Abstract

The ocean floor makes up the majority of the Earth's surface and yet, its geomorphology is not fully understood. Recent debate has focused on whether sea level changes --- driven by Milankovitch glacial cycles --- generate the abyssal hill fabric of the ocean floor by modulating mid-ocean ridge magma supply. However, periodicities longer than Milankovitch cycles are prominent in the ocean bathymetry. Using crustal thickness estimates from two-phase flow simulations of ridge magma transport, I show that persistent melt-rich porosity waves are responsible for the ocean floor fabric at periods of 100 kyrs and longer, except in the case of fast-spreading ridges. For periods longer than 100 kyrs, spectral energy is notably present at large mantle permeabilities regardless of spreading rates. Therefore, two-phase flow models can provide constraints on elusive mantle parameters such as permeability and viscosity when directly linked to the ocean floor fabric produced.