Transcript Holt McDougal

3.1 Weather and Climate
The Big Idea
The sun, location, wind, water, and mountains affect weather
and climate.
Main Ideas
I.
While weather is short term, climate is a region’s average
weather over a long period.
II. The amount of sun at a given location is affected by
Earth’s tilt, movement, and shape.
III. Wind and water move heat around Earth, affecting how
warm or wet a place is.
IV. Mountains influence temperature and precipitation.
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Main Idea 1:
I. While weather is short term, climate is a
region’s average weather over a long period.
A. Weather
1. The short-term changes in the air for a given place and time
2. Temperature and precipitation from hour to hour or day to
day
B. Climate
1. A region’s average weather conditions over a long period
2. The expected weather for a place based on data and
experience
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Main Idea 2:
II. The amount of sun at a given location is
affected by Earth’s tilt, movement,
and shape.
A. Tilt
B. Movement
C. Shape
• The part of the
Earth tilted
toward the sun
receives more
solar energy
than the part
tilted away from
the sun.
• As Earth
revolves
around the sun,
the part of
Earth that is
tilted toward
the sun
changes during
the year, thus
creating the
seasons.
• Earth’s spherical
shape means
that the sun’s
rays directly
strike the
equator, but only
somewhat strike
the poles.
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• The farther
from the
equator, or the
higher the
latitude, the
colder the
climate.
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Main Idea 3:
III. Wind and water move heat around Earth,
affecting how warm or wet a place is.
• Air and water warmed by the sun are constantly
on the move, making different areas of Earth
warmer or cooler.
• Wind, or the sideways movement of air, blows in
great streams around the planet.
• Prevailing winds are winds that blow in the
same direction over large areas of Earth.
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Prevailing Winds
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1. Weight of air
A. Wind
a. Cold air is heavier than warm
air.
b. When air cools, it gets heavier
and sinks.
c. When air warms, it gets lighter
and rises.
d. As warm air rises, cooler air
moves in to take its place, creating
wind.
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2. The rising, sinking, and flowing of air
creates Earth’s prevailing wind patterns.
a. At the equator, hot air rises and flows
toward the poles.
b. At the poles, cold air sinks and flows
toward the equator.
c. Earth’s rotation causes prevailing winds
to curve east or west.
3. Prevailing winds can make a region
warmer or colder and drier or wetter.
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Ocean Currents
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B. Water and Wind
1. Ocean currents—large streams of
surface seawater driven by winds—
move heat around Earth.
a. Carry warm or cool water to
different areas
b. Water’s temperature affects air
temperature near it.
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B. Water and Wind
2. Large bodies of water, such as an
ocean or sea, also affect climate.
a. Water heats and cools more
slowly than land does.
b. Large bodies of water make the
temperature of the land nearby
milder.
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B. Water and Wind
3. The place where two air masses of
different temperatures or moisture
content meet is a front.
–Can produce rain, snow,
thunderstorms, and blizzards
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C. Storms
1. Thunderstorms
2. Blizzards
•
Produce rain, lightning, and thunder
•
Most common in spring and summer
•
Produce strong winds and large amounts of snow
•
Most common during winter
•
Small, rapidly twisting funnel of air that touches
the ground
•
Can be destructive and deadly
•
Large, rotating storms that form over tropical
waters in the Atlantic Ocean (hurricanes) or Pacific
Ocean (typhoons).
•
Produce drenching rains, strong winds, and storm
surges
•
Largest, most destructive storms
3. Tornadoes
4. Hurricanes
and Typhoons
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Main Idea 4:
IV. Mountains influence temperature and
precipitation.
A. Mountains can influence an area’s climate by affecting
both temperature and precipitation.
B. Temperature decreases with elevation, the height on
Earth’s surface above sea level.
C. Mountains also create wet and dry areas.
1. Air blowing against mountains is forced to rise.
2. As the air rises, it cools and precipitation falls.
3. This effect produces a rain shadow, a dry area on the
mountainside facing away from the direction of the wind.
