• Alison Kartevold

Mt St Helens, My First "Quarantine"

May 18th marks the 40th anniversary of the eruption of Mount St Helens that turned day to night and encircled the globe's atmosphere with ash. It is also the second anniversary for Gist Say'n. To acknowledge both, we revisit our very first episode that includes memories of my first "quarantine."

In the 90s I made documentaries through KSPS and the PBS system, during this time I did several programs about volcanoes.

For one, I traveled to three different countries plus California, Oregon, and Washington, to examine how prepared America's west coast would be for a major volcanic eruption. For two others, I spent a lot of time at Mount Saint Helens, recapping and exploring the impact of the 1980 explosion and examining how the environment and people around it had been coming back in the first 15 and then 20 years after that mind-blowing day of May 18th.

These old programs, with altogether 90's production values, still have a surprising amount of relevant information. KSPS has both "When Sleeping Giants Wake" and "St Helens: Out of the Ash" up on its YouTube channel. To take a trip back in time just follow the links.

A Time of Uncertainty

In the spring of 1980, I lived in Rathdrum, Idaho, about 350 miles, as the crow flies, from Mount Saint Helens. I still remember that the 18th of May was a beautiful warm sunny day, and I was hanging around waiting for my parents to come home because we were supposed to go to Lake Coeur d'Alene.

As I waited for them, I happened to turn on the TV, to one of the four, mind you, available channels, and that's how I learned about the catastrophic eruption that was taking place that morning.

Mount St Helens is a stratovolcano, meaning it was built up by alternating layers of lava flows and ash deposits, often through very violent eruptions. Stratovolcanoes generally have very symmetrical cones, with steep slopes that can reach high elevations. St Helens was a pristine example.

After sitting silently for more than 120 years, the mountain had woke just two months before. It started with a series of small earthquakes back on March 16th, which continued until March 27th when a small crater broke through the ice cap. Within a week, that crater grew to about 13-hundred feet in diameter, and two giant cracks appeared across the entire summit.

By May 17th, there had been at least 10,000 relatively small earthquakes under St Helens, and the north flank of the volcano now bulged out an additional 450 feet. It was like a balloon was inflating underneath the surface of the ridge.

Back then geologists weren't sure exactly what to expect, they knew magma had been moving up into the volcano, but at the time no one alive had ever had a front-row seat to an eruption like this. The United States Geological Service (USGS) was tasked with trying to give information to public officials that could keep people safe but not over-hype what might happen next.

This is a delicate balance its personnel are still tasked with achieving to this day. Volcanoes work on their own timetable, even with all the improvements made with monitoring systems, no one can say precisely what they're going to do or when.

The Eruption

On May 18th in 1980, officials were about to let people go into the Spirit Lake area along St Helen's northern slope to remove belongings from their homes and cabins. The mountain's activity had been attracting a lot of attention, and people wanted to get close and see it, so a no-go or red zone was established. As a result, there was a lot of pressure from area residents to be allowed to go home.

Then at 8:32 a.m. right after a 5.1 earthquake, the volcano's bulging summit gave way resulting in the largest landslide ever recorded in human history. That landslide depressurized the volcano's magma system and caused an explosion that blew 13-hundred feet off the top of the mountain. Boom, just like that, the landscape around St Helens was forever changed. The perfectly symmetrical cone now had a crater almost two miles across in a form more like a crescent moon than a circle.

Photos taken by Gary Rosenquist 1980
The Massive Landslide at beginning of St Helens Eruption

The lateral blast, which contained volcanic gas, rocks and ash heated to temperatures of 350 degrees, scorched and scoured everything in its path, moving at a pace of at least 300 miles an hour. It covered 230 square miles and, at its farthest point, reached 17 miles Northwest of the crater. It blew down 4 billion board feet of timber, that's enough to build 300-thousand two-bedroom homes. It was as if a 24 megaton thermal energy bomb had been detonated.

