June 19 - Two Minor Swarms at the Caldera

On June 19, 2019, two small earthquake swarms struck Yellowstone Caldera. One struck south of West Thumb Lake and another swarm, albeit far smaller, struck somewhere along the southeastern shores of Yellowstone Lake, near station YTP. I will simply show some plots and seismic audio pertaining to these events. If you wish to continue, please click the title of this post or "read more"...

Yellowstone Station Locations

USGS EQ Map

June 12, 2019 Swarm

On June 19, 2019, two small earthquake swarms struck Yellowstone Caldera. Please review the buttons above for seismic station locations at Yellowstone and the USGS EQ map for this location and time period.

The first swarm, which started at 5:53UTC, occurred parallel to the East Mount Sheridan fault system. This swarm is almost identical to the June 12, 2019 earthquake swarm (click the button above to view that swarm). Although it is the same as the June 12th swarm, it carried far less energy. Then, a little less than 10 hours later, an extremely minor rapid-fire swarm struck somewhere within the circle on the map above, along the southeastern shores of Yellowstone Lake. That location is not 100% so keep checking the USGS EQ map to see if any additional quakes were reported.

In this post, as usual, I will show seismic plots detailing both swarms. I will show helicorder plots first and then each swarm, starting with the East Mount Sheridan swarm of June 19th. I will include seismogram, spectrogram, and spectra plots, information, and seismic audio.

June 19, 2019 swarm (south of West Thumb Lake)
 
Start of swarm: 05:53UTC
End of swarm: 06:25UTC (Total of 32 minutes.)
Info: This earthquake swarm is a continuation of the June 12, 2019 swarm along the East Mount Sheridan fault system, just south of West Thumb Lake. This, at least in my opinion, cannot be characterized as a rapid-fire swarm. However, it can almost be! Over time, my definition of a “rapid-fire” swarm is slightly changing.
Total earthquake count (includes even the tiniest, unreported events): ~32 events of all sizes.
Reported count: 6
Largest reported earthquake of this swarm: M1.8 at 6.8km in depth
Largest amplitude: ~18,400 (B944-EHZ), ~6,500 (YLT-EHZ)
Severity: Minor

DISCLAIMER: If you wish to see which earthquakes in the plots below were reported, simply go to one of the buttons I provided somewhere above that shows you the USGS earthquake map for Yellowstone during this time period. Earthquakes are reported in UTC and the times on the plots are in UTC as well. You can also find the locations of all stations at Yellowstone by looking for one of the two buttons I posted in the beginning of this post. Also, I do not detail every single event of the swarm in the plots below. However, I do try to show most of them. Severity is a personal determination, with the April 11, 2018 swarm acting as a sort of baseline for a major rapid-fire swarm. Severity ranges from minor, to moderate, to major. In rare cases, “extreme” will be used. However, I have not seen a rapid-fire swarm that could ever be labeled as such. But you never know what will happen in the future!

The following is the seismic audio to this earthquake swarm, taken from the seismic station used for the plots above. All seismic audio is best heard when it is sped up. Please use your headphones but be wary of the volume! Every pop or crack you hear is an earthquake. Enjoy!

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June 19, 2019 swarm (Southern Yellowstone Lake near YTP)
 
Start of swarm: 15:19UTC
End of swarm: 15:28UTC (Total of 9 minutes.)
Info: This very small burst in seismicity occurred a little less than 10 hours after the swarm earlier on this day. It occurred far east near station YTP.
Total earthquake count (includes even the tiniest, unreported events): ~19 events of all sizes, many of which were extremely small.
Reported count: None yet. Keep checking the USGS EQ map to see if they have reported any.
Largest reported earthquake of this swarm: None reported yet.
Largest amplitude: ~6,800 (YTP-EHZ), ~4,600 (YLT-EHZ)
Severity: Very minor
 
DISCLAIMER: If you wish to see which earthquakes in the plots below were reported, simply go to one of the buttons I provided somewhere above that shows you the USGS earthquake map for Yellowstone during this time period. Earthquakes are reported in UTC and the times on the plots are in UTC as well. You can also find the locations of all stations at Yellowstone by looking for one of the two buttons I posted in the beginning of this post. Also, I do not detail every single event of the swarm in the plots below. However, I do try to show most of them. Severity is a personal determination, with the April 11, 2018 swarm acting as a sort of baseline for a major rapid-fire swarm. Severity ranges from minor, to moderate, to major. In rare cases, “extreme” will be used. However, I have not seen a rapid-fire swarm that could ever be labeled as such. But you never know what will happen in the future!

The following is the seismic audio to this earthquake swarm, taken from the seismic station used for the plots above. All seismic audio is best heard when it is sped up. Please use your headphones but be wary of the volume! Every pop or crack you hear is an earthquake. Enjoy!