The problem of behavior of lower layer of the Earth crust in the process of continental subduction was studied basing on conception of two-staged plate tectonic. An equation of the behavior of a film was derived using approximation of hydrodynamic film theory. An analyses of this equation and its numerical solution was accomplished. Thus this work resulted in the model that can be used for description of processes of the crust thickening in the regions of litospere plates interaction.

Geology and geophysics, 1991, #7, pp.3-8 (in Pussian).

Two-dimentional mechanical and thermal model under continental collision is used to calculate the features of the structure and the development of the collision belt. Two-layer crust is under study. The upper layer is considered with an elastic and lower layer with a viscous rheology behavior. The intercontinental subduction resulted in sharp submersion of the mantle lithosphere is assumed considered as a cause of the crust deformation development.

The Newton rheology is considered when designing a mechanical model for the lower crust. The height of raising is about 5 km during 20 m.y., horizontal dimensions is several hundred kilometers. An asymmetry of the raising is developing. Foredeep from one to two kilometers in depth and about 100 km in horizontal dimension are developing when elastic reaction of mantle lithosphere is considered. With the development of the raising an initial compression state in his central part is converting into tension state. Erosion processes are playing a considerable role at the postcollision stage. The material which is taken away is resisting the running of the raising and thus can support its existence for a considerable period after the end of subduction.

An exponential rheological function taking into account the influence of temperature is considered for the thermal model of lower crust. Modeling is showing that in comparison to the "normal" continental crust temperature distribution, an additional 80-150^o C warming up for 20 million years is taking place resulting in increase of heat flow and partial melting of crust material. Under unchangeable boundary conditions the system is tending to the new steady state.

TERRA abstracts. Abstract supplement ¹1 to TERRA nova, volume 7, p.116, 1995, Blackwell Scientific Publication, Oxford.

In a series of papers published in 1997 V.E. Khain and N.A. Yablonskaya tried to revive the Emile Argands concept concerning the origin of the collision belt of Eurasia. According to this concept the structural pattern of the Alpine-Himalayan and Central Asian mountain belts is interpreted as reflecting the elastic-viscous upper crustal deformations. A model of the Cenozoic structure of the collision area, revealing certain regularities similarity symmetry of its different elements and their ensembles.

The model of the whole collision belt is compiled on the base if detailed investigations of the Cenozoic structure of the Tien-Shan-Kyzylcum region. Here multi order structural parageneses are pointing to rotational elastic-viscous flow of the upper part if the crust (Yablonskaya, 1997). The seismicity analysis has shown that in these deformations the upper crustal layer up to the depth of 20 km participates (95% of earthquakes).

Its proposed to consider as E. Argand cover folds (plis de couverture) dislocations of the appear, seismically active layer of the Earth's crust (seismic activity testify its brittle or elastic-viscous properties) and under basement fold (plis defend)-dislocations of its base, or of the surface of the underlying plastic layer, were the seismicity attenuates. In his case, meganticlines and megasynclines of the collision belt, must correspond to basement folds, situated in the depth and the folds and strike-slip and thrust faults, complicating there structure-to cover folds.

The concept of the plastic behaviors of the lower crust could explain the possibility of very large horizontal translations along this structural level, suggested by Argand. the variations of its thickness, the formation of "mountain roots", by its capability to out flow and pump under the influence of tangential strain. "The horizontal migration of deep matter could be detected by vertical movement. This movement, if not masked by movements, induced by more powerful agents, are characterized by subsidence when the matter is escaping from the given region and by uplift in case of its influx."(Argand, 1922, p. 111).

Computer modeling shows that the viscous flow in the lower crust plays a leading role in the transmission of the acting forces in the intraplate deformations on a long distance. The dynamic of the change of the crust thickness in the orogens in 20 m.y. time in obtained, which corresponds to the real collision time. Considerable (up to twofold) increasing of the crust thickness, asymmetry of the slopes of the collision uplift, horizontal dimensions of the orogen - several hundreds of kilometers, the height of uplifts, attaining 8 km, are the characteristic features of these models of the collision orogens. The velocity field in the lower crust indicates a substantial moving of the material of this layer. The distribution of the shearing strain points to the extension conditions on the upper surface of the plastic layer in the general compression setting.

The result of numerical modeling of thermal processes with participation of dissipate heat generation in the condition of viscous flow in the lower crust points to a substantial (50-200oC in 20 m.y.) temperature rise on the crust base. The temperature of the granite melting is thus obtained. In the combination with the strain, acting in the lower crust, this creates conditions, favorable to granitoid magmatism.

