Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 47022 ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ Numerical analysis of geodynamic evolution of the Earth based on a thermochemical model of mantle convection: 3-D model Numerical analysis of geodynamic evolution of the Earth based on a thermochemical model of mantle convection: 3-D model Kotelkin V D Kotelkin V D Lobkovsky L I Lobkovsky L I Moscow State University, Moscow, Russia ru Moscow State University, Moscow, Russia ru Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia ru Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia ru 6 6 385 389 10 11 2021 https://rjes.ru/en/nauka/article/47022/view

Evolution of the Earth's mantle from a hot initial state is modelled in the Boussinesq approximation within the framework of a thermochemical model. The spatial dynamics of substance within a spherical layer is illustrated by video records. Introduction of a chemical component into intermittent with regard for an endothermic phase transition thermal convection facilitates the overcoming of the phase barrier, enhances nonlinearity of the dynamic process, and promotes the formation of new cycles in the evolutionary process. As a result, avalanches become more numerous in the thermochemical variant and reduce to a regional scale; therefore, it is more natural to associate them with Bertrand rather than Wilson cycles. A basically new result of the numerical modelling is that convection developing from an unstable hot initial state gives rise to global mantle overturns see Animations 2, 3, 4 decaying with cooling material and remarkably correlating with data of historical geology on Wilson cycles. The inferred spatial patterns of overturns are represented by a single funnel-shaped sink and a few uprising superplumes, accounting for the origins of supercontinents, opening of oceans, and the observed asymmetry of the planet.

Evolution of the Earth's mantle from a hot initial state is modelled in the Boussinesq approximation within the framework of a thermochemical model. The spatial dynamics of substance within a spherical layer is illustrated by video records. Introduction of a chemical component into intermittent with regard for an endothermic phase transition thermal convection facilitates the overcoming of the phase barrier, enhances nonlinearity of the dynamic process, and promotes the formation of new cycles in the evolutionary process. As a result, avalanches become more numerous in the thermochemical variant and reduce to a regional scale; therefore, it is more natural to associate them with Bertrand rather than Wilson cycles. A basically new result of the numerical modelling is that convection developing from an unstable hot initial state gives rise to global mantle overturns see Animations 2, 3, 4 decaying with cooling material and remarkably correlating with data of historical geology on Wilson cycles. The inferred spatial patterns of overturns are represented by a single funnel-shaped sink and a few uprising superplumes, accounting for the origins of supercontinents, opening of oceans, and the observed asymmetry of the planet.

 numerical analysis geodynamic evolution Earth's mantle origins of supercontinents numerical simulation. numerical analysis geodynamic evolution Earth's mantle origins of supercontinents numerical simulation.

Fuka, J. Geol. Soc. Japan, v. 100, no. 1, 1994. Fuka, J. Geol. Soc. Japan, v. 100, no. 1, 1994. Keondzhyan, Doklady AN SSSR, v. 253, no. 1, 1980. Keondzhyan, Doklady AN SSSR, v. 253, no. 1, 1980. Khain, Fundamental Problems of General Tectonics, 2001. Khain, Fundamental Problems of General Tectonics, 2001. Kobozev, Doklady AN SSSR, v. 296, no. 3, 1987. Kobozev, Doklady AN SSSR, v. 296, no. 3, 1987. Lobkovsky, Russian J. Earth Sci., v. 6, no. 1, 2004. Lobkovsky, Russian J. Earth Sci., v. 6, no. 1, 2004. Machetel, Nature, v. 350, 1991., doi: 10.1023/A:1021798313221 Machetel, Nature, v. 350, 1991., doi: 10.1023/A:1021798313221 Maruyama, J. Geol. Soc. Japan, v. 100, no. 1, 1994. Maruyama, J. Geol. Soc. Japan, v. 100, no. 1, 1994. Monin, Doklady AN SSSR, v. 294, no. 1, 1987. Monin, Doklady AN SSSR, v. 294, no. 1, 1987. Monin, Doklady AN SSSR, v. 295, no. 5, 1987. Monin, Doklady AN SSSR, v. 295, no. 5, 1987. Myasnikov, Doklady AN SSSR, v. 237, no. 5, 1977. Myasnikov, Doklady AN SSSR, v. 237, no. 5, 1977. Myasnikov, Doklady AN SSSR, v. 238, no. 5, 1978. Myasnikov, Doklady AN SSSR, v. 238, no. 5, 1978. Safronov, Evolution of the Protoplanetary Cloud and Formation of the Earth and Planets, 1969. Safronov, Evolution of the Protoplanetary Cloud and Formation of the Earth and Planets, 1969. Solheim, J. Geophys. Res., v. 99, no. B4, 1994., doi: 10.1029/93JB02168 Solheim, J. Geophys. Res., v. 99, no. B4, 1994., doi: 10.1029/93JB02168 Stein, Nature, v. 372, 1994., doi: 10.1038/372063a0 Stein, Nature, v. 372, 1994., doi: 10.1038/372063a0 Tackley, Nature, v. 361, 1993., doi: 10.1038/361699a0 Tackley, Nature, v. 361, 1993., doi: 10.1038/361699a0 Vityazev, Zemlya i Vselennaya, v. 2, no. 2, 1990. Vityazev, Zemlya i Vselennaya, v. 2, no. 2, 1990.