5 Convection Many scientists now think that: large-scale motion in the mantle (Earth’s interior between the crust and the core)drives the movement of tectonic plates.Convection - the transfer of thermal energy by the movement of heated material from one place to another.
6 Convection The cooling of matter causes it to: A convection current. contract slightly and increase in density.The cooled matter then sinks as a result of gravity.Warmed matter is then displaced and forced to rise.This up-and-down flow produces a pattern of motion calledA convection current.
8 Convection in the Mantle Convection currentsdevelop in the mantlemove the crustmove outermost part of the mantletransfer thermal energy from Earth’s interior to its exterior.
9 Convection in the Mantle The rising material in a convection currentspreads out as it reaches the upper mantlecauses both upward and sideways forcesThese forceslift the crustsplit the crustat divergent plate boundaries.
10 Convection in the Mantle The downward part of a convection current occurs whereA sinking force pulls tectonic plates downwardOccurs at convergent boundaries.
11 Ridge PushRidge push is the tectonic process associated with convection currents in Earth’s mantle that occurs whenthe weight of an elevated ridge pushes oceanic platesThe force of the magma moving upward pushes oceanic platesthe plates move toward a subduction zone.
12 Slab PullSlab pull is the tectonic process associated with convection currents in Earth’s mantle that occurs asthe weight of the subducting plate pulls the trailing crustThe plate is pulled into a subduction zone.
13 The Result Move the tectonic plates Causing Continental Drift The convection currents in the mantle, in combination with ridge push and slab pull:Move the tectonic platesCausing Continental DriftWegener was correct!!!!!