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Washington's Volcanoes: Know Your Sleeping Giants

Posted by Loren D at May 14, 2013 03:30 PM |
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With Washington being the home of multiple volcanoes, here is some information for observing volcano awareness month.

by Carolyn Driedger Mastin

Northwest hikers frequently hand down rich traditions of favorite trails to younger generations. While these multi-generational traditions provide the illusion of landscape permanence, observant hikers often witness geologic change in progress—rockfall, water erosion, and glacier change. You might recognize that your views of mountain landscapes are a little bit different from the views of your grandparents, and what you see will likely be different from what your own grandchildren will eventually see.

Some geologic change happens over generations, centuries and millennia. Other changes occur in mere moments.

Once in a while, landscape change happens on a scale so grand that it transforms not just a landscape, but our collective understanding of earth’s power and permanence. Geologic change is expectable and inescapable, and as a society we are wise to prepare for it.

A history of volcano eruptions in the Cascades

On May 18, 1980, Mount St. Helens captured the world’s attention when the largest historic landslide on Earth and a powerful explosion reshaped the mountain and dramatically modified the surrounding landscape. Twenty eruptions between 1980 and 1986, followed by the continuous eruption of lava onto the crater floor between 2004 and 2008, prompt our vigilance. Hundreds of eruptions have shaken Cascade Range volcanoes during the past 4,000 years, and future eruptions are certain.

Volcano Eruptions in the last 4000 Years
Volcano eruptions in the last 4,000 years. USGS

During the 1980s, measurements of subtle changes at Mount St. Helens took on new meaning for scientists as the volcano demonstrated that patterns of change could help them forecast eruptions. Since then, tools for tracking the movement of magma have evolved rapidly from the use of isolated instruments to networks of ground-based sensors that measure earthquakes, surface swelling and gases. Satellite-based instruments also detect patterns of change on Earth’s surface.

Monitoring volcanoes

Technological revolutions in low-power instrumentation are fueling a new era of volcano monitoring systems capable of collecting and transmitting real-time data with increased precision and resolution for improved eruption forecasting.

During the past decade in Washington, the U.S. Geological Survey (USGS) and the Pacific Northwest Seismograph Network have expanded monitoring networks on Mount St. Helens and Mount Rainier, and plans are in development now to augment sparse monitoring on other hazardous Washington volcanoes including Mount Baker and Glacier Peak.

While hiking in these areas, you might see these instruments on a volcano’s slopes. These instruments are hard at work for communities downwind and downstream of the volcano.

How to prepare for volcano eruptions

When volcanoes are quiet, they aren't high on people’s daily list of concerns. That doesn’t mean that we shouldn’t be aware.

  • Learn about the location of volcano hazard zones near your home, schools and places of business.
  • Inquire about community evacuation plans, and follow official advisories to help you survive with less disruption.
  • Prepare your home with extra supplies and an emergency communication plan to reduce losses and help your family live with greater peace of mind.

For more information on volcano awareness and preparedness information, visit:



nullThis article originally appeared in the May+Jun 2013 issue of Washington Trails magazine. Join WTA to get your one-year subscription.