Barrier island

Barrier Island

A barrier island is a long, narrow, offshore deposit of sand or sediment that runs parallel to the coastline. These islands are separated from the main land by a shallow sound, bay, or lagoon and are often found in chains along the coastlines of the United States, Canada, New Zealand, and Europe.

Formation

Barrier islands are formed through the process of wave and tide action. They begin as sandbars or spits that are built up by the action of waves and currents. Over time, these sandbars grow in size and height until they become stable enough to support vegetation. The vegetation stabilizes the island and allows it to grow further.

Characteristics

Barrier islands are characterized by a series of dunes, a wide beach, and a marshy backside. The dunes are typically the highest point on the island and are formed by wind-blown sand. The beach is the area that is exposed to wave action and is typically composed of sand. The backside of the island is often marshy and is influenced by tides.

Ecology

The ecology of barrier islands is complex and diverse, supporting a wide range of plant and animal species. The dunes and beaches provide habitat for many species of birds, while the marshes are home to a variety of aquatic species.

Threats

Barrier islands are vulnerable to storm surge, sea level rise, and erosion. These threats can lead to the destruction of the island's dunes and beaches, and can also result in the island being overwashed or completely submerged.

See also

• Coastal geography
• Coastal erosion
• Coastal management

External links

• Barrier Islands Organization