Transcript PPT

Weather and Climate
Chapter 3
Weather & Climate
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Climate is what you expect
Weather is what you get
Weather
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weather – condition of atmosphere over a short
time
climate – weather over a long time
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latitude affects climate – middle and high have
distinct seasons
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polar – cold all year
tropics – warm all year
temperature – measurement of heat
Weather
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greenhouse effect – atmosphere traps heat and
keeps the planet warm
global warming – increase in temperatures
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caused by burning fossil fuels?
natural? volcanoes? oceans?
What might be the results of global warming?
Atmospheric Pressure
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The earth distributes the sun’s heat.
This affects climate
Example: elevation = less air = less pressure = colder
low pressure – air moves higher = storms, cyclones, monsoons
high pressure – air sinks = dry
There are 4 major air pressure zones: DIAGRAM ON PAGE 43
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equatorial lows
subtropical highs
subpolar lows
polar highs
Global Wind Effects
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Wind flows from high to low pressure
Winds maintain balance of heat and energy.
prevailing winds – constant blowing in the same
direction
trade winds – blow towards the equator – NE and SE
toward equator
doldrums – wind/lack of wind – along the equator
westerly winds – in the middle latitude – west to east
A diagram illustrating Columbus? first route to the New
World (in red) and the trade winds he used to get there (in
black). Columbus return trip was powered by the
Westerlies.
Triangular Trade
Wind & Weather
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front – hot air meets cold air – Virginia Beach
jet stream – “rivers” of air in the upper
atmosphere
Oceans & Currents
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water cools slower than land
Virginia Beach vs Richmond (influence of ocean)
ocean currents move around the globe
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Gulf Stream – warm water current off the east coast
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page 52-53 – hot to cold and cold to hot
currents move the sun’s heat
influences the climate of W. Europe
California Current – a cool current off of the west coast
of the US
Weather Factors
Precipitation
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evaporation – water changes from liquid to gas
humidity – amount of water vapor in the air
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the higher the temp.= higher ability to hold water
condensation – when air cannot hold more it
condenses
gas to liquid - fog, dew, frost, cloud
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will fall as snow, rain, hail, sleet
Elevation and Mountain Effects
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orographic precipitation – moist air rises up the
side of a mountain, condenses, then falls as
precipitation
windward – wet side of mountain – gets the
wind
leeward – dry side of the mountain
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where desert would form
called the rain shadow
Storms
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hot air rises and mixes with cold air
tornadoes – most of these occur in the US
hurricanes – over 74 mph – start over
Africa/Caribbean Sea
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travel to the west due to the winds – trade winds
typhoons – western pacific
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same type of storm as hurricanes
Tornadoes
Tornado Alley – Central US/Great Plains
Hurricanes & Typhoons
Weather Systems
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Read “Weather Systems”
Climate and
Vegetation
Patterns
Tropical Climates
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ecosystem – a community of plants, animals, soil, climate
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tropical humid (wet) – rains all year – hot all year
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the most diverse are in the hot
regions
convectional rainfall – rains same time every day – rains-evaporatesrains –hot air
tropical wet and dry – (tropical savanna) – 3 seasons =
wet, dry, fire
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affected by monsoon winds
savanna – savanna grasslands – depends on wind direction
Dry Climates
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arid – dry – can have constant high pressure
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located about 30º north and south of the equator
less than 10” of rain per year
rain shadow
interior of continents
dry coastal areas – cold currents keep air stable (coast of Chili)
semiarid – 10-20” of rain
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transition between arid and humid regions
grasses grow well (Great Plains)
used for growing grains
