Transcript environmental science chapter 3

ENVIRONMENTAL SCIENCE
CHAPTER 3
THE DYNAMIC EARTH
• SECTION 1: THE GEOSPHERE
VOCABULARY
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GEOSPHERE
CRUST
MANTLE
CORE
LITHOSPHERE
ASTHENOSPHERE
TECTONIC PLATE
EROSION
THE COMPOSITION OF EARTH
• The Earth is composed of 3 major layers
• Crust: less than 1% of earth’s mass, outer layer
• Mantle: middle layer, makes up 64% of earth’s
mass
• Core: inner most layer, radius of 3,400 km
• 245 mya all land on Earth was joined in super
continent Pangea
THE STRUCTURE OF EARTH
• 5 LAYERS
• Lithosphere: divided into huge tectonic plates
• Asthenosphere: slightly fluid layer beneath
lithosphere…tectonic plates float on it
• Mesosphere: “middle” sphere
• Outer Core: made of liquid nickel and iron
• Inner Core: solid nickel and iron
DISCUSSION
• WHY IS IT IMPORTANT THAT ALL THE LAYERS
OF THE EARTH MOVE EXCEPT THE CORE?
• WHY IS IT THAT THE CORE AND THE CRUST
ARE THE ONLY SOLID LAYERS ON THE EARTH?
• WHY IS THIS IMPORTANT?
PLATE TECTONICS
• Most of the geologic activity that happens on
Earth occurs here
• Plates are constantly moving on Earth’s
surface
• Separate…volcanoes
• Collide…mountains
• Slip…earthquakes
Recent Quakes
• http://earthquake.usgs.gov/earthquakes/rece
nteqsww/
EROSION
• CAUSED BY WIND AND WATER
• RIVERS AND OCEANS CAN CAUSE DRAMATIC
CHANGES OF THE EARTH’S SURFACE
• WIND CHANGES SOIL LEVELS
– IF THERE ARE NO PLANTS TO HOLD SOIL DOWN
WITH ROOTS, THEN SOIL BLOWS AWAY
• SECTION 2: THE ATMOSPHERE
VOCABULARY
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ATMOSPHERE
TROPOSPHERE
STRATOSPHERE
OZONE
RADIATION
CONDUCTION
CONVECTION
GREENHOUSE EFFECT
COMPOSITION OF ATMOSPHERE
• 78% Nitrogen…comes from volcano eruption
and plant/animal decay
• 21% Oxygen….comes from plant production
• 1% Other Gases…Argon, CO2, Methane, and
Water Vapor
• Also contains dust….dirt, salt, ash, skin, etc.
• AIR PRESSURE: caused by gravity pulling
atmosphere toward surface of Earth
– How does air pressure change as the elevation
change?
LAYERS OF ATMOSPHERE
• TROPOSPHERE: layer nearest earth surface,
almost all weather occurs in this layer
• STRATOSPHERE: above troposphere, contains
the ozone layer (protects us from UV rays)
• MESOSPHERE: coldest layer of atmosphere
• THERMOSPHERE: layer farthest away from
earth surface, extremely high temperatures, first
layer of defense against solar radiation
ENERGY IN ATMOSPHERE
• CONDUCTION transfers heat from object to
object and CONVECTION carries the heat in
waves around the planet
– Hot air rises….cold air sinks…causes weather
• Solar energy heats the atmosphere…dark
colors absorb heat, light colors reflect it
• Air is constantly moving up and down due to
convection currents
GREENHOUSE EFFECT
• The gas in our atmosphere lets heat in, but
not out….like a car and its windows
• Some heat will escape the atmosphere, but
most is absorbed by GREENHOUSE GASSES
• SECTION 3:
• THE HYDROSPHERE AND BIOSPHERE
VOCABULARY
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WATER CYCLE
EVAPORATION
CONDENSATION
PRECIPITATION
SALINITY
FRESH WATER
BIOSPHERE
CLOSED SYSTEM
OPEN SYSTEM
THE HYDROSPHERE & WATER CYCLE
• HYDROSPHERE – includes all water on or near
earth surface
• WATER CYCLE – constant motion of water into
air, onto land and back again
• Evaporation, condensation & precipitation are
3 main steps
EARTH’S OCEANS
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ALL OCEANS ARE CONNCETED
Make up 70% of Earth’s surface
Largest is the Pacific…Smallest is the Arctic
Ocean water is high in salt content…comes
from rocks and volcanic eruptions
• The deeper you go in the ocean the colder it
gets….WHY?
• Oceans are a temperature regulator
• Absorbs and stores energy from the sun
• Absorbs over ½ of the solar radiation that
reaches the surface
• Ocean currents are responsible for localized
weather
• If an area has warm ocean currents then they
will have warmer weather
• If an area has cool/cold ocean currents then
they will have cool/cold weather
FRESH WATER & GROUND WATER
• Little more than 3% of water on earth is fresh
water…mostly locked up in icecaps and
glaciers
• Made up of river systems…interconnected
rivers and tributaries
• Precipitation sinks into ground and collects as
ground water in rock layers called AQUIFERS
THE BIOSPHERE
• Earth compared to apple…biosphere
compared to apple skin…small layer of Earth
that actually supports life
• Biosphere located near Earth’s surface
because most of sunlight is available at Earth’s
surface
ENERGY FLOW IN BIOSPHERE
• CLOSED SYSTEM: energy enters environment,
matter does not
• Earth mostly closed system to matter, but
open system to energy
• FOOD CHAINS/WEBS
• OPEN SYSTEM: both matter and energy are
exchanged