Seismoacoustic And Electromagnetic Emission Of Rocks In Boreholes

One of the few opportunities to receive information on a stress field and deformation processes within geomedium volume is connected with the investigation of spatial-temporal distribution of seismoacoustic (SAE) and electromagnetic (EME) emission according to sections of deep boreholes. SAE and EME were observed at low and high pressure, exceeding 100 MPa. Anomalously high SAE and EME levels are often connected with blocks’ boundaries, zones of crushing and increased rocks’ jointing. In this case, SAE and EME are sufficiently sensitive indicators of stressed state in the Earth’s crust, reflecting even so weak actions, as Earth’s tides at depths of at least 5 km. Corresponding data were received with instruments, including acoustic channel in 20-2500 Hz frequency band with three orthogonal sensors and electromagnetic channel in 46-120 kHz frequency band with vertical magnetic aerial. Simultaneous use of acoustic and electromagnetic channels raised the authenticity of measured signals, caused by deformation processes and not other factors.