Geodynamic model of the interaction between the continental lithosphere and the active continental margin in East Asia

Abstract

We propose a concept for a geodynamic model of East Asia, taking into account the mechanism of the interaction between the stable part of the regional continental lithosphere and the active continental margin along the Kuril-Kamchatka and Japan island arcs. The concept involves upper mantle convection combined with keyboard-block mechanism explaining seismic cycle patterns in the active continental margin and provides grounds to resolve the paradoxes of the present-day velocity field observed by satellite geodesy methods. These paradoxes are associated with enormous variation in the velocity field, such as sometimes contradict directions of surface motions in the adjacent portions of the earth’s surface. We propose a model that attribute the observed motion pattern to the superposition of the long-term subduction-driven convection regime beneath the continent causing the ocean-ward lithosphere extension and the shorter-term cyclic motion of seismogenic blocks with alternating directions. The model contributes to the development of the physically-based theoretical concepts of modern plate tectonics and eliminates the contradictions between the observed data and classical plate tectonics in East Asia region.