An ocean bank, sometimes referred to as a fishing bank or simply bank, is a part of the

seabed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most o ...

that is shallow compared to its surrounding area, such as a

shoal In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material and rises from the bed of a body of water to near the surface. It ...

or the top of an underwater hill. Somewhat like continental slopes, ocean bank slopes can upwell as tidal and other flows intercept them, sometimes resulting in nutrient-rich currents. Because of this, some large banks, such as

Dogger Bank Dogger Bank ( Dutch: ''Doggersbank'', German: ''Doggerbank'', Danish: ''Doggerbanke'') is a large sandbank in a shallow area of the North Sea about off the east coast of England. During the last ice age the bank was part of a large landmass ...

and the

Grand Banks of Newfoundland The Grand Banks of Newfoundland are a series of underwater plateaus south-east of the island of Newfoundland on the North American continental shelf. The Grand Banks are one of the world's richest fishing grounds, supporting Atlantic cod, sword ...

, are among the richest fishing grounds in the world. There are some banks that were reported in the 19th century by navigators, such as Wachusett Reef, whose existence is doubtful.

Types

Ocean banks may be of

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plat ...

nature. Banks may be

carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate ...

or terrigenous. In tropical areas some banks are submerged

atoll An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can gro ...

s. As they are not associated with any

landmass A landmass, or land mass, is a large region or area of land. The term is often used to refer to lands surrounded by an ocean or sea, such as a continent or a large island. In the field of geology, a landmass is a defined section of continen ...

, banks have no outside source of

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...

s. Carbonate banks are typically platforms, rising from the ocean depths, whereas terrigenous banks are elevated sedimentary deposits. Seamounts, by contrast, are mountains rising from the deep sea and are steeper and higher in comparison to the surrounding

.Farallones Marine Sanctuary Association
Islands, Banks & Seamounts: Geologic Features Under the Sea
. Examples of these are Pioneer and Guide Seamounts, west of the

Farallon Islands The Farallon Islands, or Farallones (from the Spanish ''farallón'' meaning "pillar" or "sea cliff"), are a group of islands and sea stacks in the Gulf of the Farallones, off the coast of San Francisco, California, United States. The isl ...

. The Pioneer Seamount has a depth of 1,000 meters, In other cases, parts of a bank may reach above the water surface, thereby forming

island An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An isla ...

Important banks

The largest banks in the world are: #

(280,000 km²) - terrigenous bank # Agulhas Bank (116,000 km²) # Great Bahama Bank (95,798.12 km², has islands, area without islands) # Saya de Malha (35,000 km², excluding the separate North bank, least depth 7 m) # Seychelles Bank (31,000 km², including islands of 266 km²) # Georges Bank (28,800 km²) - terrigenous bank # Lansdowne Bank (4,300 km²,Le parc naturel de la mer de Corail
p. 26 west of

New Caledonia ) , anthem = "" , image_map = New Caledonia on the globe (small islands magnified) (Polynesia centered).svg , map_alt = Location of New Caledonia , map_caption = Location of New Caledonia , mapsize = 290px , subdivision_type = Sovereign st ...

, least depth 3.7 m) #

(17,600 km², least depth 13 m) # Little Bahama Bank (14,260.64 km², has islands, area without islands) # Great Chagos Bank (12,642 km², including islands of 4.5 km²) # Reed Bank, Spratly Islands (8,866 km², least depth 9 m) # Caicos Bank,

Caicos Islands The Turks and Caicos Islands (abbreviated TCI; and ) are a British Overseas Territory consisting of the larger Caicos Islands and smaller Turks Islands, two groups of tropical islands in the Lucayan Archipelago of the Atlantic Ocean and nor ...

(7,680 km², including islands of 589.5 km²) #

Macclesfield Bank Macclesfield Bank is an elongated sunken atoll of underwater reefs and shoals in the South China Sea. It lies east of the Paracel Islands, southwest of Pratas Island and north of the Spratly Islands. It is about long from southwest to northeas ...

(6,448 km², least depth 9.2 m) # North Bank or Ritchie Bank (5,800 km², north of Saya de Malha, least depth <10 m) # Cay Sal Bank (5,226.73 km², including islands of 14.87 km²) # Rosalind Bank (4,500 km², least depth 7.3 m) # Bassas de Pedro (2,474.33 km², least depth 16.4 m), part of the Amindivi Subgroup of

Lakshadweep Lakshadweep (), also known as Laccadives (), is a union territory of India. It is an archipelago of 36 islands in the Arabian sea, located off the Malabar Coast. The name ''Lakshadweep'' means "one lakh islands" in Sanskrit, though the Lac ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

Notes

External links

Definitions – Islands, Banks & Seamounts: Geologic Features Under the Sea
{{fishing by country Physical oceanography

Types

Important banks

See also

Notes

External links