A beach is a landform along the coastline of a body of water, such as an ocean or sea. It usually consists of loose particles such as sand, gravel, shingle or pebbles. These can be biological in origin (for example, mollusc shells or coralline algae) but the most common mineral found on beaches is quartz.
The sand that makes up most beaches comes from the weathering of rocks on land. Rain, ice, wind, heat, and cold, plus plants and animals, wear away rock and break large boulders into smaller rocks. Waves and currents can also wear the sand off of a beach.
Some beaches have man-made infrastructure, such as lifeguard posts, changing rooms, and showers. Others are wild and undeveloped. People often use beaches for recreation, such as swimming, surfing, and other water sports.
A beach can be part of a broader coastal landscape, including cliffs, rocky bluffs, and headlands. It can also be a strip of land that is only exposed at low tide, such as New Romney in Kent or Dungeness in England.
It is also an area of land that is protected from storms and waves by a barrier, such as a beach berm.
During certain times of the year, beaches are nourished, which means that sand is moved from other areas to a beach in order to make it look better. Some major beaches, such as Waikiki Beach in Honolulu, Hawaii, have been nourished for decades to prevent erosion and maintain their quality.
Tides and currents are the main way that beaches are formed, changed, and even destroyed. They move sediment from one place to another, carrying it long distances a few meters or hundreds of kilometers.
Sediment is a mixture of sand, shells, salts, and other material that can be deposited as sand dunes, beaches, or bars by winds, tides, water, and ice. The materials can be transported as sand, pebbles, or mud, or as salts that are later dissolved in water.
The materials can also be deposited by evaporation. A bar, for instance, is a sand formation that forms where the waves break and sets up a shoreward current with a counter-current along the bottom.
Sand is the most common type of material that makes up a beach, although other granular materials are used. These can include soil, silt, gravel, cobble, shingle, or boulders.
In the United States, beach sand is often mined from quarries or other sources to produce finer-grained sands for use as beaches. These sands can also be cultivated for other uses, such as filling in depressions or erosion areas.
These sands can also be mixed with chemicals, such as bleach, to create white sand. The result can be a brighter, more attractive beach that is easier to clean than sand without chemicals.
The materials that make up a beach can also be the product of natural events, such as earthquakes or volcanic eruptions. For example, on the coast of southwestern Great Britain, fossil beaches are made up of thousands of ancient creatures such as plants, fish, and insects.