1. How do physical processes shape Earth’s surface?
THE PHYSICAL WORLD
How do physical processes shape Earth’s surface?

2. PLANET EARTH

3. OUR SOLAR SYSTEM Sun at the center 8 known planets
Mercury, Venus, Earth, Mars (inner planets)
Jupiter, Saturn, Uranus, and Neptune (outer planets)
Jupiter is largest
Pluto is a dwarf planet---too small; not enough gravitational pull

4. SOLAR SYSTEM CONTINUED
Inner planets are terrestrial planets---have solid, rocky crusts
Only Earth has temps to support life
Outer planets are gas giant planets---gaseous and less dense
Asteroid belt btwn Mars and Jupiter

5. EARTH Circumference of 24,900 miles
70% of surface is water---all water on Earth makes up the HYDROSPHERE
30% is land---LITHOSPHERE
Air we breathe makes up the ATMOSPHERE(78% nitrogen, 21% oxygen, argon, others)
All life makes up the BIOSPHERE

6. LANDFORMS Natural features of Earth’s surface
Largest are the continents
CONTINENTAL SHELF: part of a continent that extends out underneath the ocean
Lowest point on Earth’s crust: Mariana Trench (36,198 feet)
Highest point: Mt. Everest (29,029 feet)

7. FORCES OF CHANGE
How is Earth’s structure related to the creation of continents, oceans, and mountain ranges?

8. EARTH’S STRUCTURE 3 main layers:
1. CORE: innermost layer; super- hot, solid inner core; super-hot liquid outer core (mostly nickel and iron)
2. MANTLE: middle layer; dense hot rock that is flexible
3. CRUST: outer layer; hard, rocky shell---broken into tectonic plates

9. CONTINENTAL DRIFT
Theory that the continents were once joined and then slowly drifted apart
Supercontinent was called Pangaea

10. PLATE TECTONICS
Def: activities of continental drift and magma flow, which create many of Earth’s physical features
MAGMA: molten rock (below surface)
Belief is that this has been happening for billion years
Don’t know exactly what causes it

11. INTERNAL FORCES OF CHANGE
How does plate tectonics affect Earth’s surface?

12. COLLIDING PLATES
SUBDUCTION: process by which oceanic plates dive beneath continental plates, often causing mountains to form on land
ACCRETION: slow process in which an oceanic plate slides under a continental plate, creating debris that can cause a continent to grow
Called convergent boundaries

13. SPREADING PLATES
SPREADING: process by which magma wells up btwn oceanic plates and pushes them apart
Called divergent boundaries
Creates rifts
Mid-Atlantic Ridge

14. FOLDS AND FAULTS
FOLD: a bend in layers of rock, sometimes caused by plate movement
FAULT: a crack or break in Earth’s crust
FAULTING: process of cracking that occurs when the folded land cannot be bent any further

15. EARTHQUAKES
Sudden, violent movements of the lithosphere along fault lines
Caused by built up tension btwn plates
Measured by the Richter Scale

16. VOLCANOES
Mountains formed by lava or magma that breaks through the Earth’s crust

17. EXTERNAL FORCES OF CHANGE

18. Weathering
Def: chemical or physical processes that break down rocks into smaller pieces
Physical weathering involves physically breaking down rocks into smaller pieces
Chemical weathering changes the chemical makeup of rocks

19. EROSION
Def: the movement of weathered rock and material by wind, glaciers, and moving water
GLACIER: large body of ice that moves across the surface of the Earth
MORAINE: piles of rocky debris left by melting glaciers

20. SOIL BUILDUP Five factors of soil formation
1. Climate: wind, temp, and rainfall determine type of soil
2. Topography: affects flow or runoff water
3. Geology: determines parent material
4. Biology: adds organic matter to soil
5. Time

21. What drives the water cycle?
Earth’s water
What drives the water cycle?

22. THE WATER CYCLE
Def: regular movement of Earth’s water from ocean to air to ground and back to the ocean
Total amount of water on Earth does not change
Sun drives the cycle by evaporation…

23. EVAPORATION Def: the changing of liquid water into vapor
Water vapor is gathered in the air
Warm air holds vapor better than cool air
Air cools, water condenses…

24. CONDENSATION
Def: process of excess water vapor changing into liquid water when warm air cools
Tiny droplets form together to create clouds
When they get too full, they release the water

25. PRECIPITATION
Def: moisture that falls to Earth as rain, sleet, hail, or snow
Precipitation sinks into the ground
Collects in streams and lakes
Gets returned to oceans
Hakuna matata!

26. BODIES OF SALT WATER 70% of Earth is water
97% of that is one continuous body of water
Divided into 5 oceans:
1. Pacific
2. Atlantic
3. Indian
4. Arctic
5. Southern

27. DESALINATION
Def: the removal of salt from seawater to make it usable for drinking and farming
Expensive process

28. BODIES OF FRESH WATER 3% Earth’s water is freshwater
2/3 is trapped in glaciers and ice caps
GROUNDWATER: water located underground; supplies wells and springs
AQUIFER: underground water- bearing layers of porous rock, sand, and gravel