Global geodynamic model of the Earth and its application for the Arctic region

Abstract

A geodynamic model of the modern Earth is constructed based on the SMEAN2 global seismic tomography model with an emphasis on the Arctic region. For a spherical Earth model, a solution to the Stokes equation for a viscous fluid was obtained based on seismic tomography data using the finite element method using the CitcomS code. The resulting distributions of temperature anomalies and velocity fields of mantle flows explain the main features of the modern geodynamics of the Arctic region. The temperature difference in the subcrustal mantle between the relatively “cold” western Arctic shelf (Barents and Kara seas) and the “warmer” eastern Arctic shelf (from the Laptev Sea to the Bering Strait) reaches 100 degrees, which correlates with the observed intense methane emission from the shallow shelf of the Eastern Arctic caused by permafrost degradation and destruction of gas hydrates against the background of elevated environmental temperatures. The greenhouse effect of methane in the atmosphere, in turn, contributes to climate warming in the Arctic. The region of Iceland and eastern part of Greenland, under the influence of the mantle upwelling, is characterized by a hot subcrustal mantle and increased heat flow at the surface, causing instability and melting of the Greenland ice sheet from below.