Features of the Earth surface deformations in the Kamchatka peninsula and their relation to geoacoustic emission

Abstract

Abstract. The paper presents the results of investigations of deformation processes in the near-surface sedimentary rocks, which have been carried out in a seismically active region of the Kamchatka peninsula since 2007. The peculiarity of the experiments on registration of geodeformations is the application of a laser strainmeter-interferometer constructed according to the Michelson interferometer scheme. Besides rock deformations, geoacoustic emission in the frequency range from several hertz to the first tens of kilohertz is under investigation. Piezoceramic hydrophones installed in artificial water reservoirs are applied. It is shown that periods of primary rock compression and tension with a duration of up to several months are distinguished in the geodeformation process at the observation site. During the direction change in the deformations, when the geodeformation process rate grows, an increase in geoacoustic radiation is observed.

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].…”

“…Since 2007, the Laboratory of Acoustic Research of the Institute of Cosmpphysical Rasearch and Radio Wave Propagation (IKIR) FEB RAS has carried out geodynamic observations of the near surface sedimentary rocks as they are characterized by weak strength, high plasticity and are the most available to investigate deformation processes [3]. 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].…”

Complex atmospheric-lithospheric observations of acoustic emission at «Karymshina» site in Kamchatka

“…3. Thus, we may suppose that the occurring deformation disturbances cause acoustic vibration not only in solid medium [3][4][5] but also during the solid-gas transition.…”

“…Air pressure and temperature changes are quite slow processes which occur within several hours that allows us to estimate faster deformation processes. On the basis of estimation data, the strainmeter, installed in such conditions, has the accuracy of relative deformation measurement not less than 10 −8 [4,5].…”

Joint analysis of low-frequency geoacoustic and deformation signals

“…At the output of the laser strainmeter recording system, the rock relative deformation ε is considered with the accuracy of not less than 10 −8 taking into account the meteorological parameters. The measurement frequency is 1 kHz [4]. The seismic receiver is mounted on a strainmeter optical bench end.…”