CAREER: Re-evaluating the evolution of the southern San Andreas Fault along its restraining bend from Holocene to Mid-Quaternary timescales via 36Cl/10Be burial and cosmogenic...

San Jose State University Foundation, San Jose CA

Investigators

Abstract

This study will re-evaluate the seismic hazard potential of individual faults that make up the southern San Andrea Fault system, in particular the potential hazard associated with a newly identified fault of the San Andreas Fault system. The investigation will document and characterize the amount of movement along this newly identified fault over multiple timescales, to better understand its displacement history and evolution relative to other faults in the region. To accomplish this end goal, the application of a new dating technique, 36Cl/10Be burial dating, will be developed. The societal impact of this study is high because the results will help refine earthquake hazard models that forecast the potential of future earthquakes and their recurrence in California. This study of seismogenic faults will then be integrated into a place-based mentoring program for undergraduate students, Promoting Undergraduate Research Experiences (PURE) in Geology at San Jose State University (SJSU). The program will provide opportunities for students to investigate fault processes and their associated hazard. The development and application of the 36Cl/10Be burial dating technique in sediment over the 200,000 to 700,000 year age range will expand the capability and capacity of earth scientists to quantify geologic processes, such as rates of deformation of lateral faults, fold and thrust belts and sedimentary successions worldwide over a timescale missing in most geologic histories. Accordingly, quantifying the continuous displacement history of faults and fault zones into mid-Quaternary timescales will provide new insights into the behavior of continental strike slip faults, in particular the San Andreas Fault. Such data are critical to understanding the evolution of fault systems. Detailed field and geochronologic data at multiple locations and timescales provide important constraints and boundary conditions that can be applied to geophysical models of plate boundary strain, faults, dynamic earthquake rupture models, seismologic models and models assessing seismic hazard. Funding for the project is provided by the EAR Tectonics Program and the GEO Prediction of and Resilience against Extreme Events (PREEVENTS) Program. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.