A beach is a landform that exists along bodies of water such as oceans, lakes and rivers. It is characterized by the presence of organic sediments like sand, pebbles, rock and shell fragments. The formation of a beach typically takes thousands of years and results from weathering, erosion and transportation processes. Most beaches are found at the edge of an ocean, however they can also exist at the edges of rivers and lakes. Beaches are constantly changing and have many different characteristics that make them unique.
The word “beach” is derived from the Latin term for shore, which refers to the edge of a body of water. Beaches are essentially areas of loosely packed sand or gravel and are found all over the world. They are a common feature of oceans, lakes and rivers and have many unique features that distinguish them from other types of coastlines.
Beaches are formed by a process called weathering, which is the breaking down of rocks into smaller pieces. This can occur naturally through erosion over a long period of time, or it can be caused by a number of other natural phenomena such as waves beating against a rocky cliff for decades. Once rocks are weathered into small particles, they can be carried away by rain and river waters until they reach the shoreline. There they are then deposited on the beach where they gradually accumulate to form a strip of land.
Over time, beaches can be subject to erosion or accretion, and the shape and size of a beach can vary greatly depending on the balance between these two processes. Beaches are also highly dynamic environments, and they can undergo drastic changes within a matter of hours.
Sand is the most common element found on a beach. It can be made up of a variety of materials such as silt, clay, coarse sand, fine sand or cobbles. In general, sand beaches have a slow sloping profile, while rocky beaches have more extreme slope angles. The difference in slope angle is due to the particle size of the sand. Coarse sands are more effective at resisting erosion, while fine sands will quickly erode and be carried off the beach.
Beaches can also contain marine plants, animals and debris, including rocks, seashells, sand dollars and other seashells, driftwood, piers and fishing equipment. They may also contain layers of mud, which contains fine sediments that are deposited by wave action or transported by currents. Mud can be of salt marsh or freshwater origin and is generally less stable than sand. Layers of mud often shift, being washed away by the incoming tide and redeposited further up on the beach where they can mix with the underlying sand.