1. The Dynamic Earth

2. Section 1: The Geosphere The Earth is an integrated system (rocks, air, water) Geosphere: all rock and sediment on Earth Earth’s Interior: 3 layers (crust, mantle, core) Crust: made of lighter elements, <1% Mantle: 64% of Earth’s mass, medium elements Core: Made up of the densest elements

3. Earth’s Composition: Earth can be divided into 5 regions based on composition Lithosphere: outer most layer Includes both crust and part of mantle Asthenosphere: layer beneath the lithosphere Plastic, movable layer Allows plates to slide around The core can be split in 2 Inner (Solid-nickel & iron) Outer (liquid iron)

4. Earth’s Processes: Plate Tectonics: Earth is divided into tectonic plates These plates glide along the asthenosphere Most geologic activity takes place along the boundaries of plates Ex.) Earthquakes and Volcanoes Also can form mountains Ex.) Himalayas…Mt. Everest

5. Continued… Earthquakes: Usually occurs at a fault Ex.) San Andreas fault in California Measure using the Richter scale Each step in magnitude increases by 37.1 times Let’s do the math…How many times greater is magnitude 7 than a magnitude 5 Cannot predict Earthquakes However, animals can sometimes “sense” them

6. Continued… Volcanoes: A mountain built from magma On land or by sea Destructive: Some areas are greatly affected by volcanism Ex.) Mt. St. Helens Can affect the world Ex.) 1991, Mt. Pinatubo (changed Earth’s temp.)

7. Continued… Erosion: Removal and transport of material 2 types: Water Rivers, rain, oceans Ex.) Grand Canyon Wind Plants reduce this Great erosion rates took place during the dirty 30’s

8. Ch. 3-2: Atmosphere Mixture of gases the surround Earth Nitrogen, oxygen, carbon dioxide, & other gases These Gases can be added or removed by biotic ways or abiotic ways The atmosphere is the Earth’s greatest insulator for warmth and cold

9. Composition of Gases Nitrogen makes up 78% of all the atmosphere Comes from volcanoes, dead plants and animals decaying as well Oxygen makes up 21% of all gases Primarily produced from plants Argon, CO 2, CH 4, and Water Vapor make up the rest Also contains dust, salt, ash, skin, hair, pollen, bacteria, and viruses…ewww!

10. Layers of the Atmosphere We will talk about 4 layers of the atmosphere 1.) Troposphere: layer closest to Earth’s surface Almost all weather occurs in this layer Densest atmospheric layer 2.) Stratosphere: above the troposphere Temperature rises as altitude increases Contains O 3 Ozone blocks UV rays causing this layer to be warmer What are the negative of UV?

11. Continued… 3.) Mesosphere: above the stratosphere Coldest layer of the atmosphere As cold as -93 degrees C 4.) Thermosphere: Farthest layer out (kind of) Nitrogen and Oxygen molecules absorb solar radiation Temps. as high as 2000 degrees C Would not feel hot to us though…air molecules are so thin Lower thermosphere is called the ionosphere (has electrons) Where AM radio signals travel Also where Northern Lights occur

12. Energy in the Atmosphere Energy travels 3 ways in the atmosphere 1.) Radiation: transfer of energy across space Ex.) Stand by a fire or in the sun 2.) Conduction: flow of energy from warmer to colder Ex.) Direct physical contact with a hot water bottle 3.) Convection: transfer of heat by air currents Hot air rises, cold air sinks Lets think survival (Bear Grylls)

13. Heating the atmosphere & Movement of Energy Solar energy reaches Earth as electromagnetic radiation Visible light, UV, infrared About half of energy hitting Earth reflects back into space Air is moved in the atmosphere by heating and cooling Hot air rise and cool air sinks forming winds This process is known as a convection current

14. Greenhouse effect Earth’s atmosphere is like the windows in a car Some heat escapes to space some stays in car The process in which gases trap heat near the Earth (greenhouse effect) Gases that trap heat are greenhouse gases Ex.) CH 4, CO 2, H 2 O In very low concentrations Why?

15. Biosphere…we skipped water Narrow layer around Earth in which life can exist 11 km into the ocean, 9 km into the atmosphere Ex.) Bacteria, birds, fish, etc. Life requires: Liquid water Temps. Between 10 and 40 C Sunlight (energy) Now there are some exceptions but majority of life exists here

16. Energy Flow in Biosphere Energy from the sun is constantly added Matter is not! The matter is constantly recycled What breaks down dead organisms? Closed system: energy enters environment but matter does not Earth is mainly a closed system Open system: both matter and energy exchanged Early Earth being bombarded with comets and meteorites