One of the most fascinating scientific topics is the study of the 5 oceans and 7 continents. The reason for this is that, even though most of us study the world’s oceans and continents at school, very often we found ourselves in conversations where people do not seem to agree on the exact number of continents and oceans.
When we contemplate the whole globe as one great dewdrop, striped and dotted with continents and islands, flying through space with other stars all singing and shining together as one, the whole universe appears as an infinite storm of beauty. – John Muir
Can you name the 7 continents of the world:
- North America
- South America
And even when we know that the correct number is 7 continents and 5 oceans, it is more challenging than it may initially seem to name them all.
Why does studying continents and oceans so important? Because if you want to understand Planet Earth, you really need to understand the planet’s surface. Most of the surface is actually covered in water (about 70%). More than 95% of it is salt water. This saltwater surface has been organized into 5 distinct oceans, whereas the relatively small land surface we have organized into 7 distinct continents.
|Four Continents||Five Continents||Six Continents||Six Continents (Alt.)||Seven Continents|
|Australia||Antarctica||America||South America||North America|
What Are Continents?
At its most basic, we could say that continents are the areas of our planet’s surface that is not underwater.
Anyone with a sharp mind would immediately pick holes in that definition. Why? Because the shapes and boundaries of continents are always changing. As oceans rise, continents become, by that definition, smaller.
But not only that, the land masses that we now call continents are the result of shifts that broke up a supercontinent that scientists have called Pangea. It would be a mistake to think that the shifts that created the 7 continents have stopped. For these shifts continue and will create new continents in the distant future (we are talking about hundreds of millions of years from now).
Although the number seven is the most common for continents there are two other widely spread and fairly accepted number of continents.
It used to be believed that there were only 5 continents. Indeed some people still believe to be the case. The five continents would be the following:
Other people believe that there are 6 continents, as follows:
- Australia (Oceania).
But, by far, the most commonly agreed number of continents is 7:
- North America.
- South America.
- Australia (Oceania).
Whether you believe there are 5, 6, or 7 continents would largely depend on when and where (i.e., which country) you went to school.
Some people would also take the landmass that encompasses Europe and Asia as one whole known as Eurasia. There is also a common misconception concerning Australia (the continent) and Australia (the country). The continent known indistinctly as Australia or Oceania should not be confused with the country of Australia, for Australia (the continent) includes Australia, Tasmania, New Guinea, and New Zealand, as well as Polynesian and Micronesian islands.
Let’s look at each of the 7 continents individually:
This continent has a land mass of 11,670,0000 (square miles) or 28,489,869 (square kilometers).
Africa is the second continent on the planet both in terms of size and population (1,119,307,147 as of 2016).
It is estimated that about 15% of the world’s population currently live in Africa.
With the equator traversing the African continent roughly through its middle, Africa has distinct climatic regions. The areas immediately north and south of the equator have climates that vary from warm to tropical or a combination of both. The far north and the far south are, in contrast to the central areas, relatively temperate.
Because of this climatic diversity, Africa is home to some to many different animal and insect species that are unique to the continent. Elephants, hippos, giraffes are just some of the animals that have made Africa globally famous.
From a historical perspective, Africa is hugely important as it is now credited to be the birthplace of humankind.
Present-day Africa is made up of 54 independent countries, most of which are the result of continent-wide independence and decolonization movements in the 20th century. Some of the arbitrary borders that were drawn by the former colonial overseers have resulted in bloody conflicts in many different parts of the continent.
Africa is surrounded by the Mediterranean Sea to the north, the Red Sea to the northeast, the Atlantic Ocean to the west, and the Indian Ocean to the east.
The largest city in the whole continent is Lagos, Nigeria inhabited by 15,188,780 people as of 2014.
Other large cities in Africa include Cairo, Egypt; Kinshasa, Democratic Republic of Congo; Johannesburg, South Africa; Khartoum, Sudan; Dar Es Salaam, Tanzania; and Alexandria, Egypt.
This continent has a land mass of 5,405,000 (square miles) or 12,949,940 (square kilometers).
