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Why are abyssal hills generally larger near slow-spreading centres?

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World map highlighting major features of the ocean basins, including trenches, ridges, basins, and plateaus labeled throughout the Pacific, Atlantic, Indian, Southern, and Arctic Oceans. Continents are shown with shaded terrain, and prominent undersea features such as the Mid-Atlantic Ridge, Mariana Trench, and Kerguelen Plateau are marked across the map. — ocean basin Major features of the ocean basins.

Abyssal hills are formed through a combination of volcanism and block faulting. The size and relief of these hills are directly influenced by the rate at which the seafloor spreads at spreading centres.1

At slower spreading rates, block faulting of the oceanic crust becomes the dominant process in shaping the seafloor's topography. Because this faulting is more pronounced at these lower rates, the resulting abyssal hills exhibit greater relief and are generally larger than those found near faster-spreading ridges, which tend to have much smoother flanks.12