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transcript
Chapter 3:The Dynamic Earth
31. The Geosphere3.2 The Atmosphere
3.3 The Hydrosphere and Biospherep.58-83
Key Terms• Geosphere• Crust• Mantle• Core• Lithosphere• Asthenosphere• Tectonic plate• Erosion• Atmosphere• Troposphere• Stratosphere• Ozone
• Radiation• Conduction • Convention• Greenhouse effect• Water cycle• Evaporation• Condensation• Precipitation• Salinity• Fresh water• Biosphere• Closed system• Open system
3.1 The Geosphere
• Describe the composition and structure of the Earth
• Describe the Earth’s tectonic plates• Explain the main cause of earthquakes and their
effects• Identify the relationship between volcanic
eruptions and climate change• Describe how wind and water alter the Earth’s
surface
The Earth as a SystemWhat are the conditions that allow us to survive
on a constantly changing planet?The earth is divide into 4 parts
1. Geosphere (rock)2. Atmosphere (air)3. Hydrosphere (water)4. Biosphere (living things)http://www.youtube.com/watch?v=uG3ql0vLioU
Geosphere• The solid part of the Earth that consists of all
rock, soils and sediments on Earth’s Surface• Most is located in interior • http://volcano.oregonstate.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers1.html
Discovering Earth’s Interior
• Very difficult to study – we have only looked at 12km deep • Seismic waves to study Earth’s Interior (waves travel differently in
physical layers)Composition of Earth-
http://www.youtube.com/watch?v=_iUfi8XqEos&feature=related
1. Crust- thin outer layer, light elements, less than 1% of planet’s mass2. Mantle 64% mass of Earth, 2,900km thick, rock medium density, iron
rich layer3. Core densest element radius of 3,400km, hot nickel and iron center of
EarthBill Nye- http://www.youtube.com/watch?v=5qp-EVOsZOs (18mins)
Composition of Earth-3 layers
1. Crust- think outer layer, light elements, less than 1% of planet’s mass, 5-8km thick beneath the oceans and 20-70km beneath the continents
2. Mantle- layer under crust, makes up 64% of mass, 2,900km thick, made of rock, medium dense
3. Core- innermost layer, densest elements, radius of 3,400 km
The Structure of the Earth
5 layers- http://video.about.com/geography/The-Four-Earth-Spheres.htm
1. Lithosphere (stone)2. Asthenosphere3. Mesosphere4. Outer Core5. Inner Core
Lithosphere- stone
• 15-300 km thick• Cool rigid• Outermost layer of Earth• Crust and uppermost part of mantle• Divided into huge pieces called plate tectonic • Both continental and oceanic crust
Asthenosphere
• 250 km thick• Solid plastic layer of mantle between the
mesosphere and the lithospehre• Made of mantle rock that flows very slowly,
allows for plates to move on top of it
Mesosphere
• 2,550 km thick• Middle sphere• Lower layer of the mantle between the
asthenosphere and the outer core
Outer core
• 2,200 km thick• Outer shell of Earth’s core• Made of liquid nickel and iron
Inner Core
• 1,228 km radius• Spere of solid nickel and iron at the center of
the Earth
Thicknesses and density
Plate Tectonics• Glide across the underlying asthenosphere like ice on a pond• Continents are located on them and move with them• Pacific, North American, South American, African, Eurasian, and Antarctic
plates• Plate boundaries- this movement may cause mountains, earthquakes,
volcanoes erupt• Plate Tectonics and Mountain Building- Himalaya Mountains (Asia and India
plates collided 50mya)• Alfred Wegener- first proposed theory of continental drift
• http://www.ucmp.berkeley.edu/geology/tectonics.htm• http://www.youtube.com/watch?v=1-HwPR_4mP4 (7mins)• NGO- 50minshttp://www.youtube.com/watch?v=KCSJNBMOjJs&feature=relatedBill- 23mins
https://www.youtube.com/watch?v=2hKssFQdZ0k&feature=related
Matching fossils, mountains, rock deposits…
Plate Boundaries1. Convergent Boundaries- crashing
Places where plates crash or crunch together.2. Divergent Boundaries- pulling apart
Places where plates are coming apart 3. Transform Boundaries-side swiping
Places where plates slide past each other are
More info : http://www.cotf.edu/ete/modules/msese/earthsysflr/plates1.html
