Question

In the D" layer, the portion of the mantle closest to the core-mantle Boundary is hypothesized to be partially melted because the S-wave velocities decrease by 30% when passing through it.

A) True
B) False

Answer 1

True

Step-by-step explanation:

The D layer is a transition zone between the solid portion of the lower mantle and the liquid outer core. Because S-waves only travel through solids, it has been hypothesized that a partially molten transition zone would affect the velocity of these S-waves by slowing them down considerably as the rock layer becomes less solid. The waves that are able to travel through a non-solid medium are the P-waves, which are more energetic than S-waves.