GEOLOGY

Detailed explanation-1: -Use the time difference between the arrival of the P and S waves to estimate the distance from the earthquake to the station. (From Bolt, 1978.) Measure the distance between the first P wave and the first S wave. In this case, the first P and S waves are 24 seconds apart.

Detailed explanation-2: -P waves travel fastest and are the first to arrive from the earthquake. In S or shear waves, rock oscillates perpendicular to the direction of wave propagation. In rock, S waves generally travel about 60% the speed of P waves, and the S wave always arrives after the P wave.

Detailed explanation-3: -Measure the difference in arrival times between the first shear (s) wave and the first compressional (p) wave, which can be interpreted from the seismogram. Multiply the difference by 8.4 to estimate the distance, in kilometers, from the seismograph station to the epicenter.

Detailed explanation-4: -The arrival times of the P-and S-waves at different seismometers are used to determine the location of the earthquake. Assuming that we know the relative speed of P-and S-waves, the time difference between the arrivals of the P-and S-waves determines the distance the earthquake is from the seismometer.

Detailed explanation-5: -Difference in arrival times between P and S waves can be used to determine the distance between the station and an earthquake. By knowing how far away the quake was from three stations we can draw a circle around each station with a radius equal to its distance from the earthquake.