A beach is a shoreline at which sea meets land. This area is constantly influenced by waves and currents, and can undergo dramatic changes within a very short period of time. It is also home to a wide variety of animal and plant species that have adapted to the coastal environment. Beaches are also often a popular recreational destination for humans, offering a place for swimming, surfing, sunbathing, fishing and other outdoor activities.
During high energy events, such as storms and tropical cyclones, beaches can experience considerable erosion and loss of sediment. However, most beaches are able to recover from these events and regain their cross-sectional profile in equilibrium with the wave and tidal conditions.
The sediment that makes up a beach can be either biogenic or terrigenous in origin. Biogenic sediment is created by marine organisms such as coral reefs and shells. Terrigenous sediment is the product of erosion from nearby cliffs or rocky areas, and can be supplied to a beach by rivers and glaciers. Beach sand is often created from the erosion of volcanic rock, and can be a different color depending on the type of rock, for example red beaches come from iron-rich lava, green from olivine, and black from obsidian.
Beach sand is primarily composed of small granules, typically less than 1 millimeter in diameter. However, beach sand can contain larger particles such as gravel (2-4 mm), pebbles (4-64 mm) or cobbles (>64 mm). Beaches consisting of predominantly biogenic sediments are called sandy beaches, and those with mainly terrigenous sediments are called gravel or rocky beaches.
Beaches can be characterized by their color, erosion rate, vegetation and biodiversity. They can also be classified by their sand quality, including its grain size and color, which is often indicative of the mineral content. Beaches may also be characterized by their sand-to-water ratio, which is indicative of the amount of water mixed in with the sand.
Beach access is an issue of great importance to the public, and many people do not understand that they have a right to freely enjoy beaches located on private property. Fortunately, there are numerous ways that beach access can be improved through education, better funding and renewed enforcement of laws that protect this right. Additionally, Surfrider Foundation advocates for development setback requirements that account for projected sea level rise to ensure that new structures are not encroaching on eroding beaches. This approach will help to preserve natural beaches for future generations, and provide an optimal setting for leisure activities and recreation.