Discrimination between earthquakes and quarry blasts in the Aswan region, southern Egypt using P-wave source spectra

We analyzed 3,069 seismic signals from 413 events (112 explosions and 301 shallow earthquakes, depths < 5 km) recorded by the Aswan seismic sub-network in southern Egypt from 2010 to 2021 to discriminate between shallow earthquakes and quarrying activity. We investigated the spectral properties and related source parameters (e.g., seismic moment and corner frequency) using the estimated P-wave source spectra for both earthquakes and quarry blasts. The analysis showed that the P-wave source spectra of shallow earthquakes have higher corner frequencies (8.8–23 Hz) than quarry blasts (1.0–2.6 Hz) within the same magnitude range. The source spectra of quarry blasts exhibited significant misfits with the omega-square model and had steeper falloffs at high frequencies. The selected quarry blasts have a narrow seismic moment range, from 2.03⋅10 11 to 1.35⋅10 12 Nm. Our results demonstrate that the evaluation of misfit of P-wave spectra from the omega-square source model based on spectral amplitude characteristics of high and low frequency bands is the most reliable discriminant method in the routine data analysis of the target area.