Mid-Latitude Climates (temperate)
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Mediterranean Climate – hot, dry summer and cool, moist winter
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Humid Subtropical Climate – hot, wet summer and cool winter
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eastern side of continent – where there is warm water – example: Virginia Beach
vegetation includes deciduous forest – broadleaf tress where leaves die
coniferous forest – tress are cone bearing with needles
Marine West Coast – mild all year – influenced by the ocean
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Mediterranean Sea, California, Spain, Chili, Australia
usually west coast of a continent
Mediterranean scrub woodland vegetation
short trees and shrubs
on the west coasts in the upper middle latitudes – W. Europe, NW US and Canada
can support dense coniferous forests – called “Temperate Rainforests”
Humid Continental – hot summer, cold winter
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interior and east coast of upper middle latitude continents
High Latitudes Climates
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subarctic – long, cold winter and short warm summer
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generally above 50º north -- far north of Asia, Europe and North
America
supports vast evergreen forests – these are called boreal forests
Skagway = 200 year old trees
tundra – coastal areas of high latitudes
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temperature is above freezing only in the short summer
permafrost – permanently frozen soil
In the short summer, top layer turns to bog, swamp, marsh since
water cannot seep into the frozen ground – buildings collapse
vegetation includes lichens, moss, grasses and low shrubs
Highlands Climates
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highlands climates – on the side of
mountains
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changes as you go
higher in elevation
Ex. Mt. Kilimanjaro
in Africa
 READ
CASE STUDIES –
“THE POLES” – PAGES 5859.
 Complete climate chart
Landforms, Water, and
Natural Resources
Chapter 4
Chapter 4.1: Landforms
Forces below the earth
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Geology – the study of the earth’s physical
structures and the processes that have
created them
Parts of the earth
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Inner core: center of the earth
Outer core: dense liquid material
Mantle: liquid rock (magma); becomes lava when
it breaks through the surface
Crust: surface (lithosphere)
The Earth’s Layers
Internal Forces
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plate tectonics: crust is made up of moving plates
continental drift: plates are moving by convection
along the magma
Volcanoes: happen along the plate boundaries
Earthquakes: happen along the plate boundaries
Pangea: super continent – rock formations and
fossils line up
Pangea
Watch how
the
continents
move to
form the
Earth as
we see it
today.
Plate Movement
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Spreading: plates spread apart, forming a diverging
plate boundary; such areas are likely to have a rift
valley, earthquakes, or volcanic action (ex. MidAtlantic Ridge, rift valley on land – Iceland, Africa)
Collision: plates collide & mountains form (ex.
Himalayas formed millions of years ago when the
Indo-Australian plate crashed into the Eurasian
Plate at a rate of about two inches per year)
Subduction: plates dive under one another (ex.
Andes Mountains formed over millions of years as
the Nazca Plate slid under the South American plate)
Faulting: plates slip past one another (ex. California
San Andreas Fault)
Abyssal Plain
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Abyssal Plain: area of ocean floor where
rocks gradually sink; they have no supporting
heat below; these are the world’s flattest and
smoothest regions
Continental Shelf – the shallow land around
a continent
Continental Shelf
When Plates Collide…
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under the ocean – 1 dives and a trench is
formed – diving plate generates heat – this
may cause a volcano -- mountains / islands
are formed
mountains are formed – Himalayas, Alps -folds – like a towel – a head on collision -faults – cracks in the earth
plates moving latterly – San Andreas Fault -pressure builds and has to go some where
San Andreas Fault
Some Quake and Dirty Facts…
What's the world's largest earthquake?
9.5 magnitude in Chile on May 22, 1960
What's the U.S.' largest earthquake?
9.2 magnitude in Prince William Sound, Alaska, on March 27,
1964. The earthquake and ensuing tsunami killed 125 people
(tsunami 110, earthquake 15), and caused about $311 million in
property loss.
What's the world's most destructive earthquake?
830,000 died in Shansi, China, on January 23, 1556.
Which state has the most damaging earthquakes?
California.
Some Quake and Dirty Facts…
When will California slide into the ocean?
Hey, are you from the East Coast? There is no scientific reason for
California to fall into the ocean.
Is Los Angeles moving closer to San Francisco?
