Mysterious seismoacoustic signals of eastern Helwan quarry blasts 2022
Published in Scientific Reports, 2025
Abstract
Mysterious seismoacoustic events were reported at the beginning of 2022 near Helwan, Cairo, Egypt, recorded by the Egyptian National Seismic Network with unknown source characteristics. In May 2022, a temporary infrasound array with a 450 m aperture was established in Helwan. Over a 6-month monitoring period, a recursive STA/LTA trigger method across all sensors detected impulsive seismoacoustic events. Infrasound propagation models coupled with F-K analysis confirmed event locations and directions, corroborated by satellite imagery of the azimuth directions. The mysterious signals were identified as originating from Egypt’s high-speed railway train corridor construction project. This study demonstrates the effectiveness of integrating seismic sensors with infrasound arrays for enhanced source characterisation and precise discrimination of quarry blasts, while showing that inexpensive sensors can cost-effectively monitor higher-frequency events.
Recommended citation: Hamama, I., Elkhouly, S.H., Gaber, H., et al. (2025). "Mysterious seismoacoustic signals of eastern Helwan quarry blasts 2022." Scientific Reports, 15, 18527.
Download Paper