Ongoing Yellowstone Earthquake Swarm North of West Yellowstone, MT.

August 03, 2017 UPDATE: The University of Utah Seismograph Stations (UUSS) is monitoring an earthquake swarm which is currently active on the western edge of Yellowstone National Park.  The swarm began on June 12th, 2017 and, as of 13:00 MDT on August 2nd, 2017, is composed of 1,562 events with the largest magnitude of ML 4.4 (MW 4.4) (Figure 1).  The swarm consists of one earthquake in the magnitude 4 range, 8 earthquakes in the magnitude 3 range, 134 earthquakes in the magnitude 2 range, 505 earthquakes in the magnitude 1 range, 879 earthquakes in the magnitude 0 range, and 35 earthquakes with magnitudes of less than zero.  These events have depths from ~0.0 km to ~14.0 km, relative to sea level.  At the time of this report, there were 125 felt reports for the M4.4 event that occurred on June 16, 2017 at 00:48:46.94 UTC (June 15, 2017 at 18:48:46.94 MDT).  The M4.4 event has an oblique strike-slip moment tensor solution (Figures 1 & 2).  In addition, four other earthquakes in the swarm have been reported felt.

 

 

Figure 1. Location of the earthquakes that are part of the swarm as of August 3, 2017 at 01:00 PM MDT (red symbols).

 

Figure 2. Moment Tensor solution for the M4.4 event showing the fit between data (black) and synthetics (red dashed).

Moment Tensor for M 4.5

Figure 3. Animation of the June 2017 Yellowstone earthquake swarm.  Earthquakes appear as red circles as they happen, then transition to blue.  After they have occurred, they appear as black circles.  The size of the circles are proportional to the earthquakes magnitude.

Earthquake swarms are common in Yellowstone and, on average, comprise about 50% of the total seismicity in the Yellowstone region.

UUSS will continue to monitor this swarm and will provide updates as necessary.

 

If you think you felt an earthquake, please fill out a felt report at: http://earthquake.usgs.gov/earthquakes/dyfi/.

Yellowstone swarm continues with M 3.6 felt near West Yellowstone, MT

Released: July 18, 2017 03:15 PM MDT

The University of Utah Seismograph Stations reports that a minor
earthquake of magnitude 3.6 occurred at 02:31 PM on July 18, 2017
(MDT). The epicenter of the shock was located 9.3 mi N of W.
Yellowstone, MT. This earthquake is part of an ongoing sequence
of earthquakes that began on June 12, 2017 and included a
a magnitude 4.4 event on June 15, 2017, 9.0 mi NNE of W.
Yellowstone, MT. Today’s M 3.6 earthquake was reported felt in
Yellowstone National Park and in West Yellowstone, MT. It was
followed by numerous smaller earthquakes, the largest of which
had magnitudes of 2.8 and 2.9. The total number of located
earthquakes in the current sequence has now exceeded 1200.

Anyone who felt the earthquake is encouraged to fill out a survey form
either on the Seismograph Stations website: www.quake.utah.edu or the
US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:

Date (UTC): July 18, 2017 Time (UTC): 20:31

Date (local): July 18, 2017 Time (local): 02:31 PM MDT

Latitude: 44 47.25′ N

Longitude: 111 2.27′ W

Preferred magnitude: 3.60 Ml

1928 – Helena, MT – M 5½ ±

Intermountain Seismic Belt Historical Earthquake Project

February 29, 1928 – Helena, MT – M 5½ ±

The 1928 Helena, Montana earthquake had no reported injuries or damage. The shaking startled people throughout the city of Helena and was more noticeable on upper floors of buildings with two or more stories above ground. The shaking was severe enough to disrupt a trial in one city courthouse. Without taking time to formally adjourn the proceedings, the judge and others fled the courtroom as the shaking began.

The earthquake was reported felt in areas southeast of Helena including: Trident, Three Forks, Manhattan, Logan, Lombard, and Sixteen-Mile Canyon. White Sulphur Springs, to the east of Helena, also reported earthquake shaking.

There were reports of shaken buildings, windows rattling, furniture moving, and goods being shaken from shelves.

 

For additional information about this earthquake:

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Magnitude 3.4 Arizona earthquake near St. George, UT

PRESS RELEASE

University of Utah Seismograph Stations 

Released: July 12, 2017 09:10 AM MDT

The University of Utah Seismograph Stations reports that a minor earthquake of magnitude 3.4 occurred at 08:41 AM on July 12, 2017 (MDT).  The epicenter of the shock was located nine miles SSE of St. George, UT.  A total of 6 earthquakes of magnitude 3.0 or greater have occurred within 16 miles of the epicenter of this event since 1962. The largest of these events was a magnitude 5.9 on September 02, 1992, two miles SSE of Washington, UT.