The present-day island arcs are known to be connected mainly with the western frame of the Pacific Ocean, whereas the subduction beneath its eastern frame is not followed by opening of back-arc basins, and so it is represented by the Andean-type active continental margins. This global asymmetry reflects the fundamental difference between the regimes of the current westward and eastward subduction. The difference is thought to be caused by the direction of rotational strains and by such its effect as the general lag and the net westward drift of continental lithosphere with respect to underlying mantle.

The extinct island arcs and back-arc basins of Early and Middle Mesozoic, on the contrary, are represented by terranes at the both sides of the Pacific, particularly in the Cordilleras and in the Andes. So the subduction of that time didn't express any distinct west-east polarity. Consequently, besides the permanent rotational forces, should be found some other factors responsible for the growing polarity of subduction since the Late Mesozoic.

We accept that for the back-arc opening (i.e. for the generation of island arcs) low absolute velocities of the overriding plates and high age (high density, low buoyancy) of the underriding plates are favorable. It is known also that certain phases of back-arc spreading correlate with the deceleration of plate convergence.

Since the breakup of Pangaea (about 170 Ma) the circum-Pacific subduction was greatly affected by this phenomenon. For the fragments of Pangaea the vector systems of relative motions have been analysed in comparison with the vector systems of absolute motions at the same time moments. The result suggests that the breakup kinematics may be responsible for the extinction of East Pacific island arcs and for the increasing asymmetry of all circum-Pacific subductional frame. The westward directional mode of the Pangaea breakup (in hot spot reference) seems to be the decisive factor. The latitudinal displacements of the eastern continental fragments were restricted, and so the whole latitudinal widening of Pangaea domain (due to the spreading of intercontinental oceans) was compensated mainly by westward migration of the Mid-Atlantic spreading axis and of the American continents.

In the East-Pacific subduction zones (in contrast to the West-Pacific) this directional breakup of Pangaea caused high absolute velocities of the overriding continental plates and their fast advance towards the spreading axis, where the increasingly young oceanic lithosphere became subducted. The both factors changed the geodynamic conditions above the East-Pacific subduction zones, and led to transformation of the island arc / back-arc systems into the active continental margins of Andean type. At the same time it progressed the internal asymmetry of the Pacific realm with respect to its main subduction axis.

Taking into consideration the concept of the Pangaea cycles, we assume that the breakup stage of every cycle could be marked by the same global asymmetry of island arcs distribution. For the last cycles the duration of such asymmetric subduction spanned from a quarter to one third of the whole time. Semiquantitative data show that the global asymmetry of the current breakup stage is coupled with significant intensification of the Andean-type magmatism (if compared with the similar magmatic activity at the supercontinental stage and at the foregoing stage of continental agglomeration). When it will become possible, the changes of ratio between island arc and Andean-type magmatites should be traced throughout the geologic history. It will be one of the criteria to estimate correctness of the suggestions we advanced in this paper.

Modern island arcs are largely confined to the western periphery of the Pacific Ocean. Subduction near the Ocean's eastern coast is expressed as Andean-type active margins. This global asymmetry is widely known and reflects the essential differences in the mode of subduction between westward and eastward subduction zones explained by rotation stress orientations. However, more and more data suggest that in the geologic past, at least early in the Mesozoic, island arcs developed on both sides of the Paleo-Pacific Ocean. The present-day asymmetry developed during the Late Mesozoic in correlation with the phases of the breakup of Pangaea. The centrifugal drift of its fragments is expressed by vectors derived by subtraction of the general westward drift of the lithosphere from the total vectors of the present-day motion of continents, relative to the underlying mantle (using the-HS2-NUVEL1 global plate motion model). After the initial breakup of Pangaea, when the centrifugal motion was superimposed upon the general westward drift, the differences in subduction mode between the two active margins of the supercontinent were bound to increase: the westward component of the absolute plate motion markedly increased on the western periphery but might have slowed down to zero on the eastern periphery, where opposite movements met. On the American side of the Paleo-Pacific Ocean, where continents were thrust onto the increasingly younger portions of the subducting lithosphere, island arcs gradually closed, giving way to Andean-type volcano-plutonic belts. This concept of the cycles of Pangaea suggests that island arc distribution may have been asymmetrical before, during the fragmentation of earlier supercontinents. Data on the preserved Andean-type volcano-plutonic complexes suggests that the extent of global subduction asymmetry varied from one cycle to another.

