Hi all,

Recognizing that microearthquakes do not portend larger quakes, a series has caught my attention.
Just NW of Livermore, between Doolan and Collier Canyons, a series of micro's have been consistently appearing in almost the same spot. I believe this has been going on for a few years.
http://quake.usgs.gov/recenteqs/Quakes/nc40169852.htm

I cannot find any mention of a fault in that specific area. They are also deep for the SF Bay area at 10+ miles.
Is there such a thing as a long period swarm? This area is susceptible to swarms all over the valley.
Any thoughts?