Back to the future II: Four views of future tides

The Earth is currently 180Myr into a supercontinent cycle that began with the break-up of Pangaea and which will end around 200–250Myr (million years) in the future, as the next supercontinent forms. As the continents move around the planet they change the geometry of ocean basins, and thereby modify their resonant properties.Indoingso,oceansmovethroughtidalresonance,causingtheglobaltidestobeprofoundlyaffected. Here, we use a dedicated and established global tidal model to simulate the evolution of tides during four future supercontinentscenarios.WeshowthatthenumberoftidalresonancesonEarthvariesbetweenoneandfiveina supercontinentcycleandthattheylastfornolongerthan20Myr.Theyoccurinopeningbasinsafterabout140– 180Myr, an age equivalent to the present-day Atlantic Ocean, which is near resonance for the dominating semidiurnal tide. They also occur when an ocean basin is closing, highlighting that within its lifetime, a large ocean basin – its history described by the Wilson cycle – may go through two resonances: one when opening and one when closing. The results further support the existence of a super-tidal cycle associated with the supercontinent cycle and gives a deep-time proxy for global tidal energetics.