section_path: Geography
section_name: Geography
paragraph_text: Geography
  
  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 coastline spans 2,700 km (1,700 miles), receiving water from 33 major rivers that drain 31 states and 2 Canadian provinces, and consisting of the coastline from the southern tip of Florida and the Florida Keys to the U.S.–Mexican border between Brownsville, Texas, and Matamoros, Tamaulipas. The Mexican coastline spans 2,200 km (1,400 miles), consisting of the coastline from the US border to the Cabo Catoche Light (near Cancún) at the northern tip of the Yucatán Peninsula. Cuba has only 100–400 km (60–250 miles) of official gulf coastline, along its northern land boundary. The southwestern and southern shores of the gulf lie along the Mexican states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatán, and the northernmost tip of Quintana Roo. 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 a permanent cyclonic gyre in the Bay of Campeche and anticyclonic gyres, which are shed by the Loop Current and travel westwards, where they eventually dissipate. The Bay of Campeche constitutes a major arm of the Gulf of Mexico. Numerous bays and smaller inlets fringe the gulf's shoreline. Streams that empty into the gulf include the Mississippi River and the Rio Grande 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 defined by marshes, swamps, and 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, notably at the Florida and Yucatán Peninsulas. The shelf is exploited for its oil through offshore drilling rigs, most of which are situated in the western gulf and 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 bays and sounds. Other important industries along the coast include shipping, petrochemical processing and storage, military use, paper manufacture, and tourism.
  
  The gulf is considered aseismic; however, mild tremors have been recorded throughout history (usually 5.0 or less on the Richter magnitude scale). Interactions between sediment loading on the sea floor and adjustment by the crust may cause earthquakes. On September 10, 2006, the U.S. Geological Survey National Earthquake Information Center reported that a magnitude 6.0 earthquake occurred about 400 km (250 miles) west-southwest of Anna Maria, Florida. The quake was reportedly felt from Louisiana to Florida. There were no reports of damage or injuries. Items were knocked from shelves and seiches were observed in swimming pools in parts of Florida. The earthquake was described by the USGS as an intraplate earthquake, the largest and most widely felt recorded in the past three decades in the region. According to The Tampa Tribune on the following day, earthquake tremors were last felt in Florida in 1952, recorded in Quincy, 32 km (20 miles) northwest of Tallahassee.
  
  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 coastline spans 2,700 km (1,700 miles), receiving water from 33 major rivers that drain 31 states and 2 Canadian provinces, and consisting of the coastline from the southern tip of Florida and the Florida Keys to the U.S.–Mexican border between Brownsville, Texas, and Matamoros, Tamaulipas. The Mexican coastline spans 2,200 km (1,400 miles), consisting of the coastline from the US border to the Cabo Catoche Light (near Cancún) at the northern tip of the Yucatán Peninsula. Cuba has only 100–400 km (60–250 miles) of official gulf coastline, along its northern land boundary. The southwestern and southern shores of the gulf lie along the Mexican states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatán, and the northernmost tip of Quintana Roo. 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 a permanent cyclonic gyre in the Bay of Campeche and anticyclonic gyres, which are shed by the Loop Current and travel westwards, where they eventually dissipate. The Bay of Campeche constitutes a major arm of the Gulf of Mexico. Numerous bays and smaller inlets fringe the gulf's shoreline. Streams that empty into the gulf include the Mississippi River and the Rio Grande 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 defined by marshes, swamps, and 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, notably at the Florida and Yucatán Peninsulas. The shelf is exploited for its oil through offshore drilling rigs, most of which are situated in the western gulf and 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 bays and sounds. Other important industries along the coast include shipping, petrochemical processing and storage, military use, paper manufacture, and tourism.
  
  The gulf is considered aseismic; however, mild tremors have been recorded throughout history (usually 5.0 or less on the Richter magnitude scale). Interactions between sediment loading on the sea floor and adjustment by the crust may cause earthquakes. On September 10, 2006, the U.S. Geological Survey National Earthquake Information Center reported that a magnitude 6.0 earthquake occurred about 400 km (250 miles) west-southwest of Anna Maria, Florida. The quake was reportedly felt from Louisiana to Florida. There were no reports of damage or injuries. Items were knocked from shelves and seiches were observed in swimming pools in parts of Florida. The earthquake was described by the USGS as an intraplate earthquake, the largest and most widely felt recorded in the past three decades in the region. According to The Tampa Tribune on the following day, earthquake tremors were last felt in Florida in 1952, recorded in Quincy, 32 km (20 miles) northwest of Tallahassee.