St Helens Then and Kilauea Now
Hello there, I'm Alison Kartevold and this is a special sneak peek episode of Gist Say’n, a new podcast being designed to both inform and hopefully entertain. The idea behind it is to draw from my reservoir of more than two decades of journalistic experience, and sprinkle in a few of my personal anecdotes, while we sort through and cleanly lay out the gist of current and relevant topics of interest.
The website isn't up, the little portable studio isn't complete, and I don't even have a very good microphone here with me, but a relevant example topic has developed. It's timely with a bit of a deadline and nothing gets me motivated like a deadline, so let's give this a try.
The topic for this sneak peek of Gist Say’n is ... Mount Saint Helens Then and Kilauea Now
Way back when I used to make documentaries through KSPS and the PBS system, I did several programs about volcanoes. For one I traveled to three different countries besides the states of 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 eruption 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.
Even though these programs are now really old, with totally 90’s production values, a surprising amount of the information is still relevant. In fact, I just learned that KSPS has both “When Sleeping Giants Wake” and “St Helens: Out of the Ash” up on its YouTube channel. If you really want to take a trip back in time you can check them out by clicking the two photos below.
The anniversary of Saint Helens’ big eruption always seems to peak people's interest in that event. Since it is May, plus the fact that activity at Kilauea is revving up, people's interest in volcanoes in general is bound to spike. So there's no time like the present to give you the GIST on these two events.
On May 18th of 1980 I lived in Rathdrum, Idaho, about 350 miles, as the crow flies, from Mount Saint Helens. I still remember, it 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 had begun to take place that morning.
After sitting silent 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 crossed the entire summit. By May 17th there had been at least 10,000 relatively small earthquakes under the St Helen's and the north flank of the volcano now bulged out an additional 450 feet. It was like a balloon was being inflated underneath the surface of the ridge.
You should understand that back then geologists really weren't sure exactly what to expect, they knew magma had been moving up into the volcano, but no one alive had ever had a front row seat to an eruption like this before. The United States Geological Service or USGS was tasked with trying to give information to public officials that could keep people safe, but at the same time not over-hype what might happen. A delicate balance its personnel are still tasked with to this day. Volcanoes work on their own timetable, even with all the improvements that have been made with monitoring systems, no one can say exactly what they're going to do and when.
So back on May 18th in 1980 officials were about to let people go in to the Spirit Lake area along St Helens 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 had been established, if memory serves I think it was about a 10 mile radius, but there was a lot of pressure from the people who lived in the area to just let them go home.
Then at 8:32 a.m. right after a 5.1 earthquake, the volcano’s bulging summit just 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.
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 like 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 huge 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 left stranded in ports because the Columbia River’s channel depth was reduced from 40 ft 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 continued to pump 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 3 days it spread across the United States and in 15 days it completely encircled the earth.
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 bright sunny afternoon into night. I think that had to be the most surreal day of my young life. At that point no one knew what the composition of the ash, was so we were told to avoid it, for fear that it might have some kind of toxic or acidic component to it. This meant I had to put on my ski goggles and gloves and wear a bandanna over my mouth to go 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 kind of like the stillness after a snowstorm, but there was no crunching snow under your feet, just this quiet “puff” when you stepped. Everything was muffled. 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 bloated out all color.
As it turned out, the ash itself was not toxic at all, but actually sterile, so sterile that plant life couldn't grow in it until mixed with topsoil. It was extremely abrasive though, and messed up all the machinery that had to operate in it. As a result my district cancelled the last two weeks of school. Partially because it didn’t want to have to rebuild all the bus engines, or ventilation systems in the schools. No finals. I remember that being very exciting as a teenager.
Now again 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 it off their roofs and yards. Cities hauled it away in dump trucks, 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, damages from the 1980 eruption are estimated to have cost more than 3-billion, that is billion with a B.
So that was Saint Helens then, now in May of 2018 folks in Hawaii are trying to cope with increased activity at Kilauea. Is Kilauea like St Helens? Well, yes they are both active volcanoes, but there are significant differences. Mount St Helens is stratovolcano, meaning it was build up by alternative layers of lava flows and ash deposits, often through very violent eruptions. Stratovolcanoes are generally very symmetrical cones, with steep slopes that can reach great elevations. In contrast, Kilauea is what is called a shield volcano. Shield volcanoes typically have more gradual slopes than the steep coned stratovolcanoes, but over time can cover massive areas with their thick flowing lava. In fact, the second largest volcano in the world is Kilauea’s immediate neighbor, Mauna Loa. In all there are five shield volcanoes that make up the big island. Their eruptions are generally far less violent than those of say, St Helens, meaning they are easier to get close to to view and study while they are actually erupting.
I have been in the crater of St Helens, it is so massive that you can lose sight of a helicopter flying inside its rim. I have also been to the edge of craters on Hawaii. By comparison you don’t really feel like you’ve climbed a mountain to get there, it feels more like coming across a very large, sometimes glowing, hole in the ground. Nevertheless, Kilauea is extremely active and living in its space can become problematic and even dangerous.
Kilauea has erupted virtually none stop since 1983, at times causing considerable property damage, like when in 1990 it destroyed the town of Kalapana. Now on May 3rd, a magnitude 6.9 earthquake seems to have signaled the beginning of a new chapter of increased volcanic activity with the opening several new lava vents downrift from the summit. Thus far about 2,000 residents have been evacuated and almost 30 homes have been destroyed, mostly by slow moving walls of molten lava. On May 16th the Halemaumau crater began venting significant ash plumes that reached 12-thousand feet and forced the USGS to issue an aviation red alert. Now contrary to what some people believe, this does not mean that a more violent eruption is imminent, but rather that the ash has extended high enough into the atmosphere as to be a potential hazard to passing planes and jets. USGS volcanologists say this condition will continue to wax and wane.
The USGS has also been busy trying to quash rumors that there is a high risk of tsunamis due to this recent activity. That is not the major concern. However, it does look like residents on the big island are going to have to stay alert to the potential hazards caused by dangerous gas emissions and possible ash fallout for sometime to come, as indications are that this latest eruption will continue into the foreseeable future.
So there you go, I hope you like what you heard and will follow along for updates as we prepare to officially launch this new podcast. Until then, this is Alison Kartevold and I’m Gist Say’n.