Golfo dei Poeti

The Gulf of Mexico () is the ninth largest It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. The shape of its basin is roughly oval and is approximately 810 nautical miles (1,500�km) wide and filled with sedimentary rocks and debris. It is part of the Atlantic Ocean and is connected to it through the Florida Straits between the U.S. and Cuba, and with the Caribbean Sea (with which it forms the American Mediterranean Sea) via the Yucatan Channel between Mexico and Cuba. With this narrow connection to the Atlantic, the Gulf experiences very small tidal ranges. The size of the Gulf basin is approximately 615,000 mi² (1.6 million km²). Almost half of the basin is shallow continental shelf waters. At its deepest it is 14,383�ft (4,384 m) at the Sigsbee Deep, an irregular trough more than 300 nautical miles (550�km) long. The basin contains a volume of roughly 660 quadrillion gallons (2.5 × 10¹⁵ m³). It was probably formed approximately 300 million years ago as a result of the seafloor sinking. It is one of the world's warmest bodies of water.

cite web

url=http://www.epa.gov/gmpo/about/facts.html
title=General Facts about the Gulf of Mexico
publisher=
accessdate=2006-12-27

Extent

The International Hydrographic Organization defines the southeast limit of the Gulf of Mexico as follows:

A line joining Cape Catoche Light () 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 eastern end of Florida Bay, all the narrow waters between the Dry Tortugas and the mainland being considered to be within the Gulf.

Geology

in the Gulf of Mexico Little is known about the geologic history of the Gulf of Mexico Basin before Late Triassic time. Some authors have postulated the presence of a basin in the area during most of Paleozoic time, but most evidence seems to indicate that Paleozoic rocks do not underlie most of the Gulf of Mexico basin and that the area was, at the end of Paleozoic time, part of the large supercontinent of Pangea, the result of the collision of several continental plates. The present Gulf of Mexico basin is believed to have had its origin in Late Triassic time as the result of rifting within the North American Plate as it began to crack and drift away from the African and South American plates. Rifting probably continued through Early and Middle Jurassic time with the formation of "stretched" or "transitional" continental crust throughout the central part of the basin. Intermittent advance of the sea into the continental area from the west during late Middle Jurassic time resulted in the formation of the extensive salt deposits such as the Louann Salt. It appears that the main drifting episode, during which the Yucatan block moved southward and separated from the North American Plate and true oceanic crust formed in the central part of the basin, took place during the early Late Jurassic, after the formation of the salt deposits. In 2002 geologist Michael Stanton published a speculative essay suggesting an impact origin for the Gulf of Mexico at the close of the Permian, which could have caused the Permian–Triassic extinction event. Since Late Jurassic time, the basin has been a stable geologic province characterized by the persistent subsidence of its central part, which probably came about first because of thermal cooling and later because of sediment loading as the basin filled with thick prograding clastic wedges along its northwestern and northern margins, particularly during the Cenozoic. To the east, the stable Florida platform was not covered by the sea until the latest Jurassic or the beginning of Cretaceous time. The Yucatan 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 Tertiary in a compressive deformation episode, the Laramide Orogeny, which created the Sierra Madre Oriental of eastern Mexico. Today, there are 7 main areas of the gulf:
Gulf of Mexico Basin, which contains the Sigsbee Deep and can be further divided into the continental rise, the Sigsbee Abyssal Plain, and the Mississippi Cone.
Northeast Gulf of Mexico, which extends from just east of the Mississippi Delta near Biloxi to the eastern side of Apalachee Bay.
South Florida Continental Shelf and Slope, which extends along the coast from Apalachee Bay to the Straits of Florida and includes the Florida Keys and Dry Tortugas.
Campeche Bank, which extends from the Yucatan Straits in the east to the Tabasco–Campeche Basin in the west and includes Arrecife Alacran.
Bay of Campeche, which is an isthmian embayment extending from the western edge of Campeche Bank to the offshore regions just east of the port of Veracruz.
Western Gulf of Mexico, which is located between Veracruz to the south and the Rio Grande to the north.
Northwest Gulf of Mexico, which extends from Alabama to the U.S.-Mexico border.

