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The Impact – 42nd Anniversary of Mount Saint Helens Eruption

Mike McClanahan profile by Mike McClanahan

Forty-two years ago one mountain showed the world it can happen here.

At 8:32 am on the clear Sunday morning of May 18th, 1980, Mount Saint Helens exploded. The blast sent more than 500 million tons of ash into the sky. Winds topping 600 degrees and moving three hundred miles per hour flattened hundreds of square miles of forested slopes in the popular summer getaway. When the cinder cone collapsed, the largest landslide in recorded history stormed down the mountain. The cement-like mudflow swept up boulders and trees as it smashed down the Toutle River destroying  bridges, roads, and virtually anything else in its path.  In all, the eruption claimed the lives of 57 people.

Andre Stepankowsky has vivid memories of the day the mountain exploded and was one of the few people to get a bird’s eye view of the volcano’s fury.  He was part of the team at The Daily News in Longview that would later be awarded the Pulitzer Prize for the newspaper’s coverage of the eruption and its aftermath. 

“I was at a restaurant in Longview that morning and I’d just started my breakfast. You could see immediately, because the restaurant had a view of the volcano, this big, gigantic explosion started right away. The whole eastern horizon turned black as midnight and started to blot out the sun,” said Stepankowsky. “We knew there was a sense of doom that sort of overtook the restaurant that morning.” 

“Within a few minutes, after wolfing down my breakfast, me and Roger Werth, one of our staff photographers, the only staff photographer on duty that day, got to fly around the mountain. I think we were the first reporters up there in the sky and it was something, it was something that was beyond your comprehension. I mean, it’s this gigantic column of ash and steam with lightning bolts shooting through it, material falling back down on the flanks of the volcano,” said Stepankowsky. “There almost weren’t words to describe it.”

 “I saw one of the first mudflows come down and south fork of the Toutle River and take out one of the county roads,” said Stepankowsky.  

The eruption was loud enough to be heard in other states, but due to a trick of the atmosphere, it wasn’t as deafening as you might expect in towns much closer to the mountain.

“We did not hear anything because as people found later, the sound of the initial explosion sort of went upwards and then came back down to earth,” said Stepankowsky. “And the people that were in-between those two points didn’t hear anything. So, people heard the eruption in Seattle and Vancouver and out at the coast. We didn’t hear a thing, but we saw it,” said Stepankowsky. “I was in the plane when that famous photo that Roger Werth took that was on the cover of Time magazine was taken. I mean, any time I look at the mountain, I think of that day.”

“It was a humbling experience, but it was an experience that in a lot of ways made me a journalist. It gave me something to write about and a story to cover and learn how to think like a journalist. And I’ll always be grateful for that opportunity, as tragic as it was for a lot of the people involved,” said Stepankowsky.

May is Volcano Awareness Month in Washington. The state has five active volcanoes: Glacier Peak, Mount Adams, Mount Baker, Mount Rainier, and Mount St. Helens. Some are more active than others. “We consider them active. They’re not currently erupting, but they’re kind of in a just-add-magma state. They have before. They have in the past 10,000 years, some much more recently. We know they could erupt again,” said Brian Terbush.

 Terbush leads the Washington State Emergency Management Division’s volcano program. His work involves helping to educate communities about the potential hazards to their specific communities.   Mount Rainier is ranked as the second most dangerous volcano in the country and Mount St. Helens is number three on the list. Glacier Peak and Mount Baker are in the top 25.  

“So starting from the north, we have Mount Baker, kind of one of our less explosive, but it’s very snow covered, could have a lot of these volcanic mudflows called lahars,” said Terbush. “Next on the list, we have Glacier Peak, kind of hidden a little bit in Snohomish County, one of our definitely more explosive volcanoes. Talking about these different hazards, they each have kind of their own personality, which is why they all have their own names initially as well.  But that volcano’s a little more explosive, hasn’t erupted in historical times, as far as I know.”

“Coming back down a little further within Pierce County, we have Mt. Rainier. That is our volcano that has the biggest lahar hazard. It has the most snow cover of any mountain in the Cascades, as much as all of them put together. So anything starts erupting, it’s going to melt a lot of snow, push a lot of lahar, mud, ash downstream, even though this is not a very explosive volcano,” he continued.

Terbush says Rainier’s largest explosion was only a tenth of the one at Mount St. Helens in 1980.

“Down south we have Mount Saint Helens, definitely our most active of our volcanoes in Washington, has erupted the most times in the past 10,000 years, and if we had to guess, probably most likely to happen, most likely to erupt again soon. That’s if we had to guess though. Any of them could if we get that magma injection,” said Terbush. “And then we have Mount Adams which is our lowest hazard of the volcanoes at least as far as the deposits go and the number of people at risk from it potentially.”

Terbush emphasizes that Mount Adams isn’t completely tame.

“It could have those lahars, could have landslides, could have lava flows, just not very explosive,” said Terbush.

 The biggest threat, to the greatest number of people in Washington, is neither a tree flattening lateral blast nor a superheated wall of ash traveling near the speed of sound, according to Terbush.

“So as far as people that actually live in the vicinity, it’s definitely lahars. Now, most of our volcanoes are nicely surrounded by this buffer of federal land. We have a national park around all of them,” said Terbush. “The pyroclastic flows, these huge clouds of gas and ash coming down the mountain really hot, these are the kind of hazards that happen in that zone. Very unpredictable, but they’re all within the national park boundary where you don’t have very many people living.”

“ But when you move into these river valleys off the volcano, these lahars, they’re volcanic mudflows, kind of again this mix of ash, this mix of mud and everything that melted and all the debris it picks up coming down the road, it’s kind of like liquid cement as it moves away. If you watch videos from what happened today, 42 years ago, you can see these mudflows coming down carrying a whole bunch of logs. They destroyed 27 bridges down the Toutle River as this happened. So these are extremely destructive in these communities,” said Terbush. “What I want people to know is, these lahars are much more likely to impact you. So it’s the people in the Nisqually River, the White River valley, the Puyallup River valley that are most likely to be impacted by these eruptions because even a small one can start to melt that snow on top of it.”

The good news? Volcano monitoring technology has come a long way in the last 42 years.

“Oh, a lot. For one, we have a lot better communication technology. Things can get sent back to the stations that are monitoring them much, much quicker. Seismometers are cheaper and easier to deploy, so it’s easier to get more of them out of the mountain and there are actually a lot more of them out on, especially Mount Saint Helens and Mount Rainier.  Those are our two highest risk volcanoes, highest threat. They’re number two and three in the United States out of 161 volcanoes being monitored so each of them has a ton of seismometers out on it. But GPS itself is a huge, huge advance that’s happened. If you watch some of the videos from 40 years ago when they were watching them back from March to May in Mount Saint Helens, they were using I think it’s electronic distance measurement. They have lasers and they triangulate the position of a disc or a little mirror on the side of the mountain and then the next day they look to see if it’s moved. One day they couldn’t find, they couldn’t find the disc the next day because it had moved so much. So the GPS just sitting out there on the mountain and automatically sending back this information is a huge advance,” said Terbush. “Mount Rainier actually has a lahar detection system. There’s a number of seismometers and acoustic flow monitors that detect acoustic signals that are coming from the volcano. So these are sitting up in the river valleys and ideally, specifically the Nisqually River valley and the Puyallup River valley to detect if there is a huge rumble coming from the mountain. And these can let the folks know at South Sound 911 at Pierce County, at Washington Emergency Management, that a lahar is coming so they can hit a button and set off Pierce County’s lahar warning system, a series of sirens that are located in the valley to warn people that it’s coming.”

Watch the rest of the interview here:

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