New evidence from a tsunami 67 years ago is helping scientists plan for future tsunamis.
The history of tsunamis in California dates back to the late 1700s. Up until recently, much of the information about prior tsunamis came from personal accounts and photos.
A new sedimentary deposit found near Half Moon Bay from a tsunami in 1947 is allowing scientists to piece together evidence for better long-term hazard analysis.
This finding was part of a year-long study examining sediments throughout the state. Scientists from U.S. Geological Survey SAFRR (Science Application for Risk Reduction) Tsunami Scenario project, experts from the USGS, Humboldt State University and the California Geological Survey concentrated on areas with the greatest potential for paleo-tsunami deposits to better understand the history of tsunamis in the state.
Their findings, along with personal accounts and photos will increase baseline knowledge for future tsunamis. The goal is to create a broader picture of the long-term risk of tsunamis in the state. This would hopefully result in better preparedness.
Reconstructing the tsunami history in California had its challenges due to the rocky coastline. Marshes, ponds and lagoons offer the best analysis for tsunami deposits. The scientists were able to find some of these deposits near Crescent City and Half Moon Bay.
Another area near Santa Barbara is still being analyzed for possible prior tsunami origin.