Continents PDF

**Continents** - Click to Listen Key Vocabulary: 1. **Continent**: One of the Earth's seven main divisions of land. 2. **Geographer**: A person who studies the Earth and its land, features, and inhabitants. 3. **Tectonic Plate**: Large pieces of Earth's crust that...

**Continents** - Click to Listen Key Vocabulary: 1. **Continent**: One of the Earth's seven main divisions of land. 2. **Geographer**: A person who studies the Earth and its land, features, and inhabitants. 3. **Tectonic Plate**: Large pieces of Earth's crust that move and interact with one another. 4. **Plate Tectonics**: The theory explaining the movement of tectonic plates and their role in forming Earth's features. 5. **Subduction**: A process where one tectonic plate moves under another. 6. **Erosion**: The process by which soil and rock are removed from the Earth's surface by wind, water, or other natural agents. 7. **Crust**: The outermost layer of the Earth. 8. **Mantle**: The layer of the Earth between the crust and the core. 9. **Core**: The central part of the Earth below the mantle. 10. **Ecosystem**: A community of living organisms and their physical environment. A continent is a large area of land. Earth has seven continents: Asia, Africa, North America, South America, Antarctica, Europe, and Australia. **Islands and Continents** When talking about continents, geographers include nearby islands. For example, Japan is part of Asia, and Greenland is part of North America. **Continental Area** All the continents together cover about 148 million square kilometers (57 million square miles). Continents make up most of Earth’s land, but some land is in islands not part of any continent. The ocean covers almost three-fourths of Earth’s surface. Each continent borders at least one ocean. Asia, the largest continent, has the longest coastlines. **Continental Shelves** The true boundaries of continents are their continental shelves. A continental shelf is a shallow area extending from the beach far into the ocean. It's part of the ocean but also part of the continent. **Cultural Differences** Continents also differ culturally. For instance, Europe and Asia are part of one large landmass called Eurasia but are divided due to cultural differences. The Ural Mountains in Russia and the Caspian and Black Seas mark the boundary between Europe and Asia. **Formation of Continents** Earth formed 4.6 billion years ago from a cloud of dust and gas. The planet’s heat melted some materials, which rose to form a crust. Heavier materials sank to form the core. Earth has three main layers: the core, the mantle, and the crust. The crust and top mantle form tectonic plates, which move around on the molten mantle due to heat from inside Earth. This movement, known as plate tectonics, helped form continents. Rocks in North America show that the oldest parts of continents formed nearly four billion years ago. Early continents grew as plates collided, causing one plate to slide under another in a process called subduction. This caused volcanic activity, forming igneous rock that built up into islands and, eventually, continents. **Moving Continents** Continents have moved over time. About 480 million years ago, they were scattered around the Equator. By 240 million years ago, they formed one large landmass called Pangaea. Around 200 million years ago, Pangaea began to break apart, forming the continents we know today. Continents continue to move slowly. North America and Europe, for example, move apart by about 2.5 centimeters (one inch) per year. **Continental Features** Continents have changed shape many times due to mountain building, weathering, erosion, and sediment build-up. All continents have mountains, plains, plateaus, and river systems. Each continent has old, stable regions and younger, more active regions. Mountains often form where tectonic plates collide, like the Himalayas in Asia. **North America** North America extends from the Aleutian Islands in Alaska to the Isthmus of Panama. It includes Greenland. The Rocky Mountains in the west and older Appalachian Mountains in the east are its major ranges. The plains between them have rich soil, making it a major agricultural area. The continent features canyons like the Grand Canyon, geysers like those in Yellowstone National Park, and large lakes like the Great Lakes. **South America** South America connects to North America by the Isthmus of Panama. It stretches from the Caribbean Sea to the Antarctic waters. The Andes, the longest mountain range in the world, run along its western edge. The Amazon River, with the largest volume of water in the world, flows through the continent. South America is home to the world’s highest waterfall, Angel Falls, and vast rainforests with diverse wildlife.