History

European exploration

and Rita. Although Katrina cooled waters in its path by up to 4 °C, they had rebounded by the time of Rita's appearance. Although Christopher Columbus was credited with the discovery of the Americas by Europeans, the ships in his four voyages never reached the Gulf of Mexico. Instead, Columbus sailed into the Caribbean around Cuba and Hispaniola. The first European exploration of the Gulf of Mexico was by Amerigo Vespucci in 1497. He followed the coastal land mass of Central America before returning to the Atlantic Ocean via the Straits of Florida between Florida and Cuba. In his letters, Vespucci described this trip, and once Juan de la Cosa returned to Spain, a famous world map, depicting Cuba as an island, was produced. In 1506, Hernán Cortés took part in the conquest of Hispaniola and Cuba, receiving a large estate of land and Indian 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 the voyage, and disappointed in the knowledge that Diego Velázquez had given precedence to Grijalva as the captain of the next expedition to Yucatán. In 1523, Ángel de Villafañe sailed toward Mexico City, but was shipwrecked en route along the coast of Padre Island, Texas, in 1554. When word of the disaster reached Mexico City, the viceroy requested a rescue fleet and immediately sent Villafañe marching overland to find the treasure-laden vessels. Villafañe traveled to Pánuco and hired a ship to transport him to the site, which had already been visited from that community. He arrived in time to greet García de Escalante Alvarado (a nephew of Pedro de Alvarado), commander of the salvage operation, when Alvarado arrived by sea on July 22, 1554. The team labored until September 12 to salvage the Padre Island treasure. This loss, in combination with other ship disasters around the Gulf of Mexico, gave rise to a plan for establishing a settlement on the northern Gulf Coast to protect shipping and more quickly rescue castaways. As a result, the expedition of Tristán de Luna y Arellano was sent and landed at Pensacola Bay on August 15, 1559. On December 11, 1526, Charles V granted Pánfilo de Narváez a license to claim what is now the Gulf Coast of the United States, known as the Narváez expedition. The contract gave him one year to gather an army, leave Spain, be large enough to found at least two towns of 100 people each, and garrison two more fortresses anywhere along the coast. On April 7, 1528, they spotted land north of what is now Tampa Bay. They turned south and traveled for two days looking for a great harbor the master pilot Miruelo knew of. Sometime during these two days, one of the five remaining ships was lost on the rugged coast, but nothing else is known of it. In 1697, Pierre Le Moyne d'Iberville sailed for France and was chosen by the Minister of Marine to lead an expedition to rediscover the mouth of the Mississippi River and to colonize Louisiana which the English coveted. Iberville's fleet sailed from Brest on 24 October 1698. On January 25, 1699, Iberville reached Santa Rosa Island in front of Pensacola founded by the Spanish; he sailed from there to Mobile Bay and explored Massacre Island, later renamed Dauphin Island. He cast anchor between Cat Island and Ship Island; and on February 13, 1699, he went to the mainland, Biloxi, with his brother Jean-Baptiste Le Moyne de Bienville. On May 1, 1699, he completed a fort on the north-east side of the Bay of Biloxi, a little to the rear of what is now Ocean Springs, Mississippi. This fort was known as Fort Maurepas or Old Biloxi. A few days later, on May 4, Pierre Le Moyne sailed for France leaving his teenage brother, Jean-Baptiste Le Moyne, as second in command to the French commandant.

Geography

watershed drains into the Gulf of Mexico. The Gulf of Mexico's eastern, northern, and northwestern shores lie along the US states of Florida, Alabama, Mississippi, Louisiana, and Texas. The US portion of the Gulf coastline spans , receiving water from thirty-three major rivers that drain 31 states.

cite web

url=http://www.epa.gov/water/waterplan/documents/05guidance.htm#gulf
title= National Water Program Guidance: FY 2005
publisher=epa.gov
accessdate=2007-01-21
The Gulf's southwestern and southern shores lie along the Mexican states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatán, and the northernmost tip of Quintana Roo. The Mexican portion of the Gulf coastline spans . On its southeast quadrant the Gulf is bordered by Cuba. It supports major American, Mexican and Cuban fishing industries. The outer margins of the wide continental shelves of Yucatán and Florida receive cooler, nutrient-enriched waters from the deep by a process known as upwelling, which stimulates plankton growth in the euphotic zone. This attracts fish, shrimp, and squid. River drainage and atmospheric fallout from industrial coastal cities also provide nutrients to the coastal zone. The Gulf Stream, a warm Atlantic Ocean current and one of the strongest ocean currents known, originates in the gulf, as a continuation of the Caribbean Current-Yucatán Current-Loop Current system. Other circulation features include the anticyclonic gyres which are shed by the Loop Current and travel westward where they eventually dissipate, and a permanent cyclonic gyre in the Bay of Campeche. The Bay of Campeche in Mexico constitutes a major arm of the Gulf of Mexico. Additionally, the gulf's shoreline is fringed by numerous bays and smaller inlets. A number of rivers empty into the gulf, most notably the Mississippi and Rio Grande rivers in the northern gulf, and the Grijalva and Usumacinta rivers in the southern gulf. The land that forms the gulf's coast, including many long, narrow barrier islands, is almost uniformly low-lying and is characterized by marshes and swamps as well as stretches of sandy beach. The Gulf of Mexico is an excellent example of a passive margin. The continental shelf is quite wide at most points along the coast, most notably at the Florida and Yucatán Peninsulas. The shelf is exploited for its oil by means of offshore drilling rigs, most of which are situated in the western gulf and in the Bay of Campeche. Another important commercial activity is fishing; major catches include red snapper, amberjack, tilefish, swordfish, and various grouper, as well as shrimp and crabs. Oysters are also harvested on a large scale from many of the bays and sounds. Other important industries along the coast include shipping, petrochemical processing and storage, military use, paper manufacture, and tourism. The gulf's warm water temperature can feed powerful Atlantic hurricanes causing extensive human death and other destruction as happened with Hurricane Katrina in 2005. In the Atlantic, a hurricane will draw up cool water from the depths and making it less likely that further hurricanes will follow in its wake (warm water being one of the preconditions necessary for their formation). However, the Gulf is shallower; when a hurricane passes over the water temperature may drop but it soon rebounds and becomes capable of supporting another tropical storm. The Gulf is considered aseismic; however, mild tremors have been recorded throughout history (usually 5.0 or less on the Richter scale). Earthquakes may be caused by interactions between sediment loading on the sea floor and adjustment by the crust.

