LOKI

LOKI (LOcation of seismic events through traveltime staKIng) is a code that performs earthquake detection and location using waveform coherence analysis (waveform stacking).

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Installation

It is always good habit to create (or work) in environments. For more information please see conda or pipenv

For example:

$ conda create -n loki python=3.7
$ conda activate loki

To use LOKI you will need:

• GCC6 or later versions or any C compiler that supports OpenMP calls
• Python3 libraries, numpy (needed also at installation stage) and obspy
• Python3 library: LatLonUTMconverter, provided here but developed by third parts. (soon this dependence will be removed by adding an internal function) From v1.0.0 the main module has been incorporated in loki (from loki import LatLonUTMconverter)

The software now comes with an installer! simply digit:

$ # activate the envionment (optional)
$ pip install numpy  # v1.18 or higher (needed for C-compilation)
$ cd WHERE_LOKI_IS_STORED
$ pip install .

NB: before running the pip install command, make sure to change accordingly the os.environ["CC"] variable with a compiler that supports OpenMP calls.

Testing

If installation didn't throw any error, you should be fine. If you still want to double-check, the ultimiate installation, you could find a tests dir with an executable script. Run it anc compare the output results with the expected_results dir. Results will be equals up to significant float digits.

Usage

To use LOKI you could use the carbon-print RunLoki.py script (in bin folder). You could copy it anywhere in the system, just make sure to make it executable. Open the file to change the configuration's options at your preference.

Citing

Please cite the following articles in documents showing outputs of LOKI:

For location:

• Grigoli et al. 2013, Automated seismic event location via traveltime stacking: An application to mining induced seismicity, Seismological Research Letters, https://doi.org/10.1785/0220120191

• Grigoli et al 2014, Automated seismic event location by waveform coherence analysis, Geophysical Journal international, https://doi.org/10.1093/gji/ggt477

• Grigoli et al. 2016, Automated microseismic event location using Master-Event Waveform Stacking, Scientific Reports, https://doi.org/10.1038/srep25744

For detection:

• Grigoli et al. 2018, Pick-and waveform-based techniques for real-time detection of induced seismicity, Geophysical Journal International, https://doi.org/10.1093/gji/ggy019

Author contact details:

Copyright(C) 2013 Francesco Grigoli

Author: Francesco Grigoli

Mail: fsco.grigoli@gmail.com or francesco.grigoli@sed.ethz.ch

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.