Is the Earth currently in a Global tidal maximum? 500 Ma of coupled tectonic and tidal modelling

Earth’s continents in the present day are the dispersed fragments of the former supercontinent Pangea which existed from 330 - 180 Ma. In around 200 - 250 Myr, following the progression of the current supercontinent cycle, the Earth’s continents will reform into another supercontinent. The supercontinent cycle is closely linked to the Wilson cycle which describes the life cycle of oceans as they form, grow, shrink, and eventually close. As oceans grow and shrink with theWilson cycle the tides within them are affected. The present day North Atlantic ocean, which formed as a result of the breakup of Pangea, is resonant with the M2 tide, causing macrotidal (>4m) tidal amplitudes and strengthening the global M2 tidal dissipation rate to 2.5 TW. Is this a unique occurrence in the present supercontinent cycle or is the tide periodically buoyed by resonance in ocean basins because of geometry changes brought about by the progression of the Wilson cycle? Here we will reconstruct predictions of the progression of the current supercontinent cycle into the future (+250 Ma) with GPlates which we will then use as a boundary condition for tidal modelling at 20 Myr intervals with OTIS (Oregon state Tidal Inversion Software). We present four unique scenarios of the Earth’s future, each arguing a different style of supercontinent formation. In all scenarios of the future, we find that the Atlantic continues to widen over the next 25 Myrs, causing the tide within it to weaken as resonance is lost. However, we find several other occurrences of tidal resonance during the future scenarios, which causes tidal dissipation rates to increase to 70 – 250% of the present-day value. This periodic increase in tidal amplitudes and dissipation affects the evolution of the Earth-Moon system over geological time and has implications for ocean circulation, climate and the ocean’s ability to host and support life in the past and future.Instituto Dom Luiz, grant no. IF/00702/201