Resumo
For a long time, intense methane emissions into the atmosphere from the subsurface of permafrost have been observed in the shelf and coastal zones of the Arctic region. Due to the potential danger of this phenomenon to the environment and infrastructure, there is a need for periodic monitoring of gas pockets, including through ground-based seismic exploration. This paper contains the results of a study of this process using numerical modeling. A model of layered frozen sandy soil with curviliinear boundaries between the sheets is constructed, reflecting the main specifics of the region. The process of gas migration in vertical and horizontal directions is reconstructed by increasing the number of methane reservoirs. The defining system of hyperbolic equations of the linear theory of elasticity is used. The problem is solved by the grid-characteristic method in a two-dimensional formulation on a rectangular grid, in each cell of which the elastic characteristics of the layers are set. The resulting wave structures are studied in detail on the obtained synthetic wave patterns and seismograms, which make it possible to determine the direction of gas propagation. The results obtained can be used to interpret similar field experiments.