The top of the asthenosphere is closest to the surface ________.
A)along a mid-ocean ridge
B)along the length of a deep mantle plume
C)along a transform fault
D)along a subduction zone

Question

Quizplus · Accepted Answer

The asthenosphere is located just beneath the lithosphere, which includes the Earth's crust and the uppermost part of the mantle. Along a mid-ocean ridge, the lithosphere is spreading apart, and the asthenosphere is closer to the surface, making it a good choice for the answer. Along the length of a deep mantle plume or a subduction zone, the lithosphere is being pushed down into the mantle, making the asthenosphere farther from the surface. Along a transform fault, the lithosphere is sliding past each other, but there is typically no significant change in depth to the asthenosphere.

The Top of the Asthenosphere Is Closest to the Surface