Transcript 20130926123994

Section 2
Land, Water, Climate
Landforms
Land covers 30%
of the earth.
4 Main Landforms
Mountains
Hills
Plateaus
Plains
Mountains
High relief (highest)
2,000 feet above sea level
Himalayas – Central Asia
Mt. Everest – 29,028 ft. (highest
mountain)
Hills
•Moderate Relief
•500-2,000 ft.
Plateaus
Low relief
Raised areas of flat or
almost flat land
300-3,000 ft.
Plains
• Low relief
• Large areas of flat or gently rolling land
• Less than 1,000 ft.
• Largest Plain – North European Plain
(more than 1,000 miles from west
coast of France to the Ural Mountains
of Russia
Earth’s 3 Layers
Core
Mantle
Crust
Core
•Center
•Inner core – solid rock
•Outer core – melted
Mantle
Made mostly of hot, solid
rock
Heat from core
Rock in mantle begins to rise
Puts pressure on crust
Causes crust to move in sections- plate
tectonics
Plates move .8 – 2 inches per year
Movement of Plates
Move
Together
Move
Apart
Slide Past One Another
Continenta
l Drift
Continental Drift: movement of
plates
• 220 million years ago…
• Pangaea – one large land mass
• Africa & South America moved
apart
• India & Asia collided forming….
Himalayas
Volcanoes
• Created by plate movement
• Cone – shaped mountains
made when melted rock (lava)
flows up from mantle, cracks
the crust, and cools into solid
rock
• Example: the Hawaiian Islands
Earthquakes
• Created by plate movement
• Tectonic plates slide past one
another
• 800,000 earthquakes a year
(50,000 can be felt)
“Ring of Fire”
•Pacific Ocean
•Common Place for
earthquakes and
volcanoes
These plates are still
moving.
Who knows….
In thousands of years California
may be located off the coast of
Canada!
Outside forces that
shape our earth
Wind
Water
Erosion
Ice
Wind Erosion
Wind Erosion – Positive
• Plains of Northern China – wind
carries thick, rich, yellowish soil
(loess) from the desert
• Large amounts of wheat and other
crops are grown here
Wind Erosion - Negative
• Dust Bowl of 1930s
• Central U.S. – wind blew
away so much soil it became
known as Dust Bowl
Water
Erosion
Water Erosion - Positive
• Mekong River in Southeast Asia
• River carries rich soil down from
the mountains to lowlands
creating fertile farmland
Water Erosion - Negative
• Huang Ho River in Northern
China
• Overflows, flooding farms
and homes
Ice Erosion
Ice Erosion - Positive
• Ice Ages: 4 times in 500,000
years
• Glaciers (sheets of ice) created
lakes and channels for rivers;
smoothes hills into plains
Ice Erosion - Negative
•Ice Ages have driven
people and animals
from homes
How have landforms
affected history?
1. People do not settle in mountain
because:
• Travel is difficult
• Hard to breath; thin air
• Cold temperatures
2. People did settle in plains and
hilly areas because there was rich
soil to farm
Waterways
70 % of the earth’s
surface is water.
Oceans: Largest Bodies of
Water
• Atlantic
• Pacific
• Indian
• Arctic
Bodies of
Salt Water
Seas
• Partly surrounded by land
• Salt water
Lakes
• Usually fresh water
• Completely surrounded by land
Rivers
• Waterway that empties into
another body of water
• Begins in hills or mountains
Rivers
• River System – a river and all
streams that flow into it
• Nile River: Longest river system
in the world
Waterways help people decide
where to live:
Along rivers
Why?
• Trade
• Travel
• irrigation
• Hunting
• Drinking water
Climate
What shapes climate?
• Sun
• Large bodies of water
• Air movement
Climate is the pattern of
weather of a place over many
years
Climate is
shaped by the
Sun
The Sun
• Produces heat and light
• The movements of the earth
determines how the sun affects
climate
Movements of the
Earth
•Rotation
•Revolution
Rotation
• The earth rotates (spins) on its Axis
• Axis – imaginary line that runs through the
center of the earth from North Pole to
South Pole
• 24 hours = 1 rotation
• Causes day and night
Revolution
• The earth moves around the sun in an
almost circular path called an orbit
• 365 ¼ = 1 revolution
• Causes seasons
Climate
Zones
Climate Zones
• Tropical
• Temperate
• Polar
Climate and Water
• Large bodies of water keep temperature from
becoming too hot or too cold
How?
Climate / Air Movement /
Oceans
• Wind – air that moves
• Prevailing winds – blow from certain positions
almost all the time
• Monsoons – winds that change direction
according to the seasons
Ocean Currents
• Ocean water that flows in a steady
stream
• Winds and ocean currents carry heat
and moisture all over the world
Currents from equator to
pole carry warm water
Currents from pole to
equator carry cool water
Climate & Altitude
• Climate is shaped by altitude
• Higher the altitude – colder the
climate
Do people live in
high altitudes?
YES!
Incas lived in Andes Mountains
because the climate is more
comfortable
Tarahumara Indians must
migrate during cold seasons
Precipitation
• The falling of moisture such as
rain or snow
• Precipitation is affected by
altitude
Climate Shapes History
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Types of houses
Crops
Work
clothes
Entertainment
The way a country behaves to its neighbors
wars