Landslide-Triggered Large-Scale Electromagnetic Perturbations

The onset of landslides is often preceded by rock fracturing and strata failure, processes that can emit electromagnetic radiation. To analyze the relationship between magnetic perturbations and landslides, we systematically excluded influences from solar activity, lightning, artificial noise, and seismogenic faults. Using the correlation coefficient method, we examined the in-phase and out-of-phase relationships within geomagnetic data collected from approximately 100 monitoring stations. The analysis revealed that correlation coefficients exceeding 0.8 (high) and below -0.8 (low) related to landslides are distributed across areas with an extensive radius of approximately 500 km. Two distinct interfaces were identified between high (>0.8) and low (<-0.8) correlation coefficients, extending from the landslide sites. These interfaces aligned with the direction of the landslide flow and its perpendicular direction. We hypothesize the presence of two electric currents flowing along these interfaces and applied the Biot-Savart Law to compute the associated magnetic perturbations. The computed results show a reasonable agreement with observational data. Furthermore, the detection of electromagnetic radiation several minutes before landslide events suggests the potential for an early warning system. By leveraging far-field geomagnetic data, such a system could help mitigate fatalities and reduce risks associated with landslides.