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1.
The development of methods for the construction of stochastic, dynamical models for intra-year irregularity of the Earth’s
rotation is considered. A correlational model based on harmonically additive and parametrically random, colored and broadband,
gravitational-tidal perturbations from the Sun and Moon is developed. One-dimensional and multi-dimensional characteristic
functions are found for the case of Gaussian and non-Gaussian colored and broadband fluctuations in the irregularity of the
Earth’s rotation. Examples of computer modeling of the irregularity in the Earth’s rotation based on a priori and a posteriori
IERS data are presented. 相似文献
2.
Numerical celestial-mechanical models are used to compare (andg interpolate and forecast) near-diurnal tidal variations in
the Earth’s axial rotation and oscillations in the global angular momentum of the atmosphere using the IERS data and NCEP/NCAR
meteorological data. In order to improve the accuracy of interpolations and forecasts made for short and intraday time intervals,
it is expedient to include the effect of small perturbations in short-term zonal tides, which influence fluctuations in Universal
Time UT1 directly related to the Earth’s rotation. Due to the quasi-static formulation of the problem, it is assumed that
the dynamics of the thin surface atmosphere are completely determined by the gradient of the tide-generating geopotential,
which supports forced oscillations of the entire subsystem (i.e., of the mantle and atmospheric envelope). A comparison of
the numerical simulations with the NCEP/NCAR data shows that the model is effective for applications in forecasting atmospheric
tides. 相似文献
3.
Methods of celestial mechanics are used to refine a mathematical model for irregularity in the axial rotation of the Earth
proposed earlier. This refinement applies corrections (residuals) introduced by perturbations of zonal tides. We examine intraday
and near-diurnal variations in the Earth’s axial rotation, and a celestial-mechanical model explaining the origin of the intraday
and near-diurnal oscillations in the rotational angular velocity is constructed. The correspondence between the variations
of the intrayear rotational irregularity and the overall angular momentum of the atmosphere is analyzed. 相似文献
4.
In this work, we attempt to quantify forces that result from the interaction between the induced Sq-variation currents in
the Earth’s lithosphere and the regional Earth’s magnetic field, in order to assess its influence on the tectonic stress field
and on seismic activity. The study area is the Sinai Peninsula, a seismically active region where both seismic and magnetic
data are available. We show that both short-term and long-term magnetic changes correlate with the seismic activity extending
to this area in other previous studies. We also analyze a set of large earthquakes and magnetic data from observatories around
the world to deduce a relationship between earthquake magnitude and maximum distance up to which precursory variations of
the magnetic field are observed. 相似文献
5.
The results of synchronous measurements of temperature variations in a near-bottom thermocline, as well as microdeformations
of the Earth’s crust and atmospheric pressure pulsing, recorded on-shore with the help of a laser strainmeter and laser nanobarograph,
are presented. A string containing 20 thermosensors spaced at 0.5 m was used; it was placed by an anchored buoy in a place
with 21-m depth and 500 m away from the shore. A good correlation between microdeformations and atmospheric pressure variations
was observed for periods longer than 6 h. Quantitative estimates and spectral analysis via the Gilbert-Huang method for investigation
of nonstationary and nonlinear processes lead to the conclusion that, on temporal scales from tidal to several minutes, the
predominant way of formation of microdeformations in the Earth’s crust can be breaking of internal waves in a thermocline
that leads to shallow water (i.e., in the zone of “internal breakers”). 相似文献
6.
The authors identify and describe the following global forces of nature driving the Earth’s climate: (1) solar radiation as a dominant external energy supplier to the Earth, (2) outgassing as a major supplier of gases to the World Ocean and the atmosphere, and, possibly, (3) microbial activities generating and consuming atmospheric gases at the interface of lithosphere and atmosphere. The writers provide quantitative estimates of the scope and extent of their corresponding effects on the Earth’s climate. Quantitative comparison of the scope and extent of the forces of nature and anthropogenic influences on the Earth’s climate is especially important at the time of broad-scale public debates on current global warming. The writers show that the human-induced climatic changes are negligible. 相似文献
7.
