Our Volcano: Glacier Peak is the Hidden Threat in Our Backyard
May 24, 2010
Glacier Peak is the forgotten volcano.
Called Tda-ko-buh-ba by a tribe of American Indians who have lived on its flanks for hundreds of years, it erupts more explosively than any volcano in Washington, including Mount St. Helens, whose violent eruption 30 years ago this week killed 57 people and caused millions in property damage and lost infrastructure.
Photo: Glacier Peak, shown from the west, is one of 18 U.S. volcanoes listed as a “very high threat.” Its last eruption was in the 18th century.
Glacier Peak is one of 18 volcanoes in the U.S. listed as a “very high threat.”
It made the list because its historical record shows it erupts frequently and on a large scale. It last erupted about 240 years ago, just before the Revolutionary War, and its last major eruption was about 1,800 years ago.
Of the volcanoes on that list, Glacier Peak, at 10,541 feet, is among those with the fewest seismic monitoring stations.
Even so, volcanic experts believe they have enough seismometers that watch for clusters of earthquake activity to know when an eruption could be imminent. Also, a reverse 911 calling system would allow thousands of people to be notified within minutes.
In the worst-case scenario if there is a major eruption and the wind blows southwest Glacier Peak's ash fall could blot out much of the Puget Sound region, choking crops, ruining motors and making it difficult to breathe, geologists say. It would disrupt transportation, both on the ground and in the air, as ash clouds from Iceland's Eyjafjallajokull volcano have done recently in Europe.
Darrington could be flattened by one of Glacier Peak's lahars, a mud, rock, tree and melted glacier mixture that, while obliterating everything in its path, can lay down 30 feet of new soil in minutes. The small mountain town of about 1,500 people is built on dozens of such flows.
More than $750 million worth of homes, farms and other property in the Stillaguamish River basin, including parts of Arlington and Stanwood, lie in the path of a potential Glacier Peak lahar. So does all of the Skagit River Valley to the north, which is the direction a lahar is most likely to flow.
Many of those who bought their homes there for the commanding views of Mount Baker or Mount Rainier have no idea that an equally powerful volcano is right in their back pocket, tucked behind some smaller mountains east of Darrington and Granite Falls.
Only in 2007 did Snohomish County begin requiring landowners to sign a document that, for the first time, makes them acknowledge that they're buying or building a home within the long reach of Glacier Peak.
Property owners and government officials aren't the only ones oblivious to Snohomish County's only volcano.
Researchers crawl over Baker, Rainier and St. Helens, studying, cataloging and predicting when they might erupt again.
Only the hardiest scientists try to uncover Glacier Peak's secrets. Because it's hidden away and difficult to get to, it may be the least understood Cascade Range volcano. There are roads to St. Helens, Baker and Rainier. There's no road to Glacier Peak, and now all but one of the dirt roads that would get you close are blown out, destroyed by flooding.
To get there, hikers take the Mountain Loop Highway out of Granite Falls, take North Fork Sauk Road to the trailhead and then hike 17 miles to the peak. It takes three days for an in-shape climber to summit Glacier Peak, and it usually is undertaken only in the late spring or summer.
St. Helens, Rainier, and, to a lesser extent, Baker are dotted with seismometers. Continuous Global Positioning System monitors are ready to catch even the tiniest movements at the top of those volcanoes.
Glacier Peak has three seismometers and no GPS monitoring stations. Ideally, it should have 15 to 20 devices, but currently there is no money for that, said Cynthia Gardner, scientist in charge at the USGS' Cascade Volcano Observatory in Vancouver, Wash.
There is technology to track volcanoes from satellites, but it is not in real time and isn't always reliable.
Remote and beautiful
“Mount Baker is very conspicuous,” said Richard Waitt, a geologist with the U.S. Geological Survey's Cascades Volcano Observatory. “Everybody knows about Mount Rainier. Everyone knows about Mount St. Helens for a different reason. Mount Adams is a big spectacular thing from places like Goldendale and Yakima.”
