Structure & Composition of the Earth

1. Structure & Composition of the Earth 4.a. Compare & contrast the lithosphere & the asthenosphere. (DOK 1) Composition, density, & location of continental crust & oceanic crust Physical nature of the lithosphere with the asthenosphere How the lithosphere responds to tectonic forces

2. Bellwork1/27 Sean is studying the advantages of selective breeding in plants. He made the following list of possible advantages: 1) Can produce corn that attracts grasshoppers 2) Can develop grass that can grow with less water 3) Can develop wheat that can grow in different types of soil 4) Can produce oranges that are not affected by freezing temperatures Which items on the list provide logical arguments in favor of selective breeding? A. 1, 2, 3 B. 2, 3, 4 C. 2, 4 D. 3, 4

3. Bellwork 1/29 Tineapedis is a disease caused by a fungus. It affects mainly external body parts and not internal systems. Which of these could be a symptom of tineapedis? F. Difficulty breathing G. Pain in the intestines H. Headaches and dizziness J. Swollen and itching skin LOOK OVER YOUR NOTES!

4. The layersof the earth • Order of the Earth’s interior from the surfaceto the center: • Crust • Mantle • Outer core • Inner core

5. The crust • This is the layer you liveon • The crust is the most widely studied& understoodlayer of the Earth • Like the skinof an apple

6. The crust • Very thinin comparison to the other 3 layers of the Earth • 3-5miles thick under the ocean • Oceaniccrust • Thinnestpart of the crust is under the ocean • About 25 miles thick under the continents • Continentalcrust • Thickestpart of the crust is under mountain ranges

7. The crust • Broken into many pieces called plates • The plates “float” on the soft, plastic mantlethat is very hot! • Temperatures range from atmospherictemperature near the surface to 1600degrees Fahrenheit near the mantle • Thinnestlayer of the Earth

8. The crust • Composed to 2basic rock types: • Basalt • Volcanic lava rock • Oceanic crust • Granite • Continental crust • Basalt rock is much denser& heavierthan granite

9. The lithosphere • Located in the crust& the upper layer of the mantle • Rigid& brittlerock

10. The asthenosphere • Just below the lithosphere • Located in the upper part of the mantle • Plastic& flowing • Moves the platesof the Earth

11. The mantle • Located under the crust • Largestlayer • 1800miles thick • Very hot& denserock • Contains the asthenosphere& part of the lithosphere

12. The mantle • Layers of rockflow like asphaltunder a heavy weight • Due to the great temperaturedifferences from the bottom to the top of the mantle • Movementof the mantle is the reason the platesof the Earth move • The Asthenosphere • Temperature near the top of the mantle: 1600°F • Temperature near the bottom of the mantle: 4000°F

13. The outercore • Temperatures starting at 4000°F • So hot that the metalsin it are all in the liquidstate • Located 1800miles beneath the crust • 1400miles thick • Composed of 2 metals: • Nickel • Iron

14. The innercore • Temperatures& pressuresare so great that the metalsare squeezedtogether and are not able to moveabout like a liquid • Forced to vibrate in place as a solid • Begins about 4000miles beneath the crust • 800miles thick • Temperatures reach 9000°F • Pressures are 45 million pounds per square inch • This is 3 million times the air pressure at sea level

15. Facts about the inner & outer core • The inner core -- combined with the outer core -- provide the magnetic field that surrounds the earth. • The spin of the earth causes a rotation of the inner core. • The spin of the liquid outer core around the mostly-iron inner core creates the magnetic field.

16. Earth’s formation & composition • Many geologist believe that as the Earth cooled, the heavier, densermaterials sank to the center and the lightermaterials rose to the top • Scientists are concerned that the increasinglevels of CO2in the atmosphere could cause overall heatingof the Earth’s interior • Geologists drill through the oceaniccrust in their attempt to reach the mantlebecause it is thinner than the continentalcrust

17. Earth’s formation & composition • As Earth’s depth increases, the density, temperature& pressurealso increases

18. Deformation of earth’s crust • Earth’s crust can be deformedthrough: • Faulting– a break or crack along which rocks move • Folding– a bend in a rock Folding Faulting

19. Write down these questions…. • What are the 4 layers of the Earth? • What 2 types of rock is the crust composed of? • Which type of rock is found in the continental crust? • Which type of rock is found in the oceanic crust? • What part of the Earth is classified as rigid and brittle? • How thick is the mantle? • What are the 2 parts of the core? • What temperature does the inner core reach? • What factors increase as the Earth’s depth increases? • What are the two ways the Earth’s crust can become deformed? • Describe the outer core. • What layer of the Earth is the thickest? • What layer of the Earth is the thinnest? • What part of the crust is the thickest? • What part of the crust is the thinnest? • What part of the Earth is classified as plastic and flowing? • What is faulting? • What is folding? • What state is the inner core in? • What layer of the Earth is like the skin of an apple?