SCSNNiland – SCSN

08/01/2023, M4.2 near Niland

Zackary Newman — Wed, 02 Aug 2023 14:41:18 +0000

Event

01 Aug 2023 22:38:08 PDT, (33.187, -115.573), depth 3.1km.
8km SW of Niland, California

Aftershocks

As of 02 Aug 2023, 07:35AM PDT, there have been 5 aftershocks recorded.
The largest was M1.8 (smallest M1.1).
More aftershocks 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.

Possible Foreshocks

There were 4 events during the 3 days prior to the earthquake (within a 10 km radius).
The largest was M2.2 (2023/08/01).

Historical Seismicity

Since our records began in 1932 we’ve had 90 events of M4 or greater within 10km of today’s event.
The largest historic event was M5.8 on 1945/08/15.
The most recent historic event was M4.3 on 30 Apr 2023.

Faults

CFM fault associations: most likely Not associated with a CFM modeled fault (64%). Alternates: Westmorland fault; main segment (14%), Other CFM faults (22%).*

Additional Information

Links for: USGS earthquake page, ShakeMap, DYFI, waveforms.
Visit our special reports page for further information on local notable earthquakes.
Visit scedc.caltech.edu to access any data recorded by the SCSN.

Below are the waveform data associated with this event, 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

**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.

04/30/2023, M4.3 Swarm near Niland

Zackary Newman — Sun, 30 Apr 2023 08:04:58 +0000

Significant Events

Largest event: M4.3, 30 Apr 2023 00:09:34 PDT, (33.200, -115.590), depth 2.0km. 8km WSW of Niland, California.
As of 01 May 2023, 10:37AM PDT, the following event numbers have been recorded in the swarm:

M≥4: 3
M≥3: 6
M≥2: 21

All M4 events recorded:

M 4.3 30 Apr 2023 00:09:34 PDT, (33.200, -115.590), 40215575
M 4.3 30 Apr 2023 00:10:10 PDT, (33.190, -115.593), 40215583
M 4.3 30 Apr 2023 00:58:19 PDT, (33.203, -115.585), 40215735

Swarm Numbers

As of 01 May 2023, 10:37AM PDT, we have recorded 59 events in the swarm (within a 20 km radius, and counting 5 days before the largest event). The smallest event is magnitude 1.0. 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 85 events of M4 or greater within 10km of today’s event.
The largest historic event was M5.8 on 1981/04/26.
The most recent historic event was M4.0 on 23 Aug 2021.

Faults

CFM fault associations: most likely Not associated with a CFM modeled fault (64%). Alternates: Elmore Ranch fault (27%), Other CFM faults (9%).*

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 this event, as recorded in our Live Seismograms Feed.

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.

01/04/2021, M4.0 near Niland

Zackary Newman — Mon, 04 Jan 2021 19:00:52 +0000

Event

04 Jan 2021 10:04:59 PST, (33.185, -115.595), depth 2.2km.
9km SW of Niland, California

Aftershocks

As of 04 Jan 2021, 10:55AM PST, there have been 9 aftershocks recorded.
The largest was M3.0 (smallest M1.2).
More aftershocks 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.

Possible Foreshocks

There were 1 events during the 3 days prior to the earthquake (within a 10 km radius).
The largest was M1.4 (2021/01/03).

Historical Seismicity

Since our records began in 1932 we’ve had 83 events of M4 or greater within 10km of today’s event.
The largest historic event was M5.8 on 1945/08/15.
The most recent historic event was M4.0 on 01 Oct 2020.

Faults

CFM fault associations: most likely Not associated with a CFM modeled fault (67%). Alternates: Elmore Ranch fault (21%), Other CFM faults (12%).*

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 this event, as recorded in our Live Seismograms Feed.

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.

05/06/2020, M3.9 near Niland

Zackary Newman — Wed, 06 May 2020 14:37:13 +0000

Event

06 May 2020 01:27:05 PDT, (33.187, -115.618), depth 9.5km.
11km WSW of Niland, California

Aftershocks

As of 06 May 2020, 07:20AM PDT, there have been 18 aftershocks recorded.
The largest was M2.8 (smallest M1.1).
More aftershocks 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.

