1. Forces that Change Earth’s Surface
I-Interacting Earth Systems:
A-Three spheres of the earth:
1- Lithosphere = rock or land
2- Hydrosphere = water
3- Atmosphere = gases

4. B- External Forces: wear the land down to sea level.
4- The exchange of energy between the three spheres cause changes in the Earth’s surface.
B- External Forces: wear the land down to sea level.
1- Weathering breaking down of rocks into smaller pieces.
a- ice, rain, and gases.

5. 2- Types of Weathering: a- Physical weathering:
~Frost Action: repeated freezing and melting {Glaciers}

6. Water seeps into cracks and expands when it freezes breaking rock apart

8. ~Root-pry: roots grow between cracks and grow causing rocks to break apart.

9. ~Gravity: pulls loosen rocks & soil down. {Landslide}
~Abrasion: wind & water carry solid particles that sand down rock.

10. b- Chemical weathering: changes occur in the mineral composition or chemical makeup of rock.
~Water: dissolves soluble rock
~Oxidation: Oxygen combines with another substance to form a new material.

11. ~Carbonation: A weak acid is formed when carbon dioxide dissolves in water called carbonic acid which dissolves rock.

13. ~Sulfuric acid: Acid Rain When sulfurous gases combines with water
~Sulfuric acid: Acid Rain When sulfurous gases combines with water. Wears away rock and other materials very quickly.

15. C- Internal Forces: Forces
C- Internal Forces: Forces that produce mountains, earthquakes, & volcanoes.
1-Mountains, Plains, & Plateaus

16. a- Mountains produced mainly by
folding and faulting.
~Folding takes place when the
crust presses rock causing it to
bend.

19. ~Faulting occurs when forces in the crust squeezes or pull causing it to crack or break along a fault = stress in crust.

21. ~Mountains can also be formed by
~Mountains can also be formed by volcanoes: Lava pours out cools pours out cools forming layers of igneous rock.

22. b- Plains: are broad, flat regions found at low elevation
b- Plains: are broad, flat regions found at low elevation. Made of sedimentary rock layers underwater that have slowly raised.

23. c- Plateaus: Large area of flat-topped rocks, caused by faulting or lava flows.

24. D- Earthquakes: Sudden movements of rocks sliding along faults in the crust. Earthquakes cause strong vibrations that travel through the Earth.
Earthquakes are measured by seismic graphs which measure earthquake waves

25. 1- Three Types of Waves:
a- Primary waves (P-waves) can travel through liquids and solids.
b- Secondary waves (S-waves) travel only through solids.
c- Longitudinal waves (L-waves) surface waves.

27. E- Structure of Earth:
1- Crust: Outer layer of Earth Composed of solid rock material about 8-32 km thick.
a- Moho: between the crust and Mantle

28. 2- Mantle: Below the crust about. 2900 km thick consisting of iron
2- Mantle: Below the crust about km thick consisting of iron and magnesium.
3- Outer Core: Below the mantle about 2300 km thick liquid {S-waves cannot go through it}
4- Inner Core: Solid material about 1200 km {P-waves travel faster through it}

30. F- Continental Drift: was proposed by Alfred Wegener in 1912, based on the continents fitting together like a puzzle known as Pangea {pan-jee-uh}

31. 1-Wegener also based his theory of fossils, rocks, mountains, and glacial features found on both sides of the Atlantic.

32. G- Seafloor Spreading
Oceanographers discovered an underwater mountain ridge running north-south down the middle of the Atlantic Ocean (Mid-Atlantic Ridge). Along the ridge, there was volcanic activity. This building of new rock which moves east and west supports Wegener theory.

34. H- The Theory of Plate Tectonics is the combination of continental drift and ocean floor spreading.
1- According to the theory the Earth’s crust is broken up into large plates that move an interact.
2- Scientist believe the plates move due to the heat is the mantle circulating.

38. Mapping the world

39. A-Latitude- The Earth is a sphere if you cut it horizontally or vertically into circles.
The distance between the North Pole and the equator is 900.
If a circle is drawn around the Earth at each degree this is equal to a line of latitude.

40. 3. Equator = 00 latitude.
4. Lines of latitude run west to east and are measured in degrees north-south.

41. B-Longitude: Lines run north-south and are measured in degrees west-east.
1-00 longitude = the Prime Meridian.
Greenwich England.