Earthquake swarm continues at Mount St. Helens

Small magnitude earthquake rates have been steadily increasing since March, reaching nearly 40 per week.

5 May 2016 – (Excerpts from USGS website) – Over the last 8 weeks, there have been over 130 earthquakes formally located by the Pacific Northwest Seismic Network and many more earthquakes too small to be located. The earthquakes have low magnitudes of 0.5 or less; the largest a magnitude 1.3.  These earthquakes are too small to be felt at the surface.

Such events are commonly seen in active hydrothermal and magmatic systems.

The current pattern of seismicity is similar to swarms seen at Mount St. Helens in 2013 and 2014; recharge swarms in the 1990s had much higher earthquake rates and energy release.

There are no signs of an imminent eruption.

As was observed at Mount St. Helens between 1987-2004, recharge can continue for many years beneath a volcano without an eruption.

https://volcanoes.usgs.gov/observatories/cvo/

8 thoughts on “Earthquake swarm continues at Mount St. Helens”

  1. Arizona had a 3.4 magnitude earthquake near the Utah-Grand Canyon border this morning (Friday) and a 3.8 magnitude yesterday. There has been a rash of 55 quakes in recent weeks that cannot be related to any hydraulic fracking or other man-made phenomenon.

    The USGS infographic at the bottom of this report shows every earthquake in Arizona since 1970. Of prime importance is the large and extremely dramatic increase in numbers in the NW corner of the state in the past couple of years, far above the historical norm. Some are along faults not previously known, but what the USGS will say is that it’s not due to volcanic activity despite Arizona being home to more than 600 volcanoes. While I would agree with that assessment, it’s hard to explain the sudden uptick in earthquake activity.

    Perhaps this is confirmation that stress along the southern stretch of the San Andreas fault in California is at a critical load and indeed is “locked and loaded” for a catastrophic decompression event.

    http://www.abc15.com/news/region-northern-az/other/magnitude-34-quake-shakes-northwestern-arizona-friday-morning

  2. The quakes on the seismogram look like rock fracture events or A type earthquakes. If you see B type earthquakes be very concerned because that means you are detecting the resonance of magma flowing through the cracks and passage ways in the volcano. The volcano may be sealed when this happens and when that happens you have pressurization followed by an explosive eruption.
    BBC Science Documentary Volcano Hell Nature Documentary
    https://youtu.be/8QpSyXZdbX0

  3. This is amazing! I live about 500 miles South of Mt. Saint Helens and not a peep in our local news! I swear the local news wants to keep everyone ignorant of everything NOT related to their interests and Agenda!!

  4. There was news a few weeks ago of new lava dome forming . The article was not on the web long .

  5. with rather low sunspot activity
    earth quakes n volcanos almost always increase in number and strength at those times.
    as do weird weather events as the weakening magnetic field is allowing more of the cme magnetics and solar winds to reach us lower down through the troposphere.
    they affect storm rain and other patterns

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