Angelinos will be barbecuing alongside latte-sipping City folks
sooner than you can say plastic surgery. Due to motions of the
plates, L.A. is gradually creeping northward and will eventually
be a suburb of San Francisco.
I want to move to a place that doesn't have earthquakes.
Where can I go?
Grab a seal blubber-lined parka and move to Antarctica (which has
the fewest amount of earthquakes of any continent), or stay
put: Small earthquakes can occur anywhere in the world.
Some Quake and Dirty Facts…
Where can I buy a Richter scale?
At Safeway - next to the Weight Watchers scale. The Richter scale is not a
physical device, but a mathematical formula.
How many earthquakes happen every month? Day? Minute?
Per year: Approximately 1,000,000, including those too small to be felt.
Per month: Approximately 80,000
Per day: Approximately 2,600
Per minute: Approximately 2
Per second: Approximately one earthquake every 30 seconds.
What was the first instrument to record an earthquake?
In 132 A.D., Chinese philosopher Chang Heng invented the first
seismoscope, a large urn decorated with dragonheads and gapingmouthed frogs.
The Himalayas
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The 6,000 km
plus journey of
the India
landmass
(Indian Plate)
before its
collision with
Asia (Eurasian
Plate) about
40 to 50
million years
ago.
Weathering and Erosion
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Weathering: break down of rock; decay of
rock (actually breaking)
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new soil is formed
frost wedging –
splitting of rock
A rock in
southern Iceland
fragmented by
freeze-thaw
action.
Weathering and Erosion
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Chemical Weathering: dissolves rock
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Caves are formed
Limestone
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Erosion: wind, water, glaciers
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 Movement
of weathered material from place to
place
 Important for life, soil
Water, Waves, and Wind
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Water: #1 type of erosion
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no plants = more erosion
forms V shaped valleys, river valleys, canyons
Waves: erosion in Virginia Beach, North
Carolina
Wind: sand is moved by wind
Jockey’s Ridge
Dust Bowl
Dust storms in Texas, 1935
Buried machinery in barn lot.
Dallas, South Dakota, May 1936
The Power of Ice
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acts like a bulldozer
most of Greenland and Antarctica are
covered by ice – up to 2 miles
found in the high mountains – even on the
equator
forms U shaped valleys (river=V)
Glaciers
Shapes on the Land
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First: landforms formed by tectonic forces
by volcanoes, earthquakes, folding, faulting
Second: landforms formed by erosion
forms a plateau – an elevated flat land that rises
sharply above nearby land at least on 1 side
Third: landform formed by sediment deposited by
wind, water, glaciers
sand dune, flood plain, delta
Alluvial Fan
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Fan-shaped deposit of mud and gravel often
found along the bases of mountains
Most regions have many types
of landforms. The location,
size and shape of landforms
affect where people live and
their transportation.
Alluvial Fan: Death Valley
Chapter 4.2: The Hydrosphere
Water on Earth
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Only 3 percent of the water on earth is fresh
Most fresh water is in the ice
Desalination: removing salt from water
Hydrologic Cycle: movement of water
through the hydrosphere
Hydrologic Cycle
Surface Waters
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As precipitation falls on continents and
islands, it flows down hills and mountains
toward the lowlands and coasts.
Headwaters: smallest streams
Tributaries: any stream or river that flows
into a larger stream or river
watershed/drainage basin – region drained
by a river
Keep In Mind…
WATER HEATS AND
COOLS SLOWER THAN
LAND
Surface Water cont…
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Estuary: forms where a river meets an inlet,
or small arm of a sea (wide mouth of a river)
(ex. Chesapeake Bay, Thames River in
England, etc.)
