Fig. 1: Opposing torques of semidiurnal oceanic and atmospheric tides acting on Earth’s rotation.

At the point of resonance, the oceanic and atmospheric tidal torques would balance, stabilizing Earth’s rotation rate at a constant day length. The images are not to scale. Figure adapted with permission from ref. 6, Elsevier. Earth and Moon images were generated using GoogleEarth. Earth data/image sources: data (SIO, NOAA, U.S. Navy, NGA, GEBCO) and image (Landsat/Coperincus and IBCAO) and Moon image source: NASA/USGS/JAXA/SELENE. Sun image is from NASA/SDO.