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Rain Shadow
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3.2 World Climates
The Big Idea
Earth’s five major climate zones are identified by
temperature, precipitation, and plant life.
Main Ideas
I. Geographers use temperature, precipitation, and plant life
to identify climate zones.
II. Tropical climates are wet and warm, while dry climates
receive little or no rain.
III. Temperate climates have the most seasonal change.
IV. Polar climates are cold and dry, while highland climates
change with elevation.
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Main Idea 1:
I. Geographers use temperature,
precipitation, and plant life to identify climate
zones.
A. Earth is divided into five general climate zones.
1. Tropical—occur near the equator, in low latitudes
2. Temperate—occur about halfway between the equator and
the poles, in the middle latitudes
3. Polar—occur near the poles, in the high latitudes
4. Dry—occurs at many different latitudes
5. Highland—occurs at many different latitudes
B. Geographers divide some climate zones into more specific
climate regions.
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Main Idea 2:
II. Tropical climates are wet and warm, while
dry climates receive little or no rain.
Humid Tropical Climate
• At the equator
• Warm, muggy and rainy yearround
• Temperatures average 80F.
• Rainfall ranges from 70 to 450
inches.
• Some areas have monsoons,
seasonal winds that bring either
dry or moist air.
• Can support lush tropical rain
forests that host a great
diversity of plant and animal life
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Tropical Savanna Climate
• North and south away from the
equator
• Long, hot, dry season followed
by short periods of rain
• Temperatures are hot in the
summer, cooler in the winter.
• Can support savannas—areas of
tall grasses and scattered trees
and shrubs
Dry Climates
Steppe Climate
Desert Climate
• Earth’s hottest and driest
climate
• Receive less than 10
inches of rain a year
• Temperatures can reach
as high as 130F.
• Only very hardy plants
and animals can live in
these conditions.
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• Semidry grasslands or
prairies—called steppes
• Often border deserts
• Receive slightly more rain
than deserts
• Short grasses are most
common plants, but
shrubs and trees grow
along streams and rivers.
Main Idea 3:
III. Temperate climates have the most
seasonal change.
Temperate Climates
• Mild and tend to have four seasons
– Warm or hot summers
– Cool or cold winters
• Occur in the middle latitudes, the regions halfway between
the equator and the poles
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Temperate Climates
Mediterranean
Humid
Subtropical
Marine
West Coast
Humid
Continental
•
Sunny, pleasant climate occurring mainly in coastal
area
•
Summers hot, dry, and sunny; winters mild and
somewhat wet
•
Occurs along east coasts near the tropics
•
Summers are hot and muggy; winters are mild
•
Storms occur year-round.
•
Occurs on west coasts where winds carry moisture
in from the seas
•
Mild temperatures year-round
•
Occurs closer to the poles, in the upper-middle
latitudes
•
Four distinct seasons
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Mediterranean Climate
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Main Idea 4:
IV. Polar climates are cold and dry, while
highland climates change with elevation.
Subarctic Climate
• Occurs mainly in Northern
hemisphere south of Arctic
Ocean
• Winters are long and bitterly
cold; summers short and cool
• Below freezing half the year
Ice Cap Climate
Tundra Climate
• Coastal areas along the Arctic
Ocean
• Long, bitterly cold winters
• In some parts is permafrost,
or permanently frozen layers of
soil
Highland Climate
• North and South poles
• Found on mountains
• Temperature lows of more than
-120F
• Includes polar climates plus
others; several climates in one
• Snow and ice remain yearround, but little precipitation
• As you go up a mountain,
temperatures drop and plant
life grows sparser.
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3.3 Natural Environments
The Big Idea
Plants, animals, and the environment, including soil, interact
and affect one another.
Main Ideas
I. The environment and life are interconnected and exist in a
fragile balance.
II. Soils play an important role in the environment.
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Main Idea 1:
I. The environment and life are
interconnected and exist in a fragile balance.
A. Plants and animals live where they are suited to the
environment, or surroundings.
– Factors such as temperature, rainfall, and soil conditions limit
options of where they can live.
– All plants and animals are adapted to specific environments.
