1. The Parkfield Experiment
Failure or Success?

2. Parkfield M 6.0 earthquake
Tuesday, September 28, 2004
10:15 am local time
Preceded by a M5.9 quake
On the San Andreas Fault

3. San Andreas at Parkfield
Juncture of the creeping and locked sections of the San Andreas Fault
Parkfield
Earthquakes in 1980

4. Historical Seismicity
The wave forms of 1922, 1934 and 1966 quakes were very similar
The next significant earthquake was supposed to happen

5. Characteristic Earthquake
Each fault segment may rupture episodically with characteristic rupture area and recurrence interval

6. 1857 rupture

7. Seismic Gap hypothesis
The next segment to rupture will be the one that hasn’t in a while.

8. Creepmeters at Parkfield site
Coseismic offset

9. Strain gauges at Parkfield site
Coseismic distortion

11. SAFOD: San Andreas Fault Observatory at Depth

12. 2004: the experiment is a success
The earthquake recurrence is every years.
From SAFOD:
Parkfield, the self-proclaimed earthquake capital of the world, was the location of a Magnitude 6 earthquake at 10:15am today. The epicenter was 15 miles south of the drill site on the San Andreas fault at a depth of 7.9 km. The drill site was subjected to fairly intense shaking but nobody was hurt and no significant damage was sustained. Scientists are thrilled to have witnessed "the Big One" and we anticipate a wealth of data associated with this event.
Perus quake triggered a debris avalanche in Yungai resulting in 40,000 fatalities