A new (time-domain) approach for earthquake source parameter inversion

Itzhak Lior, Tel Aviv University

Wednesday, October 25, 2017 at 10:30 AM

Location:
Building 3, Rambo Auditorium
Host:
Annemarie Baltay

Determining earthquake source parameters is a challenging task, in part due to the biases and artifacts introduced when transforming the data from the time- to the frequency-domain. In addition, separating the effects of source and attenuation is difficult, especially for small earthquakes. In this study, a new approach for determining the source spectral parameters using the signals in the time domain is presented. Theoretical equations relating source spectral parameters to the root-mean-square of the ground motions (displacement, velocity and acceleration) are derived using the omega squared model of Brune. These relations constitute a set of three independent equations with three unknowns: the displacement low frequency spectral plateau, the source corner frequency and the attenuation parameter. The spectral parameters are obtained in the time domain, and the trade-off between the effects of the corner frequency and the attenuation parameter is quantified and addressed. The results of the new method are compared with those of the standard frequency-domain approach. It is concluded that the new scheme is more stable than the frequency-domain method, resulting in considerably reduced intra-event source parameter variability.

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