The dynamics of magmatic melts in the near-surface part of several kilometers depth is determined by gas release processes.
Formation of free gas share is an energy source, while decreasing of the density of the melt creates conditions for magma
motion to the Earth’s surface. As the water content in the total volume of gas is about 80% for magmatic basaltic melts, gas
release of water in the near-surface part of the magmatic column realizes the main share of energy, which leads to volcanic
bursts and continuous gas-ash flows throughout the eruption process. Gas release processes create pressure variations in magmatic
melts, and these variations are transferred into the solid medium as elastic oscillations forming seismic waves. The principal
frequency of seismic signals for active volcanoes is several hertz, and the presence of spectral peaks has been explained
by the presence of resonant sources. 相似文献
8.
A. T. Sorokina A. P. Sorokin M. A. Serov A. A. Popov 《Russian Journal of Pacific Geology》2011,5(1):13-25
The results of long-term studies of the neotectonic processes and related phenomena such as the Earth’s interior degassing,
the fluid discharge, and the high seismicity in the zone of interaction between the Amur and Okhotsk lithospheric plates at
the transition between the Verkhnii and Srednii Amur regions were used for defining the separate structural blocks with different
geodynamics and analyzing their relations with the seismic events during the periods of high seismic activity and quiescence.
The heliometric and atmochemical studies in the Zeya-Bureya basin revealed zones of high permeability. Long-term observations
of the fluid dynamics at the Konstantinovka mineral water deposit demonstrate a correlation between the variations in the
water-soluble helium contents and the changes in the stress-deformed state of the blocks located up to 200 km away from regime
observation sites. 相似文献
9.
Bondur V. G. Garagash I. A. Gokhberg M. B. Lapshin V. M. Nechaev Yu. V. 《Doklady Earth Sciences》2010,430(1):147-150
A three-dimensional geomechanical model of Southern California, including mountain relief, fault tectonics, and characteristic
internal borders, such as the roof of the consolidated crust and Moho surface, was created. The initial stress state of the
model is determined by the gravitational force and horizontal tectonic movement, established on basis of GPS observations.
Monitoring of variations in the stress state of the Earth’s crust and lithosphere, which are generated by seismic processes,
has shown that the model enables us to predict an increase of seismic activity in a region and to mark the places in which
average earthquakes can occur in the following two weeks. 相似文献
10.
Robert Tenzer Pavel Novák Peter Vajda Vladislav Gladkikh Hamayun 《Computational Geosciences》2012,16(1):193-207
We developed and applied a novel numerical scheme for a gravimetric forward modelling of the Earth’s crustal density structures
based entirely on methods for a spherical analysis and synthesis of the gravitational field. This numerical scheme utilises
expressions for the gravitational potentials and their radial derivatives generated by the homogeneous or laterally varying
mass density layers with a variable height/depth and thickness given in terms of spherical harmonics. We used these expressions
to compute globally the complete crust-corrected Earth’s gravity field and its contribution generated by the Earth’s crust.
The gravimetric forward modelling of large known mass density structures within the Earth’s crust is realised by using global
models of the Earth’s gravity field (EGM2008), topography/bathymetry (DTM2006.0), continental ice-thickness (ICE-5G), and
crustal density structures (CRUST2.0). The crust-corrected gravity field is obtained after modelling and subtracting the gravitational
contribution of the Earth’s crust from the EGM2008 gravity data. These refined gravity data mainly comprise information on
the Moho interface and mantle lithosphere. Numerical results also reveal that the gravitational contribution of the Earth’s
crust varies globally from 1,843 to 12,010 mGal. This gravitational signal is strongly correlated with the crustal thickness
with its maxima in mountainous regions (Himalayas, Tibetan Plateau and Andes) with the presence of large isostatic compensation.
The corresponding minima over the open oceans are due to the thin and heavier oceanic crust. 相似文献
11.
