Estimation of earthquake magnitude and source parameters by using evolution of P-wave for Chinese strong motion data
Abstract
Rapid and reliable estimations of the earthquake seismic moment and finite fault dimension have an essential role in predicting the potential damage zone during the occurrence of an earthquake. In this work, we measured three P-wave peak amplitude parameters on the vertical component of records, in an extended time window from the first P-wave arrival. These parameters are the P-wave peak acceleration (Pa), velocity (Pv) and displacement (Pd). For each parameter, after averaging the measurements among all the available stations and correcting the observed amplitude for distance attenuation effect, we built the logarithm of amplitude vs. time, named LPXT curve (X being D, V, or A for displacement, velocity, or acceleration, respectively). The curves have an exponential growth shape, with an initial increase and a final plateau level. By analyzing the LPXT curves, the information about earthquake rupture process and earthquake magnitude can be obtained. We applied this method to the Chinese strong motion data from 2007-2015, with surface magnitude ranging between 4 and 8, recorded at distances between 0 and 200 km from the source. We used a refined model to reproduce the shape of the curves and extract the representative parameters. Our study shows that the plateau level of LPXT curves has a clear scaling with magnitude, with no saturation effect for large events, and that the plateau time (i.e., the moment at which the curve become stable) is related to the source duration (and length). We show that the representation of data in terms of LPXT curves can be used for estimating the earthquake magnitude and source extent, without risk of underestimation for large events. Finally, the reliable information about the finite fault can be used, in turn for providing an early, real-time ShakeMap for earthquake early warning applications.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.S53G0553W
- Keywords:
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- 4341 Early warning systems;
- NATURAL HAZARDS;
- 7212 Earthquake ground motions and engineering seismology;
- SEISMOLOGY;
- 7215 Earthquake source observations;
- SEISMOLOGY