the unequal distribution of heat within Earth
causes the thermal convection in the mantle that ultimately drives plate motion.
What is the main source of downward convection movement in the mantle quizlet?
Terms in this set (10)
occurs when
oceanic lithosphere slides down the sides of ocean ridge under the influence of gravity pushing the plate in front
. The idea that slabs of the ocean lithosphere go down into lower mantles, making convection go down.
What causes a thermal convection that drives plate motion?
Geologists have hypothesized that the movement of tectonic plates is related to convection currents in the earth’s mantle. …
Tremendous heat and pressure within the earth cause the hot magma
to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth’s crust.
What is the primary force that drives plate motion quizlet?
a. Tectonic plate movement is driven by
gravitational forces
associated with the more dense lithosphere floating atop the less dense asthenosphere. b. Tectonic plate movement is a result of convection within the mantle, where the plates are passive rafts.
What is thought to be the major mechanism involved in convective flow downwards into the mantle?
Heat from the Earth’s interior
causes layers of convection to slowly swell and shrink into complex patterns. Cold ocenaic lithosphere descends into the mantle and hot mantle flumes move heat toward the surface.
What drives the plate to move?
Research has shown that the major driving force for most plate movement is
slab pull
, because the plates with more of their edges being subducted are the faster-moving ones. However, ridge push is also presented in recent research to be a force that drives the movement of plates.
What are the 3 causes of plate movement?
Mantle dynamics, gravity, and Earth’s rotation taken
altogether causes the plate movements. However, convectional currents are the general thought for the motion.
What is best explained by plate tectonics?
The theory of plate tectonics states that the Earth’s solid outer crust, the lithosphere, is
separated into plates
that move over the asthenosphere, the molten upper portion of the mantle. Oceanic and continental plates come together, spread apart, and interact at boundaries all over the planet.
What causes convection in the asthenosphere?
Convection currents within the mantle provide one potential driving force for plate movement. The
plastic movement of
the mantle material moves like the flow of mountain glaciers, carrying the lithospheric plates along as the convection movement in the mantle moves the asthenosphere.
What is the average movement of lithospheric plates per year?
They move at a rate of
one to two inches (three to five centimeters) per year
.
What is the mechanism for plate tectonics in other words what drives plate motion quizlet?
A slab of the earth’s lithosphere that can move around on the planet’s surface. A location where two plates come together. The theory that the Earth’s surface is divided into lithospheric plates that move on the planet’s surface. The driving force behind plate tectonics is
mantle convection
.
What are the 3 driving forces of plate tectonics?
- Convection in the Mantle (heat driven)
- Ridge push (gravitational force at the spreading ridges)
- Slab pull (gravitational force in subduction zones)
What is considered the most important driving factor for plate tectonics?
Heat
is continuously flowing outward from Earth’s interior, and the transfer of heat from the core to the mantle causes convection in the mantle (Figure 1.7). This convection is the primary driving force for the movement of tectonic plates.
What are the processes of ridge push and slab pull?
‘Ridge Push’ and ‘Slab Pull’ are thought to be the
major forces driving the motion of oceanic plates
. Ridge push is caused by the potential energy gradient from the high topography of the ridges. Slab pull is caused by the negative buoyancy of the subducting plate.
How do ridge push and slab pull work together?
“ridge push” The lithosphere thickens with distance (and time) away from the midocean ridge. … “slab pull” As
lithospheric plates move away from midocean ridges they cool and become denser
. They eventually become more dense than the underlying hot mantle.
What are convection currents and what causes them?
Convection currents are the
result of differential heating
. Lighter (less dense), warm material rises while heavier (more dense) cool material sinks. It is this movement that creates circulation patterns known as convection currents in the atmosphere, in water, and in the mantle of Earth.
