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JOURNALS // Vestnik KRAUNC. Fiziko-Matematicheskie Nauki // Archive

Vestnik KRAUNC. Fiz.-Mat. Nauki, 2023 Volume 44, Number 3, Pages 86–104 (Mi vkam613)

This article is cited in 1 paper

MATHEMATICAL MODELING

Research of stress-strain state of geo-environment by emanation methods on the example of $\alpha$(t)-model of radon transport

D. A. Tvyordyjab, E. O. Makarovbc, R. I. Parovikab

a Institute for Cosmophysical Research and Radio Propagation FEB RAS
b Kamchatka State University named after Vitus Bering
c Kamchatka branch Unified Geophysical Service of the RAS

Abstract: Continuous monitoring of variations in the volumetric activity of radon in order to search for its anomalous values preceding seismic events is one of the effective techniques for studying the stress-strain state of the geosphere. We propose a Cauchy problem describing the radon transport taking into account its accumulation in the chamber and the presence of the memory effect of the geo-environment. The model equation is a nonlinear differential equation with non-constant coefficients with a derivative in the sense of Gerasimov-Kaputo of fractional variable order. In the course of mathematical modeling, in MATLAB environment, of radon transport by the ereditary $\alpha$(t)-model a good agreement with experimental data was obtained. This indicates that the ereditary $\alpha$(t)-model of radon transport is more flexible, which allows it to describe various anomalous variations in the values of volumetric activity of radon due to the stress-strain state of the geosphere. It is shown that the order of the fractional derivative can be responsible for the intensity of the radon transfer process associated with the characteristics of the geo-environment. It is shown that due to the order of the fractional derivative, as well as quadratic nonlinearity in the model equation, the results of numerical modeling give a better approximation of the experimental data of radon monitoring than by classical models.

Keywords: mathematical modeling, nonlinear equations, saturation effect, fractional equations, fractional derivatives, hereditarity, memory effects, nonlocality in time, radon volumetric activity, stress-strain state, geo-environment, earthquake precursors.

UDC: 519.642.2

MSC: Primary 34A08; Secondary 34A34

DOI: 10.26117/2079-6641-2023-44-3-86-104



© Steklov Math. Inst. of RAS, 2024