Today’s earthquake was reported felt in Saint George, UT and surrounding cities.

Anyone who felt the earthquake is encouraged to fill out a survey form either on the Seismograph Stations website: www.quake.utah.edu or the US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:

Date (UTC):   July 12, 2017         Time (UTC):   14:41

Date (local): July 12, 2017           Time (local): 08:41 AM MDT

Latitude:     36º 58.79′ N

Longitude:    113º 33.96′ W

Preferred magnitude: 3.40 Ml

1947 – Virginia City, MT – M 6¼

Intermountain Seismic Belt Historical Earthquake Project

November 23, 1947 – Virginia City, MT – M 6¼

The Virginia City earthquake was reported felt in several communities in Montana, including: Billings, Missoula, Lewistown, Livingston, Helena, Harlowton, Malta, Havre, Glasgow, Kalispell, and Bozeman; and as far south as Idaho Falls, Idaho.

In most areas, the earthquake rocked buildings with, what was described in Helena as, a “long and easy” motion. There were widespread reports of swaying light fixtures, stopped clocks, dishes rattling, and window blinds and curtains moving back and forth. Cracks in plaster were observed and a plaster ceiling fell in a café in Hamilton.

Near the epicenter, in Virginia City, bricks and plaster were shaken loose from buildings, windowpanes were shattered, walls were cracked, and chimneys damaged. There were also reports of pictures being shaken off walls and dishes falling from cupboards.

In some locations sleeping residents were awakened as the shaking dislodged icicles from rooftops. Strange noises were reportedly heard during the shaking, and some residents fled their homes in fear. However, there were no reports of injuries or significant damage resulting from the earthquake.

 

For additional information about this earthquake:

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Magnitude 4.5 near West Yellowstone, MT

PRESS RELEASE

University of Utah Seismograph Stations Released: June 15, 2017 07:55 PM MDT

The University of Utah Seismograph Stations reports that a light earthquake of magnitude 4.5 occurred at 06:48 PM on June 15, 2017 (MDT). The epicenter of the shock was located in Yellowstone National Park, eight miles north-northeast of the town of West Yellowstone, Montana. The earthquake was reported felt in the towns of West Yellowstone and Gardiner, Montana, in Yellowstone National Park, and elsewhere in the surrounding region. Today’s earthquake is part of an energetic sequence of earthquakes in the same area that began on June 12. This sequence has included approximately thirty earthquakes of magnitude 2 and larger and four earthquakes of magnitude 3 and larger, including today’s magnitude 4.5 event. Today’s earthquake is the largest earthquake to occur in Yellowstone National Park since March 30, 2014, when a magnitude 4.8 event occurred 18 miles to the east, near Norris Geyser Basin.

Anyone who felt the earthquake is encouraged to fill out a survey form either on the Seismograph Stations website: www.quake.utah.edu or the US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:

Date (UTC): June 16, 2017

Time (UTC): 00:48 Date (local): June 15, 2017

Time (local): 06:48 PM MDT

Latitude: 44 46.48′ N

Longitude: 111 2.74′ W

Preferred magnitude: 4.50 Ml

The April 22, 2017 M 3.8 Earthquake Sequence near Rangely, Colorado

On April 22, 2017, a magnitude 3.8 earthquake occurred approximately 4 km northwest of Rangely, Colorado at 11:48 AM local time (05:48 PM UTC).  There were 15 felt reports from the town of Rangely, CO.  Two aftershocks, approximately 1 km NNE of the mainshock, were located by UUSS.  The first aftershock (ML 2.6) occurred on April 27 at 03:11 AM local time (09:11 AM UTC), and the second aftershock (ML 3.3) occurred on May 3 at 01:42 AM local time (07:42 AM UTC). Based on the moment tensor solution for the mainshock this was a predominantly strike-slip earthquake on steeply dipping planes with the strike either northwest or northeast.  From the distribution of the aftershock locations, we tentatively favor the northeast striking plane.  Eighteen earthquakes within 20 km of the mainshock , with magnitude greater than 2.0, have been catalogued since 1962.  The largest historical earthquake (ML 4.6, March 20, 1995) was located 2.3 km NE of the 2017 mainshock.

The Rangely area was one of the first focus sites for the study of fluid-induced earthquakes.  Some of the first documented induced earthquakes occurred near Rangely in the 1960s and 1970s.  During this time water-flood expansion was being used for secondary oil recovery.  It was a good place to test the correlation between fluid injection and seismic events with a controlled experiment (Rayleigh et al., 1976), and the experiment showed a direct link.  The seismicity during the experiment occurred on a ENE-WSW trending plane.  This is rotated from the current seismicity, but the locations of the seismic events have also migrated through time.  Water based fluid injection ended in 1983; since 1986 injection of CO2 has been used for secondary oil recovery.

