SCSNCalipatria – SCSN

06/05/2021, M5.3 swarm near Calipatria

Jennifer Andrews — Sat, 05 Jun 2021 18:58:06 +0000

Significant Events

Largest event: M5.3, 05 Jun 2021 10:55:58 PDT, (33.140, -115.635), depth 5.8km. 11km W of Calipatria, California.
As of 07 Jun 2021, 03:30PM PDT, the following event numbers have been recorded in the swarm:

M≥5: 1
M≥4: 5
M≥3: 34
M≥2: 292

All M5 events recorded:

M 5.3 05 Jun 2021 10:55:58 PDT, (33.140, -115.635), 39919392

Swarm Numbers

As of 07 Jun 2021, 03:30PM PDT, we have recorded 1004 events in the swarm (within a 20 km radius, and counting 5 days before the largest event). The smallest event is magnitude 0.5. Many of the smaller events are still being analyzed and will be gradually added to the catalogue.
More activity is expected in the next few days, swarm activity in Southern California can continue for hours, days, weeks, months or years. For more information on swarms please see our Swarm page.

Historical Seismicity

Since our records began in 1932 we’ve had 110 events of M4 or greater within 10km of today’s event.
The largest historic event was M6.2 on 1987/11/24.
The most recent historic event was M4.0 on 05 Jun 2021.

Faults

CFM fault associations: most likely Westmorland fault; main segment (94%). Alternates: Not associated with a CFM modeled fault (3%), Other CFM faults (3%).*
Nearby faults: San Jacinto fault zone, Superstition Hills section (Lone Tree fault) (13.9 km) and San Jacinto fault zone, Superstition Hills section (Superstition Hills flt) (14.7 km).**

Additional Information

Links for: USGS earthquake page, ShakeMap, DYFI, waveforms.
Visit our special reports page for further information on local notable earthquakes.

Below are the waveform data associated with the M5.3 event, as recorded in our Live Seismograms Feed. Additional waveform data associated with other M3.5+ events in this swarm will be added at a later date.

*Earthquakes can occur both near or on major known faults, and in places where no clear fault zones are known. Using the statisticalmethod of Evans et al. (in prep. 2019) the location and focal mechanism of this earthquake suggest the above association with modeled faults in the Community Fault Model (CFM) provided by the Southern California Earthquake Center (SCEC) and Harvard University. Note that the CFM fault association may be different from the nearby faults list. Differences may arise due to different fault databases, and because the CFM fault association uses the hypocenter with relation to subsurface 3-dimensional fault orientation models, while the nearby faults list utilizes mapped surface traces as they relate to the epicenter.

CFM Fault: SCEC CFM 5.0 Fault name and closest segment if available; The CFM is maintained by Harvard University, Dept of Earth & Planetary Sciences.

Probability: The probability in percent the earthquake is associated with this fault.

SCSN: Caltech/USGS Southern California Seismic Network

**U.S. Geological Survey and California Geological Survey, 2006, Quaternary fault and fold database for the United States, accessed 2015, from USGS web site: https://earthquake.usgs.gov/hazards/qfaults/

This information is subject to change as more up-to-date data become available.

02/09/2021, M3.8 swarm near Calipatria

Jennifer Andrews — Thu, 11 Feb 2021 18:36:37 +0000

Significant Events

Largest event: M3.8, 09 Feb 2021 17:01:15 PST, (33.175, -115.613), depth 3.8km. 11km WNW of Calipatria, California.
As of 11 Feb 2021, 10:19AM PST, the following event numbers have been recorded in the swarm:

M≥3: 5
M≥2: 23

All M3 events recorded:

M 3.0 09 Feb 2021 03:51:26 PST, (33.158, -115.633), 39546087
M 3.8 09 Feb 2021 17:01:15 PST, (33.175, -115.613), 39546863
M 3.2 09 Feb 2021 17:01:41 PST, (33.172, -115.600), 39546855
M 3.1 09 Feb 2021 17:25:07 PST, (33.172, -115.608), 39546951
M 3.8 09 Feb 2021 17:27:09 PST, (33.175, -115.612), 39546975

Swarm Numbers

As of 11 Feb 2021, 10:33AM PST, we have recorded 111 events in the swarm (within a 20 km radius, and counting 5 days before largest event). The smallest event is magnitude 0.5. Many of the smaller events are still being analyzed and will be gradually added to the catalogue.
More activity is expected in the next few days, swarm activity in Southern California can continue for hours, days, weeks, months or years. For more information on swarms please see our Swarm page.

Historical Seismicity

Since our records began in 1932 we’ve had 98 events of M4 or greater within 10km of today’s event.
The largest historic event was M6.2 on 1987/11/24.
The most recent historic event was M4.0 on 04 Jan 2021.

Faults

CFM fault associations: most likely Not associated with a CFM modeled fault (38%). Alternates: Elmore Ranch fault (28%), Other CFM faults (34%).*

Additional Information

Links for: USGS earthquake page, ShakeMap, DYFI, waveforms.
Visit our special reports page for further information on local notable earthquakes.

Below are the waveform data associated with the M3.8 at 17:01 PST 09/02/2021, as recorded in our Live Seismograms Feed.

*Earthquakes can occur both near or on major known faults, and in places where no clear fault zones are known. Using the statistical method of Evans et al. (in prep. 2019) the location and focal mechanism of this earthquake suggest the above association with modeled faults in the Community Fault Model (CFM) provided by the Southern California Earthquake Center (SCEC) and Harvard University. Note that the CFM fault association may be different from the nearby faults list. Differences may arise due to different fault databases, and because the CFM fault association uses the hypocenter with relation to subsurface 3-dimensional fault orientation models, while the nearby faults list utilizes mapped surface traces as they relate to the epicenter.

CFM Fault: SCEC CFM 5.0 Fault name and closest segment if available; The CFM is maintained by Harvard University, Dept of Earth & Planetary Sciences.

Probability: The probability in percent the earthquake is associated with this fault.

SCSN: Caltech/USGS Southern California Seismic Network

This information is subject to change as more up-to-date data become available.

07/26/2017, M3.6 near Calipatria

Zackary Newman — Thu, 03 Aug 2017 16:06:18 +0000

26 Jul 2017 12:43:57 PDT, (33.165, -115.647), depth 3.3km, 13km WNW of Calipatria, California
Aftershocks: so far (03 Aug 2017, 09:03AM PDT) there have been 15 aftershocks recorded, the largest M2.2 (smallest M1.1). More may be expected in the next few days, the largest expected is approximately 1 magnitude unit smaller than the mainshock. There is a small chance (about 5%) that a larger quake could occur, with the likelihood decreasing over time.
There were 8 events during the 3 days prior to the earthquake (within a 15 km radius), the largest was M3.3 (2017/07/26).
Historical seismicity: since our records began in 1932 we’ve had 44 events of M4 or greater within 10km of today’s event, the largest was M5.8 (1945/08/15) and the most recent was M4.1 on 21 May 2015.
Nearby faults: San Jacinto fault zone, Superstition Hills section (Lone Tree fault) (14.2 km) and San Jacinto fault zone, Superstition Hills section (Superstition Hills flt) (14.9 km).
Links for: USGS earthquake page, ShakeMap, DYFI, waveforms.
Visit our special reports page for further information on local notable earthquakes.