On the morning of May 18, 1980, research geologist Richard Waitt got a call from a Vancouver friend telling him a giant cloud was approaching the city from nearby Mount St. Helens.
Waitt was based in Menlo Park, Calif., but had been studying the active volcano and splitting time between California and Washington. Waitt grabbed the first flight he could get back to Portland to see what was happening. He arrived in Vancouver around 2 p.m. to find a very active scene.
“I could see the giant plume coming from Mount St. Helens,” Waitt said. “I got into the office and there was still a lot of confusion, so I ended up going out in the field. We didn’t really have much of an office, actually. We had a room in the Forest Service building.”
Scientists were aware that a giant lahar — a type of mudflow made mostly of water and sand — was sliding into the Toutle River valley from the mountain, but other details were sketchy. Waitt decided his best scientific option was to drive north on Interstate 5 toward the blast zone and collect ash from various sites — which can be used to tell where rock has moved and what type of volcanic eruption has occurred.
“On the way up in the evening, probably at 8:30 p.m., I stopped at the (Ridgefield) truck scales at I-5 and you could still see the plume growing,” Waitt said.
At about Milepost 51, the northbound traffic came to a standstill. So he turned around and headed back toward Castle Rock, but the Toutle River Bridge was closed.
And that’s when a giant flood started to rush beneath the bridge.
“I was trapped, but I got to watch,” Waitt said. “There was a huge lahar … Large logs, some just ripped off, they’d hit the bridge and finally swing by. Huge trees with root balls came through. But by midnight most of the timber was gone.”
“Not even the people monitoring for that flood were expecting it,” Waitt said. “It wasn’t clear where it came from. The initial thought was it was Spirit Lake, but it was clear on the 19th that Spirit Lake was still there.”
By about 1 a.m. the crowd had dispersed, and the bridge was still standing, so Waitt decided to drive over it.
He continued his way up to Mossyrock and then east to Randle, continuing to collect ash until he finally went to sleep around 4 a.m.
The next morning, the Old Pacific Highway Bridge across the Toutle River experienced a raging flood, and scientists realized the eruption had pushed all the timber and then all the water out of the mountain’s rivers, streams and ground.
But something was strange about this flood — the water was hot.
“It was too hot to hold my hand in,” Waitt said. “This flood had three peaks — the first was wood, then height, and then heat.”
A day or two after the eruption the geologists managed to get three aircraft to explore the area from about 9:30 a.m. to 10:30 p.m., and Waitt said that flights revealed nothing but more surprises.
“The side that had been laid flat north of the mountain was really surprising,” Waitt said. “In the early hours you couldn’t see anything, but gradually as the day wore on and the ash blew out you could see things to the west.”
The landslide geologists saw that day turned out to be the largest ever recorded in a terrestrial setting, with 1.74 miles of rock sliding off the mountain in three giant blocks. It left a deposit about 18.6 miles down the Toutle River. About 99.9 percent of the rock ejected from the mountain ended up in that landslide, Waitt said.
An analysis revealed two landslides released the pressure inside the volcano, and that pressurized material then exploded outward, leveling about 372 square miles of forest.
“All of that was unusually surprising,” Waitt said. “We also had an ash column that rose up to the stratosphere, blew to Idaho and Montana — and that we actually predicted, so it was one of the few things that wasn’t a surprise.”
Human cost
While scientists got a boon of data from that historic day 40 years ago, May 18 took a human toll. There were 57 people killed in the blast, and 250 homes, 47 bridges, 15 miles of railway and 185 miles of highway were destroyed.
Staff at The Columbian were not spared tragedy.
Photojournalist Reid Blackburn, who had been camping north of the mountain in anticipation of its eruption, was killed by the blast. His wife, Fay Blackburn, who also worked at the newspaper, said she remembers going out in the morning to look at the ash from their home in Felida.
“I was out and the neighbors were out watching,” she said. “From our view the destruction wasn’t quite as evident. I thought ‘Finally, Reid is going to come home and he’ll have all the photos we need.’ Then, a few hours later, a friend showed up at my door.”
