Geophysical research: article

Аnnotation: On the basis of the modified S-approximation method, the problems of analytical approximation of the terrain relief and geopotential fields are considered. The principle of the method is to approximate the field by a sum of potentials of the simple and double layers distributed on a set of carriers underlying the surface topography. Special attention is given to application of new highly efficient methods for solving systems of the linear algebraic equations (SLAE) of large and extra-large dimensions, to which the inverse problems of geophysics and geodesy are reduced. For their solution, the block contrasting method is proposed based on separating the area investigated into the most intense blocks. The SLAE is solved for the each block using the regularized iterative three-layer Chebyshev method. The results of numerical calculations of analytical approximations of the relief and anomalous gravity field are presented. The application efficiency of the modified S-approximation method for the indication of regional fault zones according to the satellite gravity data is illustrated on the example of the Philippine Sea.