B. Ecosystem—a group of plants and animals that depend
on each other for survival and the environment in which they
live
– Formed from interconnections between living things and the
environment
– Can be any size and can occur wherever air, water, and soil
support life
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Changes to Environments
Ecosystems exist in a fragile balance; a small change to one
part can affect the whole system.
People can affect ecosystems in many ways.
Some actions can destroy a habitat—the place where a plant or
animal lives.
Extreme changes in ecosystems can cause species to die out, or
become extinct.
Many countries are working to balance people’s needs with the
needs of the environment.
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Main Idea 2:
II. Soils play an important role in the
environment.
A. Soils help determine what plants will grow and how well.
B. Fertile soils are rich in minerals and humus, decayed plant or
animal matter.
– Support abundant life
C. Soils can lose fertility in many ways.
– Erosion
– Planting the same crops over and over
D. When soil becomes worn out, it cannot support as many plants.
– Can lead to desertification, the spread of desertlike conditions
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Desertification
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3.4 Natural Resources
The Big Idea
Earth’s natural resources have many valuable uses, and their
availability affects people in many ways.
Main Ideas
I.
Earth provides valuable resources for our use.
II. Energy resources provide fuel, heat, and electricity.
III. Mineral resources include metals, rocks, and salt.
IV. Resources shape people’s lives and countries’ wealth.
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Main Idea 1:
I. Earth provides valuable resources
for our use.
A. Using Natural
Resources
• A natural
resource is any
material in nature
that people use and
value.
• Some are used as
is.
• Some are changed
to make something
new.
B. Types of
Natural
Resources
• Renewable
resources are
resources Earth
replaces naturally.
• Nonrenewable
resources are
resources that
cannot be replaced;
they will run out
one day.
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C. Managing
Natural
Resources
• People must
manage resources
to ensure they will
be available in the
future.
• Deforestation, the
clearing of trees, is
a result of lack of
management.
• Reforestation,
planting trees to
replace lost
forestland, works to
prevent resource
loss.
Main Idea 2:
II. Energy resources provide fuel, heat,
and electricity.
A. Nonrenewable Energy
Resources
1. Most energy we use comes
from fossil fuels,
nonrenewable resources that
formed from the remains of
ancient plants and animals.
2. Coal—pollutes the air; used
mainly to create electricity at
power plants
3. Petroleum, or oil—used to
make fuels and other
products
4. Natural gas—cleanest-burning
fossil fuel; used mainly for
heating and cooking
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B. Renewable Energy
Resources
1. Will not run out
2. Generally better for the
environment
3. Hydroelectric power—the
production of electricity from
waterpower—is the main
alternative to fossil fuels.
4. Wind is used to power wind
turbines that create
electricity.
5. Solar power and geothermal
energy—heat from within
Earth—can heat water for
homes and be turned into
electricity.
Clean Energy Problems
Electric Cars Require Batteries to
Store Energy
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Nuclear Energy
• Obtained by splitting atoms, small particles of matter
• Uses the metal uranium, so some consider it a
nonrenewable resource
• Produces dangerous wastes that must be stored for
thousands of years before they are safe
• Accidents at nuclear power plants have terrible effects.
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Main Idea 3:
III. Mineral resources include metals, rocks,
and salt.
Mineral resources include metals, salt, rocks, and gemstones.
Minerals fulfill countless needs.
Minerals are nonrenewable, and therefore need to be
conserved.
Recycling can make the supply of mineral resources last longer.
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Main Idea 4:
IV. Resources shape people’s lives and
countries’ wealth.
A. The natural resources available to people affect their lifestyles
and needs.
1. People in areas with many natural resources sometimes have more
choices on ways to dress, eat, live, travel, and entertain themselves.
2. People in areas with fewer natural resources will likely have fewer
choices and different needs.
B. Availability of natural resources affects countries’ economies.
1. The many resources available in the United States have helped it
become one of the world’s wealthiest economies.
2. Countries with few natural resources often have weak economies.
3. Some countries have only one or two valuable resources but few
others.
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