101 on Washington State Volcanoes

If you live in the Northwest, you know: Those eye-popping mountain views come with a serious price t
Posted April 19, 2011
A USGS Forest Service Ranger holds up a pre-eruption photo of Mount St. Helens at the Johnson Ridge Observatory in 2004. The observatory was evacuated about an hour after the photograph was taken when the mountain began a dome-building eruption.

Our state is home to five active or potentially active stratovolcanoes—tall, conical mountains built up over the centuries by layer upon layer of volcanic material. Until Mount St. Helens’ catastrophic blast in 1980, these mountains were the stuff of science fairs and history books. Now, many of us know terms such as pyroclastic flow (a fast-moving current of hot gas) and lahar (a volcanic debris flow along a river valley), and recognize these giants as powerful neighbors who can change our lives—and the places we call home—with one big burp.

 

Glacier Peak

Mount Adams

Mount Baker

Mount Rainier

Mount St. Helens

Latest activity

Before 1800

More than 3,500 years ago

1870

1882

1980 to present

Eruption Type

Ash

Ash, lava

Ash, lava

Ash, lava

Ash, lava

Remarks

One of the most explosive erupters in our state, Glacier Peak hasn’t blown for a few hundred years, but when it goes, it goes big time. This monster produces a molten rock that’s too viscous to flow out of any vent, so it blows out in a high-pressure blast. For now, though, the beast sleeps.

Sure, it’s quieter than sister St. Helens, but geologists say this big daddy is sure to blow again—most likely from the vents on the summit. But Adams doesn’t need to erupt to wreak havoc: landslides and lahars probably pose a more immediate threat.

Baker is currently blowing off steam at flank and crater locations, but scientists say it’s stable—for now. Not known for the same violence as Glacier and St. Helens, this volcano is more apt to bully, with debris flows and avalanches brought on by steam emissions, earthquakes and even heavy rainfall.

The most beloved of all Cascade volcanoes is also the most potentially lethal; thousands of people live at its foot. Because of its massive size—and the huge volume of ice and snow on its cone—Rainier has been known to create destructive, churning mudflows after eruptions.

Still steaming after all these years, St. Helens hasn’t been the same since she blew her top back in 1980. Peek into the crater and you’ll see a lava dome that’s continuing to grow; at this rate, she’ll be back to her old self in about 200 years…that is, unless she loses it again.

The Danger Zones

Hamilton, Sedro-Woolley, Burlington, Mount Vernon, La Conner, Edison, Conway, Darrington

 

Stevenson, Carson, White Salmon, Lyle, Glenwood

Concrete, Sedro-Woolley, Burlington, Mount Vernon, Glacier, Maple Falls, Deming, Everson, Lynden, Sumas (B.C.)

Packwood, Randle, Ashford, Elbe, Carbonado, Wilkeson, Orting, Sumner, Puyallup, Auburn, Kent, Seattle

Toutle, Castle Rock, Longview, Kelso, Kid Val

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