After a month or two of almost no rapid fire swarms, Yellowstone seems to be telling us it is alive and well. I will show seismic plots, images, and even some seismic audio of this swarm. Please click the title of this post or "read more" to continue...
Although no earthquakes have been reported for this swarm at the time of writing this, if they ever are reported they can be seen if you CLICK HERE. Also if you wish to know the locations of any stations I use in this post, please CLICK HERE. Also if you wish to skip to the seismic audio of this swarm now, please scroll to the end of this post.
It seems ever since late-April 2019, rapid fire swarms are starting to increase around West Thumb Lake at Yellowstone. This is nothing new and they still are nowhere near the power of some of the historical rapid fire swarms that occur around West Thumb Lake and Yellowstone Lake (sometimes even Shoshone and Lewis lakes). If you wish to see those historical rapid fire swarms, simply go to the "Seismic Events" menu above and go to the "West Thumb, Yellowstone Energetic Swarms" page.
Today's swarm was shorter than the one on May 4, 2019 but just as interesting. On the map above, you can see the likely swarm epicenter. I had to go off of P/S wave arrivals to determine an approximate swarm epicenter, since none of the events have been reported yet. Here are some spectrogram plots of the entire swarm for May 7, 2019 which likely struck under the northern tip of West Thumb Lake:
The following is some information about this swarm:
May 7, 2019 swarm
Start of swarm: 10:52UTC
End of swarm: 11:01UTC
Info: Although the start and end of the swarm is stated above, the swarm contained 2 bursts. The first burst lasted about 4 minutes, containing approximately 18 events, and the final burst lasted about 3 minutes and contained approximately 8 events which were smaller than the events in the first burst. The start/end time above, and the total earthquake count below, is for the entire swarm (both bursts).
Total earthquake count (includes even the tiniest, unreported events): ~26 events for entire swarm
Reported count: 0 (so far)
Largest reported earthquake of this swarm: None reported yet… Largest event is likely a shallow M2.1 or so.
Largest amplitude: ~27,500 (YDD-HHZ), ~17,800 (YLT-EHZ)
Here are some helicorder plots in slideshow format from 6 of the closest seismic stations to this swarm. After that, I will detail this swarm with eight 3-plot images, also in slideshow format.
Slightly less than 10 hours before the swarm struck West Thumb Lake, a M2.5 struck at 7.7km in depth just to the west of Hebgen Lake in the West Yellowstone area.
The following is the seismic audio of the May 7, 2019 rapid fire swarm at West Thumb Lake. If you wish to view this on YouTube, please CLICK HERE. I highly suggest using headphones but be careful of the volume just in case!
Please click a post title to view the data pertaining to that event!