Which feature marks the position of a previously active transform fault and is seismically inactive?

Which feature marks the position of a previously active transform fault and is seismically inactive?

• A. Abyssal Plain
• B. Epicenter
• C. Fracture Zone
• D. Continental Margin

Answer: (C)

The idea here is about transform boundaries and what happens when one part of the boundary stops slipping. Along mid-ocean ridges, two oceanic plates slide past one another along transform faults, and those faults are typically the sites of earthquakes where the slipping actually occurs. As the plates keep moving, the trace of where that fault used to be remains on the seafloor as a fracture zone. This fracture zone marks the position of a previously active transform fault, but it’s seismically inactive because the current slip and most of the earthquake activity are concentrated on the actual active transform fault nearby. Abyssal Plain is just the flat area of the deep ocean floor, not related to fault traces. An epicenter is the surface location above an earthquake’s focus, not a seafloor feature. A continental margin is the edge where continental crust meets oceanic crust, again not a transform fault trace.

The idea here is about transform boundaries and what happens when one part of the boundary stops slipping. Along mid-ocean ridges, two oceanic plates slide past one another along transform faults, and those faults are typically the sites of earthquakes where the slipping actually occurs. As the plates keep moving, the trace of where that fault used to be remains on the seafloor as a fracture zone. This fracture zone marks the position of a previously active transform fault, but it’s seismically inactive because the current slip and most of the earthquake activity are concentrated on the actual active transform fault nearby.

Abyssal Plain is just the flat area of the deep ocean floor, not related to fault traces. An epicenter is the surface location above an earthquake’s focus, not a seafloor feature. A continental margin is the edge where continental crust meets oceanic crust, again not a transform fault trace.