Final answer:
The movement of rocks on opposite sides of a fault due to seismic activity is known as fault displacement. This phenomenon is closely linked to the movement of tectonic plates and the occurrence of earthquakes, where the measurement of the time difference between P-waves and S-waves helps determine the epicenter.
Step-by-step explanation:
The distance that rocks on opposite sides of a fault have moved is referred to as fault displacement. Fault displacement is a key indicator of the movement along a fault line during an earthquake and can be used to assess the magnitude of seismic activity. For instance, the San Andreas Fault in California is a well-studied area where significant fault displacement has been recorded over time.
With regard to seismic activity and plate tectonics, it's essential to understand how the movement of tectonic plates causes earthquakes. Tectonic plates are massive segments of the Earth's crust that move very slowly. This movement can build up stress along fault lines, which is eventually released as seismic waves during an earthquake. Seismologists use the time difference between the arrival of P-waves (primary waves) and S-waves (secondary waves) at a monitoring station to calculate the distance to the earthquake's epicenter. This process is crucial for understanding the dynamics of earthquakes and for mitigating their destructive effects.