coastline n : the outline of a coast
The coast is defined as the part of the land adjoining or near the ocean. A coastline is properly a line on a map indicating the disposition of a coast, but the word is often used to refer to the coast itself. The adjective coastal describes something as being on, near to, or associated with a coast.
Coast is a specific term, and is applied to that part of an island or continent that borders an ocean or its saltwater tributaries. A pelagic coast refers to a coast which fronts the open ocean, as opposed to a more sheltered coast in a gulf or bay. A shore on the other hand, can refer to parts of the land which adjoin any large body of water, including oceans (sea shore) and lakes (lake shore). Similarly, the somewhat related term bank refers to the land alongside or sloping down to a river (river bank) or of a body of water smaller than a lake. Bank is also used in some parts of the world to refer to an artificial ridge of earth intended to retain the water of a river or pond. In other places this may be called a levee.
While many scientific experts might agree on a common definition of the term "coast", the delineation of the inland extents of a coast differ according to jurisdiction, with many scientific and government authorities in various countries differing for economic and social policy reasons. This is usually because defining lands as part of a coast may be seen to have environmental implications which would prevent development or attach regulations to their use.
Environmental importanceThe coast and its adjacent areas on and off shore is an important part of a local ecosystem as the mixture of fresh water and salt water in estuaries provides many nutrients for marine life. Salt marshes and beaches also support a diversity of plants, animals, and insects crucial to the food chain.
Like the ocean which shapes them, coasts are a dynamic environment with constant change. The earth's natural processes, particularly sea level rise, waves and various weather phenomena, have resulted in the erosion, accretion and reshaping of coasts as well as flooding and creation of continental shelves and drowned river valleys (rias).
Human impactsfurther Marine debris Coasts also face many environmental challenges relating to human-induced impacts. The human influence on climate change is thought to be a contributing factor of an accelerated trend in sea level rise which threatens coastal habitat as natural systems struggle to adapt faster. Human development of coastal land, particularly for recreational or industrial uses are similarly threatened by sea level rise, but also contribute to aesthetic problems of land use and reduced natural coastal habitat.
Pollution is an ongoing concern along coasts with garbage and industrial debris littering beaches and sometimes entire coasts, requiring government agencies to make frequent use of beach cleaners and other volunteer cleanup efforts. The transportation of petroleum in tankers is a major hazard both for the open ocean and along coasts, particularly when large oil spills occur. Another major hazard for coastal marine life is the large number of small oil spills created by large and small vessels powered by petroleum which flush bilge water directly into the ocean.
Both the terms coast and coastal are often used to describe a geographic location or region. For example, New Zealand's West Coast, or the East and West Coasts of the United States. A large part of the global population inhabits areas near a coast, partly to take advantage of marine resources such as fish, but more importantly to participate in seaborne trade with other nations. Many of the world's major cities that have developed in recent centuries were built on or near good harbours and have large port facilities to take advantage of marine transportation. Jurisdictions which are landlocked and have no coast are often at an economic disadvantage with overseas trade being more difficult; sometimes being forced to go to extravagant measures such as building canals to permit ocean-going vessels to travel inland.
Coasts, especially those with beaches and warm water are also an important draw for tourists. In many island nations such as those of the Mediterranean, South Pacific and Caribbean, tourism by those who come to enjoy the coast is central to the economy. Coasts are popular destinations because of recreational activities such as swimming, fishing, surfing, boating, and sunbathing. Growth management can be a challenge for coastal local authorities who often struggle to provide the infrastructure required by new residents seeking seachange lifestyles.
Many tourists and residents also enjoy the salt air by the sea coast which some consider to have health benefits. Coastal weather is heavily influenced by the ocean and while this can sometimes result in dangerous storms such as Nor'easters and hurricanes, the coastal climate is often cooler and more temperate than corresponding inland areas. Consequently tourists from areas experiencing extremely warm and humid weather seek coastal areas for these reasons.
