Numerical modelling of the reflected waves from gas cavities and methane bombs in the heterogeneous media of the Northern regions

The Arctic region contains lots of underground gas layers closed from the outside. In case of their opening, the gas is of great danger for the surface buildings and drilling equipment. In this work, we observe the main dangerous gas reservoirs - gas cavities and methane bombs. We build the mathematical models of these heterogeneities and presented the main mathematical equations allowing calculating the seismic waves spread through them correctly. The grid-characteristic method of the third order of accuracy is used in all the computations. We demonstrate the results of modelling the seismic waves spread through the heterogeneous medium with the gas cavities and through the homogeneous medium with the methane bomb. The analysis of the differences between the models is carried out. The problems of computing the models with gas cavities and with methane bombs need different approaches for the correct calculations, though the problem formulations are similar.