Infrasonic and Seismic Analysis of Debris‐Flow Events at Illgraben (Switzerland): Relating Signal Features to Flow Parameters and to the Seismo‐Acoustic Source Mechanism

Debris flows are among the most dangerous phenomena in mountain environment. Recently use of seismic and infrasonic recordings has proven to be a powerful tool for study monitor debris flows. However open questions remain linking signal characteristic flow parameters fluid dynamic processes. We present seismo-acoustic analysis activity between 2017 2019 at Illgraben catchment (Switzerland). Seismic amplitudes (maximum root mean square amplitude, RMSA) peak frequencies compared with measurements (front velocity, maximum depth density). Front depth, discharge mass flux show positive correlation both RMSA, suggesting that influenced by these parameters. Comparison reveals that, unlike signals, characterized constant frequency regardless magnitude flow, infrasound decreases increasing discharge. Our results suggest waves generated different source processes, acting free surface channel bed respectively. propose is likely oscillations develop which, according dynamics, mostly wherever encounters significant irregularities. Furthermore, observed correlations features highlight potential debris-flow monitoring risk management.