THERMAL REGIME AND DYNAMICS OF COLLISION ZONE: RESULTS OF MODELING.

This paper will report on a quantitative model of mechanical and thermal processes under collisions in rheologically stratified lithosphere (upper elastic crust, lower plastic crust, elastic mantle lithosphere). In the area of collision delamination and subduction of the mantle lithosphere of undermoving plate takes place resulted in the development of plastic deformation in the lower crust.

Results of modeling indicate significant (up to 65 km in 20 m.y.) increase of the crust thickness in the collisions area. Though formation of orogen occurs in the condition of general compression, in the central part of orogen on late stages of collisions and in postcollision phase an area of extension arise, connected with gravitational spreading of the formed raising.

The dissipative heat generation originates in the process of the lower crust material viscous flow . It brings about heating both the crust and undercrust mantles as well. Simulation of heat regime shows that the area of significant temperature rise on the base of crust (50 - 200oC in 20 m.y.) has a thickness of about 10 km and hundreds of kilometers in other dimensions. Substantially heated (up to 100 oC) an upper part of the mantle lithosphere (near 10 km thick). Temperature of the crust base under wide range of parameters reaches the wet granite liquidus point. The partial melting of the lower crust material has been made possible. Thus, premise conditions for origin of the postcollision granitoid magmatism are formed. This mechanism of dissipative heat generation can also explain the existence of deep metamorphism.

FRACTAL ANALYSIS AND SEARCHING FOR DETERMINISM IN EEG DATA.

The theory of non-linear dynamics provides signal analysis techniques that may give new information on the behaviour of such networks. We calculated correlation dimension Dc for 16-channel EEG data from 7 healthy children and 7 patients with epilepsy. The signals were analysed before, during and after the absence seizures. In the absence seizures we could distinguish dynamical regions on the cerebral cortex, one that seemed to exhibit deterministic chaos whereas the other seemed to exhibit noise. The chaotic dynamics that one seems to observe is determined by a small number of variables (m=5) and has low complexity (Dc =3.5 - 3.7). Before and after the seizures no chaos was found. In the EEG of healthy children no chaotic region was found. The application of non-linear signal analysis revealed the existence of differences in EEG dynamics of healthy children and patients with epilepsy. This may contribute to the understanding of brain activity and may be useful in clinical diagnosis.

THE ANALYSIS of DYNAMIC CHARACTERISTICS of TIME SERIES OF DISPLACEMENT of the EARTH SURFACE ON GPS DATA.

We analyzed time series of displacement of the terrestrial surface, obtained on measurements of the Global Positional System (GPS) in 19 points in which the chaotic component was detect. We applied methods of the dynamic systems theory and fractal sets for the analysis of these time series and detection of their dynamic characteristics. The parameters we analyzed are: correlation dimension, spectral scaling parameter? fractal dimension and Hurst exponent. We detect that GPS time series have fractal properties in a range more than one order on frequency (1/f noise). The model of block dynamics NLO is offered. This model demonstrates complicated behavior and has comparable dynamic characteristics.

CHARACTERISTICS OF SELF-SIMILARITY OF SEISMICITY AND ACTIVE FAULTS NETWORKS OF EURASIA.

There was a research of possible relation of fractal dimensions of active faults network, spatial distribution of earthquakes epicenters and parameter b in Gutenberg-Richter law. We get quantitative characteristics of self-similarity of seismic process and of active faults network of seismically active areas of Eurasia. This self-similarity is shown in a range 2-3 orders of spatial scales and on magnitude. The received estimations of fractal dimensions of faults network Df and epicenter fields De are close to each other for all analyzed areas. It is established that for investigated areas the average factor connecting sizes D and b a little bit bigger than theoretical value of 2 and varies in a range 1.9-2.4.

FRACTAL ANALYSIS OF TIME SERIES OF RADIATED SEISMIC ENERGY (ON THE EXAMPLE OF JAPAN).

We analyzed time series of radiated seismic energy, using the JMA catalog (1992- 1996). We applied methods of the dynamic systems theory and fractal sets for the analysis of these time series and detection of their dynamic characteristics. The parameters we analyzed are correlation dimension, spectral scaling parameter, fractal dimension and Hurst exponent. Our analysis show that time series of seismic energy have fractal properties in a range more than one order on frequency.

