If you think you need to let off some steam from the pressures of daily life is something, imagine holding the pressure of dissolved gas and magma in for centuries.
May is Washington’s Volcano Preparedness Month, and DNR has all you need to know about how the stunning mammoths dominating much of our skyline handle the geothermal pressure bubbling below.
Washington is home to five major composite volcanoes or stratovolcanoes (from north to south): Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams. These volcanoes and Mount Hood to the south in Oregon are part of the Cascade Range, a volcanic arc that stretches from southwestern British Columbia to northern California. If you want to check them out, take along DNR’s five-day field trip guide of the Cascade volcanoes.
During the past 12,000 years, these volcanoes have produced more than 200 eruptions that have generated tephra (ejected material), lava flows, and lahars (volcanic debris flows) and debris avalanches.
It will be 35 years since the deadly explosion of Mount St. Helens on May 18. The eruption produced a blast that, traveling at the speed of sound, mowed down thousands of acres of forest and showered hot ash and gases across the landscape. Fifty-seven people died, including two people who were watching the eruption some 25 miles away from the mountain.
Aside from the prominent peaks of our five Cascade volcanoes, Washington also has hundreds of volcanic vents scattered across the state. You can see where they are on DNR’s Division of Geology and Earth Resources’ Geologic Information Portal.
Keep your Ear to the Ground all month for information on the volcanic forces that make Washington what it is.
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