The explosion produced a column of gas and ash that rose more than 15 miles into the atmosphere in only 15 minutes. Meanwhile, pyroclastic flows, which are a mix of superheated gas, pumice and ash began to roll down the volcano's flanks like hot avalanches.

The energy from the landslide melted the glaciers that had been on the mountain's north slopes and turned debris into massive mudslides, or lahars, that raced down river valleys leading away from the mountain. The largest of these made it all the way to the Columbia River, almost 50 miles away. Along their paths, these mudflows destroyed twenty-seven bridges and nearly 200 homes. In addition, 31 ships were stranded in ports because the Columbia River's channel depth was reduced from 40 feet to 14.

The pre-established red zone saved countless lives, but even so, 57 people were killed during the 1980 eruption of Mount Saint Helens.

As the eruptions continued and St Helens pumped ash and pumice skyward, the winds carried it to the east. Populated areas between Portland, Oregon, and Seattle, Washington, some with actual views of the volcano were spared significant ash fallout, but the finest ash shot so far up in the atmosphere and was so plentiful that in just three days it spread across the United States and in 15 days it completely encircled the earth.

Living Through the Fallout

The 1980 Eruption of Mt St Helens

Back in Rathdrum, my parents and I watched what looked like a massive black storm front roll in across the blue sky. It turned that vivid sunny afternoon into night. It was the most surreal day of my young life.

At that point, no one knew what the ash composition was, so we were told to avoid it, for fear that it might have some toxic or acidic component to it.

We didn't strictly stay inside, though, we adapted. I had to put on my ski goggles and gloves plus wear a bandanna over my mouth when going outside to feed my horses, which we had put in the neighbor's garage because we didn't have a barn.

It was so dark the street lights came on, and it was eerily quiet. It felt like the stillness after a snowstorm, but there was no crunching snow underfoot, just a soft "puff" when you stepped. The ash muffled everything. No cars passed, no dogs barked, no birds sang. It was like the world was being smothered under a dark grey blanket that coated everything and blotted out all other colors.

By the next day, my dad enlisted me to suit up and come outside to help him build a dock. He was constructing it in the yard so we could then transport it to a lake property. The point being, life did not stop. There was more to be done now than ever and people just put on bandannas and went to work.

As it turned out, the ash itself was not toxic at all, but sterile, so sterile that plant life couldn't grow in it until mixed with topsoil. It was, however, extremely abrasive and messed up all the machinery that had to operate in it. As a result, my district canceled the last two weeks of school. The decision was partially based on the fact that it didn't want to have to rebuild all the bus engines or ventilation systems in the schools.

The learning cure and clean up would take time. As a result, there were no final exams that year. Something I remember being very exciting about as a teenager. Summer vacation, however, began with kids being drafted to help their families clean up the literal tons of ash left downwind of the eruption.

Path of Ash Fallout Downwind of the Eruption

Keep in mind, I lived about 350 miles away from the actual event, in a different state, yet there was still so much ash that you could easily scoop it up off the ground with your hands. Only the finest particles made it that far, so it felt a lot like scratchy baby powder.

People used snow shovels to try and clean the ash off their roofs and yards. Cities hauled it away in dump trucks. It was hosed down and washed off, and for years you could see it in piles and skiffs along I-90 as you headed west out of Spokane into the scablands that weren't plowed by farmers.

In today's dollars, the estimated damages caused by the 1980 eruption cost more than 3-billion dollars. At the time there were predictions that it would take upwards of a hundred years for the area to recover.

I have been in the crater of St Helens. Since the explosion, it is so vast that you can lose sight of a helicopter flying inside its rim. Yet today, unless you are inside the national monument boundaries, or have a background in geology, you'd be hard-pressed to discern what happened there.

Nature and man recovered and rebuilt at a remarkable pace. If you are ever in the Northwest, it is well worth the trip to see for yourself.