Question

what causes earths lithospheric plates to move?
select all that apply
a the upwelling mantle at the mid-ocean ridge pushes plates outward
b the earths core causes plates to move outward from the mid-ocean ridge.
c the earths magnetic field draws iron-rich minerals towards the poles.
d the sinking of the cold lithosphere at a subduction zone.

Explanation:

• Option a: Mid - ocean ridge upwelling mantle (magma) creates a pushing force that moves plates outward. This is part of the ridge - push mechanism.
• Option b: The Earth's core doesn't directly cause plates to move outward from mid - ocean ridges. Plate movement is mainly due to mantle convection, ridge - push, and slab - pull.
• Option c: The Earth's magnetic field affecting iron - rich minerals is related to paleomagnetism and not plate movement.
• Option d: At subduction zones, the cold, dense lithosphere sinks (slab - pull), which is a major force driving plate movement.

Answer:

a. The upwelling mantle at the mid - ocean ridge pushes plates outward
d. The sinking of the cold lithosphere at a subduction zone.