1. Chapter 2: The Physical World
Questions to examine…
What causes the seasons?
What affects our climate (weather)?
How is our Earth’s land constantly changing?
How does the Earth’s water supply work?

2. Day 1 – The Earth – Sun Relationship

3. Our Star Solar Energy- energy from the sun
All life on Earth requires solar energy to survive
Solar Energy- energy from the sun
(plants and animals require the sun’s light and heat energy to survive)

4. The Sun’s Rotation 24 hrs. = one complete rotation
Rotation causes day & night
Rotation- one complete spin of Earth on its axis
(Does it look like the sun moves? Does it move?)
NO! THE EARTH MOVES!

5. Revolution Revolution- Earth’s trip around the sun
One revolution takes 365 ¼ days – 1 year

6. Tilt Tilted toward the sun, weather is warmer
Tilted away from the sun, weather is colder
Nearer you are to the equator, the more intense the
sunlight

7. Sun and Location Review….. Earth’s tilt causes the seasons
Earth’s shape affects the amount of sunlight places get too
Higher latitudes – cooler
Lower latitudes – warmer

8. Chapter 2: The Earth & It’s Physical Systems

9. Weather & Climate “What is it like outside today?”
Weather- Short-term changes in the air for a given place and time
“What is it usually like outside for this time of year?”
Climate- a region’s average
weather conditions over a long
period

10. The Seasons Earth’s tilt causes the changing of the seasons!
The seasons are opposite in northern/southern hemispheres
Earth tilted away from sun = winter for us
Earth tilted toward sun = summer
for us
Earth’s tilt causes the
changing of the seasons!
December in Australia

12. Climate Zones 6 Basic Climate Zones:
Tropical : hot, rainy, dense jungle
Desert : very dry, hot or cold
Humid Temperate : changing seasons
Cold Temperate : very short summer, cool
High Mountain : mountain tops, cool/windy
Polar : very cold, ice and snow

13. The Tropics
Tropics – regions close to the equator, hot experience seasons based on rainfall, wet & dry seasons

14. Climate Change??? Many scientists believe climates are
changing due to human activity…
Increase in Earth’s average temperature
Increase in chemical pollution in air & water
Rising ocean levels
Erratic/violent weather events & patterns
Global warming could threaten life on our planet

15. Headlines……… “Why are India's farmers killing themselves?”
“Alaskan village votes to relocate over global warming”
“Study: Over 90% of Great Barrier Reef suffering from coral bleaching”
“Rising sea levels a threat to coastal cities?”
“More than 80,000 warned to evacuate in raging California fire”

16. What Affects Climate? 1. Large Bodies of Water
Big bodies of water can affect temperature because water heats and cools slowly –coastal areas experience less temperature change

18. What Affects Climate? 2. Elevation
This mountain is in Africa near the equator. Why is there snow on top of this mountain? Temperatures decrease with elevation

19. Mountains & Rain Shadows
Mountains also create wet and dry areas
One side can get a bunch of rain & leave little for the other side.
Rain Shadow Effect

20. What Affects Climate? 3. Global Winds
Prevailing winds- winds that blow in the same direction over large areas of Earth
Winds can make a region warmer or colder (depending on where they come from)

21. What Affects Climate? 4. Ocean Currents
Ocean currents move heat around the Earth
Ocean Currents- large streams of surface seawater
Ocean currents can affect temperatures

22. Continents
Continents- large landmasses that are part of the Earth’s crust

23. Plate Tectonics
Plate Tectonics- the theory that Earth’s surface is divided into a dozen or so slow-moving plates or pieces of Earth’s crust

24. Earth’s Plates All of these plates move
Pressure below Earth’s surface causes plates to move a couple inches per year

25. Movement of Continents
Alfred Wegener - stated that all of the continents were once one
supercontinent - PANGEA
Over millions of years the
continents shifted to their current positions
THEORY OF CONTINENTAL DRIFT
(Other scientists told Al he was crazy…)

27. Plates Collide
Collision of plates creates different landforms like ocean trenches & mountains
(Examples:
-Marianas Trench
-Andes Mountains
-Himalaya Mountains)

28. Plates Separate
When plates separate the gap allows magma to reach earth’s surface
As lava cools it builds an underwater mountain, can create islands (Ex.: Hawaii)

29. Plates Slide
Earthquakes- sudden, violent movements of Earth’s crust

30. A Fault Near Indy??????

31. Earth’s Water Supply Water covers around 70% of the earth
Most important resource on earth

32. Salt Water 97% of Earth’s water is salt water
Salt water is unsafe to drink
(The Great Salt Lake in Utah is salt water, oceans are salt water)

33. Freshwater Freshwater- water without salt Makes up 3% of water supply
Much freshwater is in form of glaciers
Glaciers- large areas of slow moving ice

34. More Freshwater
Surface water- is found in Earth’s streams, rivers, and lakes
Water in streams, rivers, and lakes comes from precipitation
Precipitation- rain, snow, sleet, hail

35. More Freshwater Most of Earth’s available fresh water is underground
Groundwater- water found below Earth’s surface
(You get groundwater through a spring or well)

36. The Water Cycle
Water is the only thing on Earth that naturally occurs as a liquid, solid, and gas
Water cycle- movement of water from Earth’s surface to the atmosphere and back
Water cycle is not made or
destroyed—it only changes
form

37. 2. Condensation
3. Precipitation
1. Evaporation
4. Run-off

38. Weathering & Erosion
Weathering- process by which rock is broken down into smaller pieces
Ice, roots, and heat can weather rocks
Erosion- movement of sediment from one location to another
Caused by glaciers, wind, water, and ice

39. Water Problems Lack of freshwater Polluted water Flooding
Water shortages due to droughts