FRACTAL CHARACTERISTICS OF SEISMICITY AND ACTIVE FAULTS NETWORKS.

There was a research of possible relation of fractal dimensions of active faults network, spatial distribution of earthquakes epicenters and parameter b in Gutenberg-Richter law. We get quantitative characteristics of self-similarity of seismic process and of active faults network of seismically active areas of Eurasia. This self-similarity is shown in a range 2-3 orders of spatial scales and on magnitude. The received estimations of fractal dimensions of faults network Df and epicenter fields De are close to each other for all analyzed areas. It is established that for investigated areas the average factor connecting sizes D and b a little bit bigger than theoretical value of 2 and varies in a range 1.9-2.4.

FRACTAL ANALYSIS OF EEG DATA IN EPILEPSY.

The theory of non-linear dynamics provides signal analysis techniques that may give new information on the behaviour of such networks. We calculated correlation dimension Dc for 16- channel EEG data from 7 healthy children and 7 patients with epilepsy. The signals were analysed before, during and after the absence seizures. In the absence seizures we could distinguish dynamical regions on the cerebral cortex, one that seemed to exhibit deterministic chaos whereas the other seemed to exhibit noise. The chaotic dynamics that one seems to observe is determined by a small number of variables (m=5) and has low complexity (Dc =3.5 - 3.7). Before and after the seizures no chaos was found. In the EEG of healthy children no chaotic region was found. The application of non-linear signal analysis revealed the existence of differences in EEG dynamics of healthy children and patients with epilepsy. This may contribute to the understanding of brain activity and may be useful in clinical diagnosis.

INTEGRATED ANALYSIS OF THE PROGNOSTIC INFORMATION FOR DETECTION OF POTENTIAL ZONES OF LARGE EARTHQUAKES (ON THE EXAMPLE OF THE KURIL-KAMCHATKA ARC)

Prognostic data on the most representative precursors (seismological, deformation, kosmo-geodetic) for region of large earthquakes of the Kuril-Kamchatka arc (2006 and 2007) are assembled. Complex analysis of the assembled information is carried out; the new integral prognostic parameter is proposed.

COMPUTER MODELING OF COSEISMIC LANDSLIDE DISPLACEMENT

We make computer simulation of earthquake-induced landslide. Newmark model for estimating coseismic landslide displacement is used. The spatial distributions of potential coseismic landslide displacement for earthquakes of various magnitude, epicentral distance and depths for test regions of North Caucasus and Gornyi Altai are calculated.

DETECTION OF KINEMATICS OF EARTH CRUST BLOCK BY GPS DATA

We work out the technique of separation of rigid blocks of Earth crust and creation of model of region based on GPS velocity data. The procedure is applied for analysis of blocks kinematics in East Anatolia, Iran and Zagros.

ANALYSIS OF CORRELATION DIMENSION OF EEG DATA IN EPILEPSY IN CHILDREN

The electroencephalogram (EEG) indicates current of the nervous processes in a brain. EEG is of great importance for analysis of mechanism of brain activity in the norm and a pathology. Special importance EEG has at epilepsy diagnostics. The purpose of our work is to apply a research technique of nonlinear dynamic systems to detection neurophysiologic patterns according to EEG data for healthy children and children with epilepsy. On EEG data received at examination healthy children and children with epilepsy, we recovered attractors in a two-dimensional phase space. Results of our analysis show, that for the healthy children in all channels EEG attractors are similar to stochastic system attractors. For the sick children during absence seizures the attractors recovered on tracings of the most of channels, specially frontal and temporal zones, is similar to characteristic of deterministic chaotic system. In cases of registration of the expressed local epileptiform activity on EEG the same regularities for one or two zones of a brain have been discovered. We calculated correlation dimension ä and embedding dimension m for 16-channel EEG data from 10 healthy children and 12 patients with epilepsy. The signals were analysed before, during and after the absence seizures. In the absence seizures we could distinguish dynamical regions on the cerebral cortex, one that seemed to exhibit deterministic chaos whereas the other seemed to exhibit noise. The chaotic dynamics that one seems to observe is determined by a small number of variables (m = 5 - 8) and has low complexity (D = 3.5 - 4.3). Before and after the seizures no chaos was found. In the EEG of healthy children no chaotic region was found. The application of non-linear signal analysis revealed the existence of differences in EEG dynamics of healthy children and patients with epilepsy. The electroencephalogram is a development of the most complicated bioelectrochemical processes descending in a brain. Based on the approaches explained in our job, it is possible to give the following interpreting of the received results. For healthy children (and out of an attack) units of the complex system which generate EEG signal, work largely independently, "separately", that reveal to a great extent the stochasticity which is found at their probe. The epilepsy reveals as some kind of synchronisation of separate units which one in the norm are more independent. During an absence seizure there is still a large synchronisation, determinisation of systems, occurrence of a signal which is closed to the periodic one. In period after absence seizures reverse process of a desynchronization, randomisation of system occurs. This approach may contribute to the understanding of brain activity and may be useful in clinical diagnosis.

