The Parkfield Experiment: Assessing the 2004 M6.0 Earthquake and Its Implications
On September 28, 2004, the small town of Parkfield experienced a magnitude 6.0 earthquake, the first since a series of smaller quakes. This event occurred on the San Andreas Fault, at a site long identified for its seismic activity. Preceded by a M5.9 quake, it was part of a broader experiment intended to better understand earthquake patterns and the recurrence interval of seismic events, estimated to be every 22 to 35 years. While no significant damage occurred, the earthquake provided crucial data for scientists studying fault dynamics.
The Parkfield Experiment: Assessing the 2004 M6.0 Earthquake and Its Implications
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Presentation Transcript
The Parkfield Experiment Failure or Success?
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
Parkfield San Andreas at Parkfield • Juncture of the creeping and locked sections of the San Andreas Fault Earthquakes in 1980
Historical Seismicity • The wave forms of 1922, 1934 and 1966 quakes were very similar • The next significant earthquake was supposed to happen 1988-1993
Characteristic Earthquake • Each fault segment may rupture episodically with characteristic rupture area and recurrence interval
Seismic Gap hypothesis • The next segment to rupture will be the one that hasn’t in a while.
Creepmeters at Parkfield site • Coseismic offset
Strain gauges at Parkfield site • Coseismic distortion
SAFOD: San Andreas Fault Observatory at Depth http://www.icdp-online.de/sites/sanandreas/news/news.html
2004: the experiment is a success • The earthquake recurrence is every 22- 35 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.
