On Earth, the land is broken into large pieces. These pieces are separated by large bodies of water called Oceans. We call some of these pieces of land Continents. A Continent is an area of land. Some continents are surrounded by oceans and other continents are connected to other continents.

On Earth we have 7 continents. They are Africa, Antarctica, Asia, Australia, Europe, North America, and South America.

UNITED STATES Some 75 percent of the more than 260 million people in the United States live in towns and cities. Yet farmers, accounting for less than 2 percent of the population, lead the world in production of soybeans and corn. NORTH AMERICA The 455 million people of North America produce more goods and consume more resources than those on any other continent. Canada and the United States share a 5,500- mile (8,850-kilometer) border, the longest and one of the friendliest anywhere.

From 1990 to 1995 the countries of Europe mushroomed from 33 to 43, most of which have access to the ocean. In these countries live 686 million people who speak some 80 languages. RUSSIA AND THE INDEPENDENT NATIONS OF THE FORMER SOVIET UNION A few years back the Soviet Union was the biggest country in the world, dominating the Eurasian landmass from the Baltic Sea to the Pacific Ocean. In 1991 the former communist colossus fragmented into Russia and 14 other countries, which are now coping with political and economic dislocation. Yet Russia remains the world's biggest nation, comprising more than 6,500,000 square miles (17,000,000 sq km).

The Structure of the Earth and Plate Tectonics

Structure of the Earth The Earth is made up of 3 main layers: – Core – Mantle – Crust Inner core Outer core Mantle Crust

The Crust This is where we live! The Earth’s crust is made of: Continental Crust - thick (10-70km) - buoyant (less dense than oceanic crust) - mostly old Oceanic Crust - thin (~7 km) - dense (sinks under continental crust) - young

If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.

Plate Tectonics The Earth’s crust is divided into 12 major plates which are moved in various directions. This plate motion causes them to collide, pull apart, or scrape against each other. Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction.

World Plates

Ireland Capital cities: London Dublin Belfast Cardiff Edinburgh