Hybrid Green's Functions using Physical Constrains

Marine A. Denolle, & Gregory C. Beroza

In Preparation 2013, SCEC Contribution #1835

Accurate phase and amplitude measurements are important to construct realistic velocity models that we use either to probe the Earth, or to predict ground motion from potential earthquakes. We can obtain the response of the Earth to an impulse force through the stacking of correlation of diffuse seismic fields. Coda waves from earthquakes and the ambient seismic field both express characteristics of diffuse fields, but their source distributions are not uniform and this affects the Green's functions stability. Green's function must satisfy causality and symmetry. We propose to find the optimal contributions of individual correlations to form a hybrid Green's function that satisfy both causality and symmetry. We use data from a temporary array deployed during the occurrence of a local M 7+ and its aftershock sequence. We show that we clearly improve the quality of the Green's function, and that this method may be generalize to construct the Green's functions from independent estimate of the Earth's response.

Denolle, M. A., & Beroza, G. C. (2013). Hybrid Green's Functions using Physical Constrains. Geophysical Research Letters, (in preparation).