Question

Which statement explains how convection currents affect the movement of plates?

A) Gravity pulls one edge of a plate down into the mantle, which causes the rest of the plate to move as well.
B) Heat from Earth’s interior causes lithospheric plates to collide at convergent plate boundaries, causing volcanoes.
C) Heat from Earth’s interior causes currents of hot rising magma and cooler sinking magma to flow, moving the crust along with them.
D) As convection currents drift across the oceans, they bring the pieces of Earth’s crust with them as the supercontinent breaks apart.

Answer 1

C

Convection in Earth’s mantle heats rock so it rises where it's hot and sinks where it cools. Those slow circulating flows in the ductile mantle (asthenosphere) drag and push the overlying lithospheric plates, driving plate motions such as seafloor spreading at ridges and subduction at trenches.