Earth’s Landforms Chapter 1 Lesson 1
Where do Landforms come from? • Plate tectonics • Large, slow moving plates that make up Earth’s surface. When moved, they carry continents and the ocean floors!
Where do Landforms come from? • PANGEA!!! • SUPERCONTINENT! Continental drift is what broke Pangea up into the seven continents.
Where do Landforms come from? • Mountains: • Formed when plates push together, crumble and fold. Also when plates push together and one moves over the other. • Ex. Himalayas, Cascade Mts.
Where do Landforms come from? • Earthquakes….. • Caused by the movement of tectonic plates. Most common around fault (break in Earth’s surface where movement can occur). • Ex. San Andreas Fault
THINK ABOUT THIS…… • Two cars driving VEEERRRRYYYYY SLLLOOOWWW bump into one another. Do the passengers in the car feel the bump? • DUHHHH. Now multiply the size of those cars by 100,000 (tectonic plates). Will the bump feel larger or smaller?????
Volcanoes • FORM: • When two plates push together and one goes up and the other goes down. Lower plate melts into magma. • KINDS OF VOLCANOES • Shield volcano, cinder-cone mountain • SHAPED EARTH • Add land when the lava cools and hardens
THINK ABOUT THIS…… • Water on the stove… • Water gets hotter and hotter (tectonic plate) until it……. BOILS!! (volcanic eruption)
EARTH’S SURFACE • Weathering • Process of breaking up rocks into smaller pieces called sediment. • Caused by wind, water, ice, plants, heating/cooling • Wind and water are major forms of weathering http://player.discoveryeducation.com/index.cfm?guidAssetId=3A0506DF-ADE0-4A6D-9626-75712CE1520F
Erosion: • Process of moving sediment from one place to another • Deposition • Process of dropping sediment into a new location • Deposits add to the floodplain (the land next to a river) http://player.discoveryeducation.com/index.cfm?guidAssetId=3A0506DF-ADE0-4A6D-9626-75712CE1520F
People Shape the Land • People use floodplains for farming • Settle near water…..why? • Reshape waterways • Ex. Building dams, creating lakes • Direct water into dry places • Irrigation How else do people affect the shape of the land??? P. 25
GROUP QUESTIONS • HOW DO PLATE TECTONICS CHANGE THE SHAPE OF THE LAND? (3 WAYS) • HOW DOES WEATHERING AFFECT THE LAND? • WHATS THE DIFFERENCE BETWEEN EROSION AND DEPOSITION? • HOW DO VOLCANOS CHANGE THE LAND AROUND THEM?