SCEC Award Number 12083 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 Diego Melgar, graduate student researcher
SCEC Priorities 6d, 5b SCEC Groups Geodesy, Seismology, GMP
Report Due Date 03/15/2013 Date Report Submitted N/A
Project Abstract
 We are studying the use of broadband displacement waveforms from integrated GPS/seismic regional networks for enhanced earthquake early warning and rapid earthquake response. The addition of the GPS component provides the ability to compute accurate broadband displacements (including the static component) in real time at the precision and rate of collocated accelerometer data for any size earthquake of societal importance, in particular in the near source region. This seismogeodetic combination is capable of detecting the arrival of seismic P waves, so that S-wave and body wave arrivals can be predicted. Unlike seismic-only approaches the seismogeodetic approach will not saturate for large earthquakes. We are now testing a low-cost solution to upgrade existing real-time GPS stations to seismogeodetic capability, including a Geodetic Module and a MEMS accelerometer package and will be deploying it shortly at Pinyon Flat Observatory and other stations in southern California. Based on a limited set of P-wave arrivals from medium to large earthquakes (strike-slip and thrust) observed with seismogeodesy we have developed a scaling relationship that may allow estimation of the earthquake magnitude from the first few seconds of data.
Intellectual Merit The use of seismogeodesy at the observation level is a novel approach that takes advantage of the strengths of seismic and geodetic observations, and results in an improved estimates of broadband displacement compared to current seismic- and GPS-only approaches. The displacements provide an unprecedented record of the progression of dynamic and static motion for earthquake physics research. Also, they can be obtained close to the source without clipping and allow for the accurate integration of accelerometer data. Based on a limited set of P-wave arrivals from medium to large earthquakes (strike-slip and thrust) observed with seismogeodesy we have developed a scaling relationship that may allow estimation of the earthquake magnitude from the first few seconds of data.
Broader Impacts Our research provides direct societal benefits by improving the timeliness and robustness of earthquake and tsunami early warning systems using a seismogeodetic approach, which could translate into saved lives and mitigating damage to infrastructure. The research has also enhanced collaboration between those engaged in seismic and geodetic monitoring, and provided skills and training for graduate students and undergraduate students and interns. Our research also has implications for engineering seismology and has fostered collaborations with structural engineers.
Exemplary Figure Figure 1. Shown are the displacement and velocity waveforms estimated by combination of GPS and accelerometer data for a coastal station during the 2011 Mw 9.0 Tohoku-oki earthquake in Japan (from Crowell et al., 2013) derived by real-time simulation. The critical points here are that we can detect the incoming P wave in the near-source region allowing for rapid magnitude estimation using scaling relationships, observing the permanent displacements here at the several meter level, and reducing the time for CMT and finite fault slip inversions to 2-3 minutes. The actual response times are shown in the top left panel.