Question

Which of the following is evidence that our planet has plate tectonics?

Answer 1

The appropriate answer is B. Chains of volcanoes along ocean coastlines. The theory of plate tectonics states that the earth's crust is divided into plates that float on the semi-molten mantle below. Plates can converge, diverge or slide past each other. Chains of volcanoes along coastlines are evidence of plates converging with one plate subducting beneath the other. The subducting plate will melt producing magma which is lighter than surrounding rock and so will force its way through cracks and fissures in the surface. Once magma reaches the earth's surface, volcanoes are formed.