Inversion of the ionospheric signals of tsunamis using the normal modes method

Large earthquake (MW > 7) and tsunamis are known to induce perturbations which can be detected in the atmosphere and ionosphere using total electron content (TEC) measurements. In this thesis, I first investigated on the possibility of using these ionospheric signals in order to complete the tsunami monitoring and warning system. Thus, I study the coupling between the solid Earth, the ocean, the atmosphere. I demonstrate that only the resonance at 1.5 mHz between the tsunami modes and the atmospheric gravity modes can be detected through ionosphere and highlight the fact that the efficiency of the coupling ocean/atmosphere is sensitive to ocean depth and local time. These developments enables the complete modelling of the ionospheric signature of 3 tsunami with an amplitude of 2, 3 and 60cm in deep ocean : the 2012 Haida Gwaii and the 2006 Kuril tsunami in far field and the 2011 Tohoku tsunami in closer field respectively. Finally, we demonstrated that the peak-to-peak amplitude of the height of the inverted tsunami reconstructs with less than 20% error the amplitude measured by a DART buoy in these three cases.