Which term describes the depth location of an earthquake?

The term that describes the depth location of an earthquake is focal depth. This term refers to the vertical distance below the Earth’s surface where an earthquake originates, also known as the focus or hypocenter. Understanding the focal depth is crucial for assessing the potential impact of an earthquake, as it affects the intensity of shaking experienced at the surface and informs engineers and emergency responders about possible damage and required safety measures.

In contrast, other terms mentioned refer to different aspects of seismic events. A fault line refers to the fractures or zones of weakness in the Earth's crust where movement occurs, but it does not specify depth. The dip angle indicates the angle at which a fault or geological layer inclines relative to the horizontal. Ground displacement relates to the movement of the ground during an earthquake but does not denote location depth. Thus, focal depth is the precise term needed to identify the depth of an earthquake's origin.