Which Washington State Volcano Will Be The Next To Erupt?

When you hear the word volcano and Washington State you immediately think Mt. St. Helens.  The 5.1 magnitude eruption on May 18, 1980 is the most devastating and destructive eruption in United States history.  Growing up on the East Coast, we heard about the eruption.  Not knowing a ton about Washington State, a lot of us were surprised that a volcano was was in the Pacific Northwest.

When I was stunned to learn there are a bit more than one.  I'm not sure how many people are aware there are no less than five active volcanoes in Washington State.  If you knew that, do you know when each of them last erupted and the likelihood of them erupting anytime soon?  Here's the rundown

Mt. Adams (Skamania/Yakima Counties)

Of the five, Mt. Adams is the one that has gone the longest without an eruption.  While an exact year hasn't been determined, it is believed that Mt. Adams last erupted during the Stone Age.  Last fall the largest volcano in the State raised some eyebrows as there were six eruptions between 0.9 and 2.0 recorded over a two month span.  Normally eruptions were recorded at Adams every two to three years.  That rate of activity inspired the USGS to improve their monitoring capability of the stratovolcano.

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Glacier Peak (Snohomish County)

Glacier Peak last erupted around 1,100 years ago.  That incident had the last recorded lahars and pyroclastic flows emanating from the volcano.  Glacier Peak has had a number of eruptions, with the oldest believed to be 13,000 years ago.  There were three other eruptions in between putting Glacier Peak firmly in the "very high threat" to erupt category.  Of the five active volcanoes in Washington, four are designated "very high threat".

Mt. Ranier (aka Tahoma, King County)

This is the one we worry about the most as it is considered the most dangerous volcano in the State.  The last time Mt. Rainer erupted was over 650 years ago, long before Washington State was anything and 42 years before Columbus was credited with discovering America.  The eruption of 1450 is believed to have sent four lahars down the mountain into the Puget Sound.  Of the five, Mt. Rainier has the earliest recorded eruption placed around 500,000 years ago.

Mt. Baker (Whatcom County)

Mt. Baker was last heard from in 1880.  When the youngest volcano of the five last erupted, a number of hydro-thermal eruptions caused collapses of Mt. Baker resulting in some lahars moving downward.  There was concern in 1975 that Mt. Baker was on the verge of erupting again as there was a spike in activity that include the release of gases.  Those gases rose in a dark column leading to fear of a pending event and the closure of the Mt. Baker shoreline as acidic water was flowing into the lake for months.

Mt. St. Helens (Skamania County)

Mt. St. Helens is the only volcano in America to erupt in our lifetime.  It caused over $1 billion in damage in 1980 (over $3.85 billion today).  The eruption lasted roughly 9 hours, destroying its summit, and turning day into night in Eastern Washington.  Ash made its way across the United States in 3 days time and around the world in 15 days.  The 57 deaths attributed to the eruption made it the deadliest in U.S. history.  The thousands of animals killed along with the 230 square miles of land and 4 billion board feet of timber destroyed made it the most devastating.

While St. Helens has had activity into the 21st century, it is not considered likely to erupt again anytime soon.  The volcano that is expected to erupt soon, this year to be exact, is one you've probably never heard of, and is in the group of Pacific Northwest volcanoes.

Axial Seamount (Northeast Pacific Ocean)

A mile underwater and 300 miles offshore is Axial Seamount, the busiest volcano in the Pacific Northwest.  It has erupted three times in the last 25-30 years and researchers believe it will erupt again this year.  Scientists from Oregon State University and the University of Washington joined others at the American Goeophysical Union conference a few months ago to present their data.

While an eruption is expected, a threat to life is not.  Because it is so far underwater, the likelihood of a tsunami or earthquake caused by an eruption is considered extremely minimal.