Electromagnetic Tsunami Monitoring: Theory and Recommendations

Abstract

We formulated a nonlinear mathematical model of seismo-hydro-electromagentic field interaction (in presence of gravity) and calculated generation and propagation of seismic disturbances of these fields in a lithosphere-hydrosphere-atmosphere zone including the basin of a marginal sea (2D schematization of the central part of the Sea of Japan). Amplitude of the computed magnetic signals (300 pT at the ocean-atmosphere interface, 10 sec after a model seismic excitation in the upper mantle), their main frequency (0.25 Hz), delay of the seismic wave with regard to the magnetic signal (20 sec at the shore), and parameters of the tsunami wave of a small amplitude are of orders observed. So, to discover a seismic activation in ocean lithosphere and a tsunami wave far from a shore, the magnetic recordings at the sea surface and above (buoys, balloons, magnetometers, and satellite instrumentation) should be combined with seismic, magnetic and temperature recordings at the sea bottom.