Plate Boundaries
Divergent Plate Boundary• Move plates apart to expose mantle
spreading zone. • When plates move apart, it creates cracks in
the Earth called rift valley• Allows hot, melted rock to come up through
the cracks volcano opening is formed• Sea floor spreading- new sea floor created• http://geology.com/nsta/divergent-boundary-
oceanic.gif
Seafloor Spreading and Subduction
Convergent Plate Boundary
• Push plates back together until the middle forms a ridge
• When plates collide they create mountains this is called a collision zone
• Appalachian mountains – Africa collided with North America during formation of Pangea
• Destroy sea floor- ocean plates more dense than land plates, when they converge ocean plates slide under land plates
3 sub types
• Ocean to ocean• Ocean to continental • Continental to continental
• http://geology.com/nsta/convergent-plate-boundaries.shtml
Transform Plate boundary
• Slide the edges of plates against each other• This horizontal grinding and sliding of the
plates causes earthquakes• This is called a shearing fault• A fault is a fracture in the Earth’s crust• New Madrid Fault- runs along the eastern
border of Missouri• San Andreas Fault- most studied
Earthquakes• Fault- break in Earth’s crust preventing it from sliding• When it breaks and creates vibrations in crusts
creates earthquakes• Occur all the time most are too small to feel• Richter scale- quantify the amount of energy
reassessed by an earthquake or its magnitude• Smallest magnitude that can be felt is 2.0• Largest recorded 9.5• Earthquakes of 7 or greater cause widespread damage
Where do they occur?
• Take place at the boundaries due to the stress level• San Andreas Fault along California (N. American
plate and Pacific plate are slipping)• We cannot predict when they will occur but rather
the likely hood of where they can occur• High risk areas we build bridges and buildings
slightly flexible so they can sway when the ground moves
• http://earthquakestoday.info/
Japan's Tsunami - How it Happened 2011
• http://www.youtube.com/watch?v=24A8UwpYSs8&feature=related
Volcanoes• Mountains/ islands built from magma, melted
rock, that comes from the Earth’s core• Can occur on land or under the sea• Most active areas is around the pacific Ocean
plate boundaries• https://www.youtube.com/watch?v=NBPwwt0HuVo
Hot Spotshttp://www.wwnorton.com/college/geo/egeo/animations/ch2.htm
Local Effects of Volcanic Eruptions
• Loss of human life• Clouds of hot ash, dust, gases travel down at
speed of 200km/hr killing everything in its path
• Can mix with water can create a mudslide• Destroy buildings, bury crops, damage engines
of vehicles• Breathing difficulties
Global Effects of Volcanic Eruptions
Global impact: https://www.youtube.com/watch?v=TghGWlVN31chttps://www.youtube.com/watch?v=k8mAtY-7n-o
• Mt St Helen- change Earth’s climate for several years
• Ash and gases travel into the atmosphere reducing sunlight decreasing global temperatures for several years
• Top 10- https://www.youtube.com/watch?v=4aYQixhdWY4&feature=fvwrel
• Billl Nye• https://www.youtube.com/watch?v=gOc04z8jHaM• https://www.youtube.com/watch?v=MucQmSIKElU&feature=related (23mins)
Folds
Over millions of years, stress
forces can bend rock like a ribbon or soft dough.
Steady pressures of stress over
long periods of time affect sedimentary layers and can fold them into dramatic forms.
Folds
Folds : During mountain building,
compressional stresses often bend flat-lying sedimentary rocks into wavelike ripples called folds.
Folds of sedimentary strata come
in three main types Anticlines Synclines Monoclines
Anticlines and Synclines
Anticlines and Synclines : An anticline is usually formed by
the upfolding, or arching of rock layers.
Often found in association with
anticlines are downfolds, or troughs, called synclines.
The anticlines are the folds that
go upwards and the synclines are the folds that go downward.
Dips
The angle that a fold or fault makes with the horizontal is called the dip of the fold or fault.
