Earth’s Structure

1. Earth’s Structure What are the characteristics of the layers of the Earth?

2. Introduction • Click on the Earth below to understand the “big picture” of Earth’s layers. Pay close attention to the density demonstration.

3. Earth’s Layers • As you go through this powerpoint, you will fill out a graphic organizer on Earth’s layers. Flip back and forth from the chart to this PPT as you fill in the required information OR you can split the screen. The graphic organizer looks like this:

4. Earth’s Layers • Earth is made up of three main layers: • Crust • Mantle • Core

5. Earth’s Crust Let’s look at each layer’s characteristics starting from the outside layer, the CRUST. Relative Position Earth’s CRUST is the outermost layer. It is thinnest under the ocean and thickest under continents. The crust and upper part of the mantle are called the LITHOSPHERE. It is the rigid (hard) part of the crust and top part of the mantle.

6. Earth’s Crust • Density • The CRUST is the least dense of all the layers. • There are two types of CRUST: • 1. Oceanic Crust which is made up of basalt and is MORE DENSE than Continental Crust. • 2. Continental Crust which is made up of granite and is LESS DENSE than Oceanic Crust.

7. Earth’s Crust • Let’s take a sneak peak at granite and basalt, both of which make up Earth’s crust. • Basalt Granite Oceanic Crust Continental Crust

8. Earth’s Crust • Composition • Earth’s crust is composed of solid rock made of mostly silicon and oxygen. 70% of Earth’s crust is made of silica (silicon and oxygen). • We recognize silica (SiO4) as quartz, sand (like we find on the beach), or as glass (such as windows). • Quartz Vein Below • WOW!—Did you say sand and glass are made out of the same elements as quartz? • .

9. Earth’s Mantle Relative Position The Earth’s Mantle is between the crust and the core. It is the thickest layer inside Earth. Remember, the hard, top part of the mantle is called the LITHOSPHERE. Underneath the LITHOSPHERE is the semi-molten layer of the mantle called the ASTHENOSPHERE.

10. Lithosphere and Asthenosphere • So we can keep the layers straight, study the diagram of the crust and mantle below. Notice where the asthenosphere and lithosphere are in relationship to the crust and mantle.

11. Back to the Earth’s Mantle • Density • As you go deeper within the Earth, density of the layers increases with depth because of PRESSURE. • Composition • The MANTLE is composed of mostly hot, softened rock which contains some iron, nickel, and magnesium.

12. Earth’s Core • Relative Position • Innermost layer of the Earth. • There is the: • Inner Core • Outer Core

13. Earth’s Core • Density • The Earth’s core is the densest layer. • Composition • Both cores are composed mostly of the metals nickel and iron. BUT there is one main difference………….

14. Earth’s Cores • The outer core is slow-flowing molten liquid nickel and iron. • The inner core is SOLID nickel and iron. • WHY? PRESSURE!

15. In Review • Watch the video clip below

16. Test Yourself!The Applause lets you know if you’re right!! • What is the composition of Earth’s core? • A. Iron and nickel metals • B. Igneous rock • C. Nickel metal • D. Iron metal

17. Check Yourself! • Which is the correct order of Earth’s layers from the outside to the inside? • A. inner core, outer core, crust, mantle • B. mantle, inner core, outer core, crust • C. crust, mantle, outer core, inner core • D. inner core, outer core, mantle, crust

18. Check Yourself! • Which layer is the densest? • A. Crust • B. Inner Core • C. Mantle • D. Outer Core

19. Check Yourself! • What layer of the Earth includes both the crust and the hard, rigid upper part of the mantle? • A. Asthenosphere • B. Atmosphere • C. Mesosphere • D. Lithosphere