The most active volcano in the Pacific Northwest USA has begun to stir again with more than 130 small earthquakes beneath Mount St. Helens, and today, two more earthquakes struck the CASCADIA SUBDUCTION ZONE!
This behavior indicates that the volcano is steadily recharging – but while it may sound alarming, the experts say they haven’t yet spotted any signs of an imminent eruption.
Washington’s notorious volcano is best known for its ‘cataclysmic’ 1980 eruption, which brought devastation and destruction that stretched on for miles, and visible ash fall nearly 1000 miles away. The event killed 57 people and blasted more than 1,300 feet off the top of the mountain. Now, scientists say its recharging for another eruption.
THE NEW ACTIVITY
Beginning on March 14, 2016, scientists detected low magnitude earthquakes from 1.2 to 4 miles beneath Mount St. Helens. In just the last eight weeks, there have been more than 130 earthquakes, mostly of magnitudes .5 or less.
The largest so far has been a magnitude 1.3.
Scientists say the earthquakes have been steadily increasing in numbers, with up to 40 occurring per week.
So far, though, there have not been any atypical gas emissions, increases in ground inflation, or shallow seismicity.
Scientists claim this means that there are currently no signs of a potential eruption.
Washington’s notorious volcano is best known for its ‘cataclysmic’ 1980 eruption, which brought devastation and destruction that stretched on for miles, and visible ash fall nearly 1,000 miles away.
The event has come to be known as one of the ‘deadliest eruptions in US history’.
It reawakened in 2004, spewing steam and ash up to 10,000 feet into the air.
This activity continued until January 2008, and five months later, scientists concluded Mount St. Helens had gone to sleep.
Now, the volcano is once again recharging.
The blue dots on the graphic below show the locations of the recent spike in earthquakes inside the volcano at Mount St Helens:
In just the last eight weeks, they say, there have been more than 130 earthquakes, mostly of magnitudes .5 or less. The largest so far has been a magnitude 1.3. In the graph above, magnitude is indicated with increasing circle size
A similar pattern was seen at the volcano between 2013 and 2014, and, according to the USGS, recharging can go on for many years before an actual eruption takes place. They point to the activity at Mount St. Helens from 1987-2004, when the volcano slowly recharged for nearly 20 years
The largest so far has been a magnitude 1.3.
The ‘earthquake swarm’ located by the Pacific Northwest Seismic Network is steadily becoming more frequent, but the tremors are not strong enough to be felt at the surface.
As the volcano recharges, ‘most of the action is happening far beneath our feet,’ explains Erik Klemetti, an assistant professor of Geosciences at Denison University, in Wired’s ‘Eruptions’ blog.
While the volcano appears to be sleeping, magma is pushing its way upward.
The scientists predict that the rising magma is applying stresses to the surrounding crust, pushing fluids through the cracks and spurring the small earthquakes.
MAGMA BULGES APPEARING, CRATER NOW GIVING OFF STEAM!
As red hot magma travels upwards from deep within the earth, it is pushing the land above it, upwards. This is now evident as new lava dome bulges have appeared inside the volcano crater!
The photo below was taken on May 6, 2016 and in it, you can see the two new bulges in the center of the crater, and see steam very clearly emanating from the ground. Click the image below (twice) to enlarge.
This image was taken from the official volcano camera installed atop the mountain. The camera is on the peak. In the distance can be seen the other nearby volcano, Mt. Hood.
Mount St. Helens is located in Skamania County, Washington. Roughly 520 million tons of ash were blown across the United States when it erupted in 1980, causing complete darkness in Spokane, Washington – 250 miles away from the volcano! The photos below show citizens having to wear filter masks to protect themselves from the deadly volcanic ash – which turns to mud in the lungs, killing anyone who inhales it. The jogger in the photo at left had to wear the mask even though he was 350 miles away from the eruption! The photo at right below shows tens-of-thousands of trees utterly flattened along a logging road near the south fork of the Toutle River in Washington state after Mt. St. Helens erupted.
Mount St. Helens has been quiet since 2008, but as of two years ago, scientists have confirmed that the volcano has slowly but surely begun to recharge.