Which of the following statements about s waves is true?
a: s waves are also called secondary waves
b: s waves arrive at a seismograph station first
c: s waves move in pulsating motion
d: s waves travel through solids, liquids, and gases

Sudden disturbances of the earth release waves of energy called seismic waves. There are several different types of seismic waves, such as the P, and the S waves. The following statement about S waves is true:  S waves are also called secondary waves. Correct A S waves are transverse waves, which means they vibrate up and down, perpendicular to the motion of the wave as they travel.