Earthquake source parameters from S-wave displacement spectra

(c) 2011-2012 Claudio Satriano satriano@ipgp.fr

(c) 2013-2014 Claudio Satriano satriano@ipgp.fr, Emanuela Matrullo matrullo@geologie.ens.fr, Agnès Chounet chounet@ipgp.fr

(c) 2015-2021 Claudio Satriano satriano@ipgp.fr

The SourceSpec package is made of three codes:

• source_spec
• source_model
• source_residuals

The code computes spectra of the two horizontal components (and optionally of the vertical component, as well), and then modulus as:

sqrt(c1(w)^2+c2(w)^2)

It then inverts spectra for a 3-parameter model (Mw, Fc, t﹡ = T/Qs) using initial values for Mw, fc and t﹡:

log S(w)= log(coeff*Mo) + log((1/(1+(w/wc)^2)) + log(exp(-w*t_star/2))

It plots observed and inverted spectra on a single log-log graph (Mo vs log-frequency). Computes average and standard deviation of Mw, Mo, fc, t*, source radius and Brune stress drop.

To get help:

source_spec -h
source_model -h
source_residuals -h

The easiest way of installing SourceSpec is through pip:

pip install sourcespec

Clone or download this project, uncompress it (if needed) and run the codes from bin directory. Optionally, you can install the codes by running:

pip install .

A very incomplete documentation can be found at sourcespec.readthedocs.io.

Several sample runs are available in the sourcespec_testruns repository.