Seismic Noise Analysis: Assessing Station Data Quality in the Southern California Seismic Network
Dev R. Raja, Igor Stubailo, & Gabrielle TeppSubmitted September 7, 2025, SCEC Contribution #14851, 2025 SCEC Annual Meeting Poster #TBD
Regional seismic networks monitor earthquakes and seismicity for hazard assessments, earthquake response, and research. Analyzing noise data across time, site conditions, and specific seismic events can lead to more robust and responsive earthquake detection infrastructure. This study evaluates the performance of the 200+ broadband sensors from the Southern California Seismic Network (SCSN) using the SQLX software for seismic noise analysis. Through calculating statistics and generating visual plots, we aim to categorize and interpret short-term and long-term noise trends based on factors such as sensor type and geographic location. The study focuses on three aspects: 1) comparison of seismic noise at 12 stations for 2004 and 2024, 2) examine 2025 noise levels and rank the CI sites with broadband sensors on measured noise level, and 3) analysis of the sensor performance for the 2025 M8.8 Kamchatka earthquake. We approached this by calculating the typical noise level above the low noise model for each of the 12 stations, replicating the methodology from McNamara & Buland (2004, BSSA) using updated 2024 data. Then, these differences were computed for all SCSN stations, and line plots and normal distributions were generated to identify potential outlier stations for 2025. Lastly, noise data from before and after the magnitude 8.8 Kamchatka earthquake were processed to create period-specific noise maps and plots. This was to analyze the energy level during the earthquake and compare it to the noise level before to identify stations where the earthquake may not have been recorded well. These seismic noise examinations inform us of overall station reliability and help identify needed future improvements in the network. Deeper statistical interpretation of the datasets reveals detailed trends in station performance and regional seismic noise environments. For example, the 5 Dogs Range and Barre stations showed irregular noise data both before and during the Kamchatka earthquake when compared to other stations. The insights gained will support improvements to early warning systems and earthquake monitoring across Southern California.
Key Words
Noise, PDF, SCSN, Broadband, Kamchatka
Citation
Raja, D. R., Stubailo, I., & Tepp, G. (2025, 09). Seismic Noise Analysis: Assessing Station Data Quality in the Southern California Seismic Network. Poster Presentation at 2025 SCEC Annual Meeting.
Related Projects & Working Groups
Seismology
