loading page

What Causes Tides?
  • Yongfeng Yang
Yongfeng Yang
Bureau of Water Resources of Shandong Province
Author Profile


Tides represent the daily regular alternation of high and low waters at the coasts and in the oceans. This movement of water is usually explained with two paradigms: one is the equilibrium tide theory in which the tide-generating force yields a pair of water bulges, and another is the dynamic tide theory in which the tide-generating force makes water move like wave. In this study, we investigate to find that the tide-generating force is derived from a solid Earth, but its application to a fluid (watery) Earth is not too realistic, this makes the two paradigms become groundless. We here propose, the tide-generating force elongates the solid Earth, the spinning Earth allows the solid bulges to shake ocean basins, thus forming daily regular movement of water between all parts of the basins as well as the rise and fall of water levels around the globe. A tide prediction model is developed to show that the predicted tides are morphologically consistent with the observed tides, the average RMS calculated against observations for 110 globally tide-gauge stations are 15.17 cm; A further tide prediction comparison shows that the tide made by this model performs slightly better than that made by harmonic analysis, among the selected 56 sample stations, the RMS calculated against observations for 31 stations in this model is less than the RMS calculated in harmonic analysis.