The more the bend in the fold or
fault, the stronger the dip. In the figure at right, folds, faults
and dips are visible in B. In C, the folds are starting to
overturn and D and E the folds have overturned all the way and folded over completely.
Monoclines
Monoclines Folds are generally closely
related to faults in the Earth’s crust. Examples of this close association can be found in monoclines.
Monoclines are large step-like
folds in otherwise horizontal sedimentary layers.
Monoclines occur as sedimentary
layers get folded over a large faulting-block of underlying rock.
Monoclines are a prominent
feature of the Colorado Plateau region.
Hanging walls and footwalls
Faults Recall that faults are fractures in
the Earth’s crust along which movement has taken place.
The rock surface immediately
above the fault is called the hanging wall.
The rock surface below the fault
is called the footwall.
Types of Faults
Faults
The major types of faults are Normal faults Reverse faults Thrust faults Strike-slip faults
Types of Faults
Faults Normal faults occur due to
tensional stress and reverse and thrust faults occur due to compressional stress.
Compressional forces generally
produce folds as well as faults, resulting in a thickening and shortening of rocks.
Shearing stresses produce strike-
slip faults. Faults are classified according to
the type of movement that occurs along the fault.
Normal Faults
Normal Faults A normal fault occurs when the
hanging wall block moves down relative to the footwall block.
Most normal faults have steep
dips of about 60 degrees. These dips often flatten out with depth.
The movement in normal faults
is mainly in a vertical direction, up-down, with some horizontal movement as well.
Because of the slide down of the
hanging wall block, normal faults result in the lengthening, or stretching, of the crust.
Tensional stress pulls the blocks apart and lets the hanging wall drop downward
Reverse Faults
Reverse Faults: A reverse fault is a fault in which the
hanging block moves up (instead of down) relative to the footwall block.
Reverse faults are high angle
compressional faults with dips greater than 45 degrees.
Thrust Faults
Thrust Faults: Thrust faults are reverse faults
with dips of less than 45 degrees.
Because the hanging wall
block moves up and over the footwall block, reverse and thrust faults result in a compression, squeezing and shortening, of the crust.
Thrust Faults
Thrust Faults: Most high-angle reverse faults
are small in scale. They cause only local displacements in regions that are already filled with other types of faulting.
Thrust faults, however, exist at
all scales. Many can be quite large.
In the Swiss Alps, the northern
Rockies, Himalayas, and Appalachians, thrust faults have displaced layers as far as 50 kilometers.
The result of this type of
movement is that older rocks end up on top of younger rocks.
Strike-Slip Faults
Strike-Slip Faults: Faults in which the movement
is horizontal and parallel to the line of the fault is called a strike-slip fault.
Because of their large scale,
and linear nature ( in a line) many strike-slip faults produce a trace that can be seen over a great distance.
Rather than a single fracture,
large strike-slip faults usually consist of a zone of roughly parallel fractures.
Strike-Slip Faults
Strike-Slip Faults: The zone of parallel fractures
created by a strike-slip fault may be up to several kilometers wide.
The most recent movement is
often along a section only a few meters wide and may offset features such as stream channels.
Crushed and broken rocks
produced during faulting are more easily eroded, often producing linear valleys or troughs that mark strike-slip faults.
Fence break created by strike-slip fault
• The three basic types of faults are normal, reverse, and strike-slip (lateral). (A) A normal fault is one in which the rocks above the fault plane, the hanging wall, move down relative to the rocks below the fault plane in the footwall. (B) A reverse fault is one in which the hanging wall moves up relative to the footwall. (C) When rocks on either side of a nearly vertical fault plane move horizontally, the movement is called strike-slip.
Erosion• The removal and transport of surface material • Water Erosion- rivers create deep gorges or
oceans waves erode coastlines• Wind Erosion- area where plants are limited
(beaches and deserts) sandstone vs granite can erode more quickly
https://www.youtube.com/watch?v=G5Rp9MJJGCUBill- https://www.youtube.com/watch?v=HjVSiuj7Lxk&feature=related
3.2 Atmosphere
• Describe the composition of the Earth’s Atmosphere
• Describe the layers of the Earth’s atmosphere• Explain 3 mechanisms of heat transfer in
Earth’s atmosphere• Explain the greenhouse effect• http://
www.youtube.com/watch?v=fyfN9t_E0w8
Atmosphere• Mixture of gases found in first 30km above the
Earth’s surface• Constantly changing (photosynthesis, Cellular
Respiration, Volcanic eruption, cars**Insulates earths surface- allows for animals to survive.
