Coasts: erosion, deposition and coastal landforms
Geography · Key Stage 2 · The School
The sea never stops working
The sea shapes the coast all the time. It does this in three ways. EROSION wears rock away. TRANSPORT carries broken bits along the coast. DEPOSITION drops them somewhere else. All three happen together, every single day. A single storm can shape a coast more than a whole calm year.
Why some rock sticks out
Some rock is hard. Some rock is soft. The sea wears away soft rock fast. It wears away hard rock slowly. Over time the soft rock forms a bay. The hard rock is left sticking out. That sticking-out part is a HEADLAND. Walk any rocky coastline and this pattern repeats again and again.
A beach is stolen rock
A beach is not really sand from nowhere. It is rock, broken down and carried by the sea. Waves drop it where the water slows down. Most beaches are made this way. Nothing was created. It was only moved. Pick up a handful of sand and every grain has its own long story.
A cliff of soft rock is hit by waves. A small piece breaks off. Waves roll it along the seabed. It bumps other rocks and breaks smaller. It gets rounder and smaller each time. Waves carry it along the coast. They slow down near a bay. The tiny rounded piece is dropped there. It becomes part of the beach. That whole journey can take years. A single beach can hold pieces from many different cliffs.