The sky was falling. And Richard “Dick” Mack gathered a group of graduate students to help collect it. In the first few days after Mount St. Helens erupted—sending some 540 million tons of ash over an area of 22,000 square miles—the WSU ecology professor was already thinking of its potential research value.
Mack‚ now a professor emeritus in WSU’s School of Biological Sciences, spent the summer of 1980 doing field work between Pullman and Vantage, studying the effects of the ash on vegetation—particularly native plants, such as certain willows and grasses. For about five years or so after that, he and his students—using funding from the National Science Foundation and samples collected in Yakima and on the rooftops of Eastlick and Heald Halls—conducted further research. In the ash of Mount St. Helens, Mack says, “there are a lot of lessons.”
The May 18, 1980, eruption served as a sort of wake-up call to the threat of volcanoes in the Pacific Northwest. Not only was it a defining moment in a global movement to better monitor volcanoes, the blast zone itself created a sort of outdoor laboratory for scientists to study nature’s regeneration. And the ash that blew eastward over the Yakima Valley and Palouse provided researchers like Mack with the material with which to experiment. “It wasn’t research that I intended to do,” Mack says, “but there was a unique opportunity and it would be remiss of me to ignore it.”
Forty years after the May 18, 1980, eruption, here are some of the lessons learned from—and other impacts of—Mount St. Helens.
More monitoring and awareness
“Mount St. Helens was important because it was so well observed, and it spurred investigations of volcanoes in the Cascades,” says volcanologist Don Swanson (’60 Geology), a founding member of the Cascades Volcano Observatory in Vancouver. He worked on Mount St. Helens until 1990. Today, he’s a scientist emeritus at the Hawaiian Volcano Observatory, part of the U.S. Geological Survey (USGS).
“I think we’re in a much better position to monitor Cascade volcanoes than we ever have been, and it goes back to Mount St. Helens in 1980,” Swanson says. “That was really a turning point. From a tragedy, you learn a lot—which can help mitigate problems down the road. Existing observatories got increased funding, and people learned how to respond. We’re always improving how we respond, but this was a major step. Volcanoes are now more closely monitored. We have a good chance now of determining when a volcano becomes restless. A lahar detection and warning systems have been set up on several rivers draining Mount Rainier.
And public awareness is much greater than it was in 1980. All of this will save thousands of lives, maybe tens of thousands of lives.”
An earthquake with a magnitude of 5.0 triggered a landslide on the north face of Mount St. Helens, sending rocks careening down the mountain and suddenly relieving the magma underneath of a massive amount of pressure. This sudden decrease allowed all of the gases in the magma to expand, blowing out a bulging spot on the side of the mountain.
“A big lesson was that there can be a massive failure of the volcano flank,” Swanson says. “One side of the volcano just collapsed. The result of that failure was a debris avalanche. After Mount St. Helens, a lightbulb came on. People started recognizing debris avalanches around the world, like at Mt. Shasta in California. It was a kind of awakening. Those events, that sequence of events, had not been observed in action. Within a year, I think more than a hundred debris avalanches had been recognized around the world.
“These debris avalanches are exceptionally dangerous. They cause lahars, or mudflows, to occur. Now, at any volcano around the world, if measurements show that one side is bulking outward, even a little bit, people recognize the general hazard and that the volcano could collapse. We’re unlikely to see it (occur on Mount St. Helens) again in our lifetime. But give the volcano time to heal—a few thousand years—and it would be once again in a position to collapse.”
“Another very important lesson is the effects of such eruptions are long-lasting,” Swanson says. “They’re still with us. The sediment load in the Toutle River is much higher than it was in 1980. The forest was denuded. The immediate impact of the eruption is somewhat short-lived, but the long-term impact can last for decades.”
Ray Yurkewycz (’10 MS Env. Sci.), executive director of the Mount St. Helens Institute, notes geological and ecological time differs from the human experience of time. “One lesson is that there are lot things that happen more quickly and more slowly than you would expect,” he says. “We’re bounded by the time frame that we have. As humans, we think 40 years is a long time. Our time is tied into our life expectancy. We live 70 to 80 years. Geology and ecology occurs at different time scales, both shorter and longer than the human experience. For instance, some life forms come back right away. Others take decades or longer. It’s a reminder of the scale of things.”
More recently, “the mountain goat populations have soared.” Some 400 mountain goats now live on or around Mount St. Helens, he says. “They’ve started to return on their own—and are thriving.”
