Falla (the structure)

A fault is a fracture or zone of weakness in Earth's crust where rocks on either side have moved past each other due to tectonic forces. This displacement can cause earthquakes if the buildup of stress is suddenly released. Faults vary in size from tiny cracks to major boundaries spanning hundreds of kilometers. They play a key role in shaping the landscape and accommodate the Earth's ongoing internal stress, allowing crustal blocks to shift gradually or suddenly during seismic events.