Bell Ringer 1 Answer the following questions with
Bell Ringer 1) Answer the following questions with a paragraph: -What causes earthquakes? Why do some earthquakes kill so many people in some countries, while in other countries they only injure a few people? What kinds of safety measures can be used to lessen the destruction from a major earthquake? 2) Make the following corrections to your vocabulary sheet by crossing out the terms for #6 -#9, then replacing them with the following terms: #6. Weathering #7. Erosion #8. Glaciation #9. Humus
INTERNAL AND EXTERNAL FORCES Two main forces that shape the Earth: • Internal – Plate Tectonics • External - Erosion
INTERNAL FORCES
What are the layers of the Earth’s interior? 4 layers 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 Together, they generate the Earth’s magnetic field.
What is the Mantle? Surrounds the core Soft layer of molten (melted) rock called magma. • Once magma reaches the surface, it is called lava.
What is the Crust? Thin layer of rock at the earth’s surface Material on ocean floor is different from that on the continents.
How old is the Earth? 4. 5 to 6 Billion years, based on current scientific estimates. Surface constantly changes, due to Plate Tectonics, the movement of pieces of the crust. Proof: matching fossils on coasts fit like puzzle pieces
What is theory of Continental Drift? 1912 theory by Alfred Wegener Continental plates move around, so the Earth looked different in the past. Earth once had a supercontinent (all connected) called “Pangea”.
What are Plate Boundaries? • Tectonic plates are separated, and collide along these boundaries. The boundaries are called faults.
What type of movements are there? The movement along faults is characterized in four main ways, by their motion: 1. Divergent – plates spread apart 2. Convergent: Subduction – one plate goes under 3. Convergent: Collision – both plates crumple up 4. Transform – plates slide next to each other
What is an Earthquake? • Faults move, causing earth to shake. • Center of quakes is epicenter. • Measured with instrument called a seismograph. • Quakes are rated from 1 to 10 on the Richter Scale. 3 -4 is where you would start to notice it… 8+ is really bad news.
What is the “Ring of Fire”? A continuous band of volcanoes located around the rim of the Pacific Ocean
EXTERNAL FORCES
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? Examples? 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 1. Texture of the soil 2. Amount of organic material in the soil
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