The Silent, Yet Looming, Threat

Geologists who focus on the volcanoes of the west coast and

Pacific Rim are expressing heightened concern about 

Hawaii's latest activity. 

 

They're concerned because it could have implications for the 

volcanoes which run - like a string of pearls - along the 

western coastal states from Northern California to the 

Canadian border.

 

But the article linked above, while informative in certain 

respects, is also misleading to those who read it, but have

no familiarity to the region.

How? First, the article references "Spokane, WA," which is hundreds of miles to the east side, and far away from the Cascade Mountains. The picture of Mt. Rainier accompanying the article shows it framed by the bridge in Tacoma over the Thea Foss Waterway.

It should have referenced, "Tacoma, WA" or "Seattle, WA,” 

as these two cities, as mentioned later in the article, are 

much more threatened by a possible eruption from the two 

closest volcanoes.

I've lived in the Northwest for nearly 35 years now, and I 

know the geography fairly well.

 

In my early years here I took a course at the University of 

Washington in Geology; more specifically, volcanoes and the 

earth's crustal movement known as tectonic plate activity 

during the same period as the Mt. St. Helens eruption in 

1980.

 

Part of that research included David Johnston's masters 

thesis on a volcano in Alaska. Johnston was killed while 

within the vicinity of Mt. St. Helens' blast zone.

Only a few years later, I climbed to the top of both Mt. Baker 

and Mt. Rainier and learned a considerable bit more about 

the volcanic threat of the Pacific Coast volcanoes. While 

standing on its summit of Mt. Rainier, one could see Mt. 

Baker to the north and the volcanoes of Mt. Adams, Mt.St. 

Helens, and Mt. Hood to the south.

Having lived, driven and hiked/backpacked around the 

greater Puget Sound Region, I've often wondered just how 

effective the various communities which lie within eye sight 

of the volcanoes would be, should one of them erupt. 

Anyone who knows the natural geography of the area 

realizes that the valleys which snake out in all directions 

from the base of a volcano were created in the distant past 

by former eruptions and the resulting massive lahars, which 

travel downhill and out to the lower elevations, carving them 

out even more. 

 

Yet even with this knowledge, there have been many 

communities developed over the years which are on the 

valley floors of many of the paths a lahar would take. 
Any lahar - a pyroclastic flow sweeping down through the 

valleys which surround every volcano - contains a 

combination of melted glacier ice, ash and rock that turns 

into a massive moving lake of viscous, hot "cement" with the 

front of that flow essentially being a huge wall that sweeps 

clean the valley it flows through.

 

Nothing can stop it and everything in its path is destroyed 

and often buried several feet deep in scalding hot mud and 

boulders (some larger than houses). One needs only to 

search for footage of this on YouTube to see lahars from Mt. 

St. Helens flowing down the Toutle and Cowlitz Rivers.

The article claims - as do many of the communities which 

reside in the valley carved out by previous massive 

eruptions – that there are plans in place to evacuate their 

citizenry to higher ground and that they regularly practice the 

drill to evacuate. This is ludicrous. The actual time Orting, for 

instance, would actually have to evacuate, compared to the 

time they take for their evacuation drill, would be 

considerably longer.

 

With the increased housing development which has 

occurred over recent decades, and my familiarity with the 

limited roads and highways which connect to higher ground 

out of the valleys to get away from an oncoming lahar flow, 

it's obvious to me that the resulting devastation will be much 

worse than they believe will occur, and that many thousands 

– perhaps tens of thousands - will perish.

 

This fact is precisely why, when buying my house, I 

deliberately chose a property on a hill - roughly 500 to 800 

feet high- above the nearby area where a lahar will 

ultimately empty its contents; hot water, ash, boulders, and 

anything in its path, as it flows down the valley on its way to 

Puget Sound … which is exactly what happened in the past, 

well before there was any modern development.

 

Yet, hundreds of thousands of people go about their daily 

lives, working and living in their homes in the very path 

which has the potential to sweep clean any and all in the 

lahar's way.

 

God forbid that it ever happens... but if it does, we'll have 

hell to pay. And we'll have only ourselves to blame.