The friend had been asked to stay with her, although the two didn’t know what was happening at the time.
“They said they were still looking for Reid, but it was difficult,” she said.
Later that afternoon, a pilot flew to the area of Blackburn’s camp, hopeful of a rescue. They soon realized nobody had survived.
“They knew by early evening that Reid was dead,” Blackburn said. “The following days became more blurry and fluid. Reid was now part of a natural disaster.”
Anniversaries of the event are still very hard for her, but for her part she says she hopes people remember her husband as more than just a statistic.
“It makes me feel sad, and it makes me reflect on the life he could have had but never had,” Blackburn said. “One of my goals throughout these years has been keeping his memory alive and his legacy alive.”
A blast that changed science
There were horrors certainly, but also some light in the wake of the tragedy and chaos from that day.
The event drew scientists from all over the world to study and share information about the way explosive volcanoes behave. And it created new scientific networks to continue that communication. It also taught scientists about the importance of outreach and coordination with authorities like the police and Forest Service.
“In the end the eruption really has changed the way we respond to volcanoes in a lot of places,” said Carolyn Driedger, a hydrologist and outreach coordinator at the U.S. Geological Survey Cascades Volcano Observatory in Vancouver, which was founded after the eruption.
Before 1980, scientists realized Mount St. Helens was a bit different from other volcanoes in that it was relatively young and explosive.
“But there was nothing imminent, nothing pressing about it at that time, so there weren’t funds for more studies,” Driedger said. “The Cascade volcanoes back then really didn’t make the list of hazards. But in 1980, after it started to reawaken, it became suddenly very real.”
After the catastrophic eruption, geologists on the ground had a hard time getting through roadblocks into affected areas to assess and document what had happened. The main goal of the Forest Service, and police and fire departments, was to keep people out of the damaged areas. But geologists needed to get in to see what was happening with the rock — both to study it and to warn the public if another explosion was coming, Waitt said.
“President (Jimmy) Carter came to the area in the third week, and we asked him to help us get access,” Waitt said. “Carter asked for aid and then we had six helicopters. A week after he came, we had full access to everything.”
As the eruption continued, scientists from other parts of the world with similar volcanoes came to the Pacific Northwest to study Mount St. Helens. Waitt remembers sharing notes with Japanese and Italian scientists on a variety of volcano features.
“Each of us would take a little time to be with these people,” Waitt said. “They each had their own expertise, and it was a huge two-way learning streak.”
Information gathered and relationships between scientists helped in other disasters, including the El Chichon eruption in Mexico in 1982, the Nevado del Ruiz eruption in Colombia in 1985 and the Mount Pinatubo eruption in the Philippines in 1991.
“The things we learned at Mount St. Helens — the need to monitor sites well before there’s any sign of unrest — that lesson was learned at Mount St. Helens and around the world,” Driedger said.
All the data scientists gathered, and continue to gather, informs a global community of scientists about the inner workings of dangerous volcanoes — and helps them warn the public of potential hazards.
“We’ve had observations from around the world, but westernized countries adding photographs of things moving, and other studies, not to mention getting in there with helicopters, it just really helped solidify a lot of the observations from the past,” Waitt said.
In the years that followed the eruption, technology also evolved to allow scientists to remotely monitor parts of the volcano in real time. A lot of that equipment was in place for Mount St. Helens’ eruptions in 1990-1991 and 2004-2008.
“In 1980 we really didn’t have any adequate instrumentation to monitor an explosive volcano,” Driedger said. “But there have been about 20 little eruptions since then. That shows Mount St. Helens is deserving of our attention. It’s like a laboratory.”
Today most of the Cascades volcanoes are covered with remote monitoring equipment connected with global positioning software that alert scientists to any little shakes or burps that occur. Those sensors are constantly tweaked and improved, she said.
“We’re always making a better mousetrap,” Driedger said. “All the new technologies that have come in the last few decades have gone into our monitors — cellphones, large-scale telemetry, newer data collection devices, everything is in digital format now, not analog.”
Source: https://www.columbian.com
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