Wave pounding
Wave pounding is the strong force of waves crashing against cliffs. The impact shakes rocks, helping hydraulic action and abrasion break them apart. Eroded material is carried away by the water. It’s especially fierce in storms when waves are large and full of energy. This process matters for coastline erosion and for designing structures like seawalls and dams.
What affects wave pounding? The shape of the waves, the chemistry of the ocean water, the type of rock, and the coast’s shape. There are three kinds of waves involved: spilling, plunging, and surging. Spilling waves have the least energy because the sea floor is shallow; plunging and surging waves carry the energy that pounds the cliffs and occur on beaches with moderate to steep slopes.
Water chemistry also matters. Salt, calcium, and acids can weaken certain rocks and speed chemical weathering, making pounding more damaging. Wave pounding can happen anywhere in the world where the beach slope is steep enough to produce plunging or surging waves, not just at tectonic borders.
How does it work? The waves’ energy fractures or removes rock and sand at the land-sea margin. Surging water fills cracks and wedges rock apart. Some rocks are especially vulnerable, such as chert or other fractured rocks with siliceous fills.
On some coasts, loose sand cliffs and large sand deposits can suffer severe damage, especially when suspended sand in the water erodes the cliff faces. The effect can create notches and weak points that lead to large blocks of rock falling away. Tide, seasons, and longshore drift can change the beach angle and whether waves hit the cliff or wash onto the beach. Jetties and other man-made structures also feel wave pounding, which can move stones and wear down edges.
This page was last edited on 2 February 2026, at 12:41 (CET).