Evaluation of the Detection and Location Capability of the Seismic Network in the Western Part of the North Caucasus Using Network Layout and Local Microseismic Noise Level

Abstract

Abstract The power spectra of microseismic noise were investigated at 20 stations in the western part of the North Caucasus. The seismic stations are located on the eastern coast of the Black Sea and adjacent territories, covering various tectonic structures from the Greater Caucasus to the Scythian Platform. The night and day levels of microseisms were studied at different times of the year. The annual median seismic noise spectra were calculated. The most sensitive stations with the lowest and least differing day and night noise levels were identified, which are located in protected areas far from populated areas—Guzeripl, Gornoye, and Krasnaya Polyana. Most of the stations have an average noise level compared to the global average Peterson noise curves; at these stations, at frequencies above 1 Hz during the day, the noise level increases by at least an order of magnitude due to anthropogenic activity. Average noise levels in the 1–10 Hz frequency band were used to construct network capability maps according to the our method, with the application of empirical seismic wave attenuation curves, which are used to calculate the magnitudes of seismic sources in the region. The two areas of highest network sensitivity are visible on the maps of representative K Рmin values: Anapa, with a level of K Рmin = 6.0 during the day and K Рmin = 5.5 at night, and Sochi–Krasnaya Polyana, with a level of K Рmin = 5.5 during the day and K Рmin = 5.0–5.5 at night.