Laboratory investigation of coupled electrical interaction of fracturing rock with gases

Abstract In the coupled electric interaction of rock fractures and gas invasion, that is, when gases interact with newly created crack surfaces, unpaired electrons within crystal defects are thermally stimulated, released into due to temperature rise at tip via plastic work, attached ambient molecules electrify them in a negative state. Using working hypothesis this mechanism is source seismo-electromagnetic phenomena, we conducted laboratory experiments which rocks were fractured pressurized N 2 , CO CH 4 hot water vapour. Fractures induced by flat-ended indenter equipped flow channel, was loaded against blocks quartz diorite, gabbro, basalt, granite. Fracture-induced negatively electrified currents ~ 25 °C 160 successfully measured for ≥ 100 μs after full development crack. The peak as high 0.05–3 μA, depending on species area lesser extent temperature. current from fracturing granite, showed higher γ-ray activity, least 10 times than basalt. results supported validity present hypothesis, deep Earth during quasi-static rupture focal zone fault might play an important role generation pre- co-seismic electromagnetic phenomena.