Antarctica is, by far, the most sparsely populated continent on Earth, with a population of only 4,912 people as to 2015.
Antarctica is mostly known for being the southernmost continent on our planet. Because of its geographical position in the South Pole, Antarctica suffers the coldest temperatures on Earth, sometimes reaching -130°F (-90°C).
With those harsh weather conditions, it is hardly surprising that this continent is so sparsely populated. Its largest “city” is the McMurdo Station where, as of 2013, only 1,258 people live.
Antarctica is one of the smallest continents on Earth, only larger than Europe and Australia. But, even though, Antarctica is larger than Europe, its population is a lot smaller in size. In fact, Antarctica has the smallest population of all 7 continents.
With a land area of 17,210,000 (square miles) or 44,029,797 (square kilometers), Asia occupies about 9% of our planet’s surface.
Asia is also the most widely populated continent on Earth with a population of 4,494,302,221 as of 2016. This means that almost 60% of the world’s population lives in Asia.
Because of the sheer size of its population and the rising economies of many of its countries: India, China, South Korea, Japan, etc. makes Asia one of the most important countries in terms of the world’s economy.
The largest city in Asia is also the largest city on Earth. The city in question is Tokyo, Japan with 37,126,000 as of 2012.
Other large cities in Asia include Jakarta, Indonesia; Delhi, India; Karachi, Pakistan; Seoul, South Korea; Shanghai, China; Manila, Philipines; and Mumbai, India.
Although a continuing landmass with Europe, Asia is the part of the landmass east of an imaginary line going north from the Aegean Sea all the way to the Black Sea, then on to the North West of the Caspian Sea, the Ural River and finally ending at the Arctic Ocean.
The Pacific Ocean is to the east of Asia, the Indian Ocean to the south and the Arctic Ocean to the north.
This continent has a land area of 2,970,000 (square miles) or 5,179,976 (square kilometers). As of 2016, its population is 39,901,000 making it the second least populated continent on Earth only behind Antarctica.
In Australia, the largest city is Sydney which, as of 2016, has a population of 5,029,768.
Other large cities in Australia include Melbourne, Victoria; Brisbane, Queensland; Auckland, New Zealand; and Perth, Western Australia.
Australia is also known for being the remotest continent on the planet as it is the farthest from any of the other 6 continents. Australia is also the smallest continent although, paradoxically harbors one of largest countries on earth (Australia) in terms of size if not population.
When talking about this continent, we must always combat the common misconception that conflates the Commonwealth nation of Australia and, specifically, its mainland, with the whole continent, which also includes New Zealand (with its two large islands), Tasmania, and several other smaller islands.
Australia (also sometimes known as Oceania) is located between the Indian Ocean to the East and the Pacific Ocean to the West.
This continent has long fascinated botanists and biologists due to the uniqueness of the hundreds of different plant and animal species that are unique to this continent. The fact that the overwhelming percentage of animal and plant specifies present in Australia cannot be found anything else in the world is due to Australia’s remoteness.
Apart from its many different animal and plant species, this continent is also globally famous because it is home to the biggest reef in the world: The Great Barrier Reef.
With a land area of 3,931,000 (square miles) or 7,769,964 (square kilometers), Europe is the smallest continent on Earth.
It is the westernmost area of the Eurasian landmass, which only makes up about 7% of the world’s land area.
The largest city in Europe is Istanbul, Turkey with a population of 14,657,434. Interestingly, the largest European city is also partially in Asia. Turkey is one of those nations that straddle two different continents (Russia is another important example). But its main city and Europe’s largest city also straddles both continents.
Other large cities in Europe include Moscow, Russia; London, United Kingdom; Saint Petersburg, Russia; Berlin, Germany; Madrid, Spain; Kieve, Ukraine; Rome, Italy; and Paris, France.
Europe is the most densely populated continent on Earth with a populated mainland stretching east from the Atlantic Ocean to the Ural Mountains. The continent is bordered by the Mediterranean and Black seas to the south, and the Antarctic Ocean to the north. Sicily, Corsica, Sardinia, The British Isles, or the Balearic Islands are also densely populated islands that are part of Europe.
