plate tectonics
DESCRIPTION
talks about plate movements including convection currents and continental driftTRANSCRIPT
REVIEW OF REVIEW OF CONTINENTAL DRIFTCONTINENTAL DRIFT
REVIEW OF REVIEW OF CONTINENTAL DRIFTCONTINENTAL DRIFT
Continental Drift: All continents once connected into one supercontinent called Pangaea
Pangaea broke apart & continents drifted to present locations
Continental Drift: All continents once connected into one supercontinent called Pangaea
Pangaea broke apart & continents drifted to present locations
FROM CONTINENTAL DRIFT FROM CONTINENTAL DRIFT TO PLATE TECTONICSTO PLATE TECTONICS
FROM CONTINENTAL DRIFT FROM CONTINENTAL DRIFT TO PLATE TECTONICSTO PLATE TECTONICS
Problem with Continental Drift –
•Age of Earth: Earth too young for processes to occur
•No direct evidence of continents actually moving
•No known force could move continents
Problem with Continental Drift –
•Age of Earth: Earth too young for processes to occur
•No direct evidence of continents actually moving
•No known force could move continents
WWII brought new technology & new evidence!!•Age of EarthSONAR: Exploration of ocean floor showed seafloor very old & new crust forming
•No direct evidenceGPS: Measured movement of continents
•No known force:Convection currents in Earth powerful enough to move plates
WWII brought new technology & new evidence!!•Age of EarthSONAR: Exploration of ocean floor showed seafloor very old & new crust forming
•No direct evidenceGPS: Measured movement of continents
•No known force:Convection currents in Earth powerful enough to move plates Alvin: Navy's remote robot probe
FROM CONTINENTAL DRIFT FROM CONTINENTAL DRIFT TO PLATE TECTONICSTO PLATE TECTONICS
FROM CONTINENTAL DRIFT FROM CONTINENTAL DRIFT TO PLATE TECTONICSTO PLATE TECTONICS
NEW THEORY : NEW THEORY : PLATE TECTONICSPLATE TECTONICS
NEW THEORY : NEW THEORY : PLATE TECTONICSPLATE TECTONICS
Continental Drift + convection currents theory of plate tectonics
Theory of plate tectonics:
Earth is made of rigid lithospheric plates moved byconvection currents
Convection currents are heat currents insidethe mantel
Continental Drift + convection currents theory of plate tectonics
Theory of plate tectonics:
Earth is made of rigid lithospheric plates moved byconvection currents
Convection currents are heat currents insidethe mantel
LITHOSPHERIC PLATESLITHOSPHERIC PLATES
The lithosphere (crust + upper mantle) is made of rigid pieces
Lithosphere 7 large, 7 small plates
Plates “float” on the asthenosphere(liquid part of the upper mantle)
Plate Tectonics is the mechanismfor Continental Drift.
The lithosphere (crust + upper mantle) is made of rigid pieces
Lithosphere 7 large, 7 small plates
Plates “float” on the asthenosphere(liquid part of the upper mantle)
Plate Tectonics is the mechanismfor Continental Drift.
CONVECTION CURRENTSCONVECTION CURRENTS
Convection Currents = currents of rock & heat formed by temperature difference between core & mantle
Core transfers heat to the mantle where hot rock & heat rise;
Convection currents in asthenosphere move lithospheric plates
Movement between plates causes landforms & earthquakes
Convection Currents = currents of rock & heat formed by temperature difference between core & mantle
Core transfers heat to the mantle where hot rock & heat rise;
Convection currents in asthenosphere move lithospheric plates
Movement between plates causes landforms & earthquakes
Continent:continent
PLATES MOVE THREE WAYSPLATES MOVE THREE WAYSPLATES MOVE THREE WAYSPLATES MOVE THREE WAYS
At the edges of plates, convection currents cause 3 types of boundaries:
•Divergent boundary plates move AWAY from each other
•Convergent boundaryplates move TOWARDS each other
•Transform boundaryplates move SIDEWAYS to each other
At the edges of plates, convection currents cause 3 types of boundaries:
•Divergent boundary plates move AWAY from each other
•Convergent boundaryplates move TOWARDS each other
•Transform boundaryplates move SIDEWAYS to each other
Ocean: continent
Sea Floor Spreading
PLATES + CURRENTS =PLATES + CURRENTS =NEW LAND FORMSNEW LAND FORMS
PLATES + CURRENTS =PLATES + CURRENTS =NEW LAND FORMSNEW LAND FORMS
• Divergent boundary Ocean:Ocean → mid-ocean ridges
Continent:Continent → rift valleys
• Convergent boundaryOcean: (Ocean or Continent) → subduction zones, trenches & volcanoes
Continent:Continent → folded mountains
• Divergent boundary Ocean:Ocean → mid-ocean ridges
Continent:Continent → rift valleys
• Convergent boundaryOcean: (Ocean or Continent) → subduction zones, trenches & volcanoes
Continent:Continent → folded mountains