The Atlantic Ocean

The Atlantic Ocean is the world’s second largest body of water. It makes up about aquarter of the Earth’s water surface. It has been a major route for explorationand trade over the past centuries.

The Atlantic Ocean lies between the Americas in the west and the continents of Europe and Africa in the east.

The North Atlantic has many smaller seas that are a part of it: the Gulf of Mexico between North and Central America and the North Sea between the British Isles and the European mainland are the largest. The Atlantic Ocean is connected with theMediterranean Sea through the 14 km wide Strait of Gibraltar.

Geology

The Atlantic Ocean was formed when the supercontinent Pangaea broke up about 200 million years ago. Europe and Africa started to drift away from today’s Americas. 

The ocean is divided into three areas.  The continental shelf extends up to a few hundred kilometers into the open ocean and is about 100 to 200 meters deep.Beyond the shelf the continental slope drops slowly to a depth of about 4,000 meters, where the ocean floor spreads across most of the Atlantic.

There are many islands that are located in the Atlantic Ocean. The biggest – Cuba, Great Britain, Ireland and Newfoundland – lie near the coastal regions.

A giant mountain range, the Mid-Atlantic Ridge, rises in north-south direction along the middle of the Atlantic Ocean.  It is the borderlinebetween the European and the American plates. New seafloor is constantly created in this area by magma which rises up through thecrust of the Earth. Sea floor spreads in an outward direction and pushes the Americas on one side and Europe and Africa on the other away from each other.  The plates move at a speed of about 3 cm a year.

The area around the ridge is dominated by volcanic activity and earthquakes. When the mountain range emerges above the ocean’ssurface it forms islands. Iceland, the largest of these volcanic islands, was created only 20,000 years ago.

Climate

Most of the Atlantic Ocean has a mild and moderate climate because ocean water has a balancing effect on temperatures.  When cold air mixes with warm water it causes fog, which sometimes poses a big problem for ships. In the Northern Atlantic icebergs break away from ice sheets and drift southwards.

Iceberg that broke off Antarctica

Constant winds blow in all parts of the Atlantic Ocean. Trade winds blow from the Tropic of Cancer and Capricorn to the equator. Between 35° and 60° latitude western winds blow constantly in an eastward direction. They influence the weather in Europe and other continents.

Tropical storms form near the equator, causing the creation of hurricanes and cyclones which travel towards the coast and can cause a lot of damage.

Ocean Water

Major currents control the flow of water in the Atlantic Ocean.  The Gulf Streamoriginates in the Gulf of Mexico and carries warm water across the northern Atlantic to the western and northern European coasts. The Labrador Current brings cold water from the polar regions along the eastern seaboard of Canada and the United States down to Washington. The Benguela Current comes from the Antarctic and brings cold water to the West African coast.

Many coastal regions are influenced by tides.  The most powerful are in northern Canada, where the difference between low and high tide can be up to 15 meters. In the Gulf of Mexico tides are only about half a meter high.

Marine Life

There is a large diversity of animal and plant life in the Atlantic Ocean. Plankton is the basic plant form in the shelf regions. It providesfood for fish and other sea animals. Corals thrive in the Caribbean Sea and other warm areas.

More than half of the world’s fishing grounds lie in the Atlantic Ocean. For many years overfishing has threatened many fish speciesin the ocean. Some of them are in danger of becoming extinct. Most of the fish live near the shelf areas of the coast.

Many animals migrate from the warmer waters of the Atlantic to colder places.  Whales live especially in the northern areas, near Greenland and Iceland.

Pollution of the Atlantic Ocean

Pollution is one of the major problems of the world’s oceans and the Atlantic is no exception. Tankers contribute to pollution by cleaning their oil containers on the high seas. Major tanker disasters have repeatedly occurred in the Atlantic. In 2010 the explosion of an oil platform in the Gulf of Mexico caused oil to leak out for over three months.

Fire on the Deepwater Horizon oil platform

Many pollutants reach the ocean through factories and industries along the major rivers.  Densely populated areas along the Rhine in Europe and the Mississippi in North America bring waste and other pollutants into the ocean.

Ships often transport heavy metal, chemicals and radioactive waste in barrels and dump them into the sea.

Age of Exploration

The Atlantic has been an area of human exploration since the Vikings started to explore the northern half of the ocean over a thousand years ago.

During the Middle Ages European merchants were looking for new routes to Asia.  Towards the end of the 15th century Europeannavigators explored the western coast of Africa. In 1498 Vasco da Gama , a Portuguese explorer, was the first to sail around the Cape of Good Hope and find his way to India.

In 1492 Christopher Columbus became the first explorer to sail to the New World. Many others followed in the next centuries. In the 16th and 17th centuries the transatlantic slave trade brought thousands of Africans to the New World.

Words

• balance = to be equal, the same
• barrel = curved container with a flat top and bottom
• beyond = further than
• borderline = where two objects meet
• cause = lead to
• century = a hundred years
• connect = link
• constantly = all the time
• continental shelf = edge of a continent that falls down to the bottom of the ocean
• contribute = cause
• coral = hard material formed from the bones of very small sea animals
• crust = the hard outer layer of the Earth
• current = movement of ocean water
• damage = destruction
• densely populated = many people live in a small area
• depth = how deep something is
• diversity = very many kinds of
• dominate = full of
• drift = float
• drop = go down
• dump = throw, sink
• emerge = come up
• especially = above all
• exception = something that does not follow the rules or a regular habit
• exploration = travelling around in search for something new
• extend = reach out to
• extinct = die out
• fog = cloudy air near the ground which is difficult to see through
• giant = very big
• heavy metal = metal that has a high density, like gold; many are poisonous
• high seas = the oceans around the world that do not belong to any country; the area that is far away from land
• ice sheet = area of thick ice in the polar regions
• influence = to have an impact on
• latitude = the distance north or south of the equator measured in degrees
• leak = flow
• located = to be found
• mainland = the main part of land that forms a country ; not the islands
• major = very important
• migrate = to travel regularly from one part of the world to another
• moderate = not too warm and not too cold
• occur = happen
• originate = come from
• outward = away from
• overfishing = when you take too many fish from the ocean , so that its population becomes too low
• plankton = very small forms of animal and plant life that live in the water  and are eaten by fish
• plate = one of the very large sheets of rock that form the Earth’s surface
• pollutant = substance or material that makes water or air dirty
• pose = create, cause
• provide = offer
• quarter = 25% of something
• radioactive waste= harmful or dangerous substances that are left over in a nuclear reactor
• repeatedly = over and over again
• ridge = long area of high land
• seaboard = part of a country near the sea
• species = groups, kinds
• speed = how fast something is
• spread = to cover an area
• strait = narrow passage of water between two  areas of land
• surface = the top part of an object
• threaten = to become a danger to
• thrive = live, exist
• tide =   the regular rising and falling of the level of the sea
• trade = to buy and sell something
• trade winds = tropical wind that blows towards the equator
• Tropic of Cancer = line around the world that is 23,5 ° north of the equator
• Tropic of Capricorn = line around the world that is 23,5 ° south of the equator