1. Earth’s Layers and Atmosphere Layers
Objectives:
Identify and describe layers of the earth.
Identify and describe layers of the atmosphere.

2. Earth’s Layers (p.61)

3. Earth’s Layers Lithosphere (solid) Asthenosphere Outermost layer
Crust and uppermost part of mantle
“litho” means “rock”
Huge pieces called tectonic plates, which “float” on top of the asthenosphere
Asthenosphere
Upper part of the mantle
Made of mantle rock which flows slowly, allowing tectonic plates to move on top of it.

4. Earth’s Layers (cont.) Mesosphere Outer Core Inner Core
“meso” means “middle”
Lower part of the mantle
Outer Core
Liquid nickel and iron
Inner Core
Solid nickel and iron

5. Layers of the Atmosphere (p.68)

6. Layers of the Atmosphere
Troposphere
Closest to Earth’s surface
Almost all weather occurs here
Densest atmospheric layer
Temperature decreases with altitude (height)
Stratosphere
Temperatures increase with altitude
Contains ozone layer (O3)

7. Layers of the Atmosphere (cont.)
Mesosphere
“meso” means ?
Coldest layer
Thermosphere
“thermo” means ?
Highest temperatures
Contains ions in the ionosphere, which create the Northern Lights (the aurora borealis)

8. Assignment  Draw, color, and label (DCL) the layers of the earth.
DCL the layers of the atmosphere.
ON EACH DRAWING, add things to each layer that will help you remember them.
Example: What is a characteristic of the mesosphere?
Make up with a mnemonic device to help you and your classmates remember the order of the layers.

10. Where do Earthquakes Occur?

11. Volcanoes: The Ring of Fire

12. Plate Tectonics
Lithosphere – rocky, outermost layer of Earth’s crust – is divided into large pieces called tectonic plates.
Tectonic plates float across the molten magma in the asthenosphere.
Plate boundaries – most geologically active areas on Earth.
Plates collide, creating mountain ranges
Earthquakes occur here
Volcanoes occur here

13. Earthquakes
Caused by blocks of Earth’s crust sliding past each other along faults (breaks in Earth’s crust)
Magnitude (measure of the energy released) rated on the Richter scale

14. Volcanoes A mountain built from magma (melted rock)
Usually located near tectonic plate boundaries
Most are found along the edges of the Pacific Ocean (the “Ring of Fire”)
Volcanic eruptions have local and global effects.

15. Local Effects of Volcanic Eruptions
Economic devastation
Loss of human life
Difficulty breathing due to volcanic ash
Creates new crust
Produces fertile soil
Geothermal energy (“geo” = earth; “thermal” = heat)

16. Global Effects of Volcanic Eruptions
Volcanic ash in the atmosphere can block incoming sunlight.
Less sunlight = lower temperatures
Mount Pinatubo (1991)

17. Erosion Definition: the transport (movement) of surface materials
Water erosion
Ocean waves
Cliffs and sea stacks
Battered shorelines
Rivers
Canyons

18. Erosion (cont.)
Wind erosion
Removal of soil
Rock formations

19. Energy in the Atmosphere
Energy from the sun enters Earth’s atmosphere and is then transferred 3 ways (Fig. 15, pp.70-71):
Radiation – across space (EX: heat from a fire)
Convection - transfer of heat by air currents (also happens in water)
Conduction – by direct contact

20. Methods of Heat Transfer

21. Greenhouse Effect
Definition: gases in the atmosphere trap radiation and emit it as heat
Most common greenhouse gases:
Carbon dioxide
Water vapor
Methane
Nitrous oxide
Sources?
The same effect is achieved in actual greenhouses and in automobiles. (Fig. 16, p.72)