Posted on 05/06/2016 11:09:31 AM PDT by BenLurkin
Beginning March 14, 2016, a number of small magnitude earthquakes have occurred beneath Mount St. Helens, at a depth between 2 and 7 km (1.2 to 4 miles). 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. Earthquake rates have been steadily increasing since March, reaching nearly 40 located earthquakes per week. These earthquakes are too small to be felt at the surface.
The earthquakes are volcano-tectonic in nature, indicative of a slip on a small fault. Such events are commonly seen in active hydrothermal and magmatic systems. The magma chamber is likely imparting its own stresses on the crust around and above it, as the system slowly recharges. The stress drives fluids through cracks, producing the small quakes. 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.
No anomalous gases, increases in ground inflation or shallow seismicity have been detected with this swarm, and 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. For more information, see the Activity Updates for Volcanoes in CVO Area of Responsibility and Earthquake Monitoring at Mount St. Helens.
Everything I’ve read about this indicates it’s new magma moving into some spaces down in the ground quite away. It is not indicative of an imminent or future eruption.
The big eruption was 36 years ago on May 18th, 1980. Just a week and a half away.
Only in those areas not owned by the U.S. Forest Service.
Private land owners like Weyerhaeuser or Washington State have replanted those areas they control destroyed by the eruption.
USFS had decided not to replant the areas directly damaged by the eruption.
If you would like more information about what's happening in Oregon, please FReepmail me.
Please send me your name by FReepmail if you want to be on this list.
My eldest son graduated from the University of Wyoming (Laramie}that day. We had to use the windshield wipers to clear the ash off. Would hate to see a replay of that.
Now we are worried about the Yellowstone caldera. It’s over due for a major blow.
There is no way I would have asked that question if it had occurred to me that someone would use that as an opportunity to post that.
I blissfully had forgotten about her.
wow it’s been a long time. the years do pass too quickly.
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