Determination of the Parameters of the Earth’s Gravitational Field from Gradiometric Measurements

Astronomy Reports - The paper discusses the goals and objectives of the GOCE project, the measurement information and the data processing strategy used in determining the parameters of the...     

Lunar-Based Measurements of the Moon’s Physical Libration: Methods and Accuracy Estimates

Astronomy Reports - Computer simulation results are reported for planned lunar-based observations to be conducted using an automated zenith telescope that can be placed at any lunar latitude....     

Relationship between the Frequency of the Fundamental Mode 0S2 and the Speed of the Earth’s Rotation

Doklady Earth Sciences - Based on the results of instrumental observations of geomagnetic variations at the Mikhnevo Observatory of the Institute of Geosphere Dynamics, Russian Academy of Sciences,...     

In-phase Variations in the Parameters of the Earth’s Pole Motion and the Lunar Orbit Precession

Astronomy Reports - We found an oscillatory process of the Earth’s pole associated with the precession motion of the Moon’s orbit using numerical processing a series C01 of...     

The Relationship between Global Volcanic Activity and Variations in the Velocity of Earth’s Rotation

Doklady Earth Sciences - Analysis of observations of the Earth’s rotational velocity and volcanic activity of the planet from 1720 until 2015 suggests that higher volcanic activity temporally...     

Intrayear irregularities of the Earth’s rotation

The methods of celestial mechanics can be used to construct a mathematical model for the perturbed rotational motions of the deformable Earth that can adequately describe the astrometric measurements of the International Earth Rotation Service (IERS). This model describes the gravitational and tidal influences of the Sun and Moon. Fine resonant interactions of long-period zonal tides (annual, semiannual, monthly, and biweekly) with the diurnal and semidiurnal tides are revealed. These interactions can be reliably confirmed via a spectral analysis of the IERS data. Numerical modeling of tidal irregularities of the Earth’s axial rotation was carried out, focusing on the analysis and forecasting of variations of the day length occurring within short time intervals of a year or shorter (intrayear variations).     

Short-time-scale features of the Earth’s polar motion

The fundamental astrometric problem of high-accuracy interpolation and forecasting of the Earth’s polar motion on short time scales from 1–2 to 10–30 days is studied. Hierarchies of interval length and parameter accuracy are established using appropriate models for the process. Filtering algorithms are adjusted using a weighted least squares fit of measurements of the International Earth Rotation Service (IERS). Best-fit estimates for the main features of the motion are obtained for various time intervals; interpolations and forecasts are compared with the IERS measurements.     

Masses of carbon in the Earth’s hydrosphere

Recent data were summarized on the concentration and mass of inorganic and organic carbon in reservoirs of the Earth’s hydrosphere. We compared carbon masses and accumulation conditions in the surface hydrosphere and waters of the sedimentary shell and proportions between carbonate, dissolved, and suspended particulate organic carbon. It was shown that the total masses of carbon in the surface hydrosphere and in the waters of the sedimentary shell are approximately equal to 80 × 10¹⁸ g C at an organic to carbonate carbon ratio of 1 : 36 and 1 : 43, respectively. Three main forms of organic compounds in the ocean (living organisms, suspended particles, and dissolved species) occur in the proportion 1 : 13 : 250 and form the pyramid of masses 4 × 10¹⁵ g, 50 × 10¹⁵ g, and 1000 × 10¹⁵ g C_org. The descending sequence of the organic to carbonate carbon ratio in water, ocean (1 : 36) > glaciers (1 : 8) > lakes (1 : 2) > rivers (1 : 0.6) > wetlands (1 : 0.3), is in general consistent with an increase in the same direction in the mean concentrations of organic matter: 0.77 mg C_org/L in the ocean, 0.7 mg C_org/L in glaciers, 6–30 mg C_org/L in lakes, 15 mg C_org/L in rivers, and 75 mg C_org/L in wetlands. Both the mean concentrations and masses of dissolved organic matter in the pore waters of oceanic sediments and in the waters of the sedimentary shell are similar: 36–37 mg/L and 5 × 10¹⁸ and 5.6 × 10¹⁸ g, respectively. The mass of carbonate carbon in the pore waters of the ocean, (19–33) × 10¹⁸ g, is comparable with its mass in the water column, 38.1 × 10¹⁸ g.     

