Transcript Middle Latitude

Weather?
• Condition of the
atmosphere at a given
time and place
Climate?
• Condition of weather in a
geographic region over a
long period of time
Temperature?
• Measurement of heat
Tilt of the Earth
• Axis- an imaginary line running
from the North Pole, through
the center of the Earth, to the
South Pole.
–Located at 23 ½ degrees upon the
axis
–Effects temperature depending upon
tilt of the Earth towards or away
from the sun.
Rotation
• The spinning of the Earth
on its axis.
• 1 rotation= 24 hours
Revolution
• Orbit of the Earth around
the sun.
• 365 ¼ days in one year
The Seasons
• Equinoxes- “Equal Night”
12 hrs. of day/night
• Neither Pole is pointed
toward or away from sun
–Autumnal Equinox (September
21/22)
–Vernal Equinox (March 21/22)
Cancer and Capricorn
• 23 ½ degrees North- Tropic of
Cancer
–Northernmost point on Earth to receive
direct sunlight
• 23 ½ degrees South- Tropic of
Capricorn
–Southernmost point on Earth to receive
direct sunlight
The Seasons
• Summer Solstice- North pole
is pointed toward the sun at
23 ½ degrees North
• Winter Solstice- South pole
is pointed toward the sun at
23 ½ degrees South
The Poles
• Each pole receives
continuous sunlight for 6
months of the year
• When one pole receives
sunlight the other receives
little to no sunlight
5 Factors that Affect
Climate
1. Latitude
2. Elevation
3. Wind
4. Ocean Currents
5. Landforms
Latitude
90 N
60 N
High Latitude
Middle Latitude
30 N
Low Latitude
0
Low Latitude
30 S
Middle Latitude
60 S
High Latitude
90 S
Low Latitude
–Located between 0-30 degrees
North/South
–Called the “Tropics”
–Receives sunlight all year
–Very hot temperatures
–Lush vegetation
–Abundant Precipitation
Middle Latitude
• Located between 30-60
degrees North/South
• Summers Hot, Dry
• Winters Cold, Rainy
• Dramatic Seasons
High Latitude
• Located between 60-90
degrees North/South
• Poles located here
• Cold Temperatures year
round
Elevation
• As air rises it cools and
dries
–Basically
•As you go up from the ground,
the air gets colder and drier.
Elevation
Urban Heat Island- cities or urban
areas are hotter because
1. Evaporation is less
2. Land surface (concrete) stores
heat
3. More fossil fuels add CO2 which
stores heat
4. More pollution which stores heat
Global Wind Belts
• What is wind?
–The horizontal flow of air
Types of Wind
• Prevailing Winds- winds which blow
from the same direction
• Doldrums- Windless areas around the
equator
• Westerly- Prevailing winds, in the mid
latitudes, which blow from the west
• Easterly- Prevailing winds, in the mid
latitudes which blow from the east
Types of Wind Con’d
• Front- two air masses of widely
different temperatures and moisture
levels meet
• Polar Front- occurs between 40-60
degrees North/South, warm air meets
cold air
• Jet Stream- Fastest westerly wind
which moves heat and steer weather.
Types of Wind Con’d
• Coriolis Effect- causes
prevailing winds to blow at a
diagonal
–Right in the northern hemisphere
–Left in the southern hemisphere
Global Wind Belt Diagram
90 N
Polars
60 N
Westerlies
30 N
Northeast Tradewinds
Doldrums
0
30 S
Southeast Tradewinds
Easterlies
60 S
Polars
90 S
Ocean Currents
• Water heats/cools more
slowly than land
• Current- A great river of seawater
which moves in a circular flow
• Upwelling- cold water from the ocean
floor rises to the surface
Landforms
• As warm, moist air flows from the water and
rises up the mountain it begins to cool. The
cool air then evaporates which causes
precipitation. The precipitation allows the
windward side of the mountain to have lush
vegetation.
• As the air pushes over the mountain it dries
and heats up. This causes the leeward side
of the mountain to be hot, dry.
Rain shadow Effect/
Orographic Uplift
Bodies of Water
• Oceans
–Covers 70% of Earth
–97% of all Earth’s water
–Largest is the Pacific Ocean
Seas, Gulfs, Bays
• All Saltwater
• Usually partly enclosed by land
• Largest Mediterranean Sea
Lakes, Rivers, Streams
• Lakes- a body of water which is
completely surrounded by land.
– Fresh and Salt Water
– Most were made by glaciers cutting a
valley into the Earth
– In Texas, all lakes are man-made
• Except Lake Caddo on the TexasLouisiana border
Rivers
• All civilizations begin near water (usually
river)
– Mesopotamia- (Fertile Crescent)- the land between
the two rivers: Tigris and Euphrates Rivers
• Headwater- beginning of a river (usually a
mountain)
• Mouth- end of a river (usually in a larger body
of water)
• Groundwater- wells, springs, aquifers
Freshwater
• 3% of Earth’s water
–2% frozen in glaciers and
icecaps (melt=saltwater)
–0.5% found in aquifers- water
below the Earth’s surface
–0.5% found on the surface
Desalinization
• The process of turning salt
water into fresh water
–Boil salt water and use
condensation as the fresh water
–Problem: expensive, very little
freshwater from process
Planet Earth
• 93 million miles from sun
• 8,000 miles in diameter
Atmosphere
• Air which surrounds Earth; 19
miles above the surface
–78% Nitrogen
–21% Oxygen
–1% other gases
Biosphere
• All life on Earth
Hydrosphere
• All water on Earth
–Solid- Glaciers, Icebergs
–Liquid- oceans, rivers, lakes….
