january 04, 2018plate tectonics.notebook 10 january 04, 2018 dec 92:56 pm section 4 fault normal...
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9.1 Continental Drift
ObjectivesWhat is the hypothesis of continental drift?What evidence supports continental drift?Why was Wegener's hypothesis rejected?
Pangaea "All Earth"Wegener’s theory of one supercontinentSurrounded by one sea called Panthalassa = all sea
Pangaea puzzle
Continental DriftWegener’s theory of the movement of the continentsRejected because hard to believe that continents can move
Broke into two partsLaurasiaGondwana
Plate Tectonicstheory of how continents move7 major plates
Evidence that supports Continental Drift Picture in Textbook1. Puzzle2. Fossils Discovered fossils on different continents matched.3. SeaFloor Spreading
deepest known place on Earth = 11,033 m below sea level and 2,500 m long = Mariana Trench
4. Rock5. Climate
6. Glacier7. Magnetic Reversals
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Review Questions
1. What is the difference between Continental Drift and Plate Tectonics?
2. Name the Supercontinent.
3. Name the "One Ocean".
4. List 5 forms of evidence that support Continental Drift.
5. Who developed the Theory of Continental Drift?
6. What were the two pieces that the plates broke into?
7. What is the layer of the Earth that allows the plates to float on it?
Answers
1. Continental Drift is the belief that the plates move and Plate Tectonics is how they move.
2. Pangaea
3. Panthalassa
4. Puzzles pieces Fossils SeaFloor Spreading Magnetic Reversals Glaciers Rocks
5. Alfred Wegener
6. Northern Laurasia Southern Gondwana
7. Asthenosphere
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Section 9.2 SeaFloor SpreadingObjectives
What are the midocean ridges and deepocean trenches?What occurs during seafloor spreading?What is the evidence for seafloor spreading?
Scientists wanted to know more about the ocean floor, they used to map the Earth's ocean floor.Sonar Sound Navigation and Ranging
a system that uses sound waves to calculate the distanceto an object
ship sends out pulses that bounce off the ocean floor and is recorded for time that it takes to return to ship
Composition of the Ocean FloorIgneous RockBasaltic CompositionCovered in a thick layer of sediments
Discoveries Figure 8, page 255DeepOcean Trenches
Mariana Trench Pacific Ocean11km deep
Where are most of the trenches found?edges of the ocean basins
Subductionocean floor returns to the mantle and sinksthese areas called Subduction Zones
MidOcean RidgeMountain Range in Altantic Ocean Long chain of mountainsFormed from volcanic activityOcean floor spreading and adding new crust.
older crust moves outward and new magmarises and hardens to form new crust
Moves about 5 cm per yearMost of mountain range underwater one exception
is in Iceland above the oceanRift Valley similar to a long canyon in the center
of the ocean ridge, but on landWhere are most of the ridges found?
towards the center of the ocean basinsSeaFloor Spreading
the process of the ocean floor moving outward across the ocean basin forming new ocean floor
EvidenceMagnetic Strips
magnetizing of rocks PaleomagnetismHow does this happen?
many rocks have magnetite
Earthquake Patternsearthquakes occur around trenches
Ages of Ocean Floor Rocksrocks youngest near ridgeoldest in subduction zones
https://www.youtube.com/watch?v=SFTo3snqBRE Seafloor Spreading 13 min
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Section 9.3 The Theory of Plate Tectonics
ObjectivesWhat is the theory of plate tectonics?What are the three types of plate boundaries?
J. WilsonBelieved lithosphere is broken into pieces Plates
Plate TectonicsThe theory that explains HOW pieces of the Earth’s crust move and change shape.
What happens when plates move?causes tectonic activitiesearthquakesvolcanoesmountain buildingglacier
Boundary Page 262263 Figure 15Where tectonic plates touch.
3 Types of Boundaries1. Divergent Boundary
plates move apart and magma rises to fill gapMidAtlantic Ridge
2. Convergent Boundary2 plates collide
3 Types of Convergent Boundariesa. Continental Continental
Buckle and thicken which pushes the crust upwardb. Continental Oceanic
Oceanic plate sinks into the lithosphere Subduction Zone
Continental Volcanic Arc forms mountains c. Oceanic Oceanic
One plate will sink under the other Volcanic Island Arc
3. Transform Fault Boundaryplates slide past one another horizontally strike slip faultcauses earthquakes
Look at Page 269 Predictions of Earth's movements
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Tectonic PlatesPieces of the lithosphere that move ontop of the asthenosphere
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9.4 Mechanisms of Plate Motion
Key QuestionsWhat causes plate motions?What are the mechanisms of plate motion?
What is responsible for plate motion?Convection Current
continuous circular motion that occurs in the mantle hot = rise, cool = sinks
plates slide on the mantle that is flowing
Densityoceanic lithosphere sinks denser
SlabPullgravity pulls lithosphere into mantle
RidgePushdue to elevation of the near by ridge, lithosphere
slides down
Mantle Plumemolten rock rising to the lithosphere
https://www.youtube.com/watch?v=xWo1VsgRW8
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How and why plates move
Crust, Mantle, Core
GondwanaLaurasia
NormalBoundary
DivergentBoundary
Convergent Boundary
Squeezing
Uplift
Mantle
Asthenosphere
Tension
fossils, glaciers, rocks, magneticreversals, puzzles
Rift Zones
states the platesmove
Transform
Iron andNickel
Wegener
Lithosphere
Normal Fault
MoreMagnesium
tectonicplates
Panthalassa
Midoceanridges
SubductionZone
Convection Current
Anticlines
Monocline
Synclines
San AndreasFault