Final answer:
A fault that does not break the Earth's surface is considered a blind fault. These can be difficult to identify but are important in the study of geology for understanding seismic activity and crustal movements.
Step-by-step explanation:
If a fault does not break the Earth's surface, then it is considered to be blind. A blind fault is one where the fault plane terminates before it reaches the Earth's surface. These faults are often more difficult to detect because there are no obvious ground features to indicate their presence. Such faults can still have significant impacts on the sub-surface geology and can be associated with earthquakes.
Faults are a major feature in the study of Earth science and geology. They represent fractures or discontinuities in the Earth's crust where there has been notable movement. Different types of faults include normal faults, reverse faults, thrust faults, and strike-slip faults. These can be further characterized by their motion, with some showing vertical displacements and others showing horizontal movements. For instance, in the description provided, a fault showing right-lateral motion on a bird's eye view is referenced as a strike-slip fault, while a view of a vertical outcrop demonstrating a reverse fault indicates movement of rock layers over one another.