The impact of atmospheric circulation fluctuations (Vangengeim’s classification) on the zoobenthos dynamics in the Sea of
Azov was studied. The “western” circulation processes lead to zoobenthos biomass decrease, and the opposite pattern was observed
when “eastern” circulation processes prevail. A quasiperiodicity with 3–7 to 10–15 year cycles is revealed for the zoobenthos
biomass dynamics. These changes are closely connected with the climatically induced increase of the zoobenthos biomass in
the Sea of Azov. 相似文献
12.
Yu. V. Marapulets O. P. Rulenko I. A. Larionov M. A. Mishchenko 《Doklady Earth Sciences》2011,440(1):1349-1352
During the period of October 1–18, 2009, 41 km southwest of Petropavlovsk-Kamchatsky, in the intersection zone of tectonic
faults of various orders, simultaneous recording of the geoacoustic emission, gradient of the atmospheric electric field’s
potential, strains of the Earth’s surface, atmospheric pressure, wind speed, and rain intensity was made. It was found for
the first time that anomalous disturbances of high-frequency geoacoustic emission and atmospheric electric field near the
Earth’s surface originate as a simultaneous response to extension of near-surface sedimentary rocks. In the case of compression,
only disturbances of geoacoustic emission occur. Anomalies were recorded under quiet weather conditions and with rocks strains
being two orders greater than those of tidal ones. 相似文献
13.
Some improved methods for modeling the motions of the Earth’s pole determined by gravitational-tidal, fluctuating-dissipative
perturbations occurring on various time scales are presented. The main attention is paid to dynamical linear-regression models
and dynamical filtering models, which take into account dynamical measurement errors. Computer simulations of the oscillatory
motion of the Earth’s pole for 1995–2010 are also presented. 相似文献
14.
A. G. Tlatov 《Astronomy Reports》2006,50(4):325-332
The characteristic time scales for variations in the differential rotation of the solar corona are determined using measurements of the intensity of the FeXIV 5303 Å coronal line made from 1939–2004. Drift waves of the variations in the rotational speed with an 11-year periodicity can be distinguished. Moving averages with time intervals from two to five years are used to identify torsional waves. In addition, longer-period variations in the rotational speed can be distinguished when longer averaging intervals are used. When the interval used for the moving average is increased to 8–12 years, a quasi-22-year rotational period appears. The low-latitude corona rotates more slowly in odd cycles than in even cycles. Increasing the duration of the averaging interval further shows that rapid rotation at low latitudes was observed in 1940–1950 and 1990–2000, while slow rotation was observed in 1960–1980, possibly suggesting the presence of a 55-year period in the rotational variations. Long-term variations are found in the rotation of polar regions. The rotational variations for high-latitude corona are in antiphase with those for the low-latitude corona. The origins of zones of anomalous coronal rotation and their dynamics in the global activity cycle are discussed. 相似文献
15.
G. I. Dolgikh 《Russian Journal of Pacific Geology》2012,6(1):61-69
The paper discusses the technical characteristics of hardware-software complexes based on the application of broadband seismographs,
GPS/GLONASS receivers, and laser strainmeters in the context of the examination of their capacity to study variations in the
Earth’s stress-strain field leading to natural and technogenic catastrophes. 相似文献
16.
The Mesozoic-Cenozoic rhythmic continental sedimentary rocks are analyzed for every particular period and epoch from the Triassic
to the Pliocene. The maximal distribution areas of rhythmic deposits are within the latitudinal zone of 20°-40°. Investigation
of rhythmic Mesozoic-Cenozoic carbonate-containing deposits of Europe and North America enables us to attribute rhythmicity
to climate change owing to insolation and eustatic variations of oceanosphere’s level, on the one hand, and to compare duration
values of the rhythmic unit and rhythmic sequence with cycles of orbital precession, ecliptic plane inclination, and the eccentricity
of the Earth’s orbit, on the other hand. 相似文献
17.
