## On combined inverse problems of geophysics for multidisciplinary earthquake prediction studies

A method for the determination of the integral critical parameter (precursor) of the rocks strength and destruction has been developed using the dilatancy physical–mathematical model for the destruction of rocks in the earthquake source. This parameter is density of cracks in the unit of the volume. It is determined on...

## The combined inverse problem of acoustics and geoelectrics: numerical approach

The paper deals with the problem of combined inversion of wave and electromagnetic fields. It is assumed that there exists the functional relation between the velocity and electric conductivity the character of which is known to us.

The distributions of velocity and conductivity in the medium under study are chosen...

## Numerical solution of one inverse problem with an unknown source wavelet

The problem of the simultaneous determination of the sounding signal form and wave propagation velocity in a vertically-inhomogeneous medium is considered in the paper.

It should be noted that usually the form of the sounding signal is either unknown or given only approximately, although its accurate estimate is necessary for...

## r-solution of an operator equation in Hilbert space and its application to solve ill-posed problem

The notion of the *r*-solution for a system of linear equation in the finite dimensional Euclidean space generalizes for an equation in Hilbert space with a compact operator. The Hadamard correctness of *r*-solution is proved (i.e., its stability with respect to perturbation of right-hand side and operator).

## Expert tsunami database for the Kuril-Kamchatka region

As a result of a feasibility study, a concept and prototype of the Expert Tsunami Data Base (ETDB) was developed at the Tsunami Laboratory of the Novosibirsk Computing Center, Russian Academy of Sciences. The ETDB contains in the digital form all available information on regional earthquakes and tsunamis (source parameters,...

## Technique for digitizing bathymetry information using personal computer

In the paper the technology for creating detailed digital bathymetry on personal computer is given. Such data is necessary for numerical modeling of tsunami waves. Information about depth is based on bathymetry charts (on paper). Two methods of digitizing are proposed. Given examples illustrate fitness of this technology for this...

## Full waveform inversion of VSP data (normally-incident plane wave)

The problem to recover structure of vertically-inhomogeneous medium by VSP data with unknown source-function is considered on the basis of optimization approach. It is proved that any stationary point of the cost function provides identity of a simulated wave field with a recorded one.

A numerical algorithm to reconstruct velocity...

## The integral equation of the convolution type in inverse problems of the theory of wave propagation

A number of inverse problems of oscillation processes studied in optics, acoustics, radiophysics and geophysics may be reduced to solving the integral equation of the convolution type with the special kernel. Several theorems for uniqueness solution of this integral equation are proved. These proofs are constructive and may be used...