On the possibility of rogue wave generation based on the dynamics of modified Burridge-Knopoff model of earthquake fault

Abstract

In this study we propose a modified Burridge‐Knopoff model of earthquake fault, in which two tectonic plates are strongly coupled by nonlinear springs. By minimizing the effects of the veloci‐ ty‐weakening stick‐slip friction force between the masses and the moving surface, and in the limit of low amplitude oscillations; the system exhibits both stick‐slip and damped oscillatory motions as the values of some parameters are varied. Such motions usually characterize the dynamics of an earthquake fault, even though it is not always felt because of the low amplitude of vibrations. However when enough stress builds up in the subduction zones to overcome the frictional forces between tectonic plates, the oceanic rocks suddenly slip and there is violent release of energy at the epicentre. This outburst of energy simply signifies the generation of a very large amplitude and localized nonlinear wave. Such wave profile exactly fits the Peregrine solution of the damped/ forced nonlinear Schrodinger amplitude equation, derived from the modified one‐dimensional Burridge‐Knopoff equation of motion. In the regime of minimal or no frictional forces, these mon‐ ster waves suddenly appear and disappear without traces as shown by the numerical investigations. Our results strongly suggest that rogue waves emanates from the dynamics of nonlinearly coupled tectonic plates in subduction zones. This is further complemented by the fact that these giant waves were initially observed in Pacific and Atlantic oceans, which play hosts to the world’s largest oceanic subduction zones.