A gulf is a portion of the ocean that penetrates land. Gulfs vary greatly in size, shape, and depth. They are generally larger and more deeply indented than bays. Like bays, they often make excellent harbors. Many important trading centers are located on gulfs.

Gulfs may be formed by movements in the Earths crust. The Earths tectonic plates may rift, or break apart, creating a gulf. Or, one plate may fold under another, a process called subduction. Subduction may create a gulf by making downfolds, or troughs, in the rock under the ocean.

Gulfs are sometimes connected to the ocean by narrow passages of water called straits. Gulfs can also have wide openings and are sometimes indistinguishable from larger bodies of water.

Major Gulfs

The Gulf of Mexico, bordered by the United States, Mexico, and the island nation of Cuba, is the worlds largest gulf. It has a coastline of about 5,000 kilometers (3,100 miles). The Gulf of Mexico is connected to the Atlantic Ocean by the Straits of Florida, between Cuba and the U.S. state of Florida. It is connected to the Caribbean Sea by the Yucatn Channel, between Cuba and the Mexican peninsula of Yucatn.

The Gulf of Mexico is an important economic site for all three countries. The process of upwelling occurs near the Florida coast of the gulf, creating a rich variety of sea life. Upwelling is the process in which cold, nutrient-rich water from the bottom of the gulf is brought to the surface.

Fish and other organisms thrive in areas of upwelling. Commercial, sport, and recreational fishing thrive in the Gulf of Mexico. Oil deposits sit beneath the western Gulf of Mexico. Both Mexico (in the Bay of Campeche) and the U.S. (mainly around the coasts of Texas and Louisiana) have oil wells in the Gulf of Mexico.


The Gulf Stream, one of the most powerful ocean currents in the world, originates in the Gulf of Mexico. Gulf ports, including Houston, Texas; New Orleans, Louisiana; Veracruz, Mexico; and Havana, Cuba, continue to be important cities where goods are imported and exported by sea.

The Gulf of Mexico is also the site of strong storms. Hurricanes and other storms need warm water to develop. The Gulf of Mexico is a very warm body of water, so storms can often increase their strength. Cuba and the U.S. state of Florida are regularly hit by hurricanes on both their Atlantic and Gulf coasts.

Pollution also threatens life in the Gulf of Mexico. Oil shipping and drilling can spill tons of petroleum into the ecosystem. Two huge rivers, the Mississippi in the U.S. and the Grijalva in Mexico, empty into the gulf. Chemicals used for agriculture and industry have seeped into the water, helping to create one of the largest dead zones in the world. (A dead zone is a region where there is little oxygen or ocean life beneath the surface.)

River management has redirected the flow of the Mississippi River. Canals, dams, and drainage systems for agriculture and industry have provided power and irrigated land. They have also reduced the wetlands at the rivers mouth and delta. The Gulfs wetlands slow storms as they move toward land. The loss of these wetlands may have contributed to the destruction brought by Hurricane Katrina to the Gulf Coast between central Florida and Texas in 2005.

The Gulf of Carpentaria, on Australias northeast coast, is an inlet of the Arafura Sea. Because both the sea and the gulf are shallow, the exchange of water between the two is reduced. Sediment collects at the mouth of the gulf, forming underwater barriers. The low shore is bordered in some areas by wetlands and swamps.

This shallow gulf with a wide mouth creates the conditions for a yearly spectacle called the Morning Glory Cloud. In September and October, sea breezes from the Gulf of Carpentaria and the Arafura Sea meet and create an enormous, fast-moving cloud over the gulf. The Morning Glory Cloud can be 1,000 kilometers (621 miles) long and move at a rate of 60 kilometers per hour (37 miles per hour).

The Persian Gulf is an arm of the Arabian Sea bordered by Iran, Iraq, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emirates, and Oman. Vast deposits of petroleum in this region make the Persian Gulf strategically important. Middle Eastern countries depend on the gulf for trade and for access to the Indian Ocean. All countries that consume oil from the region, including the U.S., have a vital interest in keeping the gulf open to shipping.

gulf
The Gulf of Aqaba is named after Aqaba, a large coastal city in Jordan. It was previously named the Gulf of Eilat, a large coastal city in Israel.

