The map below shows earthquakes along and near the Hayward Fault from 2000 to the present.
The July 20, 2007 event
is indicated in green, and black dots indicate background seismicity.
Other recent clusters along and near the Hayward Fault are marked in color, with
the earthquakes from December 2006 in yellow. The Lafayette event which occurred
on the evening of March 1, 2007 and its aftershocks are denoted in dark blue.
The earthquake on the morning of July 20, 2007 occurred farther southeast along the Hayward Fault than the events in the sequence which occurred around Christmas, 2006. It was felt widely throughout the Bay Area and jolted many residents awake. Its mechanism is typical for strike-slip along the Hayward Fault. Although there have been many small events along the Hayward Fault over the past few years, in 1868 the Hayward Fault hosted the first good-sized earthquake to occur in the Bay Area in a relatively heavily populated Area.
Here is more information on the 1868 Hayward Fault earthquake.
Bob Uhrhammer & Peggy Hellweg