Mechanisms of Plate Movements Flashcards
Forces the either pull the tectonic plates apart of push them toward each other.
Driving forces
What are the 3 mechanisms/driving forces of plate tectonics?
Mantle convection, ridge push and slab pull
Giant pieces of the Earth’s crust that fit together and move around on the Earth’s surface.
Tectonic plates
TRUE OR FALSE
Lithospheric plates on the scales of continents and ocean floors are constantly moving in response to the movements in the mantle.
TRUE
It states gravity and the plates are the ones responsible for the tectonics through subduction process.
Slab pull theory
What term when continents and ocean basins have always been permanent features on the Earth’s surface?
Permanentism
What do you call when the rotation of the Earth created a centrifugal force towards the equator which broke the continents apart?
Pole-fleeing force
It helped revolutionize our understanding of the geology of the seafloor.
Seafloor mapping and the first detailed map of the ocean floor in 1957.
TRUE OR FALSE
Continental drift theory was widely accepted in the early ’90s.
FALSE, not widely accepted
Why the Continental Drift Theory was not widely accepted?
Due to the lack of a clear driving mechanism.
TRUE OR FALSE
Seafloor spreading shows how crust is formed on ridges and subducts or gets destroyed in trenches.
TRUE
The gravity driven mechanism involves what forces?
Ridge push and slab pull
What theory is currently accepted mechanism of the continental drift.
Mantle Convection Theory
Why the Mantle Convection Theory is currently the accepted mechanism of the continental drift?
Due to the energy given by the Earth’s internal heat.
What is circulating all throughout the mantle by the earth’s interior and surface temperature differences?
Convection current
This force takes place when a subducting plate sinks into the mantle.
Slab pull
It contains material less dense than the crustal plates riding above it.
Asthenosphere
It acts as a massive shear zone for the over-riding plate.
Asthenosphere
TRUE OR FALSE
Since the plate gets thicker and denser
further away from the spreading center, the ridge push force will increase towards the
orogenic belt.
FALSE, towards the subduction zone
This force happens between 2 colliding crustal plates where one is subducting under the other.
Slab (trench) suction
This force acts as a plate collides with another plate. It occurs only at subduction
zone wherein the subducting plate exerts a force directly onto the over-riding buoyant
plate which acts to oppose the forces driving the subduction.
Slab resistance
This convection current acts as a ______________,
wherein the lithospheric plates above were carried along with it.
Conveyor belt
TRUE OR FALSE
Plate with a slab subducting into the mantle moves slower towards
the subduction zone than those plates without a slab.
FALSE, moves faster
TRUE OR FALSE
In slab pull, as the plate sinks into the mantle, it acts to pull the rest of the
plate behind it.
TRUE
IDENTIFY
In slab (trench) suction, As the plate subducts, it creates ______________ in the upper mantle
that exert a pulling force, which acts to suck both the plates together.
convection currents
It oppose the movement of driving forces.
Resisting forces
They generate shearing or
frictional forces resisting the movement of lithospheric plates.
Resisting forces
The force that directly opposes the slab pull.
Collisional resistance
It occurs as the heavy basaltic plate
is pulled down into the mantle. Thecollisionalforce occurs because the mantle, although
less dense than the subducting plate, still resists subduction to some extent due to friction.
Collisional resistance
This force occurs when the spreading center along a ridge is broken by several
kilometers, the broken plates slide past each other and form a transform fault.
Transform fault resistance
IDENTIFY
Since the
movement is opposite, the plates encounter ____________ in the contact zones.
frictional resistance
This force is the resistance ordraggingforce associated with the interface
between the upper mantle and the lithosphere.
Drag force
It is the force that directly opposes the
movement of crustal plates.
Drag force
IDENTIFY
Any individual plate contains __________ and/or __________ crust.
Oceanic, continental
Plate boundaries are defined by what?
Active seismic and volcanic activity
What are the 2 main classes that characterized the forces acting on the plates?
Driving and resisting forces
What are the 4 driving forces?
Mantle convection, slab pull, ridge push and slab (trench) suction