Well, Mt. Saint Helens is active. What’s up with Mt. Rainier and Mt. Baker? I’ve heard that if there is a large eruption of Mt. Rainier, that Seattle will be devastated. True? Would it be from the lahar? Pyroclastic flow? A massive blanketing of “ash”? What about Mt. Baker? I have a nice view of it, but there are hills/mountains between Birch Bay and it. Any news from Mammoth Mountain?
I was born under the shadow of Mt. Rainier, well actually in Tacoma. Seattle really doesn’t have to much to worry about but the areas most at risk are those towns in the Puyallup River and Yakima River valleys. Puyallup, Sumner, and Orting could end up under a couple hundred feed to melted snow and mud. Volcano warning horns are scattered throughout the valley and volcano evactuation route signs are everywhere. The biggest problem faced by those farther away from the mountain would be a potential tidal wave/tsunami for those that live near Puget Sound when the mudflow hits Commencement Bay in Tacoma. Water levels could temporarily raise a couple hundred feet within the sound basin. The Bellingham/Vancouver B.C. coast could see the sound raise up to 50 feet. More info about Mt. Rainier can be found here. You can also go to the USGS main site through the link and find info about the other volcanic mountains in the Cascade range.
Well, that could be inconvenient. IIRC my house is at the top of a 38-foot hill.
I’ve asked similar questions, especially with regard to Rainier. I don’t have quick-and-dirty cites to provide (perhaps Duckster or other Washington State/PNW Dopers will know precisely what to link to, and/or be able to supplement this).
Rainier is not an immediate threat for eruption, but there has been limited activity associated with it, so it’s no longer considered extinct but dormant. The recent thread on Mt. St. Helens in MPSIMS said that an eruption is anticipated within 30 years.
Seattle and Olympia would be directly impacted only to the extent of what’s thrown into the atmosphere and carried west/north to them. However, Tacoma and the Kent Valley lie directly downhill from Rainier, with the Pullayup River Valley linking them. It is they which would be most heavily affected by lahars, not to mention lava and pyroclastic emissions in a severe enough eruption. (To what extent the White River Valley would be impacted, I’m not clear – but it’s been mentioned as even more endangered than the Pullayup, which doesn’t make sense to me with the mapping I have on the other side of the continent – perhaps somebody local who knows the topography and vulcanology better might be better able to explain this.)
Mount Baker is of course directly above Bellingham, with a similar river route. This mountain has not been discussed as a potential problem to any extent AFAIK, though I admit that I’m not on top of Cascade Range vulcanological literature.
South Sister, the other peak with “serious” potential pre-eruption activity, is located above Eugene and Bend, though both are a reasonable distance off. I believe it’s the Blue and Tymalo River Valleys that would connect them respectively.
While we’re on this subject, I’m wondering what activity has been noted in the South Cascades – the Northern California part of the range. I know there are some significant volcanoes in that area.
I’ve been here less than a year. Would that be the Nooksack? (“Nooksack! It’s a Nooksack! Nooksack, baby!”)
I was watching the NorthWest News Channel yesterday, and the (retired) vulcanologist they had on answering viewers questions stated that he would worry more about Baker than Rainier.
I was up at Mount St. Helens and witnessed today’s event. I’ve been called back to duty and will have some info later tonight.
Local news radio station (KIRO - 710 AM) stated about an hour ago that there appears to be a new bulge in the crater. Don’t know if this is true, or media hype.
Here is an overview of Mt Rainier’s history and potential. Its pretty well says we can bend over and kiss our Seattle/Tacoma (sic) goodbye when she blows.