The Gulf of Mexico (Spanish: Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean,[2] mostly surrounded by the North American continent.[3] It is bounded on the northeast, north and northwest by the Gulf Coast of the United States; on the southwest and south by the Mexican states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatán, and Quintana Roo; and on the southeast by Cuba. The Southern U.S. states of Texas, Louisiana, Mississippi, Alabama, and Florida, which border the gulf on the north, are often referred to as the "Third Coast" of the United States (in addition to its Atlantic and Pacific coasts).
The Gulf of Mexico took shape approximately 300 million years ago as a result of plate tectonics.[4] The Gulf of Mexico basin is roughly oval in shape and is approximately 810 nautical miles (1,500 km; 930 mi) wide. Its floor consists of sedimentary rocks and recent sediments. It is connected to part of the Atlantic Ocean through the Straits of Florida between the U.S. and Cuba, and with the Caribbean Sea via the Yucatán Channel between Mexico and Cuba. Because of its narrow connection to the Atlantic Ocean, the gulf experiences very small tidal ranges. The size of the gulf basin is approximately 1.6 million km2 (620,000 sq mi). Almost half of the basin consists of shallow continental shelf waters. The volume of water in the basin is roughly 2.4×106 cubic kilometers (5.8×105 cubic miles).[5] The gulf is one of the most important offshore petroleum production regions in the world, making up one-sixth of the United States' total production.[6]
The International Hydrographic Organization defines the southeast limit of the Gulf of Mexico as:[7]
A line joining Cape Catoche Light (21°37′N 87°04′W / 21.617°N 87.067°W / 21.617; -87.067) with the Light on Cape San Antonio in Cuba, through this island to the meridian of 83°W and to the Northward along this meridian to the latitude of the South point of the Dry Tortugas (24°35'N), along this parallel Eastward to Rebecca Shoal (82°35'W) thence through the shoals and Florida Keys to the mainland at the eastern end of Florida Bay and all the narrow waters between the Dry Tortugas and the mainland being considered to be within the Gulf.
The consensus among geologists[4][8][9] is that before the late Triassic, the Gulf of Mexico did not exist. Before the Late Triassic, the area consisted of dry land, which included continental crust that now underlies Yucatán, within the middle of the supercontinent Pangaea. This land lay south of a continuous mountain range that extended from north-central Mexico, through the Marathon Uplift in west Texas and the Ouachita Mountains of Oklahoma, and to Alabama where it linked directly to the Appalachian Mountains. It was created by the collision of continental plates that formed Pangaea. As interpreted by Roy Van Arsdale and Randel T. Cox, this mountain range was breached in the late Cretaceous by the formation of the Mississippi Embayment.[10][11]
The rifting that created the basin was associated with zones of weakness within Pangaea, including sutures where the Laurentia, South American, and African plates collided to create it. First, there was a late Triassic–early Jurassic phase of rifting during which rift valleys formed and filled with continental red beds. Second, as rifting progressed through early and middle Jurassic times, the continental crust was stretched and thinned. This thinning created a broad zone of transitional crust, which displays modest and uneven thinning with block faulting and a broad zone of uniformly thinned transitional crust, which is half the typical 40-kilometer (25 mi) thickness of continental crust. It was at this time that rifting first created a connection to the Pacific Ocean across central Mexico and later eastward to the Atlantic Ocean. This flooded the opening basin to create an enclosed marginal sea. The subsiding transitional crust was blanketed by the widespread deposition of Louann Salt and associated anhydrite evaporites. During the late Jurassic, continued rifting widened the basin and progressed to the point that seafloor spreading and formation of oceanic crust occurred. At this point, sufficient circulation with the Atlantic Ocean was established that the deposition of Louann Salt ceased.[8][9][12][13] Seafloor spreading stopped at the end of the Jurassic, about 145–150 million years ago.
