M 3.6 in Yellowstone National Park

PRESS RELEASE

University of Utah Seismograph Stations
Released: July 16, 2021 08:15 PM MDT


The University of Utah Seismograph Stations reports that a minor earthquake of magnitude 3.6 occurred at 06:45 PM on July 16, 2021(MDT). The epicenter of the shock was located beneath Yellowstone Lake, 7.4 mi SSE of Fishing Bridge, WY.  This earthquake is part of an intense sequence of small earthquakes, known as a swarm, that began yesterday afternoon (July 15).  There have been approximately 200 earthquakes in this swarm so far, including three others of magnitude 3.0 or larger and approximately 40 in the magnitude range 2 to 3.  Earthquake swarms are common in the Yellowstone National Park region, and account for roughly half of the total seismicity in the Yellowstone region.  The current swarm is occurring in an area that has had swarm activity in the recent past, including the 2008-2009 Yellowstone Lake swarm that included over 800 earthquakes.

Anyone who felt the earthquake is encouraged to fill out a survey formon the US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:
Date (UTC): July 17, 2021      Time (UTC): 00:45
Date (local): July 16, 2021     Time (local): 06:45 PM MDT
Latitude: 44 27.64′ N
Longitude: 110 20.83′ W
Preferred magnitude: 3.6 Ml

Recent Earthquakes in the Yellowstone Region, July 2-15, 2020

In addition to monitoring the seismicity in the Utah region, the UUSS is also responsible for the operation and analysis of the Yellowstone Seismic Network. Here is our Yellowstone biweekly update:

Map of Recent Earthquakes in Yellowstone July 2-15

Station YNM, located near the Yellowstone Norris Museum, was recently repaired and is now streaming live webicorder images that can be found here:
www.quake.utah.edu/station/heli/YNM.png

Upper Geyser Basin Seismic Imaging Experiment

In the Fall of 2015 and 2016, The University of Utah, in collaboration with the National Park Service and the University of Texas at El Paso installed dense seismic arrays centered on Old Faithful Geyser in Yellowstone National Park.  The goals of this project are to image the shallow velocity structure beneath and around Old Faithful in order to identify areas of shallow, active hydrothermal activity as well as to learn more about these hydrothermal systems, in particular Old Faithful.  The Upper Geyser Basin (Figure 1), where Old Faithful is located, has one of the highest concentrations of hydrothermal features in the world.

Figure 1: The Upper Geyser Basin near Old Faithful (red star) with the main roads in white.
Figure 1: The Upper Geyser Basin near Old Faithful (red star) with the main roads in white.

In November of 2015, 133 seismometers were deployed for 2 weeks (Figure 2) collecting continuous passive seismic data.  The average station spacing was ~50 meters and the aperture of the entire array was ~1 km.

Figure 2: The 2015 deployment of 133 seismometers (yellow circles) around Old Faithful (red star).
Figure 2: The 2015 deployment of 133 seismometers (yellow circles) around Old Faithful (red star).

In November of 2016, in order to achieve a higher station density, a different approach was taken in that smaller dense arrays with ~20 meter spacing were deployed for 24-48 hours and then were moved to different locations around Old Faithful for another 24-48 hours until the area of interest was covered (Figure 3).  In addition, while each individual array was in, we did active seismic sources using a sledgehammer throughout the array.  A subset of instruments was deployed in the same location throughout the experiment in order to tie all the individual sub-arrays together.

Figure 3: The 2016 deployment of 519 individual locations (circles).  The stations are color-coded by how long they were deployed.  Green circles represent seismometers that were deployed in the same location for the entire time-period of the experiment.  Each individual array (labeled 1-7) were deployed for 24-48 hours.
Figure 3: The 2016 deployment of 519 individual locations (circles). The stations are color-coded by how long they were deployed. Green circles represent seismometers that were deployed in the same location for the entire time-period of the experiment. Each individual array (labeled 1-7) were deployed for 24-48 hours.

Data are being analyzed to image the shallow subsurface beneath the Upper Geyser Basin near Old Faithful.

M 3.5 near southern boundary of Yellowstone National Park

University of Utah Seismograph Stations

Released: August 15, 2019 02:30 PM MDT


The University of Utah Seismograph Stations reports that a minor earthquake of magnitude 3.5 occurred at 01:46 PM on August 15, 2019 (MDT).  The epicenter was located on the southern boundary of Yellowstone National Park,  22.2 miles southeast of West Thumb Geyser Basin and 48.7 miles northeast of Jackson, WY.  Earthquake activity in this location is not unusual.  A total of 9 earthquakes of magnitude 3.0 or greater have occurred since 1962 within 16 miles of todays earthquake.  The largest of these events was a magnitude 4.3 on August 21, 2003 located 22.5 miles south-southeast of West Thumb Geyser Basin and 44.2 miles north-northeast of Jackson, WY.

There have been no felt reports for todays earthquake at the time of this writing.  Anyone who felt the earthquake is encouraged to fill out a survey form either on the University of Utah Seismograph Stations website: www.quake.utah.edu or the U.S. Geological Surveys website: earthquake.usgs.gov.

Earthquake Summary:
Date (UTC): August 15, 2019 Time (UTC): 19:46
Date (local): August 15, 2019 Time (local): 01:46 PM MDT
Latudute: 44 7.66’ N
Longitude: 110 22.73’ W
Preferred magnitude: 3.5 Ml