May 18, 2010 in City
Mount St. Helens: The blast that shaped a region
MOUNT ST. HELENS NATIONAL VOLCANIC MONUMENT – Whether he’s talking about cottonwoods or huckleberries, salamanders or elk, ecologist Charlie Crisafulli discusses life’s return to the blast zone in almost poetic terms.
Species invade, thrive and crash. A pile of elk dung or a mound of thatch ants are islands of food for a hungry landscape. Nature constantly surprises and shatters the theories of mere humans.
But as he walked down the monument’s Hummocks Trail last week, across from the gaping maw of the crater left by one of last century’s seminal geologic events, he tossed out a bit of detail to give visitors pause.
“This is essentially the insides of the volcano that we’re walking over,” he said of ground that crunched underfoot. “Or at least it was 30 years ago.”
After several months of seismic buildup, Mount St. Helens’ eruption on May 18, 1980, may have been among the most anticipated in modern history. But the size and force of the blast, the landslide and mudflow from superheated snow were far beyond expectations.
A magnitude-5.1 earthquake below the volcano triggered a blast that blew out the top 1,300 feet of the volcano, pushing some 3.7 billion cubic yards of debris to the north and west. Temperatures in the blast zone reached an estimated 600 degrees Fahrenheit. Trees were snapped off and laid down like dominoes. An avalanche of debris rushed down the North Toutle River, raising it as much as 600 feet in some spots, wiping out bridges and burying roads. Fifty-seven people died.
A cloud of ash rose an estimated 15 miles into the atmosphere in less than 15 minutes and was pushed east-northeast by the winds. In two hours it reached Eastern Washington and North Idaho, and by the next morning it had spread across Wyoming, Colorado and the Dakotas, the western edge of Minnesota and the northern edge of New Mexico.
Ross Graham, a Weyerhaeuser forester in the area, remembers flying over the blast zone two days later: “It was totally gray, as far as the eye could see, with a lingering sulfur yellow in the air. I couldn’t even tell where we were. My initial thought was we’ll probably just have to walk away from this.”
But by late spring the first signs of life were already returning, he recalled. Sword ferns were poking through the ash. Later that summer, fields of fireweed sprung up.
World’s largest lab
Crisafulli arrived in the blast zone in July 1980, a 22-year-old environmental scientist who had studied the desert Southwest, the closest thing anyone could compare to it. He didn’t expect to stay long, but serendipity presented him with the chance of a lifetime.
“Being at the right place at the right time can shape your life. This place left an imprint on every aspect of my life,” he said.
“This place” is the national volcanic monument, some 110,000 acres of protected land around the volcano, where the middle third is dedicated to the world’s largest ecologic laboratory studying the way nature reclaims the land. Three decades of research have wiped away old theories of a linear progression of smaller to larger plants and animals, showing that many species colonize a blank slate like the blast zone at the same time. Studies in the monument have spawned hundreds of research papers. Researchers get called for advice or assistance with other eruptions, and even some man-made messes like the cleanup of old mines.
“St. Helens gives us a look into the window of natural forces that have shaped not only the Cascades but areas around the world,” Crisafulli said. “The more we know about the processes that shape our world, the better stewards we’re going to be.”
Research vs. resource
Driving into the monument from the west on state Highway 504, a visitor passes miles of firs reaching 50 feet or more into the sky on Weyerhaeuser tree farms that bear signs stating when they were planted and when they’ll be harvested. The company had 68,000 acres affected by the blast; after the eruption it swapped some land closer to the volcano for government land elsewhere but replanted 7,000 acres with seedlings that its foresters fertilized and nurtured.
Some stands are so thick they must now be thinned, with logs being turned to lumber or wood chips. In the early spring, crossing over from the thick green of the tree farms to the more open spaces of the monument can be jarring to a visitor. It’s also annoying to some local residents, like Sam Gardner, who thinks the federal government should replant much of the blast zone the way Weyerhaeuser did, and open as much of the area as possible, as quickly as possible.
“It should be reforested. It’s a resource,” Gardner, a logger, fisherman and third-generation resident of the Toutle River Valley, said as he sat in the 19 Mile House restaurant that his wife owns.
Thirty years is long enough to study the effects of the blast and natural recovery, he said. The Forest Service should open up more of the monument to recreation – including Spirit Lake, a bustling resort area before the blast but now a restricted area beyond the end of the rebuilt highway – and seriously reduce the size of the laboratory, Gardner believes.
“They could study it, but they don’t need the whole darn thing.”
The federal government is spending about $8 million this year – much of it federal recovery money – rehabilitating the visitor centers and other facilities inside the monument.
But Tom Mulder, the monument manager, expects restrictions will continue in the laboratory for a very long time. “Geologic processes take Lord knows how many centuries. It’s not like we can pick 10 acres as one really cool place to watch.”
He knows local residents want access to Spirit Lake, where local lore says rainbow trout with no predators grow to 2 feet. But other lakes that are open and have been stocked are underutilized, and a huge “raft” of timber blown down by the blast remains a hazard.
Graham, the Weyerhaeuser forester who has worked the area for 35 years, thinks the reforested company lands and the slower-returning monument lands complement each other, one showing how nature restores lands eventually and the other how humans can work with nature to restore it.
Crisafulli dismisses any suggestion that after 30 years of study, he must know everything about lands that change constantly and will continue to do so for centuries. “If this were a play, it would still be Scene 1, Act 1.”