With Hawaii's ongoing eruption and May 18 marking Mount St. Helens' big belch, I'm reminded how ashfall crippled our region in 1980. Yet we learn from our past.
You've likely read news stories suggesting the likely outcomes of future Northwest eruptions. Unlike Mount Kilauea, which is oozing its usual pasty lava, Cascade stratovolcanoes explode violently with far-flung consequences.
The big threat is hot lava that swiftly melts glaciers, triggering destructive lahars (water, rock, and mudflows) that gush down slopes and bury distant valleys.
Not to unsettle you, but present-day Yelm, Orting, and Puyallup are built atop lahars triggered by Mt. Rainier eruptions. One of those eruptions blew about 2,000 feet off of Rainier's summit 5,000 years ago.
Catastrophe aside, the next big local eruption is sure to cripple transportation.
We take travel for granted. Yet we quickly found that
when St. Helens blew in 1980, many folks downwind found themselves stranded, or stuck at home. Ash particulates are fine, but gritty. And ash can destroy engines in cars, trucks, and jetliners.
Officials closed Northwest roads and highway because of poor visibility. Once the ash settled, Interstate 90 in Eastern Washington remained closed for a week. Motorists who tried to drive kicked up thick ash clouds that clogged filters and choked engines. Worse, the fine grit worked its way into oil and transmission fluids, gradually grinding pistons and cylinder walls and robbing compression. Soon, dead vehicles littered the landscape.
Crews removed 2.4 million cubic yards of ash from Washington roads and airports, taking weeks. I remember driving to north Idaho that summer and seeing massive ash piles near Moses Lake and Ritzville, where heavy machinery had plowed and scooped it into dump trucks that emptied their loads alongside I-90.
Even today, if you know where to look, white ash shrouds medians and shoulders along I-90 in the Columbia Basin.
Volcanic threat remains part of Northwest living. The U.S. Geological Survey says nine volcanoes could erupt here: Baker, Glacier Peak, Rainier, Adams, St. Helens, Hood, Three Sisters, Newberry, and Crater Lake.
The good news: Mount St. Helens taught insurers and drivers some valuable lessons we can apply following the next Cascades eruption, if we're caught downwind from ash clouds.
Minimize your driving. Don't exceed 35 mph. Change oil, filters, and fluids often, like every 100 miles in heavy ash.
Ash will scratch glass and paint, so minimize using your wipers and rolling windows up and down.
Blow ash from electrical components under the hood, and from your radiator. It can short your alternator, starter, wiper motor, and other components.
If you blow out your air filters rather than replace them,
blow them from the inside (clean side)
Locate and cover passenger-compartment air vents.
Set inside air circulation to internal,
Get your brakes cleaned often.
Rinse your car daily, if necessary, with low-pressure water. Don't wipe, rub or scrub.
The USGS offers a comprehensive resource for
how vehicles can cope with volcanic ash. Also, check out the
vivid 1980 post-St. Helens images from this