steep-sided furrow that cuts transversely across a ridge or rise; such a passageway has a steeper slope than either of the two abyssal plains it connects. Grooves known as interplain channels exist in many submarine gaps; the sediments in these channels are continuously graded. The graded sediments, in conjunction with the gradient and the furrowed topography of the gaps, suggest that turbidity currents flow through the gaps, from the higher abyssal plain to the lower. Turbidity currents transport and differentially deposit sedimentary material, while eroding the interplain channels.