To locate the epicenter of an earthquake, a minimum of three seismic stations are required. Seismic stations are equipped with seismometers, which detect and record the seismic waves produced by earthquakes. By analyzing the arrival times of these waves at different stations, scientists can determine the distance between each station and the earthquake epicenter. Using triangulation, where the circles representing the distances from each station intersect, the epicenter can be pinpointed.

Option 1, which states that three seismic stations are required, is correct. Having three stations allows for accurate triangulation and provides enough data to determine the epicenter location. Options 2, 3, and 4 are incorrect since they suggest using more than the minimum required number of stations.