During the late Jurassic through early Cretaceous, the basin experienced a period of cooling and subsidence of the crust underlying it. The subsidence was the result of a combination of crustal stretching, cooling, and loading. Initially, the combination of crustal stretching and cooling caused about 5–7 km (3.1–4.3 mi) of tectonic subsidence of the central thin transitional and oceanic crust. Because subsidence occurred faster than sediment could fill it, the basin expanded and deepened.[8][13][14]
Later, loading of the crust within the basin and adjacent coastal plain by the accumulation of kilometers of sediments during the rest of the Mesozoic and all of the Cenozoic further depressed the underlying crust to its current position about 10–20 km (6.2–12.4 mi) below sea level. Particularly during the Cenozoic, a time of relative stability for the coastal zones,[15] thick clastic wedges built out the continental shelf along the northwestern and northern margins of the basin.[8][13][14]
To the east, the stable Florida Platform was not covered by the sea until the latest Jurassic or the beginning of Cretaceous time. The Yucatán Platform was emergent until the mid-Cretaceous. After both platforms were submerged, the formation of carbonates and evaporites has characterized the geologic history of these two stable areas. Most of the basin was rimmed during the early Cretaceous by carbonate platforms, and its western flank was involved during the latest Cretaceous and early Paleogene periods in a compressive deformation episode, the Laramide Orogeny, which created the Sierra Madre Oriental of eastern Mexico.[16]
In 2014, Erik Cordes of Temple University and others discovered a brine pool 3,300 feet (1,000 m) below the gulf's surface, with a circumference of 100 feet (30 m) and 12 feet (3.7 m) feet deep, which is four to five times saltier than the rest of the water. The first exploration of the site was unmanned, using Hercules and in 2015 a team of three used the deep-submergence vehicle Alvin. The site cannot sustain any kind of life other than bacteria, mussels with a symbiotic relationship, tube worms and certain kinds of shrimp. It has been called the "Jacuzzi of Despair". Because it is warmer than the surrounding water (65 °F or 18 °C compared to 39 °F or 4 °C), animals are attracted to it but cannot survive once they enter it.[17]
The Gulf of Mexico is 41 percent continental slope, 32 percent continental shelf, and 24 percent abyssal plain with the greatest depth of 12,467 feet in the Sigsbee Deep.[18] Seven main areas are given as:[citation needed]
As early as the Maya civilization, the Gulf of Mexico was used as a trade route off the coast of the Yucatán Peninsula and present-day Veracruz.
Although the Spanish voyage of Christopher Columbus was credited with the discovery of the Americas by Europeans, the ships in his four voyages did not reach the Gulf of Mexico. Instead, the Spanish sailed into the Caribbean around Cuba and Hispaniola.[19] The first alleged European exploration of the Gulf of Mexico was by Amerigo Vespucci in 1497. Vespucci is purported to have followed the coastal land mass of Central America before returning to the Atlantic Ocean via the Straits of Florida between Florida and Cuba. However, this first voyage of 1497 is widely disputed, and many historians doubt that it took place as described.[20] In his letters, Vespucci described this trip, and once Juan de la Cosa returned to Spain, a famous world map was produced.
In 1506 Hernán Cortés took part in the conquest of Hispaniola and Cuba, receiving a large estate of land and indigenous slaves for his effort. In 1510 he accompanied Diego Velázquez de Cuéllar, an aide of the governor of Hispaniola, in his expedition to conquer Cuba. In 1518 Velázquez put him in command of an expedition to explore and secure the interior of Mexico for colonization.
In 1517 Francisco Hernández de Córdoba discovered the Yucatán Peninsula. This was the first European encounter with an advanced civilization in the Americas, with solidly built buildings and a complex social organization which they recognized as being comparable to those of the Old World; they also had reason to expect that this new land would have gold. All of this encouraged two further expeditions, the first in 1518 under the command of Juan de Grijalva, and the second in 1519 under the command of Hernán Cortés, which led to the Spanish exploration, military invasion, and ultimately settlement and colonization known as the Conquest of Mexico. Hernández did not live to see the continuation of his work: he died in 1517, the year of his expedition, as the result of the injuries and the extreme thirst suffered during th