cite web

url=http://www.clas.ufl.edu/users/russo/florida_eq.html
title=Earthquakes in the Gulf of Mexico
publisher=
accessdate=2006-12-27

2006 earthquake

On September 10, 2006, the U.S. Geological Survey National Earthquake Information Center reported that a strong earthquake, ranking 6.0 on the Richter scale, occurred about west-southwest of Anna Maria, Florida, around 10:56 AM EDT. The quake was reportedly felt from Louisiana to Florida in the Southeastern United States. There were no reports of major damages, injuries or casualties. The earthquake was described by the USGS as a midplate earthquake, the largest and most widely felt recorded in the past three decades in the region. According to the September 11, 2006 issue of ''The Tampa Tribune'', earthquake tremors were last felt in Florida in 1952, recorded in Quincy, northwest of Tallahassee.

Maritime boundary delimitation agreements

Cuba and Mexico: Exchange of notes constituting an agreement on the delimitation of the exclusive economic zone of Mexico in the sector adjacent to Cuban maritime areas (with map), of July 26, 1976. Cuba and United States of America: Maritime boundary agreement between the United States of America and the Republic of Cuba, of December 16, 1977. Mexico and United States of America: Treaty to resolve pending boundary differences and maintain the rio Grande and Colorado river as the international boundary, of November 23, 1970; Treaty on maritime boundaries between the United States of America and the United Mexican States (Caribbean Sea and Pacific Ocean), of May 4, 1978, and Treaty between the Government of the United States of America and the Government of the United Mexican States on the delimitation of the continental shelf in the Western Gulf of Mexico beyond 200 Nautical Miles, of June 9, 2000.

Biota

Various biota include chemosynthetic communities near cold seeps and nonchemosynthetic communities such as bacteria and other microbenthos, meiofauna, macrofauna, and megafauna (larger organisms such as crabs, sea pens, crinoids, and demersal fish and cetaceans including endangered ones) are living in the Gulf of Mexico. The Gulf of Mexico yields more finfish, shrimp, and shellfish annually than the south and mid-Atlantic, Chesapeake, and New England areas combined. The Smithsonian Institution Gulf of Mexico holdings are expected to provide an important baseline of understanding for future scientific studies on the impact of the Deepwater Horizon oil spill.

Pollution

There are frequent "red tide" algae blooms

cite web

url=http://www.tulane.edu/~bfleury/envirobio/enviroweb/DeadZone.htm
title=The Gulf of Mexico Dead Zone and Red Tides
publisher=
accessdate=2006-12-27
that kill fish and marine mammals and cause respiratory problems in humans and some domestic animals when the blooms reach close to shore. This has especially been plaguing the southwest and southern Florida coast, from the Florida Keys to north of Pasco County, Florida. In June 1979, the ''Ixtoc I'' oil platform in the Bay of Campeche suffered a blowout leading to a catastrophic explosion, which resulted in a massive oil spill that continued for nine months before the well was finally capped. This was ranked as the largest oil spill in the Gulf of Mexico until the ''Deepwater Horizon'' oil spill in 2010. In July 2008, researchers reported that the dead zone that runs east-west, from near Galveston, Texas, to near Venice, Louisiana, was about , nearly the record. Between 1985 and 2008, the area roughly doubled in size. There are 27,000 abandoned oil and gas wells beneath the Gulf. These have generally not been checked for potential environmental problems.

''Deepwater Horizon'' explosion and oil spill

On April 20, 2010, the ''Deepwater Horizon'' oil platform, located in the Mississippi Canyon about 40 miles off the Louisiana coast, suffered a catastrophic explosion; it sank a day-and-a-half later. and estimates continue to increase. On July 15, 2010, BP announced that the leak stopped for the first time in 88 days.

''Vermilion 380'' explosion and oil spill

On September 2, 2010, an explosion occured on ''Vermilion 380'', a platform in the Gulf of Mexico owned by Mariner Energy. All 13 crew members on board were rescued. The lat/long coordinates of the platform is 28.060010°, -92.271206° (http://www.gomr.boemre.gov/homepg/fastfacts/platform/master.asp Area=Vermilion and Block=380). It was installed 1/1/1980, the water depth is 340m.

See also

Brine pool
Charlotte Harbor Estuary, Florida
Gulf Coast
Hypoxia
Jack 2 (a test well in the deep waters of the Gulf of Mexico)
Orca Basin
Outer Continental Shelf
Territorial evolution of the Caribbean

References

External links

Resource Database for Gulf of Mexico Research
6.0 Earthquake reported on 9-10-2006
GSA article on Gulf seismic activity from 1982
EPA factsheet on hypoxia
Gulf of Mexico hypoxia
Gulf of Mexico Integrated Science
Northern Gulf Institute

Golfo dei Poeti