no vulcanologist, but the readings on the freemont station at Rainier look to me like localized magma movement. Notice the other seismos aren't picking it up and it's definitely not sympathetic readings from StHelens.

Here is the Mt Rainier cam.
Some guy set up his webcam to stream it.You have to refresh it manually though.
Mt Rainier cam

Wow, interesting stuff. I was wondering just the other day what happened to St. Helens, as I haven't heard much after the smaller eruptions earlier

Guess I'd better get the camera ready.

This is strange...
As soon as Mt. Rainier stopped Mt. Baker started.
Something moving underground?

Mt. Rainier - 6 December

Mt. Baker - 6 December

sorry didnt reply for a while Helmutt, Ive just been on online to investgate, and Baker is still kicking up stink, the seismos are still registering a lot of movement and activity. St Helens, and Rainier still active and seismos still registering alot of movement. Also there is sustained and "unusual" activity also effecting Mt Hood and Adams also the same is being registered at Crater Lake......never before can I remember all od the seismos showing so much prolonged and sustained activity through the cascades range, my uneducated guess is that there must be a large and sustained movement of magma at the lower depths. Im going to do some more digging