Numerical modeling of tectonic plate dynamics: A spherical model
We discuss the numerical simulation of global tectonic plate dynamics on a sphere. On the basis of block models, the method used assumes the block structure to be a part of a spherical layer between two concentric spheres, one of which (the outer sphere) represents the Earth's surface. The system of perfectly rigid blocks moves as a consequence of the movements prescribed to the boundaries and the underlying medium. Displacements of the blocks are determined when the system is in quasistatic equilibrium. Block interaction, along with the underlying medium, appears to be viscoelastic. The stress/pressure ratio remains below a certain strength level. When this level exceeds along a part of a fault, a stress-drop (fractures) occurs in accordance with the dry friction model. The failures represent earthquakes. A synthetic earthquake catalog results from numerical simulation. We present some preliminary results of simulating the dynamics of a simple subsystem of tectonic plates; in particular, we indicate the directions of block movements and examine the characteristics of block interaction. We note some features of the resulting synthetic catalog of earthquakes inherent in observed data.