Why Rivers Flow to the Ocean: Gravity, Topography, and the Coriolis Effect

Rivers flow toward the ocean primarily due to gravity: water moves downhill from higher elevations to lower ones, and oceans are the lowest collection points. Topography shapes the path, with rivers forming in mountainous areas and merging into larger channels as they descend. The Coriolis effect from Earth's rotation causes a slight deflection—right in the Northern Hemisphere, left in the Southern—influencing river curvature but not the overall direction.