Convection in Earth's mantle created by the dissipation of internal heat produces up-welling hot columns called mantle plumes and cold, sinking sheets. Numerical modeling suggests the presence of three types of mantle plumes. Regular mantle plumes originate from the core-mantle boundary (a depth of approximately 1,802 mi [2,900 km]) and may be stable for several hundred million years. Such plumes act as fixed reference frames for plate motion. A second type of plume, also originating from the core-mantle boundary, can be bent and move relative to the global circulation in the mantle. Several mantle plumes may also collide to form superplumes. Superplumes rising from the core-mantle boundary may produce additional, secondary plumes that develop above a 416 mi (670 km) boundary layer in Earth's mantle.

Mantle plumes impinge on the base of Earth's lithosphere in all plate tectonic settings and result in surface uplift of up to 875 yd (800 m), lithospheric...