A beach is a landform along the edge of a body of water such as an ocean or a lake. It usually consists of loose particles such as sand, gravel, shingle, pebbles, and sometimes bits of coral and even igneous rock. Beaches are popular for recreation including swimming, sunbathing, and beach games. They are also important habitats for marine life. Beaches form from natural processes over long periods of time. These processes include weathering, erosion, sediment transport, and depositional processes such as attrition, abrasion, and chemical breakdown.
Most of the sand on beaches comes from weathering. This is when rocks break down into small pieces by wind, rain, and wave action. Then sand from these particles is carried by waves, currents, and drifting debris to the shore. Some sand also gets transported from offshore by glaciation. In addition, sand is often carried to beaches from upland areas by rivers and streams.
When a large amount of sand is washed out to sea by waves it becomes suspended in the water and moves slowly to the coastline. This is called backwash. The movement of the sand is controlled by its particle size and the strength and direction of the wave action. Coarse-grained sand will move more rapidly to the beach than fine-grained sand.
The sand on a beach is often mixed with silt and clay. When this is wet it is known as mud, and when dry it is known as dust. This fine-grained material is normally the weathering products of rocks that lie far inland from the beach. Mud and dust can be moved seaward by the waves or landward into soundings and marshes behind barrier islands.
Many different types of beaches exist, ranging from broad, sandy stretches to coves and rocky cliffs. Most beaches have a distinctive sand color, often bright white or light-colored, which is caused by the deposition of fine-grained sand. Some beaches have a more rugged appearance, with rock outcrops and gullies, and are often known as rocky or boulder beaches.
Beach profiles change dramatically from hour to hour and season to season, depending on the nature of sediment transport and wave conditions. They may be destroyed by wave action and then rebuilt a short distance away, or they may disappear completely for a period of time.
People have been visiting beaches for thousands of years to swim and play. Commercial bathing began in the United States and Britain by the late 19th century, and seaside resorts grew in popularity during this time. The romantic ideal of the picturesque landscape promoted by artists and embraced by Jane Austen’s unfinished novel Sanditon in 1815 helped to popularize the idea of taking one’s health and pleasure at the seaside. The emergence of paved highways and railways in the United States made it easier for travelers to reach distant beaches.