–Gas- Fog
• a cloud that has come to Earth’s
surface
Lithosphere
• Solid crust of the planet
• Continents- 7 large landmasses
–Australia, Asia, Antarctica, Africa,
Europe, North and South America
Europe
North
America
Asia
Africa
South
America
Australia
Antarctica
Lithosphere
• Highest point- Mount Everest
– Himalaya mountains in South Asia
– 29,035 feet above sea level (asl)
• Lowest point- Dead Sea
– Southwest Asia (Middle East)
– (-)1,349 feet below sea level (bsl)
• Deepest point- Mariana Trench
– Pacific Ocean
– 38,827 feet
Inside the Earth
• Crust- Made up of huge, platelike sections of rock
• Mantle- Hot dense rock
• Outer Core- melted nickel and
iron
• Inner Core- solid iron and nickel
Layers of the Earth
Continental Drift
• Theory that the
continents were
all once joined in
a super continent
called “Pangaea”
but slowly drifted
apart
Plate Tectonics
• Movement of plates
What happens when
plates meet?
Converging
(Collision) Zone
They collide and push slowly
against each other and form
a collision or converging
zone.
Converging (Collision)
Zone
• If 2 continental plates collide,
mountains are formed.
Example: Himalayas
• If 2 oceanic plates collide, 1
slides under the other. Islands
often form this way.
Subduction
• Heavier sea plate dives below
the lighter continental plate
–The sea plate becomes magma
(molten rock)
–The magma burst to the surface
and forms volcanic mountains
• Example- the Andes Mountains in
South America
Accretion
• Pieces of the surface come
together as the sea and the
continental plates collide
–Results in sea mountsunderwater mountains with
steep sides and sharp peaks.
Spreading
Sea plates pull apart
Result- Rift or Valley on the
ocean floor
Faults
A continental plate slides past
or next to another continental
plate
Resulting in an Earthquake
What is an
Earthquake?
• A sudden, violent movement of
plates along fault lines
• Measured on the Richter Scale
• 1- lightest
• 10- epic
Ring of Fire
Area of volcanic and
earthquake activity along
the rim of the Pacific Ocean
What is a volcano?
Volcano- form when magma
inside the earth breaks
through the crust. Lava flows
and may produce a large,
cone-shaped mountain
Weathering
• The chemical or physical process of
breaking down rocks
• Physical weathering- large pieces of
rock are physically broken off
• Chemical weathering- changes on the
rocks chemical makeup causes changes
to the rock
Erosion
• Wearing away of the
Earth’s surface by wind,
water, glaciers
Wind Erosion
•Movement of
dust, sand, or soil
from one place to
another
Wind created alcove in Utah
Glacial Erosion
•Wearing away
of the Earth’s
surface by
moving ice
Water Erosion
•Wearing away of
the Earth’s surface
by flowing water
Sediment
•Small particles of
sand and gravel
flow through a
body of water
which aids in
water erosion
Tornado
•Twisting spirals of
wind
–Occurs in the middle
latitudes
–USA has more than
any other country
–Does not follow a
pattern
–April-June usually
between 3-7 pm
Tornado Con’d
•Fujita Scalemeasurement of the
intensity of tornado
–F0- 40 to 70 mph
–F1- 71 to 112 mph
–F2- 113 to 157 mph
–F3- 158-206 mph
–F4- 207-260 mph
–F5- 261+ mph
Tropical Cyclones
(Hurricanes/Typhoons)
•Most powerful and
destructive force of
nature in the Atlantic
Ocean (Hurricane) or
Pacific Ocean
(Typhoon)
–Tropical wave
–Tropical depression
–Tropical Storm
–Hurricane (74 mph)
Cyclone Con’d
• Produce powerful winds, torrential rains,
high waves and damaging storm surges
• Can also produce tornadoes
• Develop over large bodies of warm water
• Lose strength once they move onto land
• Named alphabetically, alternating
female/male by years.
Monsoon
•Seasonal
reversing wind
accompanied by
seasonal changes
in precipitation.
–Rainy phase
–Drought Phase
El Nino
• Periodic change in the pattern of
ocean currents and water
temperature in the Pacific Ocean
• Changes in wind currents cause
warm water from Indonesia to
move along the South American
Coast towards the US coast.
Effects of El Nino
• Precipitation increases along North
and South America coasts (floods)
• Precipitation decreases along SE
Asia, Australia, and East Asia
(Drought)
• ***Has been linked to Global
Warming
Greenhouse Effect
Earth’s atmosphere traps heat and filters the rays
of the sun which help keep the Earth warm.
Global Warming
The burning of fossil fuels
(gasoline, oil, coal…) causes
gases to be emitted into the
atmosphere which trap and store
heat which increases the
greenhouse effect and causes the
Earth to warm at a faster rate.
Effects of Global
Warming
• Rising sea levels
• Increased global temperatures
• Extreme weather events (drought,
hurricanes, tsunamis)
• Arctic ice shrinking
• Greenland ice sheets shrinking/breaking
off
• Dramatic effect on future food supplies