There was just a swarm of 3+ quakes (and of course smaller) in the Brawley seismic zone. If I was a seismologist, I would try and get the focal mechanisms and relocations quickly to see what is firing up. While it is common to say that the San Andreas fault ends as it encounters the NE coast of Salton Sea, a narrow band of strike-slip seismicity continues across Salton Sea and beyond to the south (Seeber and Ambruster, probably Magistrale). So, this swarm may be on or near the true SE end of the San Andreas fault proper.

I've been watching quakes in California since 1988 and it seems like Brawley swarms were more common in the 80s and 90s than in the last few years, but I could be wrong.

This swarm is ongoing so we will see what happens next. Usually, nothing happens...swarms just taper off.

Chris

• Brawley swarm