In populated areas, Glacier Peak is mostly hidden from view.
“Glacier Peak isn't really visible from anywhere,” Waitt said. “That's the one that's most surrounded by other mountains. It's only when you get up on mountains that you get up high enough to see it. When you're closer to it on the east side, or when you're hiking close to it on a trail, it can be a stunning big peak.”
The volcano has always been held in high esteem by those who make the long trek to see it.
According to historical accounts, members of the Sauk-Suiattle Indian Tribe called Glacier Peak Tda-ko-buh-ba or Takobia. Translations are difficult, according to one accounting by tribal elders.
It's called “Da Kobad,” which translates to “great white mother mountain” in “Indian stories and legends of the Stillaguamish, Sauks and allied tribes,” a booklet first printed in 1926.
Those who know the volcano love it.
They count it as one of the country's most wild places, rising from the heart of one of the largest contiguous pieces of wilderness in the country outside of Alaska.
The Glacier Peak Wilderness, edged by the Stephen Mather Wilderness in North Cascades National Park to the north and the Henry M. Jackson Wilderness to the south, is so rugged and untrammeled that grizzly bears and wolves are believed to live there.
“The setting is kind of unparalleled,” said Gary Paull, trails and wilderness manager for the Mount Baker-Snoqualmie National Forest. “It's a big mountain. It towers up more than 7,000 feet from the valley floor. You don't see logging roads. You don't see (clear-cut) harvest units. It's just one of the more wild settings you're going to find yourself in.”
Working on the mountain
Tom Sisson is equal parts geologist and mountain man.
He's done a lot of hiking and camping on Glacier Peak to find out what makes the volcano tick. Sisson's job is to determine what a future eruption might look like.
By building on existing knowledge and by doing new research, he's tasked with getting better dates on past eruptions and to see how long the eruptions lasted. Officially, he's putting together a geological hazards assessment.
“(Sisson) is doing a detailed geologic map of the volcano. He's looking at how large and explosive past eruptions have been,” USGS geologist Gardner said. “Each volcano has its own history of eruptive behavior.”
Thanks to how difficult it is to get to and its lack of notoriety, Glacier Peak is one of the last volcanoes in the Cascades to get such a study, she said.
Sisson is hearty and hale, which makes him the right candidate for Glacier Peak, Gardner said.
“He's a really expert mountaineer in addition to an expert geologist,” she said. “He's extremely capable in the back country as a mountaineer.”
His work as a geologist only begins after he hikes in to the mountain.
First Sisson must find a lava flow or rock deposit that looks like it could be from an eruption that he's interested in studying.
Then he must break off a piece and haul it back to his lab, something that's difficult to do when the only tools you're allowed to use are a pickaxe, shovel and muscle.
And rocks are heavy.
“We've been working with a horse packer out of Darrington,” Sisson said, giving credit to the U.S. Forest Service for granting him unrestricted access to the area. “We'll bring the rocks out to a base camp and he'll haul them off the mountain for us.”
Camping out for two weeks at a time, Sisson and any fellow geologists he can talk into helping him will find a “hundred or so rocks” to take back to his lab in Menlo Park, Calif.
Each rock tells part of the story. It's Sisson's job to put the pieces together.
“We want to know what kind of lava it was,” he said. “We want to know when the eruption took place.”
Geologist Jim Beget did his thesis on Glacier Peak in 1970, sketching out a picture of a volcano that has an active and explosive eruptive history with major eruptions roughly 1,800, 5,000, 11,500 and 13,000 years ago.
In his thesis work, Beget also found lahars from smaller, more recent events closer to the mountain, from Darrington and out to the east, said Joe Dragovich, a geologist with the state Department of Natural Resources Division of Geology and Earth Resources. The mountain has erupted at least seven times in the past 13,000 years.