Yurkewycz’s Mount St. Helens Institute promotes Mount St. Helens license plates
“When a volcano erupts you generally get supersonic flow. You get this big shock wave, and interesting things happen because of it. One of the things that happens is it draws in air from the atmosphere,” says WSU Vancouver associate professor Stephen Solovitz, a fluid dynamicist who studies how ash plumes grow. “The rule is: you don’t fly through an ash plume. But you can fly through dilute ash. And that’s what our research team got into: What is the actual threshold of ash? What will it do to an engine? Ash ends up orbiting the earth for years to come, in some cases. It affects air traffic, furnace filters, air-conditioning systems, agriculture, the weather, the atmosphere. There’s a never-ending list of things you can look at.”
Research from a WSU Pullman geology professor, the late Ronald Sorem, has informed some of Solovitz’s work. Sorem studied how ash behaves, specifically how it clusters and aggregates together. “He took a black piece of paper, this cardboard, and collected particles as they were coming down,” Solovitz says. “He found they were made up of clumps of ash particles. They had glommed together. He did the work that day. He was just out there, as it was coming down, in Pullman. It’s amazing.”
Now, Solovitz says, “what we’re studying is the mechanism responsible for the ash clumping together and how that affects that growth. The two things we looked at were moisture—like whether it’s really humid or there’s a lot of moisture in the air—and static cling, basically. All these particles are rubbing against each other, and they can pull themselves together or blow themselves apart.”
Solovitz and his team build models to study how a plume evolves—how high and how fast it grows. “There are scaling challenges we run into,” he says. “But we’re looking at some ways of trying to study time variation. We’re also looking at vent shape. When a volcano erupts, it changes the shape of the vent. From there, it changes the shape and speed of the fluid coming out.”
Read more about Solovitz’s research.
Mack produced about a half-dozen papers related to the impact of the ash fall on native plants. He wasn’t planning on it, but it became “a significant part of my research for at least five years,” says Mack, who came to WSU in 1975 and reached emeritus status in 2015. He found the region’s cryptobiotic crust—composed of mosses, lichens, liverworts, and algae—died in the cover of ash. But they recolonized very quickly, within 12 to 18 months. “It was not a lasting effect but it was a major effect,” he says.
Mack also studied mouse runs in the field, finding that green algae grew successfully in the nitrogen-rich paths made by mice excretions. “It showed a phenomena we weren’t aware of before—because these ‘mouse runways’ were created atop the white ash,” he says. “Without the masking of the litter and soil, we could see the algae as never before.”
“Mount St. Helens Ash: Recreating Its Effects on the Steppe Environment and Ecophysiology” (PDF) R. Alan Black and Richard N. Mack, Ecology, 67(5), 1986, pp. 1289-1302)
After Mount St. Helens erupted, “everything was gray scale,” says biology professor John Bishop, associate dean and interim co-academic director of the College of Arts and Sciences at WSU Vancouver. “A huge area was sterile. There was nothing there—nothing alive, nothing dead. There was no biological legacy left. Plants, animals, insects, microbes, organic matter—it was all burned or blown away or buried by rock. You have this extreme environment, this massive area that’s been disturbed.”
Two years after the eruption, a single pioneering lupine plant was found, circled by seedlings, on the Pumice Plain—much to the surprise of ecologists. “Lupine has a magic trick,” says Bishop, who’s been studying Mount St. Helens since 1990 and keeps a piece of pumice on a shelf in his office. “When phosphorous is trapped in minerals in the ground, they create a special root. It’s like they’re mining it. They’re one of the heroes of the story.”
Lupines, self-fertilizing and members of the legume family, add nitrogen and organic matter to the ash, creating soils and helping other plants grow. By 2007, about 40 percent of the Pumice Plain was covered with plant growth and the number of species was multiplying. Immediately following the eruption, there was zero life. By 2007, some 78 different species were counted. By 2013, the number of species totaled 137. In 2016, it was 155. “There is actually a lot of biodiversity out there,” says Bishop, whose team helps monitor a series of 175 permanent survey plots for WSU. And lupine, once the most prolific on the Pumice Plain and vital to its regrowth, has since been surpassed. “Lupine was first, but now there is actually more moss,” Bishop says. “Lupine is in second place.”
Bishop found their numbers kept climbing and crashing, and that insects—particularly caterpillars—were living in the roots of lupine plants, eating their seeds, and preventing them from spreading quickly. He also found an invasive species of weevils has a penchant for the Sitka willow, burrowing in its stems and restricting growth. His work was among the first examples of herbivores controlling revegetation.
