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.
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.
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!
Term Part of Speech Definition Encyclopedic Entry access Noun
ability to use.
the art and science of cultivating the land for growing crops (farming) or raising livestock (ranching).
Encyclopedic Entry: agriculture bay Noun
body of water partially surrounded by land, usually with a wide mouth to a larger body of water.
Encyclopedic Entry: bay border Verb
to exist on the edge of a boundary.
light wind or air current.
outer boundary of a shore.
having to do with the buying and selling of goods and services.
to use up.
rocky outermost layer of Earth or other planet.
Encyclopedic Entry: crust dam Noun
structure built across a river or other waterway to control the flow of water.
dead zone Noun
area of low oxygen in a body of water.
Encyclopedic Entry: dead zone delta Noun
the flat, low-lying plain that sometimes forms at the mouth of a river from deposits of sediments.
Encyclopedic Entry: delta drainage system Noun
series of pipes, gutters, or other waterways used to carry off excess water.
having to do with money.
community and interactions of living and nonliving things in an area.
Encyclopedic Entry: ecosystem enormous Adjective
to transport goods to another place for trade.
object or service that serves a human need or want.
portion of an ocean or sea that penetrates land.
Encyclopedic Entry: gulf 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.
part of a body of water deep enough for ships to dock.
Encyclopedic Entry: harbor 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.
to bring in a good or service from another area for trade.
activity that produces goods and services.
small indentation in a shoreline.
body of land surrounded by water.
Encyclopedic Entry: island 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.
place where a river empties its water. Usually rivers enter another body of water at their mouths.
Encyclopedic Entry: mouth nation Noun
political unit made of people who share a common territory.
Encyclopedic Entry: nation nutrient Noun
substance an organism needs for energy, growth, and life.
Encyclopedic Entry: nutrient ocean Noun
large body of salt water that covers most of the Earth.
Encyclopedic Entry: ocean oil deposit Noun
natural accumulation of petroleum, usually underground or under the ocean floor.
to begin or start.
to push through.
piece of land jutting into a body of water.
Encyclopedic Entry: peninsula petroleum Noun
fossil fuel formed from the remains of ancient organisms. Also called crude oil.
introduction of harmful materials into the environment.
Encyclopedic Entry: pollution port Noun
place on a body of water where ships can tie up or dock and load and unload cargo.
Encyclopedic Entry: port portion Noun
part of a whole.
to lower or lessen.
any area on Earth with one or more common characteristics. Regions are the basic units of geography.
Encyclopedic Entry: region 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.
solid material transported and deposited by water, ice, and wind.
Encyclopedic Entry: sediment seep Verb
to slowly flow through a border.
transportation of goods, usually by large boat.
severe weather indicating a disturbed state of the atmosphere resulting from uplifted air.
narrow passage of water that connects two larger bodies of water.
Encyclopedic Entry: strait strategic Adjective
important part of a place or plan.
process of one tectonic plate melting, sliding, or falling beneath another.
land permanently saturated with water and sometimes covered with it.
Encyclopedic Entry: swamp tectonic plate Noun
massive slab of solid rock made up of Earth's lithosphere (crust and upper mantle). Also called lithospheric plate.
to scare or be a source of danger.
to develop and be successful.
buying, selling, or exchanging of goods and services.
trading center Noun
settlement or business area where goods and services are exchanged.
a gently sloping depression in the ocean floor.
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.
Encyclopedic Entry: upwelling vary Verb
huge and spread out.
necessary or very important.
area of land covered by shallow water or saturated by water.
Encyclopedic Entry: wetland