Download Layers of the Earth and Plate Tectonics

Layers of the Earth and
Plate Tectonics
Layers of the Earth
Crust= solid
Mantle= solid/liquid
Outer Core= liquid
Inner Core= solid
Lithosphere= crust & upper mantle
Asthenosphere= middle mantle/liquid
Seismic Waves
P-waves- (Primary waves) they are FASTEST. They go through liquid and solid
S-waves- (secondary waves) They ONLY go through a solid
Convection Currents
Relate the paper dot lab to the convection currents in the mantle.
*When the paper dots heated up they raised to the top (less dense). As the
dots cooled (denser) they sank to the bottom. This creates a circular motion.
*This is like the magma in the mantle. The magma heats and rises to the
surface and then cools and sinks.
*Convection currents are what makes our plates move.
*The heat from the core powers convection currents.
Continental Drift
* This is Alfred Wegner’s Theory
* Describe how Continental Drift changed Pangaea to the present day continents.
* Wegener was not taken seriously, because he couldn’t explain the force used
to move HUGE continents.
*Evidence:
a. correlating rock layers & fossil distribution
b. continents fit together like a puzzle
- todays theory used to explain the movement of the lithospheric plates
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Supported through- satellites, lasers, fossil evidence, computers match the coast line
Plates move on average 3 CENTIMETERS/year
- makes mountains (Himalayans)
Subduction- makes trench, it’s destructive
*ONLY layer to be a destructive process
- ridges and new crust (Mid-Atlantic Ridge)
Constructive Process
- earthquakes ( San- Andreas Fault- California)
Faults*Compression is at a reverse fault
* Tension is at a normal fault (normal to have 10 fingers)
Syncline rock deformation: