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

Bellwork 1/26 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

The layers of the earth Order of the Earth’s interior from the surface to the center: Crust Mantle Outer core Inner core

The crust This is the layer you live on The crust is the most widely studied & understood layer of the Earth Like the skin of an apple

The crust Very thin in comparison to the other 3 layers of the Earth 3-5 miles thick under the ocean Oceanic crust Thinnest part of the crust is under the ocean About 25 miles thick under the continents Continental crust Thickest part of the crust is under mountain ranges

The crust Broken into many pieces called plates The plates “float” on the soft, plastic mantle that is very hot! Temperatures range from atmospheric temperature near the surface to 1600 degrees Fahrenheit near the mantle Thinnest layer of the Earth

The crust Composed to 2 basic rock types: Basalt Granite Volcanic lava rock Oceanic crust Granite Continental crust Basalt rock is much denser & heavier than granite

The lithosphere Located in the crust & the upper layer of the mantle Rigid & brittle rock

The asthenosphere Just below the lithosphere Located in the upper part of the mantle Plastic & flowing Moves the plates of the Earth

The mantle Located under the crust Largest layer 1800 miles thick Very hot & dense rock Contains the asthenosphere & part of the lithosphere

The mantle Layers of rock flow like asphalt under a heavy weight Due to the great temperature differences from the bottom to the top of the mantle Movement of the mantle is the reason the plates of the Earth move The Asthenosphere Temperature near the top of the mantle: 1600°F Temperature near the bottom of the mantle: 4000°F

The outer core Temperatures starting at 4000°F So hot that the metals in it are all in the liquid state Located 1800 miles beneath the crust 1400 miles thick Composed of 2 metals: Nickel Iron

The inner core Temperatures & pressures are so great that the metals are squeezed together and are not able to move about like a liquid Forced to vibrate in place as a solid Begins about 4000 miles beneath the crust 800 miles thick Temperatures reach 9000°F Pressures are 45 million pounds per square inch This is 3 million times the air pressure at sea level

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.

Earth’s formation & composition Many geologist believe that as the Earth cooled, the heavier, denser materials sank to the center and the lighter materials rose to the top Scientists are concerned that the increasing levels of CO2 in the atmosphere could cause overall heating of the Earth’s interior Geologists drill through the oceanic crust in their attempt to reach the mantle because it is thinner than the continental crust

Earth’s formation & composition As Earth’s depth increases, the density, temperature & pressure also increases

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

Write down these questions…. 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? 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?

Bellwork 1/27 Tinea pedis 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 tinea pedis? F. Difficulty breathing G. Pain in the intestines H. Headaches and dizziness J. Swollen and itching skin

Classwork Complete Layers of the Earth worksheet packet. If you finish before the bell rings, you may read a book or work on something from another class.

Bellwork 1/28 List the layers of the Earth in order from the surface to the interior. Study your notes!