Question

When reading a seismograph, _____ waves come first, then _____ waves, and, finally, _____ waves. S, P, L L, P, S P, S, L L, S, P P, L, S

Answer 1

When reading a seismograph, P waves (Fastest) come first, then S waves (Second fastest), and, finally, L  (Love) R (Rayleigh) waves.

Considering answer options: P, S, L waves. Answer

Answer 2

Answer;

P, S, L

When reading a seismograph, P waves come first, then S waves, and, finally, L waves.

Explanation;

• Seismic waves are used to measure the strength of an earthquake using and instrument called  seismograph. The major three seismic waves used are the primary waves (P-waves), secondary waves (S-waves) and the L waves.

• Secondary waves move through earth by causing particles in rocks to move at right angles to the direction of the waves.  Primary waves on the other hand move through the earth by causing particles of rocks to move back and forth in the same direction as the waves.

• The primary waves are the first to reach a seismograph after an earthquake . These waves move in a push-and-pull motion.