Section 1 Inside the Earth

1. Chapter 7 Section1 Inside the Earth The Composition of the Earth • 3 layers • Crust, mantle & core • Crust - outermost layer of the Earth. • 5 to 100 km thick, • thinnest layer of the Earth.

2. Chapter 7 Section1 Inside the Earth The Composition of the Earth, continued • 2 types of crust—continental and oceanic. • Oceanic crust is thinner and denser than continental crust.

3. Chapter 7 Section1 Inside the Earth The Composition of the Earth, continued • Mantle= layer between the crust and the core. • much thicker than the crust • contains most of the Earth’s mass.

4. Chapter 7 Section1 Inside the Earth The Composition of the Earth, continued • Core = central part lies below the mantle. • makes up about one-third of Earth’s mass. • made mostly of iron

5. Chapter 7 Section1 Inside the Earth

6. Chapter 7 Section1 Inside the Earth The Physical Structure of the Earth • The Earth is divided into five physical layers: • Each layer has its own set of physical properties.

7. Chapter 7 Section1 Inside the Earth Physical Structure of the Earth, continued • lithosphere - outermost, rigid layer of the Earth • the crust and the rigid upper part of the mantle. • divided into pieces = tectonic plates.

8. Chapter 7 Section1 Inside the Earth Physical Structure of the Earth, continued • asthenosphere = soft, plastic layer of the mantle • tectonic plates move. • solid rock that flows very slowly.

9. Chapter 7 Section1 Inside the Earth

10. Chapter 7 Section1 Inside the Earth Physical Structure of the Earth, continued • mesosphere = strong, lower part of the mantle • between the asthenosphere and the outer core.

11. Chapter 7 Section1 Inside the Earth Physical Structure of the Earth, continued • The Earth’s core is divided into two parts. • outer core - liquid layer of the Earth’s core that lies beneath the mantle. • inner core - is the solid, dense center of • about 6,380 km beneath the surface.

12. Chapter 7 Section1 Inside the Earth

13. Chapter 7 Section1 Inside the Earth Tectonic Plates, continued • A Giant Jigsaw Puzzle Each tectonic plate fits together with the others. • Consists of mantle, oceanic crust and continental crust • lithosphere = puzzle. • Plates = pieces

14. Chapter 7 Section1 Inside the Earth Tectonic Plates Click below to watch the Visual Concept. You may stop the video at any time by pressing the Esc key. Visual Concept

15. Chapter 7 Section1 Inside the Earth Tectonic Plates, continued • plates “float” on asthenosphere.

16. Chapter 7 Section1 Inside the Earth Mapping the Earth’s Interior • seismic waves – earthquake sends vibrations • Travel at different speeds depending on composition and density of materials • seismographs – measure different seismic waves and their different speeds

17. Chapter 7 Section1 Inside the Earth Seismographs and Mapping Earth’s Layers Click below to watch the Visual Concept. You may stop the video at any time by pressing the Esc key. Visual Concept