Composition of the Atmosphere
• Nitrogen 78%• Oxygen – 21%• Other -1 % (argon, carbon dioxide, methane, water
vapor)• Aerosols- Tiny solid particles or dust (soil, salt, ash,
skin, hair clothing, pollen, bacteria, viruses,)• Air pressure- due to the gravity, more dense closer
to earth, difficult to breath at higher elevations, all/ most atmosphere gases located within 30 km to earth surface
• http://www.youtube.com/watch?v=jmQ8FWnM0fA
Layers of the Atmosphere- based on temperature
1. Troposphere2. Stratosphere3. Mesosphere4. Thermospherehttp://www.youtube.com/watch?v=1YAOT92wuD8&list=PLtXf78zN40CILuFkZqcgLKaVidMRxQdkE
Troposphere-
a. layer closes to the Earth’s surface to 18km aboveb. weather occurs in this layerc. densest layerd. temperature decreases as altitude increases
Stratosphere-
• Above the troposphere• Extends from 18km to altitude of 50km• Temperatures rise as altitude increases in the
stratosphere, because the ozone absorbs the suns UV energy and warms the air
• Ozone- O3- molecule that is made up of 3 oxygen atoms (ozone layer),Reduced the amount of UV that reaches the Earth, (blanket of protection)
Mesosphere
• Layer above the stratosphere• Extended to an altitude of 80km• Coldest layer as low as -93’C
Thermosphere• Farthest from the Earth• Nitrogen and oxygen absorb solar radiation-
temperatures have been measured above 2,000’C• Would not feel hot to us because this layer is so thin
that air particles rarely collide – little heat is transferred
• Lower level is called ionosphere – it absorbs X and gamma rays, causing the atoms to be electrically charged (ions)
• Ions can radiate energy as light- Aurora Borealis or Northern Lights (North and South poles)
Energy in the Atmosphere
• Energy is neither created or destroyed transferred and transformed1. Radiation- transfer of energy across a space (fire,
sunlight)2. Conduction- flow of heat from one object to
another3. Convection- air currents (hot air rises)– http://www.youtube.com/watch?v=7Y3mfAGVn1c
Heating of the Atmosphere• Solar energy reaches the Earth as electromagnetic
radiation, visible light, infrared radiation, UV light• Only ½ actually reaches the Earth• Most is absorbed or reflected by clouds, gases and dust• Ocean/ lakes and land radiate the energy back into the
atmosphere• 50% absorbed by Earth’s Surface• 25% scattered and reflected by clouds and air• 20% absorbed by ozone, clouds and gases• 5% reflected by Earth surface
The Movement of Energy in the Atmosphere
• Convection Currents- movement of the air in a circular pattern that are caused by the unequal heating of the Atmosphere
• Cold air sinks and hot air rises– Sea Breeze– Land breezeCoriolis Effect– http://www.youtube.com/watch?v=i2mec3vgeaI
The Greenhouse Effect
• Gases trap heat near the Earthhttp://www.epa.gov/climatestudents/basics/today/greenhouse-effect.html
• Like heat being trapped into a car on a hot day, the glass window would be the atmosphere
• This allows for the Earth to be warm, if it did not occur Earth would be too cold for life
3 mins- http://www.youtube.com/watch?v=ZzCA60WnoMkDiscovery Channel - Global Warming, What You Need To Know, with Tom Brokaw80mins- http://www.youtube.com/watch?v=xcVwLrAavyA&feature=relatedhttp://www.epa.gov/climatechange/kids/index.html
3.1The Hydrosphere and Biosphere
• Name 3 major processes in the water cycle• Describe the properties of ocean water• Describe the 2 types of ocean currents• Explain how the ocean regulates Earth’s
Temperature• Discuss the factors that confine life to the
biosphere• Explain the difference between open and closed
systems
Hydrosphere
