Ongoing Yellowstone Earthquake Swarm 29 Yellowstone Earthquakes from 2.4 to 4.5 Magnitude For The Last 30 Days

June 26, 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 09:40 MDT on June 26th, 2017, is composed of 878 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, 5 earthquakes in the magnitude 3 range, 68 earthquakes in the magnitude 2 range, 277 earthquakes in the magnitude 1 range, 508 earthquakes in the magnitude 0 range, and 19 earthquakes with magnitudes of less than zero. These events have depths from ~0.0 km to ~14.5 km, relative to sea level. At the time of this report, there were 121 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).

Figure 1. Location of the earthquakes that are part of the swarm as of June 19, 2017 at 13:30 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

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/.

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
Posted in Earthquake Press Release
Magnitude 3.8 near Bluff, UT
Posted on April 24, 2017 by Paul Roberson

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