Seismo-acoustic and GNSS monitoring of a record-breaking storm in the Black Sea: Evidence of climate change and intensifying natural hazards

Abstract. In August 2024, a devastating storm struck Romania’s Black Sea coast, setting new precipitation records and highlighting the increasing frequency of extreme weather events. This study explores the integration of non-conventional sensors (seismic, GNSS, infrasound, and satellite data) with ERA5 meteorological reanalysis to monitor storm dynamics. High-frequency (>30 Hz) seismic signals captured precipitation, while microseismic bands (0.1–1 Hz) reflected wave-induced ground motion. Infrasound data, analyzed using unsupervised learning, revealed distinct storm phases and showed strong spectral correlation with recorded ground motion, pointing to coupled atmosphere-lithosphere processes induced by the storm. The infrasound array also detected over 1,100 signals in the 0.6–7 Hz band, matching lightning discharges observed by geostationary satellites. GNSS-derived estimates of precipitable water vapor tracked atmospheric moisture buildup and showed clear correlation with intense rainfall, including potential precursory signals days before peak precipitation. This study highlights the value of integrating diverse, non-traditional datasets to enhance the resolution and depth of storm analysis. Their combined use offers a more holistic understanding of storm evolution and supports the development of improved early-warning systems in vulnerable coastal regions.