As usual, please click the title of this post or "read more" to continue...
March 11-12, 2019 Yellowstone saw a small increase in seismicity in 3 locations: just south of Purple Mountain, far south of Yellowstone Lake, and the northern tip of Yellowstone Lake. If you wish to see the info and data pertaining to the first two locations, please CLICK HERE to visit my post about it.
Again, the third location of the increase in seismicity is circled in the image above. The 6 stations I used for cross correlation are also labeled, with B206 and YML beyond the map frame. This swarm was one of the smallest rapid fire swarms I have ever seen at Yellowstone. Not only were the magnitudes very small, but the quantity was quite low as well. Also, according the the waveform data, it appears this minor swarm was extremely shallow. I am now guessing it struck within that circled area above at about 1km to 3km in depth. Although you cannot notice on the helicorders shown at the end of this post, these events did appear on 5 out of the 6 stations labeled above. Here are two examples using the program WAVES. The diagonal lines show where the earthquakes appeared within each seismogram from each seismometer's data stream:
So many of the micro-quakes within this minuscule swarm did appear on 5 out of the 6 surrounding stations. So we know these earthquakes occurred, but B208 was basically the only station to detect clear P and S wave arrivals. That means it is highly unlikely these earthquakes will be reported, basically because the University of Utah does not like to report earthquakes without knowing the exact epicenter (*shrug*). Below is some information regarding this burst in seismicity. It will be followed by a slideshow of a few 3-plot images detailing this event and then a slideshow showing the helicorders from the 6 stations labeled above.
March 11, 2019:
Start of swarm: 10:29UTC
End of swarm: 10:32UTC
Note: The time period above is ONLY for the main burst of seismicity. Very tiny micro-quakes popped off many times throughout the rest of the day.
Total earthquake count (includes even the tiniest events): Approximately 13 micro-quakes at the maximum for the main burst, with likely another 13 to 15 throughout the day.
Reported count: 0
Magnitudes/Depths of reported events for this swarm from newest to oldest: None reported
Largest reported earthquake of this swarm: None reported
Largest amplitude: 4,400 (B208)
USGS EQ map for this swarm: None were reported
Severity: Extremely minor
Please click a post title to view the data pertaining to that event!