A beach is a landform along a body of water, such as the sea or lake. It’s typically made of sand, pebbles or cobbles, and can also contain shells. Beach material accumulates during periods of accretion and moves away during periods of erosion. The movement of materials defines a beach and can change its appearance dramatically. A beach is not a specific type of landscape; it can be warm and sandy, or rocky and stony. Some beaches are lined with palm or mangrove trees, while others are bare and stark. Beaches are found in tropical and temperate areas of the world.
A beach consists of a broad, shallow strip of sand near the edge of a coastline, or in some cases, a lake shore. The sand is usually composed of fine particles, but it can include larger gravel or even large stones. The sands on tropical beaches are often rich in minerals, especially feldspars and quartz. Beaches on the Arctic and Antarctic coasts tend to be icy and snow-covered.
In addition to the sand, the surface of a beach can be covered by seaweed, rocks and driftwood. Some beaches are littered with garbage, including plastic bags and cans, as well as medical waste, such as needles and surgical instruments. In the event of a storm, some beaches can be contaminated with bacteria and toxic chemicals from sewage and other industrial pollutants that wash up into ocean waters from inland sources.
Every beach has a profile, or shape, when viewed from the air. The part that’s mostly above the water is called the beach berm. This is characterized by its height and slope, which differ depending on the size of waves that hit it. Beaches with coarser sand have steeper slopes, while those with finer sand have flatter slopes.
A sandbar is an offshore ridge of sand that’s partially or completely submerged at low tide. This is a result of sand transport, which happens when waves and currents carry sediment through the water and deposit it on the beach. Over time, the larger grains of sand sink to the bottom of the ocean and become buried under the smaller ones.
A beach can be a popular place for recreational activities, such as swimming and sunbathing. People may also go to a beach to surf, fish or hunt for shells. Beaches are often used as tourist attractions and are a major source of income for local businesses, such as restaurants, hotels and tour companies. In some cities, artificial beaches are built in parks and other urban areas to recreate the feel of a natural beach. This can be a controversial practice, as it can disrupt the natural environment and attract undesirable visitors.