Isostatic ideas appeared within the framework of E. de Beaumont’s contractional hypothesis, which based on views of Kant–Laplace as well as on ideas of primarily smelted Earth and processes of its gradual cooling and compression. Formed as a shell Earth’s crust gradually increased the thickness with clenching into the folds and stay in hydrostatical balance with the underlying substratum. During triangulations of XVIII—XIX centuries differences between the measured deflection of the vertical near mountain ranges and estimates were fixated, so J. Pratt and G. B. Airy had an opportunity to suggest the existence of deep compensating masses. C. E. Dutton, the author of the term «isostasy», considered the wide range of geological problems. Distinction of measured deflection of the vertical is explained by known in gravimetry effect of «neighbor» masses, which formed the North-Atlantic and Indian planetary anomalies of geoid, as well as by real «macrodesdensity» of rock massifs, which is not detected by surveying of density and porosity of small samples of rocks. Modern difficulties with the concept are connected with the explanation of global displacements of asthenosphere masses in planetary eustasy, hydro- and glaciostasy on the rotating Earth as well as the explanation of negative result of gravimetrical experiment for the verification of Fennoscandian «floating»’ isostatic mechanism. The reaction of Earth surface and oceans’ bed to the changes of external loads is usually considered according the unified process of maintaining the isostatic equilibrium. These hypotheses are contradicted with the facts of «high crustal sensitivity» even to small oscillations of external loads as well as total fracturing of the Earth’s crust and scale addictions of its physical and deformation properties from the size of the application area loads. Two mechanisms of the crust’s reaction are suggested: «compression–dilatation» of macropored areas in the layer of 0—10 km and, according to the results of ultradeep boring on the Kola Peninsula, — the phase mechanism at great depths. The ways of experimental research of such effects in the areas of abnormal natural and anthropogenic stresses are discussed.

It is shown, that such a phenomenon as the undulating bottom simulating reflector, which was revealed in 1992 in Lake Baikal, could be explained by the presence here of the thermal convection cell. However, the hypothesis of the tectonic origin of this phenomenon is more probable. The numerical modelling of the thermohydrodynamic regime evolution of the «Malenkij» mud volcano in Lake Baikal is carried out. It is based on solving of the problem of methane hydrate phase transition in porous sediments. The choice of an adequate model and its parameters is carried out by analyzing the data of the multichannel seismic profiling. The large inflow of water in the volcan channel might be explained by the action of shear faults. Estimations of the over-hydrostatic pressure of the methane-gas, generated by dissociation of methane hydrates, show that this pressure is low. It can not be the cause of the breaking of near-bottom sediments and subsequent downward flow of lake water along formed fractures. The method of simultaneous numerical evaluation both the maximum velocity of the water inflow into the channel and the age of the mud volcanoes, formed in the decomposition conditions of gas hydrates, is proposed. Using this method it was found, in particular, that the mud volcano «Malenkij» was formed not earlier than 6.4 and not later than 5 thousand years ago at the maximum velocity of the water inflow through the channel's base equal 7.7±1.4 cm/yr.

Planetary boundary layers contribute to the shaping and maintaining of the Earth’s climate. The deep penetrative convection and convective adjustment cool the planet and controls the hydrological cycle. Hence, the convective processes are intensively studied by climatologists. By contrast, the shallow stably-stratified boundary layer receives much less attention. Its impact is mostly associated with local climate features. This study demonstrates that the stratified boundary layer has significant impact on the global earth’s climate. The study identifies the stably-stratified boundary layer depth as a leading factor modulating the surface air temperature response to anomalous climate heat balance. Geographically, the regions with the largest surface air temperature trends and variability are collocated with the regions where the shallow stably-stratified boundary layers frequently occur. The linear correlation coefficients between the inverse stably-stratified boundary layer depth and the surface air temperature reach 0.4—0.6 over Eurasia and the Arctic sea ice. Particularly strong correlations are found for the continental climates over Siberia where the impacts of soil moisture and cloudiness are less pronounced. Climate models do not adequately represent the depth of the stably-stratified boundary layer which results in systematic model biases both in climate temperature trends and in short-term temperature variability.

The aim of the study is to develop a methodology of combined statistical analysis of spatial and temporal variability of hydrological and hydrooptical observations data and their synchronization rate using the wavelet analysis. The technique of the wavelet analysis allows to identify non-stationary fluctuations in the studied signal associated with local transient processes in the water column. The wavelet transform provides a two-dimensional scan of one-dimensional implementation, the frequency and time are considered as the independent variables. This gives the opportunity to analyze many things in physical and spectral space. On the basis of experimental data obtained during the expedition in August 2013 in the White Sea on the boundary of the Basin and the Strait Western Solovetsky Salma, a joint statistical analysis of spatial and temporal variability of temperature and indicator light attenuation in the layer jump based on wavelet transform is done. The basic energy-scale fluctuations in the range of 1.5—3 h and 5—8 h are indicated. High coherence between the vertical displacement of the thermocline according to temperature and light attenuation index is revealed in these bands. An increase in the attenuation takes place with a lag phase of temperature by 3—4 h within the scope of oscillations 5—8 h and at 0.5—1 h, in the range of 1.5—3 h. Fluctuations in these ranges can be identified as internal waves and be registered by optical means. As a result of researches it is revealed that for the space-time diagnosis and evaluation of the contribution of fluctuations of the temperature field as an indicator of internal unrest in the variability of hydrooptical characteristics, it is preferable to make the analysis of signals based on time series of vertical displacements of these characteristics, because the distribution of the spectral estimates on depths only provides a general information about the state of the oscillating system.

