Self-Generating Processes in the System Atmosphere–Earth’s Crust

Doklady Earth Sciences - Based on analysis of experimental data, the self-generating processes in the system atmosphere–Earth’s crust are considered, in which energy is sequentially...     

Free oscillations of water level in the Posyet Gulf bays (the Sea of Japan)

The results of the experiments on the registration of hydrosphere pressure variations are analyzed. The experiments were conducted in 2011, 2012, and 2014 using the laser meter ofhydrosphere pressure variations and the laser hydrophone in some bays of the Posyet Gulf in the Sea of Japan. Basic attention is given to the wind waves and fundamental modes of free oscillations in the bays.     

Studying the variability of the wind wave period

Analyzed are the experimental data on the range of the sea wind waves obtained using a laser meter of hydrospheric pressure variations in 2007, 2010, 2011, and 2012 at different points of the shelf of the Sea of Japan. It is demonstrated that the variations of wind wave periods at their leaving the zone of cyclonic action can be associated not only with the dispersion but also with the Doppler effect and variations of the wind speed and wind direction in the zone of cyclonic action. Carried out was the analysis of the results of the processing of experimental data of the laser meter of hydrospheric pressure variations and the mobile laser meter of hydrospheric pressure variations; this analysis revealed that the transformation of wind waves with the decrease in the period and energy takes place in the case of their movement along the shelf of the decreasing depth.     

Some regularities in the dynamics of the periods of sea wind waves

An empirical equation on a change in the periods of wind waves at the point of recording, which makes it possible to calculate the period of wind waves in any direction on a time scale, is derived based on the experimental data.     

Laser meter for hydrosphere pressure variations with a mechanical temperature compensation system

Based on modern laser interferometric methods, a laser meter has been developed, equipped with a mechanical external thermal effect compensation system designed to record hydrospheric pressure variations in the frequency range from 0 (conventionally) to 1000 Hz with an accuracy of 50 μPa.     

Features of Propagation and Transformation of Low-Frequency Hydroacoustic Signals on a Shelf of Decreasing Depth

Doklady Earth Sciences - By the analysis of the experimental data and model calculations, features of the propagation of hydroacoustic signals over a shelf of decreasing depth generated by a...     

Dynamic Features of Infra-Gravity Sea Waves on the Shelf

Doklady Earth Sciences - The dynamic features of shelf infra-gravity sea waves and their relation to the main parameters of gravity sea waves are studied using experimental data obtained from a...     

Peculiarities of spreading of acoustic waves over a shelf with decreasing depth

We analyze experimental data collected in Vityaz Bay of the Sea of Japan during study of the peculiarities of spreading of hydroacoustic waves over a shelf with decreasing depth. We found that the waves propagate over a shelf with depths greater than half of the hydroacoustic wave according to the law of cylindrical divergence with least losses of the wave energy. If the depths are shallower than half of the hydroacoustic wave, they spread along the water-bottom boundary as Rayleigh waves of decaying and undamped types with significant absorption of the wave energy by the bottom.     

Development of tomographic technology for the Earth’s crust in the shelf regions

On the basis of experimental data obtained during a comprehensive experiment in Vityaz Bay of the Sea of Japan using onshore laser strainmeters and a low-frequency hydroacoustic emitter generating complex phase-manipulated signals with a central frequency of 33 Hz, we developed the basic principles of contactless tomography of the Earth’s crust in the shelf regions of various seas, including those covered by ice, making it possible to determine efficiently the structure and composition of the upper Earth’s crust under seas.