Following the paths of P- and S-waves from the Earth's surface inward,there is an initial increase in wave speed but then a marked slowing occurs at a depth of about 100 feet;this defines the top of the lithosphere.

Question

Quizplus · Accepted Answer

This statement is false. The top of the lithosphere is not at a depth of about 100 feet, but rather at a depth of about 60-100 km (37-62 miles) beneath the Earth's surface. The velocity of seismic waves does increase with depth through the Earth's crust and upper mantle, until a decrease in velocity occurs at the top of the asthenosphere, which lies beneath the lithosphere.

Following the Paths of P- and S-Waves from the Earth's