Earth’s Forces Warm-Ups • In August 2011 , Hurricane Irene hit the east coast of the US and did millions of dollars worth of damage. • If you were the mayor of a city, which could be affected by a hurricane, how would you protect the city and its citizens? • Write at least 5 sentences
How many different layers make up the Earth’s structure? What are they? • Inner Core • Outer Core • Mantle • Crust
What is the Earth’s Core? • Solid metallic Inner Core • Liquid metallic Outer Core • Both made of iron and nickel
What is the Mantle? • Surrounds the core • Soft layer of molten (melted) rock called magma!!!
What is the Crust? • Thin layer of rock at the earth’s surface
What is the Atmosphere? • Layer of gases surrounding the earth
What is the Lithosphere? • Solid rock portion of the Earth’s surface
What is the Hydrosphere? • All the water elements of the Earth • Oceans • Seas • Rivers • Lakes
What is the Biosphere? • Where plants and animals live • Includes: Atmosphere, Lithosphere, & Hydrosphere
What is Plate Tectonics? • Movement of large plates (crust) above magma in the mantle • What proof is there? • Fossils, plants and animals along coastlines of separated continents
What is the theory of Continental Drift? • 1912 theory by Alfred Wegener • Earth once had a supercontinent (all connected) • Called “Pangea”
Plate Boundaries Plates collide, separate, and shift along these boundaries
What type of movements are there? • Divergent • Convergent: Subduction • Convergent: Collision • Transform
Example: Transform Boundary San Andreas Fault-California What type of movement takes place? • Transform Movement
How are Earthquakes measured? Seismograph Measures the size of waves created by the earthquake
Review: Plate Tectonics • Plate Movement • Spreading – usually ocean floor • Sub-duction – form Volcanoes • Collision – form mountains • Sliding/Shearing – cause earthquakes • Boundaries – where plates meet • Divergent- moving apart • Convergent - collide • Transform – slide past each other
Volcanoes • What is the Ring of Fire? • Most volcanoes located around the rim of the Pacific Ocean
What is Weathering? Types of Weathering are… • Mechanical – When rocks and other minerals are broken into smaller pieces. • Chemical – When minerals are changed completely when they mix with water and air. Like metal changing to rust.
What is Wind Erosion? • Loess is wind-blown silt, sand, and clay. • Can form sand dunes 100’s of feet deep!
What is Water Erosion? • Precipitation • Mudslides • Avalanche
What is Glacial Erosion? • Glaciation – changes in a landform made from a slowly moving sheet of ice (glacier) • Moraines – rocks left behind after a glacier moves • Creates new valleys, hills, or ridges
What is soil, how is it made? • Through the process of weathering and erosion of rocks • Humus – quality of soil • Texture of the soil • Amount of organic material in the soil