Absolute Dating of Prehistoric Earthquakes by Tree-Ring Analysis in California

This research is to carry out tree-ring studies that have been proven to yield information, absolute year dates and zones of rupture, for prehistoric earthquakes. The testing does not damage the trees. Paleoseismology is essential for establishing a long enough record of earthquakes to enable estimation of probabilities for future major earthquakes. The immediate future is likely to be similar to the most recent past. Coastal redwood trees or well-preserved stumps exist along several faults in northern California and some ages extend back over 600 years. The research will concentrate on two main project areas, the San Andreas fault north of San Francisco and the Little Salmon Creek fault zone at the southern end of the Cascadia Subduction Zone. This research is a component of the National Earthquake Hazard Reduction Program.