Earthquake swarm near Salton Sea, S. California

[Astronuc]

M 4.9 - 4km NE of Westmorland, CA
https://earthquake.usgs.gov/earthquakes/eventpage/ci39641528/executive

• 2020-10-01 00:31:27 (UTC)
• 33.056°N 115.590°W
• 11.5 km depth

M 4.5 - 4km NE of Westmorland, CA
https://earthquake.usgs.gov/earthquakes/eventpage/ci39643328/executive

• 2020-10-01 03:36:34 (UTC)
• 33.066°N 115.597°W
• 5.7 km depth

Hundreds of earthquakes continue to rattle Southern California, USGS says
https://news.yahoo.com/swarm-nearly-30-earthquakes-rocks-005043056.html

https://earthquake.usgs.gov/earthqu...listOnlyShown=true&settings=true&help=missing

 

[jedishrfu]

Is this cause for worry, portends of the BIG one?

 

[Tom.G]

Not necessarily... but it's complicated... There are three significant faults there, along with a multitude of minor ones; plus the recent quakes appear to have occurred in an active spreading center (Brawley Spreading Center). The Northern boundary of the spreading center is the infamous San Andreas Fault.

Here is a link to a 30pg pamphlet that gives details of the underlying geology.
https://fire.biol.wwu.edu//trent/alles/GeologySaltonTrough.pdf

Cheers,
Tom

 

[RedOrb]

Is this cause for worry, portends of the BIG one?

The big one is not likely to be preceded by hundreds of smaller quakes that all relieve stress