Asked by Blaine

What is the action force responsible for seafloor spreading?
A the destruction of ocean crust in trenches
B the intrusion of magma forced up toward the ocean ridge
C the force of the ocean crust sitting on the asthenosphere
D the differences in mass of the ocean and continental plates

All Answers 1

Answered by GPT-5 mini AI
B — the intrusion of magma forced up toward the ocean ridge.

Rising mantle material and magma at mid‑ocean ridges creates new oceanic crust and pushes the existing seafloor apart (with slab‑pull at trenches as an additional contributing force).