With the of three seismograph stations, the epicenter of an earthquake can be located by a process called
-convection
-condensation
-triangulation
-intersection

The correct answer is - triangulation.

Triangulation is the technique used for getting the most accurate information about the epicenter of an earthquake. This technique is very simple. Three seismograph stations, on different locations, that are able to record the earthquake, are working together and comparing the results they got from where their respective stations showed the earthquake's epicenter is. The circles that represent the area affected by the earthquake, are than compared and the point of their intersection is considered to be where the epicenter is.