I found a few links about this...I dont know if they might help?

[link to geologycafe.com]
and...
[link to www.livescience.com]

This article says "In volcanically active areas, earthquake swarms often indicate imminent eruptions, Dutton said. The only potential candidates for volcanic eruptions near Brawley are the Salton Buttes, five small lava domes that flank the Salton Sea and haven't erupted in close to 10,000 years"

Very scary!