Energy inputs along a coastline A. Tides - daily fluctuations in water level caused by the differential pull of gravity on water in ocean basins and the solid earth. Inertia causes water in ocean basins on the far side of the earth the also bulge away from the earth. These highest tidal fluctuations are called spring tides . These lowest tidal fluctuations are called neap tides . Tides can be magnified or diminished by coastline configuration.
Waves migrate across the ocean's surface, sometimes for thousands of miles.
The water that a wave moves through bobs up and down in a circular motion, but does not experience a net lateral movement in the open ocean. As waves approach a coastline, they will eventually get into shallow water. When this happens, waves build vertically and eventually break, causing water near shore to wash onto the beach. This longshore current is important in moving sand progressively from one end to the other of a beach. As a wave splashes onto the beach, then flows back into the ocean, sand particles are moved, in small increments, along the beach in the direction of the longshore current.