Unit 2 Review and Solutions

1• Lithosphere (Rock)• Hydrosphere (Water)• Atmosphere (Air)• Biosphere (Living things)

– Volcano - L - Creates new rock, large amounts of ash produced, plate movements

– A - larges amounts of ash enter the air polluting it, darkens the sky blocking the sun, sulfur dioxide

– H - Gases like sulfur Dioxide mix with water vapour to create Sulfuric Acid (Acid Rain)

– Bio - Ash can wipe out trees with pyroclastic flows, obviously kill people

2• Precambrain (Eon)

– Hadean (Era)– Archeaen (Era)– Proterozoic (Era)

Largest aspect of the geologic Timeline

Paleozioc

Mesozoic (Triassic, Jurassic, Cretaceous)

Cenozoic

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• Geologic events take 1000’s of years to form

• Human life span is 80 years• We cannot see formation and process

happening• Human existance has really only been

around for a fraction of time in the earths history (I step on a football field)

4• Sedimentary - Rock that mainly forms in layers

– Clastic (Cementation) – Biogenic (Formed form Living Organism and Sea Creatures

when they die)– Chemical (Rock formed from natural chemical processes

and cementation)

• Igneous– Extrusive (Lava hardened on surface)– Intrusive (Magma hardened below the surface)

• Metamorphic – Add heat and pressure to change the state of a rock from

one form to another

5• Relative Dating (Not an exact date)

– Superposition - Each layer of rock is older than the one above it

– Uniformitarianism - To understand how a geologic structure is formed we assume that present day processes operated in the same way thousands of years ago. (ex. Erosion) We can determine the relative age of a geological structure by observing how quickly or slow it is changing today

– Fossil Correlation - A period of time can be define by it’s fossil content in a layers of rock

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• Earthquakes happen because of the interactions at plate boundaries– Plates get stuck and move to create an

earthquake

7• BODY WAVES - Travel in the interior of the earth• P-Waves - Travel through any medium (solid or

liquid) and reach the seismic station first• S-Waves - Travel through solid material only and

are slower to reach the seismic station• SURFACE WAVES - Travel along the surface of

the earth• Love Waves - Moves the ground from side to

side• Rayleigh Waves - Travel slowly and make the

ground move like the waves on a ocean or roller coaster

8• Epicentre point on the earths surface

directly overtop of the focus

• Focus is where the movement takes place in the lithosphere

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• Magma pushes through the centre of the ridge• As the magma/lava solidifies moves the

existing rock outwards• Connected to the other ridges in the oceans • Convection currents in the asthenosphere

help to contribute to motion that sets up plate movements

• Plates are both oceanic and continental so when you’re pushing one your pushing the other

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• Convection Currents - Take place in the upper mantle (asthenosphere)

• They operate much like boiling water or pasta• Heats up to surface, cools off and falls back

to bottom, where it then heats up and repeats the process

• Think about laying a piece of toast on top!

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• Location of Oceanic Ridges

• Sea floor Spreading

• Continental Shelves

• Seismological evidence (Quakes)

• Movement of crust caused the crust to crack forming plates

• Magnetism

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• Pacific Plate

• Subducting under the surrounding continental plates

• In theory the plate is getting smaller

• N/A and Asia will collide (In theory)

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• Divergent (Mid Atlantic Ridge)

• Convergent (India and Eurasian Plate - Himalayan Mountains)

• Transform aka Strike Slip (San Andres fault)

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• Mountain Building - Orogenic Process– Folding, Faulting, Volcanism – Folds upwards as the plates collide – Occurs when rocks pull apart and/or

fracture– Volcanism molten rock reaches the surface

forming volcanoes and new rock

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• Strike Slip

• Subduction Fault

• Extention Fault

• ******Collision Fault

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• Stratovolcano aka composite cone• Layers of Rock and Ash• Branches of magma flows off the main conduit -

Fissures - Harden to create even more pressure• When an explosion takes place they can re-

activate old fissures and explode an entire side of a mountain causing great damage

• Pyroclastic Flows are created as a result– Super heated ash debris moving downslope a a very

quick speed

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• Hot spots in the asthenosphere

• Weaknesses in the crust

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• Pyroclastic Flow - Landslide of Ash, rock and hot gases at 2000oF

• They are unpredictable an often more deadly than an actual volcanic eruption

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• Scientists can determine the age of rocks on both continents and in the ocean

• Found continental rocks were older • Ocean floor and conveyor belt

movements - New rock forms at the Mid Atlantic Ridge(200 Million years old, Pangaea Break up

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• Review the Mid-Atlantic Ridge Profile and reading

• Be aware of the continental margin features, Mid-Atlantic Ridge shape

21

• Tsunami’s are very destructive because they are not just one or two waves crashing ashore.

• Rather, a Tsunami is a surge of water moving inland up to 2 - 3km

• They destroy everything in their path and when they retreat they often carry many things out to sea

• Formation…See pg 133 of text

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• Tokyo lies on overtop the boundary of 3 major plates

• Earthquakes happen regularly and they are a part of life there

• Buildings are often built out of steel that can bend and contort as an earthquake shakes

• Also the foundations of buildings are built on shocks to absorb the shaking

• Lastly building are not built out of rigid concrete as they cannot withstand shaking

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• Subduction is what causes Mega-Thrust Earthquakes

• Stick slip properties (the bending of the continental landmass

• Earthquakes releases pressure and snaps the continental plate back into regular position

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• Volcanoes - Seismic stations to monitor earthquake activity around the volcano

• Tsunamis - Early warning detection systems in the Pacific

• Earthquakes - Seismographs to measure the strength of quakes and GPS to monitor the movement of tectonic plates

• Mass media - Warnings over the internet, TV, Cell phones, Twitter etc. The word travels very quickly