Computed seaquake and tsunami precursors and recommedations for monnitoring
Abstract
According to our computations on the basis of the combined magneto-thermo-elasticity and magneto-hydrodynamic principles along with geophysical data oscillations of the magnetic field components may be recorded at the sea floor i e at the top of a sedimentary layer 3 div 4 sec after the beginning of weak the amplitude is of the order of a few cm vertical displacements in the upper mantle namely 40 km under the sea level in the case described here We suppose that similar weak disturbances of the stationary configuration of the oceanic lithosphere elastic field are arising in the course of accumulation of deformations of lithosphere geological structures during a seaquake and tsunami preparation period The delay of the computed seismic P wave in regard to the EM one depends on the elastic and EM parameters of rocks along the trace in the oceanic lithosphere and is of the order of 0 1 sec per 1 km on the average The computed magnetic signal amplitude at the sea bottom is approximately proportional to one of elastic displacements see above and is of the order of a few hundreds of pT It is the first measurable signal of a seismic excitation beneath a sea floor The amplitude of the electric and temperature seismic oscillations is of the order of a few mu V m and mK respectively quartz thermo-resistors are needed at the sea floor At the sea surface and in the atmosphere up to the ionosphere the computed EM oscillations similar to ones at the seafloor are arising together with the hydro-acoustic wave caused by the delayed seismic P
- Publication:
-
36th COSPAR Scientific Assembly
- Pub Date:
- 2006
- Bibcode:
- 2006cosp...36.1418N