Mt St Helens - More than 400 earthquakes, yet no imminent eruption

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SUMMARY

Mount St. Helens has recorded over 400 earthquakes since mid-July, primarily small quakes with magnitudes less than 1.0, indicating no imminent eruption according to the U.S. Geological Survey. The current seismic activity is significantly lower than the patterns observed prior to the 2004 eruption, which began with a similar swarm of small earthquakes. In 2004, increased seismic activity led to explosive eruptions, highlighting the importance of monitoring changes in earthquake frequency and magnitude.

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  • Awareness of historical volcanic eruptions, particularly Mount St. Helens' activity
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Geologists, volcanologists, emergency management professionals, and anyone interested in volcanic activity and earthquake monitoring will benefit from this discussion.

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Mount St. Helens records more than 400 earthquakes since mid-July, but no signs of imminent eruption
https://apnews.com/article/how-many-earthquakes-mount-st-helens-621b5c405f4cf80c76ba68d10b2f5094

VANCOUVER, Wash. (AP) — More than 400 earthquakes have been detected beneath Washington’s Mount St. Helens in recent months, though there are no signs of an imminent eruption, according to the U.S. Geological Survey.

Most of the quakes over a three-month span beginning in mid-July were less than magnitude 1.0 and too small to be felt at the surface, the agency reported last week.
Maybe if the quakes were 2 or 3 Mag and increasing in strength, that would be a concern.

 
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Lets hope we don't have a repeat of 2004. It was fun being up there during the dome building eruption.
https://www.usgs.gov/volcanoes/mount-st.-helens/2004-2008-renewed-volcanic-activity
The sudden reawakening of Mount St. Helens in late September 2004 was surprising because the preceding four years had seen the fewest earthquakes since the 1980-86 eruption ended.

In the early hours of 23 September 2004, a swarm of small-magnitude (< 1), shallow earthquakes (< 1 km or about 0.5 mi below the surface) began beneath the 1980-1986 lava dome. Over the next seven days, earthquakefrequency and size increased and a growing welt formed on the SE margin of the 1980-86 lava dome and nearby portions of Crater Glacier. By September 26, 2004, the rise in activity led scientists to warn of an increased chance of explosions from the lava dome.

On October 1, 2004, the first of several explosions shot a plume of volcanic ash and gases into the atmosphere from a vent on the southwest margin of the growing welt. Four additional steam and ash explosions occurred through October 5th, and three produced noticeable fallout of fine ash downwind.

https://www.usgs.gov/media/videos/mount-st-helens-steam-ash-emissions-and-dome-growth-october-2004
 
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