A beach is a landform along the shoreline of a body of water. Beaches are made up of sediment, which is carried to the shore by waves or winds. The material can vary from sand to gravel to rock fragments. They also contain shells and mollusks, and can be gentle or steep.
Some beaches have little shell content. In coastal areas, seaweed and other biological components of the ocean may be present in the sediment. Other beaches have a lot of shell. Sea turtles lay their eggs on these beaches. These beaches are known as fossil beaches. Fossils are important clues to the history of the formation of the beach.
Beaches are not always the same color, but generally are a shade of brown. This is due to the geology of the area where the beach is located. If the beach is in a tropical area, the sand will be derived from coral reefs and other marine organisms.
Beaches can be narrow or wide. A narrow beach tends to be less steep than a wide beach. It is also more likely to have sandbars or dunes, which are areas of exposed sand. Depending on the type of beach, it can be hundreds of kilometers long.
Beaches can be very polluted. They are a source of toxic chemicals and other pollutants. For this reason, it is important to avoid leaving trash on the beach. Plastic debris can prevent the development of algae and sea plants. Similarly, birds can choke on plastic pieces. Also, it can block the rain from falling where it falls.
Beaches are formed through a combination of erosion, shoaling, and the movement of ocean currents. Generally, these processes occur over time, but they can be affected by weather systems and ocean currents. Large cyclonic storms, for example, can redistribute the sand on the beach.
Beaches can also be formed from a mixture of sand, rocks, and other materials. Beaches have been found with shells, mud, and cobbles. Occasionally, the beach may have tree stumps or tree roots. Birds may nest on beaches.
During the summer, ocean waves build up the beach. But during the winter, strong winds can blow the sand off the beach. Similarly, storm winds can also erode beaches. Especially on low-lying sand islands, the storms can erode the beach and cause sandbars. Similarly, in hurricanes and tornadoes, the winds can be so strong that they can disintegrate the beach.
In addition to sand, some beaches have calcium carbonate. This is the same stuff that forms the shells of corals. However, the sand on the beaches in Tuvalu, a small island nation in the South Pacific, was quickly eroding in the 1990s. This is because the islands are part of the El Nino-Southern Oscillation (ENSO).
Beaches can be made up of sand, gravel, or other material. They are usually created by the ebb and flow of tides. Ocean currents can carry the sand hundreds of miles, and sand can be deposited by wind.