Gulf of Mexico map

Geography

The Gulf of Mexico covers about 1.6 million km², making it the ninth-largest body of water in the world. It is nearly enclosed: the only openings are the Straits of Florida (to the Atlantic) and the Yucatán Channel (to the Caribbean), 217 km wide between Cabo Catoche and Cuba. The continental shelf is broad off Florida, Texas and the Yucatán (the Campeche Bank), but drops steeply into the Sigsbee abyssal plain in the centre.

Water shallower than 200 m covers about a third of the basin: the Campeche Bank reaches 250 km north of the Yucatán shore, and the West Florida Shelf is as wide. The shelf almost vanishes off central Veracruz, then levels into the Sigsbee Plain, one of the flattest surfaces on the planet.

How the basin formed

The Gulf is a Jurassic rift basin. By about 160 million years ago seafloor spreading was pushing the Yucatán block away from what is now Texas, rotating it counter-clockwise into place. While the young basin was cut off from the ocean, evaporation laid down the Louann Salt, a bed several kilometres thick, which later sediment buried. Salt is lighter than the rock above it and flows under pressure, so it has been rising ever since as domes and sheets that arch and seal the sandstones around them, the trap that holds most of the oil and gas in the northern Gulf and the Bay of Campeche. The Sigsbee Escarpment is the front of one such sheet.

The Chicxulub crater and the ring of cenotes

Under the northern rim of the Yucatán Peninsula and the shelf offshore lies the Chicxulub crater, about 180 km across, left 66 million years ago by an asteroid roughly 10 km wide — the impact tied to the extinction at the end of the Cretaceous. Nothing shows at the surface; it lies under a kilometre of younger limestone, found by Pemex geophysicists mapping gravity anomalies in the 1970s and tied to the extinction boundary in 1991. Its centre is near Chicxulub Puerto, east of Progreso. The one trace above ground is the Ring of Cenotes, an arc of sinkholes 170 km across following the buried rim, where shattered rock collapses more readily than the limestone around it — the best-known groundwater of the Yucatán Peninsula.

Currents and hurricanes

Water enters through the Yucatán Channel as the Loop Current, swings north — some years almost to the Mississippi delta, other years barely past Cuba — and leaves through the Straits of Florida to become the Gulf Stream. Every six to eleven months the loop pinches off a warm-core eddy 200 to 300 km wide that drifts west across the basin. The eddies hold warm water far deeper than the Gulf around them, so a hurricane crossing one cannot cool the sea beneath it and often intensifies quickly. Hurricane season runs June–November; storms enter from the Caribbean via the Yucatán Channel or form over the warm central Gulf, and the climate map shows the tracks.

Mexican Gulf coast, north to south

Those states are covered on the Gulf Coast region map, and the rivers feeding the basin on the rivers map.

US Gulf coast

Texas (Brownsville, Corpus Christi, Houston–Galveston), Louisiana (New Orleans, the Mississippi delta), Mississippi, Alabama (Mobile) and Florida (Tampa, the Keys). The Mississippi delivers about 90% of the river water entering the Gulf. It also carries the nitrogen and phosphorus washed off the farmland of the interior, feeding a summer algal bloom off Louisiana that strips oxygen from the bottom water as it decays. The hypoxic zone that results, measured every July since 1985, commonly covers around 15,000 km² and reached about 22,700 km² in 2017.

Reefs, fish and the shrimp fleet

Shrimp and red snapper are the main fisheries. The Mexican shrimp fleet trawls the muddy shelf out of Tampico, Alvarado, Ciudad del Carmen and Campeche, and the Campeche Bank carries Mexico's largest octopus fishery, worked on hand lines between August and December; menhaden is the largest US catch by weight. Reefs inside the Gulf are few, the largest being Alacranes, 130 km north of Progreso. At Cabo Catoche, the north-east corner of the Yucatán where the Gulf meets the Caribbean, the Mesoamerican Reef begins and runs 1,000 km south past Cancún, Cozumel and Belize to Honduras, the second-longest barrier reef system in the world. The beaches map follows that shore.

Offshore oil

The Bay of Campeche holds Mexico's main offshore fields (Cantarell, Ku-Maloob-Zaap), and the US side has over 1,800 platforms. Cantarell, named after the fisherman who reported oil surfacing in his nets in 1971, was producing about 2.1 million barrels a day by 2004 before declining steeply and giving up first place to Ku-Maloob-Zaap. Two blowouts mark the record. Ixtoc I, in shallow water off Ciudad del Carmen, blew out on 3 June 1979 and flowed for 290 days until capped in March 1980, releasing roughly 3 million barrels. Deepwater Horizon, in 1,500 m of water 66 km off Louisiana, exploded on 20 April 2010, killed 11 workers and released about 4.9 million barrels before the well was sealed that September.

Ports around the basin

Veracruz, founded in 1519, is Mexico's oldest and busiest general-cargo port. Altamira handles containers, steel and petrochemicals; Coatzacoalcos anchors the petrochemical belt and the rail corridor across the Isthmus of Tehuantepec; Dos Bocas in Tabasco is an oil terminal with a refinery inaugurated in 2022. The US–Mexico border meets the Gulf between Brownsville and Matamoros; the Mississippi ports and Houston handle far more tonnage than any port on the Mexican side.

Questions about the Gulf of Mexico

Which states border the Gulf of Mexico?

Five Mexican states — Tamaulipas, Veracruz, Tabasco, Campeche and Yucatán — and five US states: Texas, Louisiana, Mississippi, Alabama and Florida. Cuba's north-west coast closes the basin.

How deep is the Gulf of Mexico?

The Sigsbee Deep, in the central basin about 320 km south-east of the Texas coast, reaches roughly 4,384 m (14,383 ft). Average depth is about 1,615 m.

Is the Gulf of Mexico part of the Atlantic Ocean?

Yes. It is a marginal sea of the Atlantic, connected to it by the Straits of Florida and to the Caribbean by the Yucatán Channel. The Loop Current enters through the Yucatán Channel and exits to become the Gulf Stream.

Where is the Chicxulub crater?

Buried about a kilometre deep under the northern edge of the Yucatán Peninsula and the shelf offshore, centred near Chicxulub Puerto just east of Progreso. Nothing of the 66-million-year-old crater is visible except the arc of sinkholes above its rim.

Was the Gulf of Mexico renamed?

In 2025 the US federal government adopted “Gulf of America” for its own official use. Mexico, international bodies and the International Hydrographic Organization continue to use Gulf of Mexico, which is the name used on this map.