Robust earthquake spectra from envelope inversion

This repository contains the source code for the reproduction of results and figures of the following publication:

Tom Eulenfeld, Sebastian Heimann, Torsten Dahm and Ulrich Wegler (2021), Fast and robust earthquake source spectra and moment magnitudes from envelope inversion, Bulletin of the Seismological Society of America, doi: 10.1785/0120210200. [pdf]

Additionally, this repository contains result files and figures.

Preparation

1. Download or clone this repository.
2. Install the the relevant python packages: python>=3.7 qopen>=4.1 grond>=1.4 obspy>=1.2 pyrocko>=2021.06.29 matplotlib>=3.4 utm mtspec. The minimum version also specifies the versions I used. The following is working for me when using conda

conda --add channels conda-forge
conda create -n eqspec obspy statsmodels utm mtspec
conda activate eqspec
conda install -c pyrocko pyrocko
pip install qopen grond

3. Prepare data: The data is hosted on zenodo with doi:10.5281/zenodo.3741464. Copy the data into a new data folder. Finish preparing the data with the script python prepare_data.py. The data/waveforms folder can be deleted afterwards.

Running Qopen

Switch to the qopen folder with the Qopen configuration and results. Check out the run_qopen.sh script which runs the Qopen commands described in the article (figure 3). Run these one by one or the script itself to recreate the results.

Running Grond

First download the used Green's function database and insert the directory where it is stored in the file $HOME/.pyrocko/config.pf in the gf_store_superdirs: [your_gf_path] field. Switch to the grond folder with the Grond configuration already in place. Run the commands in the script run_grond.sh or the script itself. Optionally the --parallel option can be used, please check the help with -h flag.

Calculate spectra from direct onsets

Switch to the scripts directory and run

python calc_onset_spectra_and_plot_comparison.py

Reproduce figures

Switch to the scripts directory and run all the plot*.py python scripts. The figure with Grond fits is created by the bash script montage_grond_fits.sh (montage program needed).

Results

The above scripts repopulate the folders figs, grond, onsets and qopen. The results for Qopen are located in the qopen folder. Grond results can be viewed here . Results from the spectra of direct onsets are located in the onsets folder. All created figures are stored in the figs folder. Results can be loaded into Python with the following Python code inside the scripts directory:

from util.events import load_grond, load_qopen, load_qopen_grond_sds

qopen_results = load_qopen('Q')  # Load g0 and b values
qopen_event_results = load_qopen('events')  # Load fc, M0, etc determined with Qopen
grond_results = load_grond()  # Grond moment tensors, etc
all_results = load_qopen_grond_sds()  # Load a dictionary {event_id: event_result} with all event related results