How do tensional forces create abyssal hills and faulted mountains on the seafloor?

Tensional forces play a fundamental role in shaping the seafloor at spreading centres, where lithospheric plates diverge. As these plates move apart, the oceanic crust is subjected to extensional stress, causing it to rift and fracture.123

This process creates abyssal hills and block-faulted mountains through the following mechanisms:

• Block Faulting: As the crust stretches, it breaks into large blocks along faults. This block faulting is a dominant process in forming seafloor relief, particularly at slower spreading rates where the crust is more prone to brittle deformation.4
• Structural Alignment: These faulted mountains and abyssal hills typically trend parallel to the oceanic ridges, reflecting the orientation of the spreading axis where the tensional forces are concentrated.14
• Interaction with Volcanism: While tensional forces drive the faulting, volcanism also contributes to the construction of these features. Volcanic hills are often initiated at the spreading centre and subsequently modified or uplifted by the ongoing tectonic faulting.4

Over time, these features may be partially buried by sedimentation, though they remain a defining characteristic of the ocean basin floor.14