How is beach formed

With destructive waves, the sediment is not given a chance to settle and become compacted. Although beaches share the same basic characteristics, they also exhibit a variety of differences.

These differences mean that beaches may be classified into several types, including sandy, rocky, tropical, and frozen. Sand and rocky beaches get their names from the type of particle that can be found covering their surface. Sandy beaches are often characterized by their slowly sloping profile, whereas rocky beaches tend to exhibit more extreme slope angles.

This difference in slope is because of the difference in particle size. The larger particles on rocky beaches, for example, cause the waves to lose their power more quickly.

A tropical beach is typically home to a large variety of plant life, which is supported by fertile soil. A frozen beach rarely has vegetation and is most commonly covered in ice and rock. In addition to these specific types of beaches, coastlines may also develop spits over time.

A spit is an area of land that extends from the beach into the nearby body of water. These formations occur as a result of wind blowing at an angle against the beach. As the spit becomes larger, it works to protect the beach area from large waves and strong wind. This protected area often collects a very fine type of sediment known as silt, which results in the formation of marsh-like habitats. Just as beaches can grow over time, they can also recede. Beach recession may occur at a rapid rate or take place over a longer period of time.

Strong waves and winds batter storm beaches into narrow, steep landforms. The shingles on storm beaches are usually small near the water and large at the highest elevation. Other types of beaches Some beaches, called barrier beach es, protect the mainland from the battering of ocean waves. These beaches may lie at the heads of islands called barrier islands.

Many barrier beaches and barrier islands stretch along the Atlantic and Gulf coasts of the United States. These narrow beaches form barriers between the open ocean and protected harbors, lagoons, and sounds. Beaches near rivers are often muddy or soft. Beach berms can be many different colors. Coral beaches, common on islands in the Caribbean Sea, are white and powdery.

They are made from the eroded exoskeleton s of tiny animals called corals. Some coral beaches, such as Harbour Island, Bahamas, actually have pink sand. The coral that created these beaches were pink or red.

On some volcanic island s, beaches are jet-black. The sand on Punaluu Beach, Hawaii, is made of basalt, or lava that flowed into the ocean and instantly cooled. As it cooled, the basalt exploded into thousands of tiny fragment s. Some volcanic beaches, such as those on the South Pacific island of Guam, are green.

The basalt in these beaches contained a large amount of the mineral olivine. Threats to Beaches Coastal Erosion The most significant threat to beaches is natural coastal erosion. Coastal erosion is the natural process of the beach moving due to waves, storms, and wind. Beaches that experience consistent coastal erosion are said to be in retreat. Coastal erosion can be influenced by weather system s.

Beaches on the island nation of Tuvalu, in the South Pacific, were retreating very quickly in the s. People respond to coastal erosion in different ways. For more than years, it has warned ships of the low-lying sandbars and islands known as the Outer Banks. Coastal erosion made the beach beneath the lighthouse unstable. In , the entire lighthouse was moved meters 2, feet inland. People also combat coastal erosion with seawall s. These large structures, built of rock, plastic, or concrete, are constructed to prevent sand and other beach material from drifting away.

Residents of Sea Gate, a community in Coney Island, New York, for instance, invested in a series of seawalls to protect their homes from powerful storms and waves from the Atlantic Ocean. However, shifting sand is a natural part of the beach ecosystem. Seawalls may protect one section of beach while leaving another with little sand. Seawalls can also increase the speed at which beaches retreat. When tides and waves hit massive seawalls instead of beaches, they bounce back to the ocean with more energy.

This tidal energy causes the sand in front of a seawall to erode much more quickly than it would without the seawall. Many of the seawalls of Sea Gate crumbled, and more than 25 homes were lost. Sea Level Rise Beaches are also threatened by sea level rise. Sea levels have been gradually rising for many years, drowning some beaches completely.

New Moore Island, for example, was a small, uninhabited island in the Bay of Bengal. Both India and Bangladesh claimed the island, which was little more than a strip of sandy beach. In March , rising sea levels drowned the island completely. New Moore Island is now a sandbar.

Development Although the natural forces of wind and water can dramatically change beaches over many years, human activity can speed up the process. Dam s, which block river sediment from reaching beaches, can cause beaches to retreat.

In some places, large quantities of sand have been removed from beaches for use in making concrete. Development threatens the natural landscape of beaches. People develop homes and businesses near beaches for many reasons. Beaches are traditional tourist destinations. Places like the U. Businesses, such as charter boat facilities, restaurants, and hotels, are built on the beach.

People also enjoy living near beaches. When there is a change in the shape of the coastline, deposition occurs. A long thin ridge of material is deposited. This is the spit. A hooked end can form if there is a change in wind direction.

Waves cannot get past a spit, therefore the water behind a spit is very sheltered. Silts are deposited here to form salt marshes or mud flats.

Bars Sometimes a spit can grow across a bay, and joins two headlands together. For more than 30 years, Greg has been actively involved in the study of life history, ecology, and physiology of sharks. His shark research has spanned the globe from the frigid waters of the Arctic Circle to coral reefs in the tropical Central Pacific.

Much of his current research centers on the use of acoustic telemetry and satellite-based tagging technology to study the ecology and behavior of sharks. He has written dozens of scientific research papers and has appeared in a number of film and television documentaries, including programs for National Geographic, Discovery Channel, BBC, and numerous television networks. His most recent book, The Shark Handbook, is a must buy for all shark enthusiasts.

Robert D. He served in the U. Navy for more than 30 years and continues to work with the Office of Naval Research. A pioneer in the development of deep-sea submersibles and remotely operated vehicle systems, he has taken part in more than deep-sea expeditions.

In , he discovered the RMS Titanic , and has succeeded in tracking down numerous other significant shipwrecks, including the German battleship Bismarck , the lost fleet of Guadalcanal, the U. He is known for his research on the ecology and evolution of fauna in deep-ocean hydrothermal, seamount, canyon and deep trench systems. He has conducted more than 60 scientific expeditions in the Arctic, Atlantic, Pacific, and Indian Oceans.

Sunita L. Her research explores how the larvae of seafloor invertebrates such as anemones and sea stars disperse to isolated, island-like habitats, how larvae settle and colonize new sites, and how their communities change over time.

Kirstin also has ongoing projects in the Arctic and on coral reefs in Palau. Her work frequently takes her underwater using remotely operated vehicles and SCUBA and carries her to the far corners of the world.

Know your Ocean: Did you know? How beach sand is created? Coral Many people think of coral as hard, rock-like formations that attract abundant, diverse marine life. Read More. Dating Corals, Knowing the Ocean Coral is a useful tool for scientists who want to understand changes in past climate, but recalling…. Why is pressure different in the ocean? Find out more. Are corals plants, animals, or rocks? The base of a coral…. Does the ocean produce oxygen? We use cookies to analyze site usage and improve user experience.

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