Bridging the Gulf
The Middle Eastern countries of Bahrain and Qatar have reached an agreement to build the world's longest oversea bridge, which will span 40 kilometers (25 miles) over the Persian Gulf. The bridge, which is expected to be completed by 2013, will cut the travel time between the two countries from five hours to 30 minutes!

access
Noun

ability to use.

Noun

the art and science of cultivating land for growing crops (farming) or raising livestock (ranching).

Noun

body of water partially surrounded by land, usually with a wide mouth to a larger body of water.

border
Verb

to exist on the edge of a boundary.

breeze
Noun

light wind or air current.

canal
Noun

artificial waterway.

coastline
Noun

outer boundary of a shore.

commercial
Adjective

having to do with the buying and selling of goods and services.

consume
Verb

to use up.

Noun

rocky outermost layer of Earth or other planet.

dam
Noun

structure built across a river or other waterway to control the flow of water.

Noun

area of low oxygen in a body of water.

Noun

the flat, low-lying plain that sometimes forms at the mouth of a river from deposits of sediments.

drainage system
Noun

series of pipes, gutters, or other waterways used to carry off excess water.

economic
Adjective

having to do with money.

Noun

community and interactions of living and nonliving things in an area.

enormous
Adjective

very large.

export
Verb

to transport goods to another place for trade.

good
Noun

object or service that serves a human need or want.

Noun

portion of an ocean or sea that penetrates land.

Gulf Stream
Noun

warm current that starts in the Gulf of Mexico and travels along the eastern coast of the U.S. and Canada before crossing the North Atlantic Ocean.

Noun

part of a body of water deep enough for ships to dock.

hurricane
Noun

tropical storm with wind speeds of at least 119 kilometers (74 miles) per hour. Hurricanes are the same thing as typhoons, but usually located in the Atlantic Ocean region.

Hurricane Katrina
Noun

2005 storm that was one of the deadliest in U.S. history.

import
Verb

to bring in a good or service from another area for trade.

industry
Noun

activity that produces goods and services.

inlet
Noun

small indentation in a shoreline.

irrigate
Verb

to water.

Noun

body of land surrounded by water.

Middle East
Noun

region of southwest Asia and northeast Africa.

Morning Glory Cloud
Noun

weather formation that results in a very large, fast-moving cloud over some shallow gulfs and bays.

Noun

place where a river empties its water. Usually rivers enter another body of water at their mouths.

Noun

political unit made of people who share a common territory.

Noun

substance an organism needs for energy, growth, and life.

Noun

large body of salt water that covers most of the Earth.

oil deposit
Noun

natural accumulation of petroleum, usually underground or under the ocean floor.

originate
Verb

to begin or start.

penetrate
Verb

to push through.

Noun

piece of land jutting into a body of water.

Noun

fossil fuel formed from the remains of ancient organisms. Also called crude oil.

Noun

introduction of harmful materials into the environment.

Noun

place on a body of water where ships can tie up or dock and load and unload cargo.

portion
Noun

part of a whole.

reduce
Verb

to lower or lessen.

Noun

any area on Earth with one or more common characteristics. Regions are the basic units of geography.

rift
Noun

break in the Earth's crust created by it spreading or splitting apart.

river management
Noun

the art and science of controlling the flow, path, and power of rivers.

Noun

solid material transported and deposited by water, ice, and wind.

seep
Verb

to slowly flow through a border.

shipping
Noun

transportation of goods, usually by large boat.

storm
Noun

severe weather indicating a disturbed state of the atmosphere resulting from uplifted air.

Noun

narrow passage of water that connects two larger bodies of water.

strategic
Adjective

important part of a place or plan.

subduction
Noun

process of one tectonic plate melting, sliding, or falling beneath another.

Noun

land permanently saturated with water and sometimes covered with it.

tectonic plate
Noun

massive slab of solid rock made up of Earth's lithosphere (crust and upper mantle). Also called lithospheric plate.

threaten
Verb

to scare or be a source of danger.

thrive
Verb

to develop and be successful.

trade
Noun

buying, selling, or exchanging of goods and services.

trading center
Noun

settlement or business area where goods and services are exchanged.

trough
Noun

a gently sloping depression in the ocean floor.

Noun

process in which cold, nutrient-rich water from the bottom of an ocean basin or lake is brought to the surface due to atmospheric effects such as the Coriolis force or wind.

vary
Verb

to change.

vast
Adjective

huge and spread out.

vital
Adjective

necessary or very important.

Noun

area of land covered by shallow water or saturated by water.