GEOLOGY

Detailed explanation-1: -A seismic station received the P-waves generated by an earthquake but did not receive the S-waves. Which statement best explains the absence of the S-waves? The earthquake was too weak to produce S-waves.

Detailed explanation-2: -Thus, P-waves are the only ones that can travel through the all of Earth and can reach every seismograph station. However, since S-waves can’t go through the liquid outer core, it creates a “shadow", where S-waves can’t be recorded, simply because they can’t reach.

Detailed explanation-3: -Scientists discovered that Earth’s outer core is liquid by observing seismic waves. P waves travel through solid and liquid, but S waves do not travel through liquid.

Detailed explanation-4: -The shadow zone is the area of the earth from angular distances of 104 to 140 degrees that, for a given earthquake, that does not receive any direct P waves. The shadow zone results from S waves (not shown in animation) being stopped entirely by the liquid core and P waves being bent (refracted) by the liquid core.

Detailed explanation-5: -Shear waves cannot travel in liquids or gases–so, for example, S waves don’t travel through the ocean or through the outer core.