A beach is a wide expanse of sand, stone or gravel along a body of water. While beaches are most often associated with the ocean, they can also be found on the shores of lakes, rivers and some inland seas.
The word “beach” derives from the Latin for “sandy.” The landscape of a beach is constantly changing due to erosion, deposition, and other natural processes. Over time, well-stabilized areas tend to accrete and unstabilized areas tend to erode, resulting in substantial changes to the shape and size of a beach. Freak wave events can also significantly alter a beach’s characteristics in just a few hours.
While most beaches consist of loose sand sediments, some contain rock debris such as boulders and shells. These rocks are primarily the result of weathering, which is the process of rock fragmentation caused by mechanical forces or chemical action. Once weathered, the smaller rocks are carried by wind or currents and deposited on the beach. Beaches are also made up of a layer of silt and clay, which is largely the result of river and stream sediments flowing into the beach.
A variety of beach ecosystems can exist, depending on the size and characteristics of the sand, the underlying rock material, and the presence or absence of vegetation. Beach vegetation can include shrubs, grasses, dune plants and trees. Beach vegetation helps to stabilize the sand by providing shade and holding soil together. Beach vegetation is also important for reducing the amount of sand drifting into coastal waters.
In addition to beach vegetation, the composition of a beach depends on the size and type of sediments that are present, the speed of flow through the water, the turbidity (cloudiness) of the water, and the degree to which the sand is compacted. The sand composition is also affected by the direction of the prevailing winds and currents.
Many beaches are popular with recreational activities such as swimming, sunbathing and surfing. Some are inhabited by wildlife including birds, reptiles and marine mammals. Some beaches have lifeguard posts, shacks, restaurants and other facilities to support their recreational uses. For many people, the beach is a place to escape the demands of everyday life and enjoy the simple pleasures of nature.