Europe harbors both the largest and the smallest nations on Earth. The largest one is Russia (although most of its territory is, in fact, in Asia), and the smallest one is Vatican City in the Italic Peninsula.
Many different European civilizations have shaped the world because their historical impact not just in Europe itself but also in every other continent on earth due to imperialistic expansion and its subsequent colonialism. Testament to this is that European languages (chiefly, English, Spanish, Portuguese, French, and Russian) are widely spoken in every other continent, mostly in North and South America (Spanish, English, French), Africa (English, French, Portuguese, Spanish), Asia (Russian, English, French, Portuguese), and Australia (English), etc.
This continent has a land area of 9,540,000 (square miles) or 23,309,892 (square kilometers). As of 2016, its population is 579,014,000. This population is spread over 23 different countries including three that occupy vast lands, such as Canada, The United States, and Mexico.
This means that around 8% of the world’s population lives in this landmass, which is approximately 17% of the planet’s landmass.
Although ethnically diverse, its population is mostly of European descent, most of which live in the United States of America, Mexico, and Canada but also in the Caribbean islands and the nations of Central America.
The largest city in North America is Mexico City with a population of 20,400,000. This also makes it the third largest city in the world behind Tokyo, Japan and São Paulo, Brazil.
Other largest cities in North America include New York City, New York; Los Angeles, California; Chicago, Illinois; Boston, Massachusetts; Toronto, Ontario; Dallas-Fort Worth, Texas; Miami, Florida; Philadelphia, Pennsylvania.
North America presents a great variety of climate, from the extreme cold in Alaska, Canada, and most of the northern section of the United States, to tropical and subtropical on the East coast, or desert conditions in the southwest of the United States, and the northwest of Mexico.
North America is also home to the world’s largest lakes, straddling Canada and United States.
Mostly due to the global economic powerhouses that are Canada and, mostly, the United States, North America is the richest continent in the world. This is in terms of Gross domestic product (GDP) per capita, which is the largest of all the continents.
This continent has a land area of 6,888,000 (square miles) or 15,539,928 (square kilometers). Its population is 414,332,000 as of 2015.
The biggest city in South America is São Paulo in Brazil with a population of 21,242,939. This makes São Paulo the second largest global city, only behind Tokyo in Japan.
Other largest cities in South America include Lima, Peru; Bogotá, Colombia; Rio de Janeiro, Brazil; Santiago, Chile; Caracas, Venezuela; Buenos Aires, Argentina; Salvador, Brazil; Brasilia, Brazil; Fortaleza, Brazil; Guayaquil, Ecuador; and Quito, Ecuador.
This continent is the southern area of the landmass it shares with North America. Like North America, South America borders with the Atlantic Ocean to the West and the Pacific to the East. South America stretches all the way to the South Pole where its nearest neighboring continent, Antarctica, is located.
Despite its vastness, there are only twelve independent nations in South America. By far, the largest of them all is Brazil. Not only is Brazil the biggest country in the continent, it also has the largest population of them all.
Because of the Amazon River, which is the longest river in the world, only followed by the Nile in Africa; and the Andes mountains, which is the longest mountain range in the world, South America has a fascinating level of biodiversity.
The ethnic diversity of South America is the result of southern migration of indigenous North American populations, followed by the arrival of Europeans who initially where the conquistadors, explorers, and colonists from Spain and Portugal and then immigrants from those countries and other European nations, and, chiefly, in Brazil the import of slaves from South Saharan Africa.
The 5 Oceans:
Although for hundreds of years, the global consensus was that there were 4 oceans, in the 21st century this number was officially increased to 5 when in the year 2000 the International Hydrographic Organization decided almost unanimously to include the Southern Ocean.
So, the list of the 5 oceans is now as follows:
- The Pacific Ocean.
- The Atlantic Ocean.
- The Indian Ocean.
- The Arctic Ocean.
- The Southern Ocean.
This ocean covers an area of 63,784,077 (square miles) or 165,200,000 (square kilometers).
The Pacific ocean covers the whole area between the eastern coasts of two continents: Australia (Oceania) and Asia, all the way to the west coasts of North and South America.
