Testing different configurations of GNSS-based rapid source products for tsunami and ground motion characterization
Abstract
The value of high-rate (1 Hz or greater), real-time Global Navigation Satellite System (GNSS) displacement data to earthquake hazards monitoring has been successfully demonstrated over the past decade. GNSS data is especially useful because it is capable of capturing the true deformation field without going off-scale, from the dynamic shaking, coseismic displacements, all the way to the long-term tectonic motions. In contrast, the ability to characterize large earthquakes is problematic with traditional near-field seismic data and techniques due to drifts and rotations at inertial sensors. Because of this, several efforts are underway to operationalize GNSS data and methods for earthquake and tsunami early warning globally.
In this study, we investigate how different configurations and assumptions within G-FAST impact the resultant tsunami and ground motion predictions. G-FAST was originally written at the University of Washington for the ShakeAlert project to rapidly characterize earthquake sources based upon peak ground displacement (PGD) scaling and a centroid moment tensor (CMT) driven finite fault inversion. It is currently being modified for use at NOAA's Tsunami Warning Centers (TWCs) to aid in near-field tsunami modeling, an area that is difficult with current seismic techniques and DART inversions. We investigate ways to weight different stations based on noise and distance, methods to stabilize CMT determination for large events, determine how different fault characterizations impact ground motion and tsunami predictions, and optimize ways to estimate offsets. The lessons learned here will guide code modifications for both the ShakeAlert and TWC versions of G-FAST.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMNH31D0864K
- Keywords:
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- 4313 Extreme events;
- NATURAL HAZARDS;
- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 7212 Earthquake ground motions and engineering seismology;
- SEISMOLOGY;
- 7223 Earthquake interaction;
- forecasting;
- and prediction;
- SEISMOLOGY