Active seismic surveys

Seismic wave velocity depends greatly on the properties of the material. During active seismic surveys, seismic vibrations are generated by hammering a metal plate along a line of seismic sensors.  The unstable slide compartments have reduced wave propagation velocity due to fragmentation, compared to bedrock. In this way, the depth of slide surfaces, subsoil stratification, velocity structure and vertical faults can be mapped.