According to a statistical data the largest number of oil spill occurs in the oil handling operations. It requires special measures for preventing emergency situations from the small amount of oil spill. In this case it’s necessary to create conditions for predicted oil slick spreading in the predefined place with favorable environment for oil spill response operation. The special equipment with required parameters for these places needs to be predefined too. An experimental study of an effect of oil simulator transfer from «ship to ship mooring» is given. Different parameters of «ship to ship mooring» were observed, exactly: distance between vessels, flow velocities, displacements of vessels relative to each other. Magnitudes of lateral velocities component are defined for different combinations of flow velocities, hull forms, distance between vessels and vessels’ displacement are defined. Analysis of the «ship to ship mooring» flow fields is given. An important role of a vessel’s mutual disposition, which changes the oil slick flow direction, is demonstrated. An increase of distance between vessels increases the velocity in wake current. Besides that a superposition velocity fields and oil simulator transfer showed a good agreement. Preliminary results allow suggest that there is the optimal distance between vessels in «ship to ship mooring». It can change oil spill response technologies for rivers raids at vessel’s oil handling operations. The second study of this investigation will be field experiments on real vessels and numerical simulation.

This study defines hydrodynamic characteristics of underwater gliders based upon numeric solution of Reynolds-averaged Navier—Stokes equation. Methodological aspects of determination of coefficients of rotary derivatives of hydrodynamic forces and moments of underwater objects based on mechanism of «sliding computation meshes» implemented in many computing software packages of mechanics of fluids are examined. The paper identifies the main stages of development of the calculation model for solving similar tasks. The non-stationary calculation of the flow of viscous fluid past the underwater object resulted in determination of velocity and pressure fields in the stream. Ratios have been obtained which allows determine the coefficients of rotary derivatives of hydrodynamic forces and moments based on the preset values of hydrodynamic impacts. A mathematical model of glider's motion is designed. Glider's motion parameters dependences on effect of alternating excessive buoyancy are presented. Based on analysis of rootes of linearized system's characteristic equation the glider's stability zones in balancing mode of motion are determined under varying values of excessive buoyancy, metacentric height and excessive buoyancy arm.

The paper presents the results of experimental and numerical studies of the regularities of formation of acoustic fields generated by low-frequency pulse signals propagating from the shelf into the deep sea. The results of an experiment conducted in the Japan Sea in April 2014 are discussed in comparison with the results obtained in August 2006, on the same acoustic track, with distances between corresponding points of more than 100 km. In April hydrological conditions on the coastal zone of the acoustic trace and in the upper layer of the deep part of the sea were characterized by a relatively weak (~0.35 s−1) negative vertical gradient of sound speed, while in August 2006 it was ~1.5 s−1. Experimental and numerical studies showed that the effect of acoustic «mudslide» in the conditions of weak negative gradient of sound speed is also apparent, but the structure of the acoustic field which is trapped by the underwater sound channel has a more complicated structure with a stretched time impulse response. However, it’s ordered, stable and well identifiable structure in all randomly selected points for measurement on the acoustic trace may provide the establishment of effective underwater navigation systems of GLONASS and GPS type for a season of spring hydrology.

The paper summarizes the results of echolocation measurements of gas flux from the bubble gas escapes at the bottom of Lake Baikal, obtained in 2005—2014. For the first time the relationship between the height of the acoustic image of the rising bubbles jet and the corresponding methane flux was established. An analysis of this dependence shows that all gas flares are divided into three groups depending on their depth: shallow, intermediate and deep gas seeps. The results of unique observations of three events of gas eruption are discussed. It is shown that the methane flux in the first emissions was by more than an order of magnitude higher than the average, typical for the steady-state emission regime. The range of bubbles radii variation was estimated by ascent rate of bubbles clouds boundaries localized by depth.

The paper focuses on optimization of weight coefficients of cylindrical sound transparent multielement antennas with account for their performance requirements. Only the antennas consisting of nondirectional elements are considered. Optimization is performed for the weight coefficients of the antenna arc, which is multiply repeated in vertical plane to make a cylindrical structure. The following methods of weight coefficient determination are covered: decreasing from the antenna beam to the backside; synthesized compromise method the frequency band and certain frequencies; partly optimized method. Directivity patterns of antennas obtained using different optimization methods are analyzed. As an alternative design, two-layer cylindrical antenna is considered, where each elementary receiver consists of two nondirectional elements arranged along the cylinder radial line. Directivity patterns of such antennas are shown to be close to those of antennas with internal shield. Performance of each optimization type is studied. The proposed performance criterion accounts for the required increase of the antenna concentration factor, reduction of beam width, absence of superdirective solutions, and mitigation of effect of lateral and back fields. The paper demonstrates that partial optimization of weight coefficients is the most preferable optimization method, and two-layer cylindrical antenna design is the most effective technical solution as regards the set of technical parameters.