Salton Sea earthquake swarm *UPDATE*



*UPDATE (Oct. 5, 9:30 a.m.)*

A recently identified fault was found running parallel to the San Andreas Fault at the Salton Sea.  For more information go to:


*UPDATE (Sept. 30, 10 p.m.)*

Just four days after the initial temblors started, the quakes have totaled 296 as of 4:22 p.m. with the largest registering today at M1.9 at 4:22 p.m.


*UPDATE (Sept. 29, noon) *

As stated earlier by University of Berkeley Seismic Lab, the number of quakes related a swarm appears to coincide to this incident, which has decreased in both number and intensity.  As of 11:24 a.m., the total number of quakes related to Bombay Beach has climbed to only 262, only 20 more than 24 hours ago.  There was one event that registered M3.0 in the past 12 hours, while the rest were less than M1.9.


*UPDATE (Sept. 28, 12:12 p.m.)*

A count of quakes since last reported appears to have slowed, and as of 12:10 p.m. stands at 242 with the largest magnitude at M2.6.


*UPDATE (Sept. 27, 8:35 p.m.)*

Bombay Beach continues to be active.  As of 8:03 p.m. there have been a total of 224 earthquakes.  There was a slight increase in intensity with the largest measuring at a M3.6 magnitude.


*UPDATE (Sept. 27, 10:42 a.m.)*

The number of quakes has continued to climb, but the intensity has so far remained relatively mild at less than M2.5.  As of 10:05 a.m. the number of quakes has risen to 179 since yesterday.  All of the quakes appear to have occurred off-shore near Bombay Beach.

According to the University of California at Berkeley Seismology Lab, “Earthquake swarms are not at all an indicator that something bigger is about to come.”  More information on earthquake swarms can be found at:


*UPDATE (11:55 p.m.)*

As of 11:48 p.m. the number of earthquakes in Bombay Beach has risen to 147 since 4:03 a.m., according to QuakeFeed and QuakeWatch.  The largest of the quakes registered M4.3 on the Richter Scale at 7:31 a.m. and 8:23 p.m.

Graphic courtesy of the Southern California Seismic Network
Graphic courtesy of the Southern California Seismic Network


Dr. Jennifer Andrews of the Southern California Seismic Network stated:

The M4.3 exhibited strike-slip motion with one nodal plane sub-parallel to the strike of the San Andreas Fault. Relocations of these events show that the are located in the depth range 4 to 9 km.

This swarm is noteworthy because it is happening near the southern terminus of the San Andreas Fault. This is the same are as the two previous swarms in this region, which occurred in 2009 and 2001. No swarms prior to 2001 with a M4.0 have been recorded in the area since 1933.

There is a small chance (about 5 percent) that a larger quake could occur, with the likelihood decreasing over time.


“California Institute of Technology (Caltech) (1926): Southern California Seismic Network. International Federation of Digital Seismograph Networks. Other/Seismic Network. doi:10.7914/SN/CI

“Data were provided by the Caltech/USGS Southern California Seismic Network (SCSN), doi:10.7914/SN/CI, operated by the Caltech Seismological Laboratory and USGS, which is archived at the Southern California Earthquake Data Center (SCEDC), doi:10.7909/C3WD3xH1




According to QuakeWatch and QuakeFeed, Bombay Beach, California, has had a swarm of 50 earthquakes ranging from M1.4 to M4.3 on the Richter Scale on Sept. 26, starting at 4:03 a.m. to 10:27 a.m.

Stay tuned to local radio and television stations for real-time alerts and be prepared as earthquakes can happen without warning.

Several smartphone apps are available, which can help anyone stay informed.

Check back as this is a developing story.

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