You are a geologist detecting S (secondary)seismic waves from a source somewhere else on Earth.You know that these S waves
A) have traveled in a straight line through Earth from the source to your detector.
B) have not passed through the center of Earth.
C) have traveled along the surface of Earth from the source to your detector.
D) must have originated only a few hundred miles away because S waves tend to attenuate quickly within Earth.

Question

Quizplus · Accepted Answer

S waves cannot pass through the liquid outer core of Earth, so they can only travel through the solid portions of the mantle and crust. Therefore, they must have taken a path that avoided the center of Earth, making choice B the best option. Choices A and C are incorrect because S waves do not travel in a straight line through Earth or along the surface. Choice D is also incorrect because S waves can travel much farther than a few hundred miles, although they do tend to attenuate (weaken) more quickly than P (primary) waves.

You Are a Geologist Detecting S (Secondary)seismic Waves from a Source