The Pacific ocean was discovered by Europeans in 1520 when Portuguese explorer Magellan accessed it from South America for the first time.
“The history of exploration has never been driven by exploration. But Columbus himself was a discoverer. So was Magellan. But the people who wrote checks were not. They had other motivations”. – Neil deGrasse Tyso
Two notable facts make this ocean world famous. On the one hand, the Pacific has the longest shoreline in the world. Taking into account all the different shorelines washed by the Pacific and add them together, the Pacific has 84,3000 miles or 135,663 kilometers of shoreline.
The other notable fact about the Pacific is that its sea floor had the deepest point in the whole planet. Back in 1875, the HMS Challenger discovered it around the US territory of Guam, specifically in the Marianas Trench. The depth of the sea floor is close to 7 miles or 11,000 meters below sea level.
With an area of 41,081,270 (square miles) or 106,400,000 (square kilometers), the Atlantic is the second largest ocean on Earth behind the Pacific.
Like the Pacific ocean, the Atlantic stretches all the way from the Arctic to the Antarctic region. It covers the area between western Europe and Africa to western North and South America.
The Atlantic includes many seas, such the Baltic, the Caribbean, the Gulf of Mexico, and the Mediterranean seas.
Europeans were able to chart this ocean fully in the 15th century when they began sailing to North and South America. This makes it, together with the eastern portion of the Indian Ocean, the oldest ocean to be chartered by Europeans.
Since then, the Atlantic has become hugely important in world trade. The Atlantic ocean has played a key role in the imperialistic and colonialist enterprises by European states (Spain, Portugal, Great Britain, France, etc.).
The fertility of the warm waters of the North Atlantic specifically has also contributed to human development thanks to the abundance of whale sperm and cod.
Comprising the area between East Africa, South East Asia and the east of Australia, the Indian Ocean covers an area of 28,400,130 (square miles) or 73,556,000 (square kilometers).
Washing the shores of some of the world’s most important civilizations, the Indian Ocean has been crucial in trade for several hundreds of years.
Historically, the Indian Ocean has been fundamental in the trade between Europe and Asia. Western (and, indeed, global) medicine and food preservation have greatly progressed thanks to the amazing spices that are found in the countries around the Indian Ocean, including its many islands.
Europeans recognized the importance of these species centuries ago, so the sailed throughout the Indian Ocean in search of them.
Both the smallest and the shallowest ocean, the Arctic Ocean covers an area of 5,400,015 (square miles) or 13,986,000 (square kilometers).
The Arctic Ocean is surrounded by North America, Asia, and Europe.
This ocean, which is mostly covered in ice for most of the year, includes the Barents, North and Hudson Bay seas.
Despite the freezing temperatures and the fact that most of the area covered in ice, different Northern civilizations from the three continents that surround it have inhabited for hundreds of years.
Perhaps this was what encouraged Europeans explorers to attempt to use the Arctic Ocean to access Asia. This was supposed to be a shorter pass that the already exploited one of the Indian Ocean. However, because of its incredibly harsh climatic conditions, this exploring enterprise was an utter failure.
The area covered by the Southern Ocean is 7,848,299 square miles or 20,327,000 square kilometers. This makes it the penultimate ocean in terms of size only in front of the Arctic Ocean.
The Southern Ocean is the “youngest” ocean on Earth as it was only considered it as such in the year 2000. Before then it was merely considered a southern extension of the Atlantic, the Pacific, and the Indian oceans. This is because its waters are joined to the north with the southern portions of the Indian, the Atlantic, and the Pacific Oceans.
The Southern Ocean is hugely important in global weather patterns, and not just those affecting the southern hemisphere.
When it comes to the study of the continents and oceans on planet Earth, we need to recognize that the number of continents and oceans (and sometimes the terminology we use) has changed and new perspectives are put forward and new consensuses are reached by the scientific community. And, although, we must always acknowledge any possible discrepancies we have to always work on the basis of the current scientific consensus.
And right now in 2017, the scientific consensus is that there are 7 continents and 5 oceans.