An ObsPy library for event detection and seismic attribute calculation: preparing waveforms for automated analysis
This package is an extension for the observational seismology obspy software package that provides a streamlined tool tailored to the processing of seismic signals from non-earthquake sources, in particular those from deforming systems such as glaciers and landslides. This seismic attributes library provides functionality to: (1) download and/or pre-process seismic waveform data; (2) detect and catalogue seismic events using multi-component signals from one or more seismometers; and (3) calculate characteristics ('attributes'/'features') of the identified events. The workflow is controlled by three main functions that have been tested for the breadth of data types expected from permanent and campaign-deployed seismic instrumentation. A selected STA/LTA-type (short-term average/long-term average), or other, event detection algorithm can be applied to the waveforms and user-defined functions implemented to calculate any required characteristics of the detected events. The code is written in Python 2/3 and has detailed documentation and worked examples available on GitHub (https://github.com/rossjturner/seismic_attributes).
This package can either be installed using pip or from a .zip file downloaded from the GitHub repository using the standard Python package distutils.
The following command will install the latest version of the seismic attributes library from the Python Packaging Index (PyPI):
pip install seismic_attributesThe package can be downloaded from the GitHub repository at https://github.com/rossjturner/seismic_attributes, or cloned with git using:
git clone https://github.com/rossjturner/seismic_attributes.gitThe package is installed by running the following command as an administrative user:
python setup.py installThe successful installation of the package can be verified using the Python package pytest. The unit tests require internet access to run as data is downloaded from the Incorporated Research Institutions for Seismology (IRIS) server; downloaded data will be saved in the working directory.
Find the path to the installed seismic_attributes package. If the package was installed using pip this is achieved as follows:
pip show seismic_attributesThe path to the seismic_attributes directory is shown next to 'Location:'.
The unit test is run with pytest (which should be installed with seismic_attributes by default) using the following command:
pytest path_to_directory/seismic_attributesThe unit test takes approximately 10-20 seconds to run. Five tests are conducted which verify the seismic_attributes package is correctly linked with obspy, can download data from the IRIS server, produces an event catalogue with the expected output, and calculates attributes for events as expected.
Full documentation of the functions included in the seismic_attributes package, in addition to worked examples, is included in seismic_attributes_user.pdf on the GitHub repository. The worked examples are additionally included in the following Jupyter notebook: seismic_attributes_example.ipynb.
Ross Turner <turner.rj@icloud.com>