Local Occurrence of the Relationship between Variations in the Earth’s Rotation Rate and the Dynamics of Seismicity: Case Study of Sakhalin

Doklady Earth Sciences - On the basis of three methods, the current seismic situation in the zone of the Central Sakhalin Fault is assessed and the scenarios of its development are predicted. It is...     

Modeling intraday oscillations of the Earth’s pole

An amplitude-frequency analysis of a few-parameter model for intraday oscillations of the Earth’s pole induced by gravitational-tidal torques exerted by the Sun and the Moon is presented. The characteristic features of the intraday oscillations in the polar coordinates are found using the dynamical Euler-Liouville equations, taking into account irregular perturbations. The modeling results for the polar motion are compared with high-accuracy VLBI observations over short time intervals. An amplitude-frequency analysis of the polar oscillations and the second zonal harmonic c ₂₀ of the geopotential is presented.     

Lateral protrusions in the structure of the Earth’s lithosphere

The factual material and modeling results concerning the geology of specific structural elements defined as lateral protrusions, or flowing layers, are considered. The formation of such structural elements is a fundamental phenomenon that controls many features of the structural evolution and geodynamics of platform basement and foldbelts. A lateral protrusion, or flowing layer, is a spatially constrained, nearly horizontal geological body with attributes of 3D tectonic flow (rheid deformation) and lateral transport of rock masses. Flowing layers are large lateral protrusions that play important role in the structure of the continental and oceanic lithosphere. They embody the internal mobility of huge rock bodies and confirm the possibility of their lateral redistribution at different depths of the continental lithosphere. The lateral displacement of rocks within such assemblies may occur in the regime of cold deformation, heating, metamorphism, and ductile flow of rocks under subsolidus conditions or in the process of their partial melting.     

Precessional motions of structural blocks of the Earth’s crust

Instrumental observations revealed a new type of motion previously not described in the literature, the precessional motions in the structural blocks of the Earth’s crust. The precession-nutation motions are caused largely by a complex response of a structural block and the adjacent tectonic structure, acting as a discontinuous zone between blocks, to tidal deformation. Irregular precession with a period of about one day complicated by the half a day period nutation defines a complex loading pattern characteristic of the internal structure of faults adjacent to the block.

     

Effect of Atmospheric Pressure on the Deformation of the Earth’s Crust

Doklady Earth Sciences - A method for estimating the contribution of atmospheric pressure variations to the deformation of the upper layer of the Earth’s crust using synchronous data from...     

Effect of the Earth’s rotation on subduction processes

Doklady Earth Sciences - The role played by the Earth’s rotation is very important in problems of physics of the atmosphere and ocean. The importance of inertia forces is traditionally...     

Barrier effect of degassing and destruction of the Earth’s crust

Doklady Earth Sciences -     

Equation of state of magnesite for the conditions of the Earth’s lower mantle

A semiempirical equation of state was derived for magnesite under the thermodynamic conditions of the Earth’s mantle. Within experimental uncertainties, it is consistent with thermochemical, ultrasonic, X-ray, and shock-wave data at temperatures from 15 K to the melting point and pressures of up to 100–130 GPa. The following values were recommended for the isothermal bulk modulus and its pressure derivative: K _T = 111.71 GPa and K′ = 4.08. Thermodynamic analysis showed that magnesite does not decompose to periclase and CO₂ under the thermodynamic conditions of the Earth’s lower mantle and outer core.     

Influence of the Growth of Earth’s Solid Core on the Effective Geodynamo

Doklady Earth Sciences - A model of the Earth’s cooling, which describes the formation of a solid core, is considered. Its formation enhances the convection due to additional energy sources...     

The influence of tropical cyclones upon the Earth’s crust

Doklady Earth Sciences - This paper discusses the influence of tropical cyclones (TCs) upon the Earth’s crust beneath the ocean bottom, which is associated with rapid variations of pressure...