From what I understand - this is how I read it - The swarms are on the Crafton Hills fault which sits between the Banning branch of the San Andreas Fault and the San Jacinto fault - both oif the strike slip faults have had some quakes recently (in the last month or so) - 4.1 ? on the san jacinto and a 3.6 and another 3 on the san jacinto -

So - due to the activity on those 2 strike slip faults, the land between them is adjusting itself having 'normal' quakes to relieve the stress - I'm not worried about these little swarms - I am a bit concerned if the San Andreas of the San Jacinto decide to break in any significant way!

See link below for info on the area

Canie

• Crafton Hills fault zone