• Makes up all of the water on the Earth’s surface (oceans, lakes, wetlands, rivers, ice caps, soil, rock layer, and clouds)
• Most is found in the oceans (3/4 globe)• Atmosphere, land and in soil
Hydrosphere and Water Cycle
Water cycle- Continuous movement into ht air, land back to water
– Evaporation- liquid water is heated by sun and goes into the atmosphere
– Condensation- water vapor cools and forms water droplets
– Precipitation- larger droplets fall from clouds (snow, sleet, or hail)
Bill Nye- (3mins)http://www.youtube.com/watch?v=hehXEYkDq_YRap- http://www.youtube.com/watch?v=i3NeMVBcXXU&feature=fvwrelMagic School Bus-
Earth’s Oceans
• World Oceans- Arctic, Pacific, Atlantic, Indian• 70% of earth surface• Regulates Planet’s environment• salinity(3.5%)High salt concentrations, lower
where freshwater or rain runs into it, high in areas where evaporation is high
• Temperature zones- surface warmed by sun, deep clod no sunlight (surface zone, thermocline- warm and cold weather)
• Lab demo: http://www.youtube.com/watch?v=wqtFeAvDOwk
Global Temperature Regulator• Absorb and store energy from sunlight regulates
temperatures in Earth’s Atmosphere• Ocean absorbs and release more slowly than land does• If it did not regulate temps conditions would be too
extreme for life today• Can warm land masses near by • The ocean is able to absorb incident solar energy, then
slowly release it in the form of heat. Land cannot absorb nearly as much heat, and land releases heat quickly. The ocean keeps global temperatures much less variable than they would be if the entire surface of the planet was land.
Ocean Currents
• Surface currents- stream like movements of water that occur at or near the surface, wind driven and a result from global wind patterns
http://www.youtube.com/watch?v=YCorkyBe66o
• Deep currents- stream like movements of water that flow very slowly along the ocean floor (Antarctic Bottom Water)
http://www.youtube.com/watch?v=XVZujRMGZzs
Bill Nye- http://www.youtube.com/watch?v=4_wLatK7sXghttp://www.youtube.com/watch?v=w_8mw-1HYFg
Fresh water
• 3% of Earth’s water• Most is locked in icecaps and glaciers• Lakes, rivers, streams, ground water, wetlands,
and atmosphere• River systems- network of streams that drains
an area of land including its tributaries (small that flow into large ones)
• Mississippi River system 40%
Ground water
• Rain and melting snow run off the land collected into the ground
• 1% of all of Earth’s Water• Aquifers- rock layer that stores and allows the
flow of ground water• Recharge zone- where water enters an aquifer• ED Aquifer- http://www.youtube.com/watch?v=NzYWOM2TmJk&list=PLyw1u3Z_dHA46BekGol8sBVYa5CIslI-6
Biosphere
• Part of Earth were life exists • Think layer at Earth’s surface down to the
bottom of the oceanhttp://www.youtube.com/watch?v=RmifaYcLPik&feature=related
Biosphere
• If the Earth was an apple- it would be the skin• Uppermost part of the geosphere, most of
hydrosphere, lower part of atmosphere• 11km into the ocean and 9km into the
atmosphereLife requires:
• liquid water• Temps between 10-40’c • Source of energy
Energy Flow in the Biosphere
• Sun light main source of energy• 4 biogeochemical cycle ( recycling of once
living organisms to be put back into the Earth’s resources)– Closed system- Earth mostly closed with respect
to matter, Eden Project– Open system- sun/ energy, energy comes in from
the sun and lost as heat
Webquest:• http://www.learner.org/interactives/dynamice
arth/structure.html
BBC- Power of the Planet
Atmosphere • http://www.youtube.com/watch?v=J5ViCNJAk
Hg&feature=endscreen&NR=1Earth• http://www.youtube.com/watch?v=a_pzxz71j
DM&feature=fvwrelice• http://www.youtube.com/watch?v=H0Maf03
wGvE&feature=relmfu