Seismic evidence suggests that Earth's core spins about 2° more per year than the surface.In roughly how many years will the surface and the core have the same relative orientation they do today?

Question

Quizplus · Accepted Answer

The difference in spin between the core and surface is 2° per year. To have a complete relative orientation, the surface needs to rotate 360° with respect to the core. Therefore, it will take 180 years (360/2 = 180) for the surface and core to have the same relative orientation they do today. Hence, the answer is D.

Seismic Evidence Suggests That Earth's Core Spins About 2° More