Often considered as a natural phenomenon, a beach is a sand-colored strip of land that consists of a sedimentary deposit that accumulates along a shoreline. Beaches can be located by oceans, lakes or large rivers. Some beaches are barren, while others are rocky. The shape and contour of a beach depends on a variety of factors, such as the type of material that makes up the beach and the erosive power of the waves that wash it up.
In tropical regions, beach sand is derived from the erosion of coral reefs and volcanic rock. The sands are usually fine grains of quartz and feldspar that appear brown or light tan. Beaches that occur in colder regions are often covered with rocks, as the water freezes all year round.
Beaches are formed from ocean currents and waves, which transport sediments and debris from the ocean to the beach. This process is called longshore drift. The sediments are moved by waves, wind and eddies. The particle size of the sand and the state of compaction affect the motion of the particles. When the particles are suspended, they add viscosity to the fluid and increase its erosive power. The volume of the moving fluid increases, as well. This creates a smoother and less-rough edge to the beach.
In the United States, most of the big waves come from the North Pacific or the North Atlantic. The shape and contour of a beach depend on the type of material, the erosive power of the waves and the coastal processes that occur. Beaches can have a variety of forms, from a long, trough-like beach to a sweeping crescent shape.
During a hurricane, waves can break through the beach and erode it. These waves can also cause the creation of sandbars, which are narrow areas of sand that are exposed to the ocean. These areas are often protected by man-made structures, such as surfboards, lifeguard stations and shacks. These structures can also contribute to the environmental costs associated with the beach.
Some sandy beaches are populated by birds, sea turtles and other marine life. These birds and sea turtles lay eggs on the beaches. In addition to birds, other animals may also feed on the material left behind by the waves. These animals include forams, single-celled amoeba-like protists that build pink shells as they die. Forams are common in Bermuda, but they may also be found in other regions.
In North America, beaches are often created by the pounding waves of the Atlantic Ocean. The sand is broken into smaller grains by the waves, which erode the rocks. Some beaches also feature a beach terrace or beach berm. These structures can help to protect the beach from inland erosion by high winds. They also help to stabilize foredunes. The shoreline can also be affected by man-made structures, such as hotels and changing rooms.
The beach can also be affected by waves coming in at an angle. If the wave hits the beach at an angle, the sand is moved to the right or left. If the waves are constructive, they are long enough for the sediment to settle before breaking. These waves are also called rip currents. These currents can also cause the erosion of deep channels.