Three EQs M3.0+ Strike USA within about 3 Hours

In this post I will detail the info and seismic data pertaining to three earthquakes that occurred across the USA within about 3 hours of each other. They weren't too crazy but all 3 seemed to have occurred with other events. I will mainly show the reported events and some of the unreported events as well. One occurred in California near Belden, another occurred in Utah, and the other one occurred at the Yellowstone Super-Volcano. The one at Yellowstone actually occurred in a strange location: far to the west of Old Faithful but also far to the south of Maple Creek. If you have not already, please click the title of this post or "read more" to continue.

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M3.1 in California

All of the USGS event pages shown below are as of 6:00UTC February 17, 2019 (10:00pm Pacific Time, February 16, 2019). Also remember you can see the number of felt reports on the event pages.

At 19:04UTC on February 16, 2019, a M3.1 earthquake supposedly at -1.2km in depth struck just south of Belden, CA. This earthquake seems to have occurred with a few other very tiny events, but other than that it seems this was the only event (the tiny events are hard to tell if they are surface noise or actual earthquakes). USGS does not show any faults at this epicenter so it is currently unknown what exact process caused this earthquake. Below is the USGS event page, the location of the event in regards to the closest seismic station, and the custom 3-plot image of this event.

M3.1 Strikes W of Old Faithful Geyser, Yellowstone

At 21:22UTC February 16, 2019, a M3.1 earthquake struck at 8.2km in depth to the west of the Upper Geyser Basin and Old Faithful Geyser at Yellowstone. Although this area does see activity from time to time, this is a rare location for a M3.1. Although it seems it did not occur as part of a swarm, this event did occur about 6 hours after a small swarm struck near the Norris/Mary Lake area. Please CLICK HERE to see some plots of that swarm in question. You can clearly see, on just a few of the helicorders below, the M3.1 did occur approximately 6 hours after the swarm near the Norris/Mary Lake area.

I will first show the USGS event page to this earthquake (note some people felt this event), the location of the event in regards to the closest seismic station, a whole look of the event and aftershocks (via spectrogram plot), and then I will show the event along with an image after it detailing a few unreported events. Again, this event did NOT take part or cause a swarm, but it did have many tiny aftershocks. Last, but certainly not least, I will show a slide show of a few select station's helicorders. All 3-plot images filtered using a 0.6Hz high pass filter.

Event and closest station locations.

USGS event page as of 6:00UTC February 17, 2019 (10:00pm PST, February 16, 2019)

A spectrogram plot detailing the whole M3.1/Aftershock sequence. A few tiny events did occur after this, but this was pretty much it (at least so far).

M3.3 in Utah

Utah has seen a good amount of seismicity lately! A few swarms have broken out, which I am still analyzing, and now we have a M3.3 at 8.0km in depth, close to the same depth as the M3.1 at Yellowstone that occurred just about 43 minutes prior (it was reported to be at 8.2km). This earthquake did see a few events before and a few events after as well.  So far, those events seem to be unreported but of course that could change in the coming days.

First I will show the location of the M3.3 in regards to the closest seismic station: TCRU in the UU network. Then I will show the helicorder from that station, the event page to the largest event, and some plots of the largest event and 2 so-far-unreported events. As always, remember to pay attention to all chart labels and any captions beneath any images.