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Continents. Mr. Lewis. What is a continent?. A large unbroken land mass completely surrounded by water. 7 Continents Total. Pangaea.
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Continents Mr. Lewis
What is a continent? • A large unbroken land mass completely surrounded by water. • 7 Continents Total
Pangaea • Have you ever noticed how South America and Africa seem to fit together? If you have, you aren't alone. Sir Francis Bacon first noticed this peculiarity in the 17th century.
Today, scientists believe that 200 million years ago the Earth's continents were joined together to form one gigantic super continent, called Pangaea. As the rock plates that the continents sit on moved, the super continent broke up and began to move apart.
This "continental drift" is far from over! The Earth's surface is constantly moving and reforming, but so slowly that you or I can't observe it ourselves. Only by taking very small measurements over a long period of time can scientists tell something is happening.
Evidence Supporting Continental Drift • The Earth's crust is constantly moving, both vertically and horizontally, at rates of up to several inches a year. A widely-held theory that explains these movements is called "plate tectonics." It was developed in the mid 1960s by geophysicists. The term "plate" refers to large rigid blocks of the Earth's surface which appear to move as a unit. These plates may include both oceans and continents. When the plates move, the continents and ocean floor above them move as well. Continential Drift occurs when the continents change position in relation to each other.
The Shapes Match • The continents look as if they were pieces of a giant jigsaw puzzle that could fit together to make one giant super-continent. The bulge of Africa fits the shape of the coast of North America while Brazil fits along the coast of Africa beneath the bulge.
The Plants and Animals Match Both side share the same fossils in certain areas
The Rocks Match • Broad belts of rocks in Africa and South America are the same type. These broad belts then match when the end of the continents are joined. • The Ice Matches • Rocks show that glaciers that created the landscape have similarities on matching continents
Interesting Facts about Continents • There are no deserts in Europe • Australia has only 1 country, Australia. • The continents are slowly moving. • There are no countries in Antarctica. The US and many other countries operate science stations there, but no one owns the land. • Asia & Europe are separated by Ural Mtns.
Continents by Size • Asia – 45 Million Square KM • Africa – 30 Million Square KM • North America – 24 Million Square KM • South America – 18 Million Square KM • Antarctica – 13 Million Square KM • Europe – 10 Million Square KM • Australia – 8 Million Square KM
Continents by Population • Asia – 3 Billion 674 Million • Africa – 778 Million • Europe – 732 Million • North America – 483 Million • South America – 342 Million • Australia – 31 Million • Antarctica - 0