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Geology powerpoint earth layers
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- 2. Three Layers • TheCrust • The Mantle • The Core
- 3. The Crust • Thesurface of Earth. • The thinnest layer. • Made of solid rock. • Contains all the mountains, rocks, water, soil and land features. • Contains the lithosphere, oceanic crust and continental crust. 5 – 25 miles thick
- 4. Lithosphere • Made fromthe Crust and Upper Mantle. • “Litho” means “stone” in Greek. • This is the layer in which we live because it contains the oceanic and continental crust.
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- 6. Oceanic versus Continental Crust •Oceanic Crust: • Below the ocean • Consists of basalt • Very dense • Continental Crust: • Forms and contains the large landmasses • Consists of granite • Less dense 5 – 25 miles thick 3 - 5 miles thick
- 7. The Mantle •Divided into two parts: • Upper mantle • Lower mantle. • Most of the mantle is solid rock. • The lower mantle rock is softer. • It makes up 85% of the Earth’s mass. • Temperatures can reach up to 870 C. 1,800 miles thick
- 8. Asthenosphere • Zone inthe Upper Mantle. • Lithosphere floats on top of it. • Consists of hot, plastic rock. • “Asthens” means “weak” in Greek.
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- 10. The Core • TheCore is Divided into two parts: • Outer Core • Inner Core Inner Core Outer Core
- 11. Outer vs. InnerCore Outer Core – only liquid layer! • Made up of liquid iron and nickel. • This layer creates the Earth’s magnetic field. • Temperatures can reach up to 2,200 C. Inner Core • The center of Earth. • Made up of scorching-hot iron and nickel. This layer stays solid though due to intense pressure. • This layer may also contain oxygen, sulfur and silicon. • Temperatures range between 9,000 C and 13,000 C.
- 12. Evidence How do Scientistsknow about the interior of the Earth? Two forms of evidence: • Direct evidence from rock samples • Indirect evidence from seismic waves
- 13. Theory of Plate Tectonics Theoryof Plate Tectonics • Theory that pieces of lithosphere move around on top of the asthenosphere
- 14. Plate Boundaries • Theedges of different pieces of The lithosphere meet at lines called plate boundaries
- 15. So the platesmove. Now What? •As the plates move, they produce changes in Earth’s surface, including volcanoes, earthquakes, mountain ranges, and deep- ocean trenches.
- 16. 3 Types ofPlate Boundaries Divergent Convergent Transform Divergent Transform
- 17. Divergent boundary -two plates move apart • Magma rises and creates new crust or seafloor Causes: mid- ocean ridges, rift valleys, new crust , volcanoes
- 18. Divergent Boundaries © AllRights Reserved. Diverging Africa
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- 20. • Convergent -when two tectonic plates push into one another.
- 21. Convergent Boundaries • Continentalvs. Continental • Continental vs. Oceanic • Oceanic vs. Oceanic
- 22. Continental vs. Continental •Whentwo continental crustal plates collide, the continents buckle upward and form mountains. Himalayas- Asia
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- 24. Oceanic vs. Continental •Theoceanic plate slides under the continental plate. •The continental crust crumbles and forms new mountains.
- 25. Oceanic vs. Continental •Ex: Andes mtn in S. America Cascade Mtns. in N. America- Mt. St. Helens
- 26. Oceanic vs. Oceanic •Twooceanic plates collide, one of the oceanic plates slides under the other. •also called a subduction zone
- 27. Transform boundary • Whentwo tectonic plates slide past each other horizontally Produces? Earthquakes
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- 30. How do theplates move? • CONVECTION CURRENTS • Hot material rises while cooler material near the surface sinks • Convection example
- 31. How do theplates move? • CONVECTION CURRENTS • Hot material from deep within the Earth rises while cooler material near the surface sinks
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- 34. How do weknow? • Sea-floor spreading new ocean floor is created as two lithospheric plates pull away from one another.