Annual Meeting - SCEC.org

Poster Abstracts | Group 2 – FARM
opportunity to preserve a spectacular San Andreas Fault exposure with a record of 6 earthquakes
and 5 lake episodes. The southernmost San Andreas Fault is one of the most likely faults to
generate a great earthquake in Southern California. Its high slip rate of 15-25mm/yr, long
quiescence of ~325 yrs compared to the average recurrence interval of 180 yrs, and single-event
displacements of greater than 3 meters for the last 3-4 events, make this portion of the fault appear
ready for a large magnitude earthquake sooner than other faults in California.
The southern 40 miles of the San Andreas fault along the shrinking Salton Sea are located within
the area of ancient Lake Cahuilla. The episodic filling and drying of Lake Cahuilla resulted in the
deposition of sediments that provide a unique high-resolution recorder of past earthquakes. We are
working at the Salt Creek South (SCS) site and the excavations offer a spectacular view of the
faultzone. The SCS site is the only “deep water” site, 70 m below the high shoreline, which
translates into an additional minimum of ~60 yrs of lacustrine deposition for each of 5 lake
episodes, or an additional 300 years of lacustrine record in the past 1300 years compared to other
paleoseismic records. Although other long record sites have been developed in the Coachella
Valley, they are all located at or above the high shoreline. Now that we are completing a phase of
this project, we are interested in preserving this trench exposure for educational purposes.
Why create a permanent San Andreas Fault Earthquake and Salton Sea Lake History Exhibit?
• It would be the only exhibit in the United States that enables visitors to see an earthquake
fault below the surface.
• It would be the only exhibit that shows the Salton Sea’s lake history.
• The exceptionally dry climate in the Salton Sea region make it feasible to preserve this site in
a nearly natural state.
• With the uncertain future of the Salton Sea restoration, this exhibit may provide a rare
scientific view of the regions past, that would facilitate appreciation of the natural history of
the region.
• Allows field trips to show how earthquake research is accomplished.
• The exhibit can encourage visitors to be prepared for future earthquakes and support future
research.
170 | Southern California Earthquake Center