1. EARTH SCIENCE A Quick Review

2. Where are we? 3 rd planet from the sun About 92 million miles –P–Perfect distance to balance warmth –“–“The Water Planet”

3. Who are we? Geosphere Hydrosphere Atmosphere Biosphere

4. Earth’s History About 4.6 billion years old (according to rock record) Geologic Time scale - broken down into eons, eras, periods and epochs. (Precambrian epoch = 87% of time scale)

5. Divisions mainly dependent on rise of certain types of organisms or major events.

6. 3 major concentric zones Core: –S–Solid inner – due to pressure (Ni & Fe) –M–Molten outer - creates magnetic field (Fe & S) Mantle: –M–Mostly solid –A–Asthenosphere = slowly flowing Lithosphere: –T–Thin rigid –C–Contains the crust Earth’s Composition

7. Earth’s Magnetic Field

8. Earth’s Crust Oceanic crust – mostly basalt (more dense, ~3.0g/cm 3 ) Continental crust – mostly granite (less dense, ~2.7g/cm 3 )

9. Plate Tectonics Nuclear decay in the core releases heat into the mantle and asthenosphere causing convection currents that create plate movement

10. Convection currents have caused the mass movement of plates over millions of years.

11. The movement of these plates is called “Continental Drift”.

12. Each individual plate (about 12) is made of lithosphere and mantle.

13. Today, the plates are still in motion – –P–PLATE TECTONICS –h–http://sos.noaa.gov/videos/Paleo3.mov

14. The plates today:

15. Plate tectonics Plate boundaries – edges of the plates –T–Three types: convergent, divergent and transform

16. Earth’s Crust Convergence (subduction) Creates mountains and volcanoes

17. Divergence (ridge formation) –C–Creates volcanoes and new crust

18. Transform – plates sliding past one another. –C–Creates earthquakes

19. Volcanoes Active Dormant Extinct Subduction volcanoes –A–At plate boundaries Hot spot volcanoes –I–In the middle of plates

20. Rift Volcanoes –F–Form new oceanic crust

21. Earthquakes Each black dot is the location of an earthquake

22. Anatomy: –F–Fault –F–Focus –E–Epicenter –W–Waves

23. Rock Cycle Rocks come from rocks Time, erosion, pressure and heat create 3 basic types –I–Igneous –S–Sedimentary –M–Metamorphic

25. Erosion

26. Soil A crucial link between biotic (living) and abiotic (nonliving)

27. Earth’s orbit and rotation Revolution, rotation and tilt determine our days and seasons.

28. Seasons Spring in the Northern, Autumn in the Southern

29. Seasons Summer in the Northern, Winter in the Southern

30. Seasons Autumn in the Northern, Spring in the Southern

31. Seasons Winter in the Northern, Summer in the Southern

32. The Atmosphere A layer of gases held close to the Earth by gravity With the help of the sun, it’s where our weather and climates occur

33. Atmosphere Troposphere – all of the weather, most of the water vapor and clouds. Well mixed layer. Area of the atmosphere that holds the greenhouse gases

34. The Greenhouse Effect Without the greenhouse gases (CO 2, H 2 O, and CH 4 ) in the atmosphere, we wouldn’t survive.

35. Atmosphere Stratosphere – not well mixed. Contains the ozone layer (O 3 )

36. Mesosphere – where meteors usually burn up.

37. Thermosphere (or Ionosphere) Thinnest gas layer –A–Aurora’s –S–Space shuttles –I–Ionization (absorption of solar wind) –R–Reflects radio waves

38. Exosphere –S–Satellites –L–Lightest gases – H 2 and He

39. Magnetosphere – area where the magnetic field of the earth dominantly controls the movements of gas and charged particles.

40. Hydrosphere & Biosphere We’ll cover these later…..