Chen,C., and A. A. Holland, (2016). PhasePApy: A Robust Pure Python Package for Automatic Identification of Seismic Phases, Seismological Research Letters, 87(6), DOI: 10.1785/0220160019.
PhasePApy is a Pure Python program package developed by Chen Chen ([email protected]; [email protected]) under the guidance of Austin Holland.
Version 1.1: 2016 -- FBpicker, AICDpicker, KTpicker; 1D and 3D Associator
PhasePApy is a Seismic Phase Picker and Associator program package, which is designed to identify and associate picks of seismic microseismic events. Please reference the paper if you use this code.
Version 1.0 has been used by Oklahoma Geological Survey (OGS) for near real time earthquake monitoring since 2014. Here, we only provide the version 1.1 to public, because we think this one is more user-friendly and easy to manipulate. You might need to modify the code a bit for your requirements. Also, we still think the code has some space for further clean-up and improvement, so please feel free to modify and update it.
If you have certain ideas to improve this package, please let us know. If you are going to use this package for any commercial purpose, please let us know.
For more information check out the wiki [https://github.com/austinholland/PhasePApy/wiki#welcome-to-the-phasepapy-wiki]
The PhasePApy package composes of two sub-packages: PhasePicker and Associator. These two sub-packages can work jointly or separately, depending on users’ requirements.
The PhasePicker contains three pickers: FBpicker, AICDpicker, and KTpicker
The Associator includes the 1D and 3D Associator modules which uses phase arrival look up tables to associate earthquakes. The associator was tested for local to regional earthquake P- and S-phases, but the algorithm can be accommodated for any distance and possibly phase.
Association is performed in the following steps:
- Create a TravelTime table
- Input picks to a Pick table
- There's no way to tell it the phase, it figures it out in the following steps
- Identify Candidates
- assocND.LocalAssociator.id_candidate_events() identifies as candidates all of one stations Pick pairs that are offset by a value consistent with the range of S-P times in the traveltime table
- Should maybe make another candidate builder that compares first arrivals across stations?
- Associate Candidates
- assocND.LocalAssociator.associate_candidates compares the projected origin
times for all candidates: if there are more than
nsta_declarestations with origin times separated by less thanassoc_ot_uncert, then an Association is declared. I think there can be more than one Association (if there is another good cluster at a different time)
- assocND.LocalAssociator.associate_candidates compares the projected origin
times for all candidates: if there are more than
- Add Single-Phase stations
assocND.LocalAssociator.single_phase()adds in stations without a good S-P time.
PhasePApy is released as public domain under the Creative Commons Public Domain Dedication [CC0 1.0] (https://creativecommons.org/publicdomain/zero/1.0/legalcode). The software was developed at the Oklahoma Geological Survey.
There are examples in the test directory if one has the required libraries the examples should run directly out of a git clone of PhasePApy.
Because the associators require travel-time tables, we have included a data set and travel- time tables in the git repository. This is not ideal, but because PhasePApy does not include a travel-time calculator for velocity models this approach seemed like the best. For this reason the repository is larger than it needs to be.
Currently PhasePApy does not have a Python installer for module installation the files need to be placed in a proper location and the PYTHON_PATH or sys.path should point to where the library exists.
The PhasePApy package relies on open libraries:
- Obspy
- Numpy
- Scipy
- MatPlotLib (Optional) if you are going to plot results with plotting scripts in this package, you need matplotlib as well. Otherwise, the users can visualize it based on their own methods.