The geography of the seashore is affected by the process of erosion (wearing away) and deposition (dep-oh-ZIH-shun; setting down), which helps determine the different types of surface found at the seashore, as well as its landforms.

Erosion and Deposition

As waves crash against a shoreline, they compress (squeeze) the air trapped in cracks in rocks. As the waves retreat, the pressure is suddenly released. This process of pressure and release widens the cracks and weakens the rock, causing it to eventually break apart. Some waves, especially those created by storms, are very high and forceful. In places where wave action is strong, the waves pick up the particles of rock and sand and throw them against the shoreline with a crashing motion. This produces a cutting action.

Some of the chunks and particles eroded from a shoreline may then be carried out...