Collaborative Research: The Southern San Andreas Fault Zone Experiment

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项目编号	1841315
	Collaborative Research: The Southern San Andreas Fault Zone Experiment
	Yehuda Ben-Zion (Principal Investigator)
主持机构	University of Southern California
项目开始年	2019
	2019-05-15
项目结束日期	2022-04-30
资助机构	US-NSF
项目类别	Continuing grant
项目经费	174834(USD)
国家	美国
语种	英语
英文摘要	The San Andreas Fault (SAF) in California is a mature plate boundary fault capable of great (magnitude 8 or greater) earthquakes. The southern section of the SAF has not produced a major earthquake in historic times (over the last 300 years), and is currently believed to pose the largest seismic risk in California. This project will use new seismic and geodetic observations to investigate the sub-surface structure and geometry of the Southern San Andreas Fault (SSAF). In particular, the project will test a hypothesis that the SSAF may not be vertical and may substantial dip to the East. If confirmed, a non-vertical fault dip would have important implications for the mechanics and the long-term tectonic evolution of the SSAF. Better knowledge of the sub-surface geometry of the SSAF will also improve predictions of seismic radiation patterns and the intensity of ground shaking due to future large earthquakes on the SSAF. The broader impacts of this work will be refined estimates of seismic hazard in densely populated areas in Southern California and Mexico as well as support for the education of two graduate students. The researchers from this joint project between the University of California San Diego, Scripps Institution of Oceanography and the University of Southern California, will investigate the fault attitude at depth by imaging a low-rigidity damage zone and/or a bi-material interface associated with the SSAF in the upper crust. This will be accomplished by deploying a dense seismic array spanning the SSAF. Data from the deployed seismic array and regional seismic networks will be used to generate high-resolution tomographic images of the fault zone throughout the seismogenic layer. Seismic data will be combined with high-resolution geodetic observations, including Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS). A joint analysis of seismic and geodetic data will provide new insights into the spatial extent and degree of damage around a mature plate boundary fault and enable comparisons with observations from other faults in California and elsewhere to examine how the distribution and amount of damage might depend on the fault age, seismic potential, and geometric complexity. The deployment of co-located dense seismic and geodetic arrays will establish a baseline for future measurements of possible time-dependent variations in mechanical properties of rocks comprising the fault zone due to external stress perturbations, which may help constrain the magnitude of absolute stress at seismogenic depth. 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.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/213000
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Yehuda Ben-Zion .Collaborative Research: The Southern San Andreas Fault Zone Experiment.2019.