Groundwater
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Groundwater: water found beneath the
surface
Water table: level below the surface that are
filled with water
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Depends on amount of rainfall
Can cause sinkholes if all water is removed
Floods
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Floods: caused by sudden heavy rains or
snow melt; they erode the land and destroy
vegetation
Floodplains are fertile and good for farming
Chapter 4.3: Natural Resources
Soil and Forests
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These are renewable resources
Soil: takes a long time to form
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includes rocky sediment and organic material
climate affects weather which affects soil
Humus: mix of bacteria, insects, worms that
breakdown plants and animals
Leaching: soil is less fertile due to rainwater washing
out minerals and nutrients
Similar climates = similar vegetation
Sustaining Soil Resources
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Contour plowing: farming at an angle; works across a
hill rather than up and down the hill; stops erosion
Soil Exhaustion: caused by same crop being planted
in the same spot every year
Rotation: planting different crops in the same spot
Irrigation: artificial watering
soil salinization: salt builds up in the soil
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soil has salt in it and evaporation leaves it behind
flooding helps this problem
Farming with row patterns nearly level around the hill—not up
and down hill. Crop row ridges built by tilling and/or planting on
the contour create hundreds of small dams. These ridges or dams
slow water flow and increase infiltration which reduces erosion.
Forests
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Deforestation: destruction/loss of forests –
clearing the land for farming or ranching
Reforestation: replanting trees
What products do
we get from plants
and trees?
Deforestation
Deforestation for agriculture
in Benambra, Australia
DE
FOREST
Jungle burned for agriculture in
southern Mexico.
ATION
Air
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Smog: smoke and fog form chemicals in the air
– leads to pollution
– L.A., Mexico City
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Acid Rain: chemicals in polluted air combine with water vapor
and form acid rain
– destroys trees – pollutes – eats away stone and natural rock
formations
– Causes industrial pollution
– acid producing agents in the ocean and volcanic activity are
among the causes of acid rain.
– Countries: Germany, China, US, Scandinavia, Canada
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Global Warming – trapped heat in the atmosphere is causing a
rise in temperatures
Smog over Beijing
A comparison of Beijing air on a day after rain and a sunny
but smoggy day
The effects of acid rain in the
Jizera Mountains of the Czech Republic
Water
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Aqueducts: bring water to the cities
Aquifers: ground water is mined
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Wells
ground water is usually renewable
Fossil water: ground water in the desert that
is used for irrigation
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not being replaced
Pont du Gard, France, a Roman
aqueduct built circa 19 BC. It is one
of France's top tourist attractions
and a World Heritage Site.
Aqueducts
The Central Arizona Project
Aqueduct, the largest and most
expensive aqueduct system ever
constructed in the United States.
Mineral Resources
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Uses of minerals
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We make things from minerals
Ore = mineral bearing rock
Mineral Recycling
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Usually metals like aluminum
Switzerland and Japan
have no resources but are
very wealthy.
Energy Resources
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Fossil fuels: energy resources formed from
the remains of ancient plants and animals,
including coal, natural gas, and petroleum
Petrochemicals: certain products made from
oil
Geothermal energy: heat of earth’s interior
Who has the oil?
Who has the oil?
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In order of amount produced in 2004 (MMbbl/d = millions of barrels per
day):
Saudi Arabia (OPEC) - 10.37 MMbbl/d
Russia - 9.27 MMbbl/d
United States 1 - 8.69 MMbbl/d
Iran (OPEC) - 4.09 MMbbl/d
Mexico 1 - 3.83 MMbbl/d
China 1 - 3.62 MMbbl/d
Norway 1 - 3.18 MMbbl/d
Canada 1,3 - 3.14 MMbbl/d
Venezuela (OPEC) 1 - 2.86 MMbbl/d
United Arab Emirates (OPEC) - 2.76 MMbbl/d
Kuwait (OPEC) - 2.51 MMbbl/d
Nigeria (OPEC) - 2.51 MMbbl/d
United Kingdom (Scotland) 1 - 2.08 MMbbl/d
Iraq (OPEC) 2 - 2.03 MMbbl/d
Final Thought…
Has the value of
resources changed
over time?