Possible Foreshocks

There were 16 events during the 3 days prior to the earthquake (within a 10 km radius).
The largest was M2.2 (2020/05/06).

Historical Seismicity

Since our records began in 1932 we’ve had 69 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 M4.1 on 27 Sep 2016.

Faults

Brawley Seismic Zone faults (orthogonal to San Andreas fault).*

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 this event, as recorded in our Live Seismograms Feed.The closest station as recorded in the Live Seismograms feed is CI.WMD at approximately 17km away from 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.

01/16/2019, M3.9 near Niland

Duty Seismologist — Thu, 17 Jan 2019 03:30:43 +0000

16 Jan 2019 18:41:34 PST, (33.182, -115.608), depth 2.9km, 10km SW of Niland, California
Aftershocks: so far (16 Jan 2019, 07:29PM PST) there have been 3 aftershocks recorded, the largest M2.9 (smallest M1.6). 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 3 events during the 3 days prior to the earthquake (within a 10 km radius), the largest was M2.2 (2019/01/14).
Historical seismicity: since our records began in 1932 we’ve had 75 events of M4 or greater within 10km of today’s event, the largest was M6.2 (1987/11/24) and the most recent was M4.1 on 27 Sep 2016.
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 this event, as recorded in our Live Seismograms Feed.

10/31/2016, M3.5 near Niland

Jennifer Andrews — Mon, 31 Oct 2016 16:48:02 +0000

31 Oct 2016 03:41:07 PDT, (33.187, -115.567), depth 3.1km, 7km SW of Niland, California
This event is the largest so far in a small cluster of events that started at about 2:30am PDT, consisting of about 35 recorded events. A few events were also recorded in the same area on 26 Oct 2016. A smaller cluster of events also occurred on the 26 Oct 2016 about 3km to the west of the most recent seismicity, giving a total of approximately 50 events over the last 6 days. We have recorded 4 events over M3 and more than 20 events over M2.

Current cumulative event rate and magnitudes for the small swarm near Niland.

The events are in the southern section of the Brawley Seismic Zone, a relatively active area for seismicity. Swarms occur relatively frequently, notably the swarms that occurred during the 1970’s and 1980’s in this area made the zone among the most active areas in all of California.
Historical seismicity: since our records began in 1932 we’ve had 11 events of M4 or greater within 10km of today’s event, the largest was M5.1 (2005/09/02) and the most recent was M4.2 on 24 Dec 2014.

Relocated events for the small swarm near Niland, forming a very tight cluster. Figure provided by Egill Hauksson, Caltech.

Catalogue events in the current small swarm near Niland coloured by time (blue early, red late) and sized by magnitude. Historic seismicity above M4.5 is marked by a grey star and the event’s magnitude.

The following information comes from our special report on the 2005 Obsidian Butte swarm
- The Brawley Seismic Zone is a north-striking zone of northwest and northeast-striking faults that extends from the southern end of the San Andreas fault to the northern end of the Imperial fault. It is often considered a remnant spreading center in the transition from the Gulf of California mid-ocean ridge to the San Andreas transform fault. Historically, activity includes both northeast-oriented cross-faults that typically involve left-lateral faulting, and activity on northerly to northwesterly-oriented strands (right-lateral faulting) of the zone. The largest events to have occurred on the cross-faults were the Elmore Ranch event in 1987, which is considered to have triggered the Superstition Hills event less than 12 hours later, and the Westmorland event in 1981. The Brawley Seismic Zone is proximal to the southern San Andreas fault, the San Jacinto fault zone, and the Imperial fault.
- The pattern of Brawley swarms of the 1970’s was a large number of very small earthquakes (sometimes exceeding 10,000 events) with up to a dozen moderate events of magnitude 4 or so, but no clear mainshock larger than the other events. The 1970’s swarms would be highly active for a few days and then taper off over the next week or two.
Links for: USGS earthquake page, ShakeMap, DYFI.
Visit our special reports page for further information on local notable earthquakes.