A fault line is of geological significance as it marks the boundary between two tectonic plates, where movement occurs. This movement can lead to seismic activity, including earthquakes. Studying fault lines helps geologists understand the dynamics of plate tectonics and predict potential earthquake zones. Fault lines can also influence the geography of an area by causing uplift or subsidence. Their study is essential for assessing risks to human structures and ecosystems and contributes to the science of geoengineering.