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PROBLEMS OF GEOCOSMOS

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Proceedings of the 7th International Conference "Problems of Geocosmos" (St. Petersburg, Russia, 26-30 May 2008)<br />

anomalies reflect sections of shift, compression or tension of rocks, as well as of jointing and higher<br />

permeability zones, which are developed along depth faults. Our heat model of subvertical inter block zone<br />

for analysis of seismogene dynamics [1] corresponds Foothills (in other words, Pshekish-Tirnaus) fracture,<br />

which controls zones of high seismicity. This fracture is traced for 300 km from the south to the North and<br />

presents itself a zone of narrow plates, falling under the monocline construction. Fissures along the plates in<br />

the depth come close into one vertical fracture. This fracture splits the frontal part of the Daghestan wedge<br />

and forms an almond–shaped structure. The focal point of the Daghestan earthquake 1970 is connected with<br />

it (M=6,6; H=13 km; Jo=96).<br />

Geological characteristics of this fault correspond in details to a well-known seismodynamic model<br />

I.A.Volodin [2]. Model is built in 2 variants of passive and active fractures as eradiating sources. This model<br />

is elaborated by means of using mechanism of Fraunhofer non-linear diffraction. The united vertical fracture<br />

in the depth forms an intensive eradiating resonator – the source of non-linear diffraction of the wave seismic<br />

field [2, p.149-157].<br />

The I.A.Volodin model as well as the Foothills fracture, contains a zone of narrow plates, alternating with<br />

the fissures. The differences are mainly in the fall of the Foothills fracture, between the two tectonic blocks<br />

of the crystal base but not under “the monocline construction” as in the model [2, p.155]. “The faults limiting<br />

these plates, are coming close at the depth into united vertical fracture, in the I.A.Volodin model are the<br />

similar. Together they form an intensive, eradiating resonator, “which selects from the common disturbance<br />

field longitude along orthogonal direction according boundaries of fracture harmonics with integer numerical<br />

relations between the fracture width and wave length” [2, p.150]. The resonator is the source of non-linear<br />

diffraction of Fraunhofer regarding the waveguide seismic field which is described by the asymptotic<br />

formula. The indicated intensity of resonator is manifested “in the dynamic of landscape… in the erosion<br />

activity of the soils, caused by the background high frequency vibration, which in the first approximation can<br />

be regarded proportional to it. This makes it possible to regard, that the diffraction pattern, described by the<br />

formula…, will be really presented in the aero-space photographs (Our Italics – А.B.) as an assemblage,<br />

packet of lineaments, parallel to the direction of the fracture in the crystal foundation. The analysis of<br />

distances between them by means of using this formula allows defining the radiation intensity and the depth<br />

of the source. This, as a result, can be interpreted as the location of the fracture and some it’s qualitative<br />

characteristics” [2, p.154].<br />

Derivation of the design formulae for such model [2, p.151-155] was made by I.A.Volodin on the basis of<br />

introducing coordinate system, orthogonal to the direction of the fracture.<br />

The wave field of disturbance weakly changes in the direction of the fracture that is independence<br />

condition from the third coordinate is introduced. This formulation of problem is a consequence of the<br />

transverse wave model [2, p.107-108], where the equation with coordinates: X2 – along the foundation<br />

orthogonal to the fracture, Y1 – in the vertical direction along the earth’s radius is examined. The equation is<br />

reduced to the following form [2, p.152]:<br />

i2k∂A/∂X2 + ∂ 2 A/∂Y1 2 + k 2 b|A| 2 A = 0, (1)<br />

where the amplitude of the transverse waves A2 = A {See[2], p.107, formula (2.38) – A.B.}, k – the wave<br />

number of asymptotical number field (of the plane seismic wave), b – arbitrary constant, determined as<br />

velocity of solution of the seismic field in reference to the non-linear equation of Shredinger describing<br />

solution effects. From the formula (1) is determined the space configuration of intensity I wave field,<br />

proportional to the square of its amplitude, for this purpose is used asymptotical formula which describes<br />

non-linear diffraction of Fraunhofer of the wave field on the slots with parameters A0 and S, having the view<br />

[2, p.152]:<br />

dI/dφ = (k/πb)ln{(k 2 φ 2 /4 + a 2 )/(k 2 φ 2 /4 + a 2 cos 2 [s(k 2 φ 2 /4 + a 2 ) 1/2 ]}, (2)<br />

where parameter a 2 = k 2 b/|A0| 2 /2 is determined by initial conditions, and φ – is an angle between the<br />

directions of propagation of radiation from the source and earth’s radius. It must be noted, that the diffraction<br />

formula (2) is true only when the source intensity is weak, specifically under the condition I = s|A0| 2 < IКР,<br />

where critical meaning of intensity IКР = π 2 /(2sbk 2 ).<br />

The lines of field intensity antinodes on the diurnal surface are determined from the formula of diffraction<br />

as lines, which derivative of intensity of waveguide seismic field is equal to zero. When X – a distance along<br />

the earth’s surface in the direction orthogonal to the fracture, and H – is the depth of the radiation source<br />

413

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