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Key Question 1 and 5 Lithosphere KQ1: What are the key elements of the structure of the earth?1) Describe the internal structure of the earth, including the characteristics of the:

core, mantle, asthenosphere.

Crust: The outermost part of the Earth. Composed of igneous, sedimentary, and metamorphic rocks. Mantle: Is the layer in between the the outer core and crust. Largest layer of the earth. Asthenosphere: This is also known as the upper mantle. It is a weak, fragile, and materials move through the convection currents easily. Core (inner and outer): Mainly iron and nickel alloy. Source of internal heat because contains radioactive materials which release heat as they decompose into more stable substancesOuter Core: Is liquid because the temperatures are high enough to melt nickel alloy. Conduction in this layer combines with earth's rotation to create a domino effect that maintains a system of current. Inner Core: Solid because intense pressure produced by overlying rocks crowds atoms tightly together and prevents liquids state even in extremely high heat.

2) Differentiate between oceanic and continental crust.a. Describe how seismic wave data provides evidence of earth structure.

-The seismic velocities would depend on the material properties like composition, mineral phase, packing structure, temperature, and pressure of the areas where the waves pass by. -Molten areas slow down p waves and stop s waves. -A seismic wave is an elastic wave that is generated by an earthquake or an explosion. -There are 4 types of waves. (Rayleigh, Love, P and S) Surface Waves : are of a lower frequency than body waves. Travels only through

the crust. Arrive after body waves. These waves are almost entirely responsible for

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the damage and destruction associated with earthquakes. Strength of the surface waves are reduced in deeper earthquakes.

-Rayleigh Wave: This wave travels near the earth’s surface. ● Most of the shaking felt from an earthquake is due to the rayleigh wave● These waves rolls so it moves the ground up and down

-Love Wave: ● This wave travels near the earth’s surface. ● This is the fastest surface wave● Moves the ground from side-to-side.

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Body Waves : arrive before surface waves emitted by an earthquake. These waves have higher frequency than surface waves

-P (primary) Wave: ● This wave travels through the earth’s interior. ● The p wave is the fastest kind of wave and usually the first to arrive at the seismic

station. ● This wave can move through solid rock and fluids like water or the liquid layers of

the earth● They are also known as compressional waves because of the pushing and pulling

they do

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-S (secondary) Wave: ● This wave travels through the earth’s interior● Second to arrive at seismic station ● Is the second wave you feel in an earthquake ● This wave is slower than a p wave and can only move through solid rock ● These waves move rock particles up and down or side to side

b. Plate tectonics:

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1) The major plates (mapping the earth’s plates)

2) Convection currents

Convection currents transfer heat to the surface where the magma is pushed by hot magma underneath it, causing it to flow outward, dragging the earth’s surface with it, creating divergent plate boundaries. This is the cause of ocean floor spreading. The magma under the surface moves faster than the oceanic crust, but it is still fast enough to slowly pull the crust with it, which is why certain parts of the earth’s crust are spreading apart and others are being pushed into each other.

3) Ocean floor spreading

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4) Plate boundaries:a) Destructive:

-Happens when an oceanic and continental plate boundary move towards each other-It is a rough movement and the plates get stuck-Pressure builds up and the plates forcefully move past one another-This causes earthquakes, volcanoes and tsunamis-Occur mostly in the Pacific and Eurasian Plate regions

Example: Nazca Plate-Oceanic tectonic plate in eastern pacific ocean off the west coast of South America-There is ongoing subduction so this plate is responsible for the Andean orogeny-Hotspots and volcanoes have been created due to the ongoing movement of this plate

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-It has also formed the Peru-Chile Trench and has created the Valdivia earthquake which was the largest ever recorded earthquake in history with a magnitude of 9.5

b) Constructive:-Also known as a tensional plate boundary-Happens when plate boundaries and margin move apart underneath the ocean-Magma rises from the earth’s mantle due to the movement and creates shield volcanoes-Occurs mostly in the American and African plate regions

Example: North American Plate-This plate covers most of North America, Greenland, and Cuba-Extends toward Mid-Atlantic Ridge-The main continental land mass is made of granite (cartoon), and crust (terranes)-Most notable hotspot created by this boundary is Yellowstone in Wyoming

c) Conservative:-Also known as transform faults-Found mainly on the oceanic floor where they offset oceanic ridges and cause plates to spread at different rates-The plates slide past each other with a horizontal movement that don't result in volcanic activity-Conservative boundaries do create areas of extensive shallow focus earthquakes that can be of high magnitude

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Example: San Andreas Fault-Marks the conjunction between the North American and Pacific Plate-Classified as a right lateral strike slip fault-Movement of the plate is sporadic and jerky-This fault has created extensive shallow focus earthquakes in San Francisco-Current average movement of the fault is 30mm-50mm each year

d) Examples chosen from two contrasting regions e.g. The Atlantic with its mid-ocean ridge and evidence drawn from neighbouring continents with the Pacific. Case studies of a major volcanic eruption, a major earthquake; these studies can of course be combined with studies in Key Question 2.

5) Post- Pangea plate movement supported by evidence from: (Global evidence; fossil record including dinosaurs, coal measures)a) Paleomagnetism-Paleomagnetism is the strongest evidence of plate tectonics as it

is the study of magnetic fields surrounding ocean ridges. Reasons for this is because rock formed from underwater volcanic activity is basalt, which is rich in iron. This allows recording of magnetic field position changing compared to point where that ocean floor was created.

b) Paleontology-Paleontology is the study of the history of life on Earth through fossil records. If the same type of fossil was found at completely different locations it would support the Pangea plate movement. This is because the two same types of fossils indicate the same species, which were once living in the same area. So it would mean that area drifted apart from each other.

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c) Geographic fit- Geographic fit is an idea explained through Continental Drift Theory. The idea is that many continents and countries seem to fit together like a puzzle. This supports the theory that all the continents were once together.

KQ5a: What pressures has human activity placed upon the resources of the lithosphere?1. The nature of renewable (water- HEP tide and waves, wind and solar energy), non-

renewable (coal,oil, and natural gas) and recyclable resources. Renewable resources provide alternative energy in a variety of ways. With HEP tide and waves it’s the use of the movement of tides and waves to create this kinetic energy that powers a turbine and creates electricity. With wind energy it utilizes the use of spinning blades being moved by wind, which in turn spins a turbine and yield electricity. In the case of solar energy it uses the sun’s energy to excite electrons in silicon cells.

Non-renewable energy is a more popular method of electricity but it has it’s consequences of pollution. Coal is pulverized into this fine powder and mixed together with hot air. This heats a boiler in a furnace to create steam from water. The steam turns a turbine and generates electricity. Oil can be used in by being burned and heating water to turn a turbine. Another way is that oil is burned under pressure to produce hot exhaust gases that turns a turbine and generates electricity. These non-renewable resources are more pressured on as a source of electricity than the renewable resource.