DYNAMIC AND FRACTAL CHARACTERISTICS OF TIME SERIES OF RELEASED SEISMIC ENERGY

We analyzed the time series of released seismic energy using the procedures devised for dynamic systems and fractals, for determination of dynamic and self-similar (fractal) properties of seismotectonic system. We used one of the best in the world catalog of earthquakes - JMA catalog for Japan (1992-1996 years) in our analysis. This catalog is characterized by the highest quality and accuracy of determinations of all parameters of earthquakes. Released seismic energy Et is determined on base of magnitude values. The magnitude is proportional to a log of seismic energy. For each earthquake we recalculated magnitude to energy, and then summed energies for all earthquakes happened within calendar days. As a result we received the time series of daily release of seismic energy for all range of magnitudes, and also for various sub- ranges. Mathematical expressions of self-similarity are the power laws for various parameters of analyzed time series. The parameters we analyzed are spectral scaling parameter 0 Hurst exponent Hu, fractal dimension D, correlation dimension D and embedding dimension m. We detected mat examined time series of seismic energy have fractal properties over the range more than one order on time and frequency. The calculated characteristics of self-similarity of analyzed time series indicate that these series for small and mean magnitudes rank to the flicker-noise dass. But time series including the large earthquakes have stochastic properties, dose to "white" noise. As values of |5, D and Hu were calculated separately in our work, it allow to confirm (within the limits of error) validity of application of the equations received on model Brownian functions, for analysis of fractal properties of natural time series. Analysis of correlation dimension Dc has allowed detecting a certain degree of determinism in investigated process, however only for mid-range of a band of magnitudes. But for time series including the large earthquakes it is not possible detecting characteristics of a degree of determinism of system. Possible explanation is that magnitudes over the range 4 to 5 are determined with the greatest accuracy, and for other bands this accuracy is less. Also small length of analyzed time series can reduce accuracy of analysis. Other possible explanation is that during large earthquake there is a radical structural readjustment, a bifurcation, of seismotectonic system at which one this system practically "forgets" the previous states. This "memory erasing" destroys determined relations, and our results show it. It gives a direction for the further investigations. Our analysis of dynamic and fractal properties of time series of released seismic energy show that the seismotedonic system generating earthquakes is determined-chaotic system. Dynamics systems of such types generate both small amplitude variations and significant (one or several orders large) peaks. Meantime value of these peaks and time intervals between them are irregular, and capabilities of prognosis of such systems are restricted or quite absent.

BLOCK MODELS WITH DRY FRICTION IN SEISMOTECTONICS

Models of a seismic regime and the block dynamics, based on frictional self-oscillations in systems with non-linear dry friction are s considered in the article. The set of Burridge—Knopoff mechanical model of an earthquake fault is considered. The disk-type models for exposition of rotational dynamics of blocks of an earth crust, a models of block dynamics in foredeeps is investigated. It is established, that in some range of parameters (friction force, rate of driving blocks and so on) the regime of chaotic oscillations realizes in this systems. Therefore in such systems the prognosis is restricted.

FEATURES OF FRACTAL ANALYSIS OF LOESS PSEUDOKARST (BY THE EXAMPLE OF THE YOVON VALLEY IN TAJIKISTAN)

The authors carry out fractal analysis of such a complex and rapidly developing in recent decades process as loess pseudokarst for the first time. They show that using Mandelbrot’s cell counting method it is possible to reveal loess pseudokarst self-similarity forms and to determine the fractal dimension values characterizing the geological risk degree. They also show that applying dynamic scaling theory makes it possible not only to describe the pseudokarst morphology but to trace the fractal surface dynamics of the loess pseudokarst in the Yovon Valley (Tajikistan) for the last 50 years too.