http://www.data.scec.org/recenteqs/Maps/120-36.html

Interesting grouping of M2+ quakes near Avenal, east
of Parkfield, south of Coalinga.

The area has had large quakes in the past. The May 2,
1983 Coalinga 6.5 was to the northwest of here.
http://earthquake.usgs.gov/regional/states/events/1983_05_02.php

There was a smaller but still significant quake sequence
on August 3, 1985, which was also to the NW, but much closer.
In fact, a line from the Coalinga even to the 1985 event
extends to the southwest to this location.

Brian