By locating active geologists determine the likelihood of earthquakes in a region

The word that would best complete the sentence, "By locating active , geologist determine the likelihood of earthquake in a region", is fault line. The presence of the fault lines increased the risk of a certain area to the disasters such as earthquake when there is a movement underground.

By locating active faults, geologists can determine the likelyhood of earthquakes in a region. A fault is a crack in the earth's surface along which movement occurs. Movement along faults cause earthquakes. Seismologists use various intruments such as GPS and seismographs to monitor movement along faults to attempt to predict the likelihood of a quake.