The Bahama Banks is a submerged carbonate platform that makes up most of the Bahamas Archipelago. The term is commonly used to refer to the Great Bahama Bank around Andros Island, or Little Bahama Bank on Grand Bahama Island and Great Abaco, which is the largest platform, and Cay Sal Bank in northern Cuba. The islands of these banks are politically part of the Bahamas. Other banks are the three banks in the Turks and Caicos Islands, the Caicos Bank in the Caicos Islands, Turks Islands bank, and Mouchoir Bank are completely submerged. Further south is the completely submerged Silver Bank and the Navidad Bank north of the Dominican Republic.
Video Bahama Banks
History and geological structure
Limestone composed of Banks has accumulated at least during the Cretaceous period, and possibly as early as Jurassic; today the total thickness under Great Bahama Bank is over 4.5 kilometers (2.8 miles). When limestone is deposited in shallow water, the only way to explain this large column is to estimate that the entire platform has subsided under its own weight at a rate of about 3.6 cm (2 inches) per 1,000 years.
The waters of the Bahamas Bank are very shallow; in the Great Bahama Bank they are generally no more than 25 meters (80 feet). But the slopes around them, like the Tongue of the Ocean border on the Great Bahama Bank, are very steep. The bank is a dry land during the last ice age, when the sea level reached 120 meters (390 feet) lower than it is today; the Bahamas currently represent only a small fraction of their prehistoric levels. When they are exposed to the atmosphere, limestone structures are subjected to chemical weathering that creates caves and exhaust pits that are common to karst fields, producing structures such as blue holes.
Maps Bahama Banks
See also
- Ocean bank (topography)
- Bahamian Geography
- Dean's Blue Hole
- Platform of carbonates
Link
- ESA: Earth From Outer Space: The Great Bahamas Bank , at http://spaceref.com, December 20, 2014 11:00 am
References
Source of the article : Wikipedia
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