Chapter 2
Section 1
Our Planet, the Earth
Solar System
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Earth, Sun, and stars
Milky way galaxy
Days and Nights
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Orbit
 The an oval-shaped path the Earth travels around the sun
Revolution
 Circular journey around the sun
 365 1/4 days
Days and Nights
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Axis
 Earth spins on it
 An imaginary line running through the South and North Poles
Rotation
 Each complete turn the Earth makes
 24 hours
Understanding Seasons
Tilt
 Days and nights are longer or shorter
Tilt and orbit also cause changes in Temperature during the seasons
 Depends on the directness of the sunlight hitting the area
Latitudes
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Equator
 0 degrees
 Mar. 21 and Sept. 23, the sun is directly over the equator
 Days are as long as nights
 Known as Spring and Fall Equinoxes
Tropics
Tropic of Cancer
 23 1/2 degrees N
 Sun shines directly above on June 21 or 22
Summer solstice (1st day of summer) in Northern Hemisphere
Tropic of Capricorn
 23 1/2 degrees S
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Sun shines directly above on December 21 or 22
Winter solstice (1st day of winter) in Northern Hemisphere
Seasons reversed in Southern Hemisphere
Latitudes
Low latitudes
 Area between the Tropics (around the equator)
 Is almost always hot
High latitudes
 66 1/2 degrees N and S
 Polar Zones - no direct sunlight
 Very cold to bitterly cold
Middle latitudes
 Temperate zones
 Have defined seasons - with distinct patterns of daylight, temperature,
and weather
Section 2
 Land, Air, and Water
Forces inside the Earth
“Ring of Fire”
 Circles the Pacific Ocean
 90% of Earth’s earthquakes happen here
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What’s the Earth made of????
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75% water
25% land
Landforms
 Shapes and types of land
Mountains
 Rise usually more than 2000 ft above sea level
What’s the Earth made of????
Hills
 Are lower and less steep than mountains with rounded tops
Plateau
 A large mostly flat area that rises above the rest of the land
Plains
 Large areas of flat or gently rolling land
Pangaea: Supercontinent
200 million years ago
Some force caused Pangaea to split and start moving apart
Plate Tectonics
The theory that Earth’s crust is made of huge, slowly moving slabs of
rock called plates
Plates
 A huge section of the Earth’s crust
Volcanoes and Earthquakes
Plates move apart
 Magma leaks through, creates ridges
Plates push together
 One going under the other
 Volcano produced
Weak places where plates rub against each other
 Forces result in earthquakes
Forces on the Earth’s surface
Weathering
 Process that breaks rocks down into tiny pieces.
 Caused by rain, wind, ice
 (Appalachian Mountains - Rocky Mountains)
Erosion
 Process by which water, wind, and ice wears away landforms and
carries the material to another place
Air and Water
Atmosphere
 A multilayered band of gases that surrounds the Earth
Oxygen - people, animals
Carbon-dioxide- plants
Acts as a blanket from the sun
97% of the Earth’s water is found in the oceans
Salty water
Fresh water
 Lakes, rivers, rain, ground, ice caps
Section 3
Climate and What Influences It
Weather or Climate??
Weather
The condition of the bottom layer of Earth’s atmosphere in one place
over a short period of time
Day to day, rainy or dry
Temperature
 How hot or cold the air feels
Precipitation
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Water that falls to the ground as rain, sleet, hail, or snow
Climate
The weather patterns that an area typically experiences over a long
period of time
What people know from experience from year to year
Wind and Water
Winds
 East - West winds
 Created by the Earth’s rotation
 North - South winds
 Hot air rises and circulates to colder regions
 Cold air sinks and moves toward hotter region
 Keeps the earth from overheating
Ocean Currents
Currents
 Created by earth’s rotation
 Fast moving rivers in the ocean
Carry warm water
Carry cold water
Affects the climate of certain places
 North Atlantic warms British Isles
 Peru Current cools Galapagos
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Ocean’s Effects
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Summer
 Cooler by the water
Winter
 Warmer by the water
Raging Storms
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Hurricanes
 “Andrew”-Florida 1992
160,000 homeless
 “Katrina” - New Orleans 2005
1.5 million homeless in Gulf Coast
Typhoons
 Similar to hurricane
 In the Pacific
Tornadoes
Rain Storms
Blizzards
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Section 4
How climate affects vegetation
Climates
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Vegetation
 The plants that grow in an area
Tropical Climates
Two types of tropical climates
 BOTH are hot and wet
Tropical wet climate
 Two seasons
Great deal of rain
A little less rain
Tropical wet and dry climate
 Two seasons
Much rain
Very little rain
Tropical Climates
Vegetation
 Tropical rain forest
Canopy
 The dense mass of leaves forming the top layer of the forest
Adaption
 Very little light gets to the bottom of the forest
Dry Climates
Arid and semiarid climates
 Hot and receive very little rain
Vegetation
 Sparse, plants are far between
Moderate Climates
Found in the middle latitudes
Mediterranean
Marine west coast
Humid subtropical
In all three rain is moderate
 Seasonal changes
 Temperature hardly ever gets below freezing
Continental Climates
Humid continental
 Summers hot, winters cold
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High grasses, large forests
Subarctic continental
 Cool summers, winters cold
 Shorter grasses
Polar Climates
High latitudes
 Cold all year long
Tundra
 Short cool summers, long even colder winters
 NO trees
 Very low grasses
Vertical Climates
Vertical climate
 The climate changes according to the mountains height
 The higher you go the colder it gets
Top of Mt. Everest much like the climate of Antarctica
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