Term 3 Flashcards
Who was the scientist that first propsed continental drift
Alfred Wegner
What is the Evidence for continental drift?
-Coastal Fit
-Fossil and Rock evidence
-Plate Tectonic theory
What are the names of the super continents
Laurasia
Gondawana
Pangea
- Recall the 7 major plates of the world
African Plate
Antarctic Plate
Eurasian Plate
Australian Plate
North American Plate
Pacific Plate
South American Plate
how were mid-ocean ridges were found
What is seafloor spreading and how doesit link to the age of rocks near mid-ocean ridges
Sea floor spreading results in two oceanic plates moving away from each other as new oceanic crust is formed from molten magma in the mantle.
It is due to the process ofsubduction;oceanic crust tends to get colder and denser with age as it spreads off the mid-ocean ridges. It gets so dense, that it sinks in the uppermantle(subduction).
Who was the scientist who proposed the idea of seafloor spreading
Harry Hess
What is magnetic stripping
New oceanic crust forms continuously at the mid-ocean ridges. While it cools down, it records the magnetic field during its formation.
The two parts of the oceanic plate are pulled apart, and magnetic stripes become older as they move away from the mid-ocean ridge.
What causes the plates of the Earth to move ?
Ridge Push, Slab Pull and Convection Currents
Explain how Ridge Push, Slab Pull and Convection Currents cause the plates of the Earth to move
Convection Currents- Hot magma in the Earth moves toward the surface, cools, then sinks again.
Creates convection currents beneath the plates that cause the plates to move.
Ridge push — the pushing force that plates experience as they slide down the raised asthenosphere underneath Mid Ocean Ridges..
Slab Pull- older, colder plates sink at subduction zones. The cooler sinking plate pulls the rest of the warmer plate along behind it.
- Recall the 3 types of plate boundaries
- Divergent Boundaries
- Convergent Boundaries
- Transform Boundaries
What is the diffrence between the different types of convergent boundaries
When continental crust converges with oceanic crust - The denser oceanic plate will be subducted under the lighter continental crust
When oceanic crust converges with oceanic crust- Whichever plate is densest will be subducted
When continental crust converges with continental crust- they eventually collide and end up producing mountains. Neither continental crust will subduct underneath one another because of their similar densities
-What feautures can occur at diffrent boundary types ?
Divergent- Mid-ocean ridges
rift valleys
fissure volcanoes
Convergent- Volcanoes,Trench, thrust faulted mountains
Transform- Earth quakes !!
What is the diffrence between oceanic and continental plates
Ocean plates - plates below the oceans denser
Continental plates - plates below the continents less dense
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What are the 2 types of volcanoes
Strava Volcano and Sheild volcano
