When an earthquake occurs s waves are the first seismic waves to arrive at a given location

The above given statement is not correct.

Explanation: S-waves are the secondary waves that can travel only through solid whereas P-waves are the primary waves that can travel both in solid as well as liquid. P-waves travels faster than S-waves.

When there occurs an earthquake, P-waves arrives at the given location first, and S waves occurs a little later than that, it is because during the time of an earthquake, the waves travels in the interior of the earth and after striking the mantle or core boundary, it gets reflected back. The time it takes for S wave to reach the given location is about the double of time it takes by P waves.