Transverse Deformation Waves in the Nonisothermal Lithosphere‒Asthenosphere System

The features of the occurrence and propagation of transverse deformation waves in the elastic lithosphere–viscous asthenosphere system under nonisothermal conditions are studied in the approximation of a thin layer. In this case, the phase transition at the boundary of the layers plays an essential role due to temperature and pressure disturbances. The qualitative and quantitative properties of the propagation of disturbances of thermomechanical fields have been studied in the long-wave approximation. It is shown that, due to the energy supply from the nonisothermal asthenosphere, weakly attenuated wave packets can occur, which spread over thousands of kilometers with a characteristic speed of about 100 km/year. This makes it possible to consider them as a possible trigger mechanism for the massive emission of methane from frozen sedimentary rocks into the atmosphere.