The potential of high-rate GPS for strong ground motion assessment

Michel, Clotaire; Kelevitz, Krisztina; Houli�, Nicolas; Edwards, Brent; Psimoulis, Panos; Su, Zhenzhong; Clinton, John; Giardini, Domenico

Abstract

We show that high-rate GPS can have a vital role to play in near real-time monitoring of potentially destructive earthquakes. We do this by investigating the potential of GPS in recording strong ground motions from earthquakes in Switzerland and Japan. The study uses finite-fault stochastic ground motion simulation based on Fourier amplitude spectra and duration models previously developed for both countries, allowing comparisons in terms of both Fourier and time domain characteristics (here the Peak Ground Velocity, PGV).
We find that earthquakes of magnitude Mw>5.8 can be expected to be recorded by GPS in real-time at 10 km distance, i.e. their Fourier spectrum exceeds the noise of the instruments enough to be used in strong motion seismology. Post-processing of GPS time series lowers the noise and can improve the minimum observable magnitude by 0.1-0.2. As GPS receivers can record at higher rates (> 10 sps), we investigate which sampling rate is sufficient to optimally record earthquake signals and conclude that a minimum sampling rate of 5 sps is recommended. This is driven by recording events at short distances (below 10 km for magnitude 6 events and below 30 km for magnitude 7 events).
Furthermore, the Maximum Ground Velocity derived from GPS is compared to the actual PGV for synthetic signals from the stochastic simulations and the 2008 Mw=6.9 Iwate earthquake. The proposed model, confirmed by synthetic and empirical data, shows that a reliable estimate of PGV for events of about magnitude 7 and greater can be basically retrieved by GPS in real-time and could be included for instance in ShakeMaps for aiding post-event disaster management.

Citation

Michel, C., Kelevitz, K., Houlié, N., Edwards, B., Psimoulis, P., Su, Z., …Giardini, D. (in press). The potential of high-rate GPS for strong ground motion assessment. Bulletin of the Seismological Society of America, 107(3), https://doi.org/10.1785/0120160296

• Journal Article Type: Article
• Acceptance Date: Mar 22, 2017
• Online Publication Date: May 16, 2017
• Deposit Date: May 23, 2017
• Publicly Available Date: May 23, 2017
• Journal: Bulletin of the Seismological Society of America
• Print ISSN: 0037-1106
• Electronic ISSN: 0037-1106
• Publisher: Seismological Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 107
• Issue: 3
• DOI: https://doi.org/10.1785/0120160296
• Public URL: https://nottingham-repository.worktribe.com/output/860528
• Publisher URL: http://mr.crossref.org/iPage?doi=10.1785%2F0120160296
• Contract Date: May 23, 2017