Gulf of Mexico is a great curved arm of the Atlantic Ocean. It is almost surrounded by the United States and Mexico. The gulf forms a huge ocean basin that covers nearly 700,000 square miles (1,800,000 square kilometers). It is 800 miles (1,300 kilometers) long (north to south) and 1,100 miles (1,770 kilometers) wide. The Yucatán Channel connects the Gulf of Mexico with the Caribbean Sea, and the Straits of Florida link it to the Atlantic Ocean. Warm gulf waters flowing through the Straits of Florida form an important Atlantic current called the Gulf Stream (see Gulf Stream ).
The low, level coastline is about 3,000 miles (4,800 kilometers) long. It has hundreds of estuaries (inlets) where fresh and salt water mix. Some of the estuaries are bordered by barrier islands, long, narrow islands running parallel to the shore. The coast has few good harbors. The best are the gulf ports of Veracruz, Mexico; Galveston, Texas; Mobile, Alabama; Pensacola and Tampa, Florida; and Havana, Cuba.
The water of the gulf is deepest (12,700 feet, or 3,871 meters) near the coast of Mexico. Most of the gulf ranges in depth from about 500 feet (150 meters) to more than 10,000 feet (3,000 meters). Along a continental shelf, the gulf has many shallow places with gently sloping beds, formed by the silt poured in by rivers.
The Mississippi is the largest river that empties into the Gulf of Mexico. Others are the Rio Grande, and the Grijalva and Usumacinta in southern Mexico. Many keys (small islands) lie in the gulf off the coasts of Florida and Yucatán.
See also Ixtoc I oil spill ; Mississippi River .
