Barrier Island

Barrier Island

Barrier Islands, a coastal landform and a type of barrier system, are relatively narrow strips of sand that are parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. Excepting the tidal inlets that separate the islands, a barrier chain may extend uninterrupted for over a hundred kilometers, the longest and widest being Padre Island. The length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends and basement controls.

Chains of barrier islands can be found along approximately thirteen percent of the world's coastlines, some displaying different settings, suggesting that they can form and be maintained in a variety of environmental settings. Numerous theories have been given to explain their formation.