Evaluation of Distributed Acoustic Sensing Phase Pick Quality and Performance for Operational Earthquake Monitoring

Gabrielle Tepp, Nytica Artiaga, & Ettore Biondi

Submitted September 7, 2025, SCEC Contribution #14768, 2025 SCEC Annual Meeting Poster #TBD

Over the past several years, distributed acoustic sensing (DAS) has been gaining use in seismological research and even seismic monitoring. The Southern California Seismic Network (SCSN) recently started incorporating DAS data into our routine regional seismic monitoring operations. Here, we present an analysis of the expected and observed impacts and effects of adding DAS data to monitoring. Prior to adding DAS data to our realtime monitoring system, we conducted a test on 228 events from 28 May to 1 August 2023 to evaluate the number and quality of phase picks from DAS data and the potential effects of those additional picks on earthquake locations. We also compared automatic picks from the machine learning picker PhaseNet-DAS to analyst picks to assess its accuracy, although it is not yet being used in operations. We then repeat this analysis for 317 events from 6 May to 8 July 2025, after 7 DAS channels were added to the realtime systems, to assess whether the performance is as expected. PhaseNet-DAS generated about twice as many picks as the analysts, and larger events tended to have more picks. When the arrival times were compared, Phase-DAS was similar to the analysts, mostly within 0.5s, with P picks more similar than S picks. The STA/LTA picker in the realtime system generated about half as many P picks as the analysts, though they were typically accurate. The detection threshold of PhaseNet-DAS was a little better than that of the analysts. For the 2023 test events, we also considered how the addition of DAS picks would affect automatic locations and found little difference in offsets from the final catalog location with or without DAS picks included. Overall, we found that adding DAS into our monitoring systems can provide more picks, especially in areas with poor seismic station coverage, with no meaningful reduction in earthquake parameter quality. PhaseNet-DAS may be able to provide accurate automatic picks to reduce additional analyst work from the extra stations.

Key Words
DAS, monitoring, network seismology

Citation
Tepp, G., Artiaga, N., & Biondi, E. (2025, 09). Evaluation of Distributed Acoustic Sensing Phase Pick Quality and Performance for Operational Earthquake Monitoring. Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology