Question

1. how can you tell how far away from an earthquake epicenter you are, based upon reading a seismogram?

Explanation:

Seismograms record the arrival times of different seismic waves. The time - interval between the arrival of P - waves (primary waves) and S - waves (secondary waves) is used. The greater the time - lag between P and S waves, the farther the distance from the epicenter. This is because P - waves travel faster than S - waves, and the time difference accumulates with distance.

Answer:

By measuring the time - interval between the arrival of P - waves and S - waves on the seismogram. The larger the time difference, the farther the distance from the earthquake epicenter.