The coast is often a crucial defensive frontier, both for warding off military invaders but also smugglers and illegal migrants. Coastal defenses have thus long been erected in many nations. Most coastal countries also have a navy and some form of coast guard.
Types of coast
An emergent coastline is a coastline which has experienced a fall in sea level, because of either a global sea level change, or local uplift. Emergent coastlines are identifiable by the coastal landforms, which are above the high tide mark, such as raised beaches. Alternatively, a submergent coastline is a coastline which has experienced a rise in sea level, due to a global sea level change, local subsidence, or isostatic rebound. Submergent coastlines are identifiable by their submerged, or "drowned" landforms, such as rias (drowned valleys) and fjords.
A concordant coastline is a coastline where bands of different rock types run parallel to the shore. These rock types are usually of alternating resistance, so the coastline forms distinctive landforms, such as coves. A discordant coastline is a type of coastline formed when rock types of alternating resistance run perpendicular to the shore. Discordant coastlines feature distinctive landforms because the rocks are eroded by ocean waves. The less resistant rocks erode faster, creating inlets or bays; the more resistant rocks erode more slowly, remaining as headlands or outcroppings.
Coastal landforms and features
Coastal features formed by sediment
Other features on the coast
- Longshore drift
- Sea level change
AnimalsAnimals living along the coast vary enormously, some live along coasts to nest like puffins, sea turtles and rockhopper penguins. Sea snails and various kinds of barnacles live on the coast and scavenge on food deposited by the sea. Most coastal animals are used to humans in developed areas, such as dolphins and seagulls who eat food thrown for them by tourists. Since the coastal areas are all part of the littoral zone, there is a profusion of marine life found just off-coast.
There are many kinds of seabirds on the coast. Pelicans and cormorants join up with terns and oystercatchers to forage for fish and shellfish on the coast.
PlantsCoastal areas are famous for their kelp beds. Kelp is a fast growing seaweed that grows up to a metre a day. Corals and anemones are true animals, but live a similar lifestyle as plants do.
- Coastal and Estuarine Research Federation
- Coastal erosion
- Coastal management
- Coral reefs
- Earth science
- Engineering geology
- How Long Is the Coast of Britain? Statistical Self-Similarity and Fractional Dimension
- Land reclamation
- List of countries by length of coastline
- List of places on land with elevations below sea level
- List of U.S. states by coastline
- Marine biology
- Marine debris
- Marine life
- Nautical chart
- Pole of inaccessibility: the locations farthest from any coastline.
coastline in Afrikaans: Kuslyn
coastline in Aragonese: Costa
coastline in Asturian: Costa
coastline in Aymara: Lamara junt'u tuqi suyu
coastline in Belarusian (Tarashkevitsa): Узьбярэжжа
coastline in Breton: Aod
coastline in Bulgarian: Бряг
coastline in Catalan: Costa
coastline in Czech: Pobřeží
coastline in Danish: Kyst
coastline in German: Küste
coastline in Estonian: Rannik
coastline in Modern Greek (1453-): Ακτή
coastline in Spanish: Costa
coastline in French: Côte (géographie)
coastline in Galician: Costa (xeografía)
coastline in Korean: 연안
coastline in Croatian: Obala
coastline in Icelandic: Strönd
coastline in Italian: Costa
coastline in Latvian: Piekraste
coastline in Dutch: Kust
coastline in Japanese: 海岸
coastline in Norwegian: Kyst
coastline in Norwegian Nynorsk: Kyst
coastline in Polish: Wybrzeże
coastline in Portuguese: Costa (geografia)
coastline in Russian: Побережье
coastline in Simple English: Coast
coastline in Slovak: Pobrežie
coastline in Slovenian: Obala
coastline in Finnish: Rannikko
coastline in Swedish: Kust
coastline in Cherokee: ᎠᎹᏳᎸᏗ
coastline in Yiddish: ברעג ים
coastline in Chinese: 海岸