A beach is a narrow, gently sloping strip of land along a coast. It is composed of sand, gravel, mud, rock, or other materials. These sediments are deposited on the shore by runoff, wind, or moving water. The type of material that makes up a beach varies according to the surrounding geology. For example, sand is commonly derived from local bedrock or from other sediments. Sand can also be organically derived from biologic components in the ocean near the beach.
Beaches vary in size and shape. Some are wide and gentle, while others are narrow and steep. A typical beach includes a berm, shallow offshore bars, and a beach face.
In most countries, the contour of a beach varies depending on the sea level, the tidal frequency, and the amount of sediment delivered. During storms, the size and direction of the waves change and redistribute the sediments on the beaches. This process affects the beaches’ configuration and their location. Usually, the lower beach margin is located at a depth that is equal to one-third the wavelength of the longest wave.
Beaches are often impacted by large cyclonic storms. These storms produce strong waves and a high surge of water. They can also erode beaches and cause them to change in shape. Storm winds can also cause sandbars and shipwrecks to form.
Depending on the beach’s geographical location, its width can change by as much as three times. Seasonal changes can also alter the beach’s width. During the summer, beaches are usually wider and less steep, while in winter, they tend to be narrower and more steep.
Unlike rocks, which are cemented by calcium carbonate, sand and pebbles are moved primarily by wind and water. As these particles move through the water, they increase the viscosity of the fluid, which enhances its erosive power. If the fluid is turbid, the particles can be carried inland to areas of calmer water. Moreover, these particles add to the volume of the moving fluid, increasing its average density.
While sand is the main material used to create a beach, other materials can be used as well. Some beaches have a considerable shell content. Others have little or no shell at all. There are many types of wildlife that nest on sandy beaches. Turtles, starfish, and seals are examples. Other types of animals that live on or near beaches include fish, sea lions, and clams. Occasionally, mobs of animals will come out of the sea and bury themselves under the sand. Likewise, buried treasure can be found under most beaches.
Many beaches are extremely polluted. To prevent contamination, people should stay off closed beaches and properly dispose of trash. Furthermore, you should avoid feeding and harassing wildlife. Besides, some species mistake plastic for food, which could harm or kill them.
A beach is a natural transition biome from the mainland to the ocean. In addition to serving as a place for humans to swim, beaches are popular resting places for shorebirds. Several species of sea turtles also nest on beaches.