Given the proximity of the recent seismicity to the Rangely Oil Field, it is fair to ask if the recent sequence is also induced.  Analysis of this sequence is ongoing, but initial work includes the following results.  An STA/LTA detector (detection threshold 3.5) was run across continuous waveforms from the two nearest stations (O20A and RDMU) for the time period April 22, 2017–May 04, 2017.  Requiring simultaneous detections on both stations, in order to reduce the number of false detections, resulted in one new detected event that occurred on May 3.  Using cross-correlation, we found similar waveforms (CC > 0.5) from the four events (mainshock, two aftershocks, and the new detected event) recorded at station O20A, suggesting possible common source properties.

The lack of close seismic stations makes it difficult to clearly associate these seismic events with oil production efforts.

Magnitude 3.7 near Rangely, CO

University of Utah Seismograph Stations

Released: April 22, 2017 02:00 PM MDT

The University of Utah Seismograph Stations reports that a minor
earthquake of magnitude 3.70 occurred at 11:48 AM on April 22, 2017
(MDT). The epicenter of the shock was located in northwestern Colorado,
2.5 miles northwest of the town of Rangely, CO. The earthquake was
reported felt in the town of Rangely. A total of 11 earthquakes of
magnitude 3.0 or greater have occurred within 16 miles of the epicenter
of this event since 1962. The largest of these events was a magnitude
4.6 on March 20, 1995, which occurred in the same area.

Anyone who felt the earthquake is encouraged to fill out a survey form
either on the Seismograph Stations website: www.quake.utah.edu or the
US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:

Date (UTC): April 22, 2017 Time (UTC): 17:48

Date (local): April 22, 2017 Time (local): 11:48 AM MDT

Latitude: 40 6.60′ N

Longitude: 108 50.48′ W

Preferred magnitude: 3.7 Ml

Magnitude 3.8 near Bluff, UT

PRESS RELEASE

University of Utah Seismograph Stations

Released: April 21, 2017 11:30 PM MDT

The University of Utah Seismograph Stations reports that a minor
earthquake of magnitude 3.8 occurred at 10:01 PM on April 21, 2017
(MDT). The epicenter of the shock was located 13 mi WSW of
Montezuma Creek, UT. One earthquake of magnitude 3.0 or greater has
occurred within 16 mi of the epicenter of this event since 1962. This
was a magnitude 3.7 on June 06, 2008, 9 mi WNW of
Montezuma Creek, UT.

Today’s earthquake was reported felt in the town of Blanding, UT.

Anyone who felt the earthquake is encouraged to fill out a survey form
either on the Seismograph Stations website: www.quake.utah.edu or the
US Geological Survey website: earthquake.usgs.gov.

Earthquake Summary:

Date (UTC): April 22, 2017 Time (UTC): 04:01

Date (local): April 21, 2017 Time (local): 10:01 PM MDT

Latitude: 37 14.73′ N

Longitude: 109 34.10′ W

Preferred magnitude: 3.8 Ml

1988 – San Rafael Swell, UT – M 5.3

Intermountain Seismic Belt Historical Earthquake Project

August 14, 1988 – San Rafael Swell, UT – M 5.3

This earthquake was located approximately 10 miles ESE of Castle Dale, Utah in Emery County.

There were no reports of injuries or serious damage resulting from the earthquake. Reports indicate that the earthquake was felt as far east as Golden, Colorado, as far south as Albuquerque, New Mexico, as far west as Delta, Utah, and as far north as Brigham City, Utah. The earthquake was reportedly felt particularly in valleys, while less noticed in mountain areas.

Minor damage in Emery County consisted of cracks in foundations, chimneys, and old buildings. Dishes and store goods fell from shelves and pictures were dislodged from wall hooks. Cracks and plaster damage were also observed in ceilings and walls.

Calls about the earthquake were received from several coal mines in the area, but there were no reports of injury or damage. Local dams were examined and found to be sound.

Rock falls were a notable feature of this earthquake. Fallen boulders impeded travel on some roadways. In many locations, falling rocks sent up clouds of dust that were visible for many miles.

Near the epicenter, north of Ferron, Utah a resident reported seeing dust clouds on the western ridge that partially obscured Ferron Mountain and the cliffs around the Wilberg Mine. “You couldn’t see the mountain up around Wilberg for five to 10 minutes because of the dust. Same on the desert [to the east]. Just a big string of dust from as far south to as far north as you could see.”

 

For additional information about this earthquake:

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For more information about this project:

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