Geoacoustic emission response to deformation processes activation during earthquake preparation

Peculiarities of geodeformation measurements of near surface sedimentary rocks

“…Based on the calculated data, a strainmeter installed in such conditions has the accuracy of relative deformation measurements not less than 10 −8 . As the observation results show, during the deformations of such order and more, the effects in sedimentary rocks generate acoustic signals in the frequency range from tens of hertz to the first ten of kilohertz [2][3][4].…”

“…A laser strainmeter-interferometer of unequal-type constructed according to Michelson interferometer scheme developed at TOI FEB RAS was used to register deformations until 2013 [2,4].…”

Electromagnetic and acoustic radiations before Kamchatka earthquake

“…The results of investigation of the acoustic emission in Kamchatka showed that acoustic radiation increase in the high-frequency range from hundreds of Hz to the first tens of kHz is determined by the intensification of rock deformations in the observation area including those associated with earthquake preparation [8]. Thus, high-frequency acoustic emission can be applied as a sensitive indicator of intensification of the deformation processes preceding seismic events [8,9].…”

On some features of geoacoustic emission signals before earthquakes

“…3). Additionally, we determined the total (integral) value of acoustic pressure registered by the corresponding channel of a combined receiver in the frequency range of 2 -6.5 kHz [1]. The signal was stored in a window of 1 s. For comparison, ℎ ( ) =7% and were calculated for 410 background periods twenty-four hour long.…”

“…This acoustic effect manifests the most brightly in the kilohertz frequency range and is determined by rock deformations at observation sites at the distances of hundreds of kilometers from the epicenters of preparing earthquakes [1,2].…”