My son is learning about the famous Mt. Saint Helen’s eruption of May 1980. Having friends across the country in Portland, OR, this event was of special interest to me when I was his age. At the time, I seem to recall the blast from the eruption shattered windows in Portland. However, I can’t find this small tidbit when Googling around. Maybe some Portland SDopers can confirm if this is factual?
Encyclopedia of Volcanoes, by Haraldur Sigurdsson, Bruce Houghton, Hazel Rymer, John Stix, & Steve McNutt refers to Mt St Helens “rattling” windows. This is what my wife also remembers. “Blast waves with overpressures of 7 KPa may break windows…” (p. 1040)," the text goes on to say, which doesn’t mean anything to me, but I’m sure there’s someone here to explain it. St Helens was not a Krakatoa-like, highly explosive volcano, IIRC. Mud and ash, not lava, are what I remember.
Missed the edit window to say: I know there was lava, but the landslide was the big deal.
Nitpick: It’s Mount Saint Helens, not St. Helen’s. Helen does not possess anything in this context, and nothing is omitted, so an apostrophe is inappropriate, but is part of the feature’s name. Mount St. Helens is quite acceptable.
Helen’s shatter’s window’s is not.
Wikipedia, initial lateral blast: “Superheated flow material flashed water in Spirit Lake and North Fork Toutle River to steam, creating a larger, secondary explosion that was heard as far away as British Columbia,[22] Montana, Idaho and Northern California. **Yet many areas closer to the eruption (Portland, Oregon, for example) did not hear the blast. **This so-called “quiet zone” extended radially a few tens of miles from the volcano and was created by the complex response of the eruption’s sound waves to differences in temperature and air motion of the atmospheric layers and, to a lesser extent, local topography.[5]” [emphasis added].
St. Helens erupted the day after my 14th birthday, when I lived in Vancouver, WA. We had an amazing view of it from our driveway, but we heard no blast and there were no shattered windows in the vicinity.
My grandmother’s house was much closer - right outside the edge of the “red zone”. No broken windows there, either.
I recall that, in the following years, the Oregon Museum of Science and Industry (OMSI) in Portland had a map of the region with pins in it to show where people heard the blast. There were random clusters of pins all around the map, and huge areas with no pins at all. It was weird.
Amusing anecdote: My dad, a Washington State Patrolman, worked at the weigh station on I-5, just north of Vancouver. His parking lot there was designated as an “official view point” for the volcano because it had a great, unobstructed view. One day, a car came flying in from the highway. The driver parked his car right on the scales, then got out and ran inside the station and demanded, "Which way is St. Helens?
Immediately grasping that this jackass had not specified Mount St. Helens, my dad politely pointed west, toward the billowing clouds of steam rising from the paper mills of St. Helens, Oregon, directly across the Columbia River. The guy ran back out to his car, parked it elsewhere, and proceeded to spend the next half hour taking photos in the wrong direction.
Portland is about 40 or so miles south, but the crater opens to the north. There is a massive crater wall facing west, south and east that directed the force of the blast away from Portland, up toward the uninhabited areas of Lewis and Skamania counties. Windows to be shattered up that way are very few and far between, with lots of non-flat ground to deflect the blast.
I was about 60 miles north at the time, driving along a highway when it happened. I heard and saw nothing, until I turned the TV on at home and saw the news.
Spirit Lake Lodge probably had some windows broken a few milliseconds before the lateral blast vaporized it. Otherwise it was largely wilderness areas north of the mountain which is the direction of the blast.
This news article will give you some idea about the heat and blast wave.
It seems that it didn’t shatter camera lenses, but there’s no mention of windows. Whole forests were blown down. I guess it would come down to one’s exact circumstances.
I grew up in Calgary and I remember a couple of days after the eruption running out to the driveway with a broom to try and sweep up some ash.
How weird. I was stationed in Whidbey Island, WA and we heard it quite clearly.
Redmond, WA and it definitely heard it. Felt and sounded like someone gave the house a nice thump.
I was living in Eugene, Oregon at the time. We got a lot of ash a couple of days after the blast. My parents lived in Portland and got a lot more ash. No shattered windows for them. I have visited the site as it is now set up for visitors. I don’t remember anything about shattered windows.
nm.
Likewise, and at the time I lived about 70 miles NNW as the guttersnipe flies. Woke me up.
I yelled at the kids, as I thought they were kicking the wall in the bedroom. 
It woke me up in Victoria B.C. A series of very low booms. We were all wondering what it was and turned on the radio to hear the announcer wondering the same thing.
Curiously, recent research shows that the magma chamber is not under Mt. St. Helens but actually closer to Mt. Adams.
Good find. Thanks.
Here’s the real study, rather than a newspaper article (with unrelated autoplay videos) about it: Seismic evidence for a cold serpentinized mantle wedge beneath Mount St Helens | Nature Communications
The verbiage is a bit much for laymen such as myself but there are some interesting diagrams as you scroll down.
Antectote: I lived in N Seattle when it erupted. I remember jolting awake, and realizing something “had happened”. Meanwhile, in the garage, a lamp fell off a shelf and shattered. My room mate was already up and said he felt a whump hit the house.