Tsvetkov Yu. P. Kuznetsov V. D. Golovkov V. P. Brekhov O. M. Pelle V. A. Krapivnyi A. V. Nikolaev N. S. 《Doklady Earth Sciences》2011,436(1):117-121
The solution to the problem of extraction of the anomaly Earth’s magnetic field (EMF) from stratospheric balloon magnetic
surveys with the help of global analytical models of the normal EMF is proposed. In the problem solution, errors for the analytical
models of the normal EMF and its secular variation at a set moment of time are assessed; the found error is introduced as
a correction to the extracted anomaly EMF. The error of the model is determined in the places where significant magnetic anomalies
are absent. In this case, the error of the model corresponds to deviations of the normal EMF components, synthesized by coefficients
of analytical models, and to deviations of the EMF secular variations from the measured values at quite a low value of the
variable EMF or one being taken into account. These places are determined when carrying out additional measurements in vertical
gradients of the EMF with the use of scalar magnetometers at the gauge length of 6 km. It has been shown that the found places
can be considered as nonanomaly, if the difference of values of the anomaly EMF at the gauge length of 6 km does not exceed
1.5 nT within the profile’s portion of about 100 km in length. An experiment in nature has revealed that errors for the IGRF-2005
and IGRF-2010 models, corrected for secular variation of the EMF, can reach 200 and 140 nT, respectively, within the limits
of the territory where the Kama-Emba magnetic anomaly is located; these errors are determined by the considered causes. Comparison
of aerostatic profiles of magnetic anomalies with data on the anomaly EMF, derived from the maps, has shown that the realizations
derived from the maps contain overestimated negative values of the anomaly EMF, because they reflect processes in the near-surface
layer of the Earth’s crust. This fact causes the situation when attempts to recalculate the anomaly EMF into the upper half-space
by the near-surface data still have not been successful. Only realizations derived at the altitudes comparable to the thickness
of the Earth’s crust can give an adequate model of the anomaly EMF in the circumterrestrial space and enable us to recalculate
magnetic anomalies reliably into any altitude levels. 相似文献
18.
According to their genesis, meteorites are classified into heliocentric (which originate from the asteroid belt) and planetocentric
(which are fragments of the satellites of giant planets, including the Proto-Earth). Heliocentric meteorites (chondrites and
primitive meteorites genetically related to them) used in this study as a characteristic of initial phases of the origin of
the terrestrial planets. Synthesis of information on planetocentric meteorites (achondrites and iron meteorites) provides
the basis for a model for the genesis of the satellites of giant planets and the Moon. The origin and primary layering of
the Earth was initially analogously to that of planets of the HH chondritic type, as follows from similarities between the
Earth’s primary crust and mantle and the chondrules of Fe-richest chondrites. The development of the Earth’s mantle and crust
precluded its explosive breakup during the transition from its protoplanetary to planetary evolutionary stage, whereas chondritic
planets underwent explosive breakup into asteroids. Lunar silicate rocks are poorer in Fe than achondrites, and this is explained
in the model for the genesis of the Moon by the separation of a small metallic core, which sometime (at 3–4 Ga) induced the
planet’s magnetic field. Iron from this core was involved into the generation of lunar depressions (lunar maria) filled with
Fe- and Ti-rich rocks. In contrast to the parent planets of achondrites, the Moon has a olivine mantle, and this fact predetermined
the isotopically heavier oxygen isotopic composition of lunar rocks. This effect also predetermined the specifics of the Earth’s
rocks, whose oxygen became systematically isotopically heavier from the Precambrian to Paleozoic and Mesozoic in the course
of olivinization of the peridotite mantle, a processes that formed the so-called roots of continents. 相似文献
19.
V. G. Kuznetsov 《Lithology and Mineral Resources》2011,46(2):186-197
Ch. Lyell’s works, the main work among which entitled Principles of Geology was published 180 years ago in 1830, created a new concept and laid the groundwork for modern geological science, methods
for the study of geological processes and geological history based on the investigation of recent environments and processes.
