A beach is a landform that occurs next to a body of water like a lake, ocean or river. It is composed of sand, gravel or shingle. Beaches are formed and destroyed by waves. The shape of the beach depends on the type of sediment and the action of the waves. Beaches are also a habitat for many different plants and animals.
Beaches are often surrounded by dunes, which protect them from high winds and freak waves. The dunes are stabilized by a layer of organic material, usually grasses and shrubs. These plant species help trap sand particles and reduce erosion by absorbing rainwater. They also encourage the growth of other beach-plant species.
Many beaches are popular places for recreation. They may have amenities such as lifeguards, changing rooms and showers. Some have food and beverage vendors, restaurants or shacks. They may also be equipped with recreational facilities such as volleyball courts and surfboards. Beaches are also popular for sports such as surfing, sailing and swimming.
The word “beach” comes from the Greek word for seashore. People have been visiting beaches for millennia, but the way they use them has changed significantly over time. In the early twentieth century, Americans looked to beaches as refreshing resorts that enabled them to escape from the stresses of city life. Inexpensive mass transit systems made it easy for urban working-class families to take a day’s vacation to the beach. The popularity of beach travel accelerated during the 1920s with the construction of the Dixie Highway, which connected beach-front vacation homes to northern cities and southern resorts.
Beaches have a very complex structure. The sand that makes up the beach is arranged in a pattern of ridges and troughs that are called a berm. The crest of the berm is above water at high tide, and the face, which is below water at low tide, slopes downward. The trough between the peaks of the berm is the beach.
A beach may have a sandbar, which is a sand ridge that forms offshore from the beach. The sandbar is formed when the motion of a wave creates longshore currents. These currents are caused by the fact that a swell coming from the north (in the case of the United States, the Pacific Coast) pushes sand toward the south as it hits the shore. This ongoing movement of sand off the shore is known as longshore drift or longshore transport.
As waves roll onto the beach, they deposit new sediments on the sand. This process is a continual cycle that results in a dynamic coastal landscape. The sand on the beach is constantly moving, and the shape of the beach changes continuously as well. Sandbars are more likely to appear in the summer, when swells come closer to the coast. In the winter, sandbars form farther out into the water. This is because the swells are larger in the winter and generate more force to move the sand.