SCEC Award Number 13120 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Enhanced Earthquake Early Warning and Response Through GPS/Seismic Integration
Investigator(s)
Name Organization
Yehuda Bock University of California, San Diego
Other Participants Yuval Reuveni, postdoctoral researcher
SCEC Priorities 6, 5 SCEC Groups Geodesy, Seismology, Transient Detection
Report Due Date 03/15/2014 Date Report Submitted N/A
Project Abstract
 This project has supported a graduate student researcher and the PI to research several topics pertaining to the use broadband displacement waveforms from integrated GPS/seismic regional networks for enhanced earthquake early warning (EEW) and rapid earthquake response. The addition of the GPS component provides at least two benefits: (1) the ability to compute accurate broadband displacements in real time at the precision and rate of collocated accelerometer data for any size earthquake, in particular in the near field and (2) to enhance EEW algorithms by consideration of finite fault slip. Our major findings include (1) published earthquake magnitude scaling relationships for P wave amplitude (Pd) and peak ground displacement (PGD) and tested PGD for the 2014 earthquake off Ferndale; (2) upgraded 17 PBO and SCIGN/SIO stations with low-cost SIO MEMS accelerometers to span the southern segment of the San Andreas fault system; (3) verified good performance of the accelerometers on a series of shaking experiments on a four-story building atop the outdoor shake table at UCSD.
Intellectual Merit Seismogeodesy, the optimal combination of GPS and strong motion data, yields substantial benefits compared to traditional GPS or seismic methods, in particular for near-source monitoring of large earthquakes, by measurement of a continuous record of coseismic (dynamic without clipping, and static) displacements, from the initial P wave arrival through to the permanent displacement. The activity has generated a new type of seismogeodetic analysis, precise point positioning with ambiguity resolution and with accelerometers (PPP-ARA) useful for earthquake early warning, earthquake magnitude scaling relationships, finite fault CMT and slip models, and tsunami forecasting.
Broader Impacts Our project has benefited three graduate students, one of Hispanic origin for his PhD research and two first year female graduate students who are learning the concepts of seismogeodesy while participating in field tests and analysis of data. We have created new data sets (100 Hz MEMS accelerometer) and 1 Hz seismogeodetic displacements and velocities, available through the Southern California Earthquake Data Center, and published several peer-reviewed papers describing the technical details and scientific applications of our research. The benefits to society are clear from early warning and response systems for earthquakes and tsunamis with the potential to save lives and mitigate the damage to essential infrastructure through to engineering seismology to monitor the health of critical infrastructure and design.
Exemplary Figure Figure 1. Seismogeodetic Pd (a), strong-motion Pd (b), and seismogeodetic PGD (c) values for five earthquakes. The solid black lines show the regression relations for magnitude as a function of hypocentral distance. The red dashed lines on (b) are the result for 3 s scaling in southern California from Wu and Zhao [2006]. Source: Crowell et al., 2013.