A break in self-similarity in the Lunigiana-Garfagnana region (northern Apennines)

In this study, stable source parameters are determined
for small earthquakes in the Lunigiana-Garfagnana region
using an empirical methodology based on coda envelope
measurements that are significantly less affected by the
source radiation pattern, directivity, and heterogeneous path
variation, than traditional direct wave measurements. We
find evidence that the scaled energy ~e(=ER/M0) increases
with moment and source spectra are not self-similar for
3.0 Mw 4.6. The calibration procedure allows for an
independent check of three important features: (1) that the
empirical path corrections provide consistent amplitude
measurements for the same event at different stations,
distances, and azimuths; (2) that the long-period levels of the
source spectra are consistent with independent M0 derived
from long-period waveform modeling; (3) that small event
spectra are flat below a conservative estimate of the corner
frequency and thereby effectively accounting for near-site
attenuation. Citation: Morasca, P., K. Mayeda, R. Go¨k,
L. Malagnini, and C. Eva (2005), A break in self-similarity in
the Lunigiana-Garfagnana region (northern Apennines)