These propositions with natural corrections are also used in geological works at present. They have demonstrated persistence
of the geological history and absence of global geological catastrophes. This fact was of great importance in science and
ideology, because it changed basically the perception of the Earth’s nature and history based on the biblical world pattern. 相似文献
20.
The paper reports results of the analysis of the spatial distribution of modern (younger than 2 Ma) volcanism in the Earth’s
northern hemisphere and relations between this volcanism and the evolution of the North Pangaea modern supercontinent and
with the spatial distribution of hotspots of the Earth’s mantle. Products of modern volcanism occur in the Earth’s northern
hemisphere in Eurasia, North America, Greenland, in the Atlantic Ocean, Arctic, Africa, and the Pacific Ocean. As anywhere
worldwide, volcanism in the northern hemisphere of the Earth occurs as (a) volcanism of mid-oceanic ridges (MOR), (b) subduction-related
volcanism in island arcs and active continental margins (IA and ACM), (c) volcanism in continental collision (CC) zones, and
(d) within-plate (WP) volcanism, which is related to mantle hotspots, continental rifts, and intercontinental belts. These
types of volcanic areas are fairly often neighboring, and then mixed volcanic areas occur with the persistent participation
of WP volcanism. Correspondingly, modern volcanism in the Earth’s northern hemisphere is of both oceanic and continental nature.
The latter is obviously related to the evolution of the North Pangaea modern supercontinent, because it results from the Meso-Cenozoic
evolution of Wegener’s Late Paleozoic Pangaea. North Pangaea in the Cenozoic comprises Eurasia, North and South America, India,
and Africa and has, similar to other supercontinents, large sizes and a predominantly continental crust. The geodynamic setting
and modern volcanism of North Pangaea are controlled by two differently acting processes: the subduction of lithospheric slabs
from the Pacific Ocean, India, and the Arabia, a process leading to the consolidation of North Pangaea, and the spreading
of oceanic plates on the side of the Atlantic Ocean, a process that “wedges” the supercontinent, modifies its morphology (compared
to that of Wegener’s Pangaea), and results in the intervention of the Atlantic geodynamic regime into the Arctic. The long-lasting
(for >200 Ma) preservation of tectonic stability and the supercontinental status of North Pangaea are controlled by subduction
processes along its boundaries according to the predominant global compression environment. The long-lasting and stable subduction
of lithospheric slabs beneath Eurasia and North America not only facilitated active IA + ACM volcanism but also resulted in
the accumulation of cold lithospheric material in the deep mantle of the region. The latter replaced the hot mantle and forced
this material toward the margins of the supercontinent; this material then ascended in the form of mantle plumes (which served
as sources of WP basite magmas), which are diverging branches of global mantle convection, and ascending flows of subordinate
convective systems at the convergent boundaries of plates. Subduction processes (compressional environments) likely suppressed
the activity of mantle plumes, which acted in the northern polar region of the Earth (including the Siberian trap magmatism)
starting at the latest Triassic until nowadays and periodically ascended to the Earth’s surface and gave rise to WP volcanism.
Starting at the breakup time of Wegener’s Pangaea, which began with the opening of the central Atlantic and systematically
propagated toward the Arctic, marine basins were formed in the place of the Arctic Ocean. However, the development of the
oceanic crust (Eurasian basin) took place in the latter as late as the Cenozoic. Before the appearance of the Gakkel Ridge
and, perhaps, also the oceanic portion of the Amerasian basin, this young ocean is thought to have been a typical basin developing
in the central part of supercontinents. Wegener’s Pangaea broke up under the effect of mantle plumes that developed during
their systematic propagation to the north and south of the Central Atlantic toward the North Pole. These mantle plumes were
formed in relation with the development of global and local mantle convection systems, when hot deep mantle material was forced
upward by cold subducted slabs, which descended down to the core-mantle boundary. The plume (WP) magmatism of Eurasia and
North America was associated with surface collision- or subduction-related magmatism and, in the Atlantic and Arctic, also
with surface spreading-related magmatism (tholeiite basalts). 相似文献