oa Assessment of Seismic Noise Levels for the Selection of a Permanent Monitoring Station: A Case Study of the KHRY Site in Ukraine

The selection of station sites plays a crucial role in enhancing national seismic monitoring and earthquake response capabilities in Ukraine. This study focuses on identifying and evaluating a potential site, “KHRY,” located in the village of Khrystanivka, Poltava region, as part of the ongoing modernization of the National Seismic Network. The reconnaissance process involved selecting locations with minimal anthropogenic and natural seismic noise through remote sensing and field surveys. To ensure high-quality seismic data collection, the study utilized spectral analysis of ambient noise, incorporating Power Spectral Density (PSD) and Probabilistic Power Spectral Density (PPSD) methods following the McNamara and Buland approach. The assessment was performed using a Nanometrics Trillium Compact Posthole sensor and Centaur digitizer, with data collected over two measurement periods in May and June 2024.

The results indicate that, despite the site’s compliance with minimum distance requirements from known anthropogenic noise sources, noise levels in the 1–10 Hz frequency range exceed Peterson’s New High Noise Model (NHNM) by 20 dB. This suggests that the location may not be suitable for recording local seismic events with high precision. The presence of the Urengoi-Pomary-Uzhhorod gas pipeline, a potential persistent noise source, was identified as a factor influencing site suitability. However, ongoing changes in gas transit activities may alter seismic noise conditions. While the site is not currently optimal for a permanent seismic station, additional studies are being conducted to reassess noise sources and explore alternative placements. This research contributes to the expansion and modernization of Ukraine’s seismic monitoring capabilities, ultimately strengthening the country’s preparedness for seismic hazards.