He’s made the trek to the Pumice Plain every summer since 1990, logging some 20 to 30 days on the mountain for field research each year and bringing students from WSU Vancouver’s biology, environmental science, and natural resource science programs. “This is a special place,” Bishop says. “And it’s spectacular in summer.”
John Bishop’s presentation on Mount St. Helens plant life (PDF)
Watch Bishop on PBS Newshour in 2016.
From the archives—Take a walk with Bishop around the Pumice Plain.
From the archives—Mount St. Helens provides Bishop with a “perfect” laboratory.
The debris avalanche blocked Spirit Lake’s natural outlet to the North Fork Toutle River and raised the lake bed, creating a much wider but shallower body of water. Authorities feared rainfall and melting snow could result in catastrophic flooding of downstream communities. A nearly 2-mile tunnel was bored through bedrock to divert water to the South Fork Coldwater Creek, a tributary of the North Fork Toutle River.
Today, that outlet tunnel, completed in 1985, is experiencing heave, or shifting of rock that compresses the tunnel and reduces its capacity, and faces periodic maintenance issues. “Right now, there’s a whole struggle about what to do about Spirit Lake,” Yurkewycz says. “In 1980, the landslide from the volcano smashed into the lake, and the lake started rising. They had to figure out what to do. Do you pump the lake? Do you dig a tunnel to drain the lake? Forty years later, they’re asking: How do we manage this thing? All of this is going to involve a lot of work in a very remote place that a lot of people value as wilderness.”
In 1982, President Ronald Reagan and Congress established the Mount St. Helens National Volcano Monument, protecting 110,000 acres within the Gifford Pinchot National Forest. The area, including the blast zone, was designated for research, recreation, and education. Now, Bishop worries the area—one of the most intensely studied plots in the world—is being threatened.
“One thing that’s very much on my mind is the U.S. Forest Service and Army Corps of Engineers want to build a road through the Pumice Plain where the bulk of my research has been,” he says. “It would absolutely cut through the outdoor laboratory, if it happens the way they are talking about. Many of our long-term plots would be destroyed or affected in ways that it would not be worth looking at them anymore. Thirty to forty plots would be impacted or destroyed.”
The road would provide access to Spirit Lake, where the U.S. Army Corps of Engineers—which built the outlet tunnel—aims to start work on a new gate for it in 2021. Because of its remote location, the project could take two or three years.
“The monument was created by Congress, and Congress said the purpose of the monument is to allow the natural processes of recovery to unfold unimpeded for public study and enjoyment. It’s to protect the landscape and to protect study and allow for research. For this (road) to occur in the heart of the most interesting place in the monument, that’s pretty devastating. We recognize the need to keep Spirit Lake operating safely, but we think it can be done without destroying the heart of the monument.”
Read more about the proposal.
Forest Service page on the Spirit Lake outflow and tunnel project
Tourism, programming, and the future
It’s not an easy climb. Even fit hikers scramble on the steep and rugged terrain to get to the rim of the crater. The route gains 4,500 feet in elevation in 5 miles and takes most trekkers anywhere from 7 to 12 hours to get up and back. But, Yurkewycz says, “You don’t have to summit the volcano. There are many spectacular hikes throughout the blast zone.”
He also recommends a stop at the Johnston Ridge Observatory, named for David Johnston, the geologist who died in the eruption while monitoring the volcano for the USGS. And, “On the east side, there’s the Windy Ridge Viewpoint. It’s more remote. There’s no big visitor center. But there’s old-growth forest and the entirety of the blast zone on that side is more intact. It’s the most wild part of the volcano.”
The institute hosts family camp and summer camps for kids—including GeoGirls, a four-night science-and-technology camp for seventh- and eighth-grade girls in Washington and Oregon. “That’s something I really care about: addressing issues of equity and diversity in STEM using Mount St. Helens,” Yurkewycz says.
“The last 40 years have really been about research and keeping people safe,” he says. “Now the place is very well monitored. How do we keep it relevant? How do we keep people coming back to it? I think it’s going to be very important to keep people interested and engaged, given the challenges we’re facing with the planet and climate change. What haven’t we learned yet? I think there are some interesting things that will happen in the next 40 years. It’s a completely different place.”
Explore at the Mount St. Helens Institute
“It was raining ash” (Stories from WSU faculty, staff, and alumni from the 1980 eruption of Mount St. Helens)
Where were you? Reader memories of Mount St. Helens