Seismological methods rely on a number of simplifying assumptions about the earthquake source to interpret observed spectra of seismic signals in terms of event durations and stress drops. Following Madariaga  and similar studies, these assumptions typically include a circular shape of the source, axi-symmetric rupture propagation with a constant rupture speed, and spatially uniform stress decrease within the ruptured area. However, this combination of assumptions is not realizable in dynamic finite-fault models and, furthermore, more realistic sources likely involve additional heterogeneity. We explore how physically plausible complexity in source behavior translates into trends in seismological spectral properties, with implications for improving the determination of source parameters and type from seismological data.
This work is also in collaboration with Caltech and National Central University, Taiwan.