The eruption 11,500 years ago altered the course of the Sauk River by blocking its previous course down the Stillaguamish Valley with volcanic debris, Beget wrote. The Sauk has flowed north to the Skagit River ever since.
Little research and monitoring have been done since Beget's thesis. Dragovich found that out when he accidentally discovered large deposits from Glacier Peak lahar runouts (when a mudflow fans out and drops its load of mud) in the Skagit River Valley. A couple lahars in the past 5,000 years have reached the mouth of the Skagit River, and some of the larger and older ones, from 80,000 to 125,000 years old, stretched all the way to Whidbey Island, he said.
A mudflow 5,000 years ago deposited nearly 10 cubic miles of material into the Skagit Valley five times the amount of the 1980 Mount St. Helens eruption, according to research by Dragovich. Like Darrington, the cities of Lyman, Sedro-Woolley and Burlington, are built on lahar deposits from Glacier Peak, he wrote.
“The fact that we can go into the lower Skagit and find all these lahars in the 1990s says there's a lot of work that remains to be done,” Dragovich said. “It's an education thing. It's a research thing.”
Four summers into a six to eight summer plan to bring Glacier Peak's research profile up to date, Sisson is learning much about the volcano.
For one, he found clues that suggest the volcano is far more active than originally thought.
“Instead of one eruption, each event was several eruptions over a long period of time, eruptive activity that could have spanned hundreds of years,” he said. “Then there are extended periods where nothing is happening. It's feast or famine there.”
Sisson also has found that Glacier Peak is much older than he expected, more than 700,000 years old. Mount St. Helens, by contrast, is about 300,000 years old, he said.
Mount St. Helens' 1980 eruption blew out the north side of the mountain, killing 57 people, destroying 250 homes, 47 bridges and 185 miles of highways. The mountain's elevation shrunk from 9,677 feet to 8,365 feet after the largest landslide on record in the United States.
Now, the volcano is a national monument and the focal point for research on Cascade volcanoes. It, along with two other volcanoes, has the highest level of monitoring in the country.
One of Glacier Peak's three monitors is at 7,500 feet on the west side of the mountain. The other two are not on the mountain but are within 25 miles of the volcano.
Photo: Views of Glacier Peak from the east such as this one from Buck Creek Pass in 2007 are spectacular, but there is no good access to hike to the top of the mountain from there. (Rob Ollikainen / Wenatchee World)
This comparative low level of monitoring is why the volcano scored average at best on the USGS National Volcano Early Warning System, a 2005 rating that said gave the volcano a 2 out of 4 score. Mount St. Helens did far better, with its eruption monitoring program scoring 4 out of 4. Rainier and Baker were among a number of Cascade volcanoes that scored 2 out of 4.
“This threat assessment it a relatively new assessment, so it's a new way of looking at things,” Gardner said. “We're using the information to build up our monitoring program in the Cascades.”
Local emergency management officials are concerned because many of the people who live in Snohomish County, one of the fastest growing counties in the state, don't know they live next to a fire-breathing mountain.
Still, thanks to the clusters of earthquakes that normally come before an eruption, they believe they will have time to warn county residents to evacuate or move to higher ground.
Even better, they now have reverse 911 calling technology that allows access to thousands per minute to warn them that, say, Glacier Peak had erupted and a lahar was rushing toward Darrington.
“All of Darrington and the surrounding area would be called and notified in two minutes,” said John Pennington, director of the Snohomish County Department of Emergency Management.
The county also is looking at putting up sirens that would tell Darrington residents to head to higher ground if a lahar were headed their way.
Lahars, like water, seek out low ground. That's an advantage for emergency responders because it means that the people most apt to be affected by a big mudflow are the same ones who get nailed by flooding.
“These folks are used to getting to higher ground pretty quickly,” Pennington said. “They see the river rise pretty quickly. They can usually anticipate and watch the signs, and move to higher ground rather quickly.”