What Is The Largest Continent

Asia Image Credit: NASA's Blue Marble project

[/caption]

There are a few different ways to answer ‘what is the largest continent’. The first is by area and another is by population. By area, Asia is the largest continent at 44,391,162 square km. It is also the largest by population with more than 4 billion people.

There is quite a bit of debate as to how many continents there are. Some areas of the world combine Asia and Europe into one continent called Eurasia. In that case, the continent of Eurasia would be the biggest continent in both area and population.

The debate as to how many continents there are is based in the basic, yet confusing definition of what a continent is. A continent is understood to be large, continuous, discrete mass of land, ideally separated by an expanse of water. Many of the seven most commonly recognized continents identified by convention are not discrete landmasses separated by water. The criteria of being large is used arbitrarily. Greenland has an area of 2,166,086 square km and is considered an island. Australia has an area of 7,617,930 square km, but it is called a continent. The distinct landmass separated by water criteria is sometimes ignored in the case of Europe and Asia. All of the criteria are a consensus, not a rule, so some countries teach a different number of continents.

Whether you have been taught that there are 6 or 7 continents, you need to know that here have been changing numbers of continents since the formation of the Earth. There have been anywhere from 1 to 7 continents. As the tectonic plates have shifted, the continents have broken apart and collided together again. The Earth’s tectonic plates are still moving, so it is hard to predict how many continents there will be in 500,000 years, 1 million years, and so forth.

The answer to ‘what is the largest continent’ is pretty cut and dry. If you consider that there are seven continents, then Asia is the largest in area and population. If you combine Europe and Asia into the continent of Eurasia, it is still the largest by area and population.

We have written many articles about Continent for Universe Today. Here’s an article about the number of continents in the Earth, and here’s an article about the Continental Drift Theory.

If you’d like more info on continents, check out NASA’s Solar System Exploration Guide on Earth. And here’s a link to NASA’s Earth Observatory.

We’ve also recorded an episode of Astronomy Cast all about planet Earth. Listen here, Episode 51: Earth.

Source:
Wikipedia

What Is A Continent

Map of Earth

[/caption]
You know that there are 7 continents(6 if you were taught geography in Europe) right now, but do you really know the definition of what is a continent? There are many different, and confusing definitions of what a continent is. The most widely accepted one says that a continent is defined as a large, continuous, discrete mass of land, ideally separated by an expanse of water. This definition somewhat confuses things. Many of the current continents are not discrete landmasses separated by water. The word large leads to arbitrary classification: Greenland, with a surface area of 2,166,086 km2 is considered the world’s largest island, but Australia with a land mass of 7,617,930 km2 is a continent. The qualification that each be a continuous landmass is disregarded because of the inclusion of the continental shelf and oceanic islands and is contradicted by classifying North and South America and Asia and Africa as continents, without a natural separation by water. This idea continues if the land mass of Europe and Asia is considered as two continents. Also, the Earth’s major landmasses are surrounded by one, continuous World ocean that has been divided into a number of principal ‘oceans’ by the land masses themselves and various other geographic criteria.

The number of continents has changed throughout the evolution of the Earth. Plate tectonics and continental drift have forced changes on continental composition. The planet began with one single land mass(the Mesezoic Era). This continent was not suddenly there. It was the result of partially solidified magma being smashed together by plate tectonics and continental drift. Those forces remain at work today.

To further confuse things, different parts of the world teach different versions of the continents. The seven-continent model is usually taught in China and most English speaking countries. A six continent model combining Europe and Asia is preferred by the geographic community, the former parts of the USSR, and Japan. Another six continent model combining North and South America is taught in Latin America and most of Europe.
The answer to ‘what is a continent’ is more by convention than strict definition. Hopefully, this will help to clear some of the confusion that you had before you started reading this article.

We have written many articles about the continents for Universe Today. Here’s an article about the biggest continent, and here’s an article about the continental drift theory.

If you’d like more info on Earth’s continents, check out NASA’s Solar System Exploration Guide on Earth. And here’s a link to NASA’s Earth Observatory.

We’ve also recorded an episode of Astronomy Cast all about planet Earth. Listen here, Episode 51: Earth.

Source: Wikipedia

Continental Drift Theory

In elementary school, every teacher had one of those pull-down maps of the world to teach geography. On occasion, I thought the largest land masses, known as continents, reminded me of pieces in a jigsaw puzzle. They just seemed like they should fit together, somehow. Not until I took Earth Science, in 8TH grade, did I discover my earlier idea was correct. My teacher explained about a phenomenon, known as, The Continental Drift Theory. He said that some German had the same idea I did.

The man my teacher mentioned, Alfred Wegener (Vay gen ner), developed The Continental Drift Theory in 1915. He was a meteorolgist and a geologist. His theory basically said that, at one time, there existed one large supercontinent, called, Pangea, pan, meaning all-encompassing, and, gea, meaning the Earth. He went on to suggest that, seismic activity, such as erthquakes, volcanic eruptions, and tsunamis, also called tidal waves, eventually created fissures, or cracks in the Earth. As these fissures became larger, longer, and deeper, 7 pieces of Pangea broke off and, over time, drifted to the places where they are now. These 7 large pieces of land are what we now call, continents. They are: North America; South America; Europe; Asia; Africa; Antarctica; and, Australia. Some people refer to the country as Australia, and the continent as, Oceania. They do this because there are other countries, such as New Zealand, included as a part of that particular continent.

At the time, people thought Wegener was, well, “nuts.” Only in the 1950s did people begin to take his idea seriously. According to the United States Geological Survey (the USGS), thanks to the use of the submarine and the technology developed during World War II, scientists learned a lot about the Ocean Floor. When they found out that it was not as old as the Crust, or Surface, of the Earth, sicentists had to ask themselves, “Why?”

The answers have to do with earthquakes, volcanoes, and magnetism. When the Earth cracks, molten magma, from the middle of the Earth, known as the Mantle, works its way to the surface, where it becomes known as, lava. That lava melts away some of the older layers; then, when the water cools that lava, it forms a new layer of Earth. For that reason, if scientists tried to determine the age of the Earth from samples taken from the Ocean Floor, they would be very wrong.

That same equipment also helped scientists recognize that heavy amounts of basalt, a volcanic rock that contains high amounts of iron, could throw compasses off course. This information provided one more pieces to the puzzle. Now, scientists recognize that the North and South Poles were not always where they currently are.

The Earth changes every day. Although we might not notice it, the continents move all the time. We don’t only revolve, or spin, around the Sun. We also drift across the surface of the planet.

The United States Geological Survey has some excellent information on this topic.

University Today has some other fabulous material about this and related topics, including Earth, Barely Habitable?, by Fraser Cain begin_of_the_skype_highlighting     end_of_the_skype_highlighting, and Interesting Facts About Planet Earth.

You can also read or listen to Episode 51: Earth, of Astronomy Cast, also produced by Universe Today.

Sources:
http://en.wikipedia.org/wiki/Continental_drift
http://www.ucmp.berkeley.edu/history/wegener.html
http://pubs.usgs.gov/gip/dynamic/historical.html