Deformation Anomalies Accompanying Tsunami Origination

Basing on the analysis of data on variations of deformations in the Earth’s crust, which were obtained with a laser strainmeter, we found that deformation anomalies (deformation jumps) occurred at the time of tsunami generation. Deformation jumps recorded by the laser strainmeter were apparently caused by bottom displacements, leading to tsunami formation. According to the data for the many recorded tsunamigenic earthquakes, we calculated the damping ratios of the identified deformation anomalies for three regions of the planet. We proved the obtained experimental results by applying the sine-Gordon equation, the one-kink and two-kink solutions of which allowed us to describe the observed deformation anomalies. We also formulated the direction of a theoretical deformation jump occurrence—a kink (bore)—during an underwater landslide causing a tsunami.

Cyclonic Process of the “Voice of the Sea” Microseism Generation and Its Remote Monitoring

The article presents the results of microseismic signals of the “voice of the sea” registration by a two-coordinate laser strainmeter during the passage of typhoons through and near the water area of the Sea of Japan. It was established that the “voice of the sea” microseisms appear and disappear almost simultaneously with primary microseisms, i.e., the powerful “voice of the sea” microseisms exist only in the presence of powerful wind waves, generated by a passing typhoon. According to the processing results of the obtained experimental data, the “voice of the sea” microseisms generation area is located in the “sea-land” transition zone, i.e., near and/or in the surf zone. Based on the data of the two-coordinate laser strainmeter, we determined the bearing of the “voice of the sea” microseisms generation area. The movement of this area coincides with the movement of the rear part of tropical cyclones.

PECULIARITIES OF HYDROACOUSTIC WAVE PROPAGATION ON A WEDGED SHELF

При исследовании различных гидрофизических и гидроакустических волновых процессов крайне важно знать закономерности их распространения в море убывающей глубины, особенно в шельфовых областях, а также закономерности их трансформации в сейсмоакустические процессы земной коры. В ходе обработки и анализа экспериментальных данных комплексного эксперимента в данной статье исследуются эти закономерности. В эксперименте использовались низкочастотный гидроакустический излучатель, генерирующий гармонические колебания на частоте 22 Гц, приемные гидроакустические системы и береговой лазерный деформограф. Установлено, что гидроакустические волны, распространяющиеся по шельфу убывающей глубины, трансформируются в сейсмоакустические волны при глубинах моря, равных или меньше половины гидроакустической длины волны. Сравнение результатов данной статьи с ранее полученными результатами позволило утверждать, что такие закономерности должны быть присущи всем гидрофизическим и гидроакустическим процессам. When studying the various hydrophysical and hydroacoustic wave processes, it is extremely important to know the regularities of their propagation in the sea of decreasing depth, especially in the shelf areas, as well as the regularities of their transformation into seismoacoustic processes of the earth’s crust. In the course of processing and analyzing the experimental data of the complex experiment, these regularities are investigated in this article. The experiment used a low- frequency hydroacoustic emitter generating harmonic oscillations at a frequency of 22 Hz, receiving hydroacoustic systems and a coastal laser strainmeter. It has been established that hydroacoustic waves propagating along a shelf of decreasing depth are transformed into seismoacoustic waves at sea depths equal to less than half of the hydroacoustic wavelength. Comparison of the results of this article with previously obtained results made it possible to assert that such regularities should be inherent in all hydrophysical and hydroacoustic processes.

Study of Low-Frequency Hydroacoustic Waves’ Behavior at the Shelf of Decreasing Depth

In research into various hydrophysical and hydroacoustic wave processes, it is extremely important to know the regularities of their propagation in the sea at decreasing depths, especially in the shelf areas, and also to know the regularities of their transformation into seismoacoustic processes in the earth crust. In the course of the processing and analysis of the experimental data of our complex experiment, in this paper we investigate these regularities. In our experiment, we used a low-frequency hydroacoustic transmitter that generated harmonic oscillations at the frequency of 22 Hz and received hydroacoustic systems with a shore laser strainmeter. It was established that hydroacoustic waves, propagating at the shelf of decreasing depth, transform into seismoacoustic waves at the depth of the sea equal to or less than a half-length of the hydroacoustic wave. A comparison of the results of this work with earlier-obtained results allows us to state that such regularities should be inherent to all hydrophysical and hydroacoustic processes.

SOME FEATURES OF ATMOSPHERIC-LITHOSPHERIC OBSERVATIONS OF ACOUSTIC EMISSION AT «KARYMSHINA» SITE IN KAMCHATKA

Излагаются результаты комплексных наблюдений акустического излучения в приповерхностных породах и в атмосфере у поверхности земли. Инструментами наблюдений служат лазерный деформограф-интерферометр и микробарометр, установленные в непосредственной близости друг от друга. В работе приводится описание способа установки оборудования, показано как влияние метеорологических помех на исследуемые величины, так и возмущения, обусловленные сейсмическими и тектоническими процессами. The results of complex observations of acoustic emission in the near surface rocks and by the ground surface in the atmosphere are presented. The observation instrumentation includes a laser strainmeter-interferometer and a microbarometer installed in the intermediate vicinity from each other. The paper describes the method of instrumentation installation, meteorological noise effect on the values under the study and disturbances determined by seismic and tectonic processes.

Assessment of the geomechanical state of the rock mass in the Streltsovsk ore field region according to high-precision deformation measurements

The paper presents a measuring set – a single-component laser strainmeter – for geodynamic monitoring within the Streltsovsk ore field. The results of experimental studies with the participation of a laser strainmeter (deformograph) are presented and the influence of external factors on the state of the massif has been estimated. The influence of distant earthquakes on the state of the mountain massif has been estimated. The features of the deformation field behavior during preparation and implementation of a rock burst have been noted. Characteristics of rock burst precursors in the low-frequency measurement region have been given.

Results of atmospheric-lithospheric observations of acoustic radiation in Kamchatka

Simultaneous atomspheric-lithospheric acoustic observations have been carried out during autumn-spring periods of 2017-2019 in Kamchatka at “Karymshina” observation site located in the zone of different-rank tectonic faults. A laser strainmeter-interferometer, a seismoacoustic receiver and a microbarometer were installed to realize the observations. It was detected that during deformation disturbances, geoacoustic signals are generated in rocks with relative deformations of 10-5 – 10-7 at the place of recording. These signals pass the Earth-atmosphere boundary and are recorded in the air by the ground surface.