PyOcto: A high-throughput seismic phase associator
Abstract
Seismic phase association is an essential task for characterising seismicity: given a collection of phase picks, identify all seismic events in the data. In recent years, machine learning pickers have lead to a rapid growth in the number of seismic phase picks. Even though new associators have been suggested, these suffer from long runtimes and sensitivity issues when faced with dense seismic sequences. Here we introduce PyOcto, a novel phase associator tackling these issues. PyOcto uses 4D space-time partitioning and can employ homogeneous and 1D velocity models. We benchmark PyOcto against popular state of the art associators on two synthetic scenarios and a real, dense aftershock sequence. PyOcto consistently achieves detection sensitivities on par or above current algorithms. Furthermore, its runtime is consistently at least 10 times lower, with many scenarios reaching speedup factors above 50.On the challenging 2014 Iquique earthquake sequence, PyOcto achieves excellent detection capability while maintaining a speedup factor of at least 70 against the other models. PyOcto is available as an open source tool for Python on Github and through PyPI.
Publisher
McGill University Library and Archives
Reference28 articles.
1. Beyreuther, M., Barsch, R., Krischer, L., Megies, T., Behr, Y., & Wassermann, J. (2010). ObsPy: A Python toolbox for seismology. Seismological Research Letters, 81(3), 530–533. https://doi.org/10.1785/gssrl.81.3.530 2. Ester, M., Kriegel, H.-P., Sander, J., Xu, X., & others. (1996). A density-based algorithm for discovering clusters in large spatial databases with noise. Kdd, 96(34), 226–231. https://doi.org/10.5555/3001460.3001507 3. GFZ German Research Centre For Geosciences, & Institut Des Sciences De L’Univers-Centre National De La Recherche CNRS-INSU. (2006). IPOC Seismic Network. Integrated Plate boundary Observatory Chile - IPOC. https://doi.org/10.14470/PK615318 4. González-Vidal, D., Moreno, M., Sippl, C., Baez, J. C., Ortega-Culaciati, F., Lange, D., Tilmann, F., Socquet, A., Bolte, J., Hormazabal, J., & others. (2023). Relation between oceanic plate structure, patterns of interplate locking and microseismicity in the 1922 Atacama seismic gap. Geophysical Research Letters, 50(15), e2023GL103565. https://doi.org/10.1029/2023GL103565 5. Graeber, F. M., & Asch, G. (1999). Three-dimensional models of P wave velocity and P-to-S velocity ratio in the southern central Andes by simultaneous inversion of local earthquake data. Journal of Geophysical Research: Solid Earth, 104(B9), 20237–20256. https://doi.org/10.1029/1999JB900037
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