Experimental erosion of North Pacific red clay

Abstract

Threshold erosion velocities for plane beds of pelagic red clay were established by ten experimental runs in a recirculating salt-water flume. Even with water content as high as 82%, observable erosion of the sediment required a velocity equivalent to a bottom current of about 30 cm/sec. Sediment beds to which manganese nodules were added, simulating an abyssal nodule field, were eroded by much slower flows (e.g., by the equivalent of a 12 cm/sec current at 84% water content). These experimentally derived values may be useful approximations of critical current speeds on the deep-sea floor, though very slow erosion may well occur there at lower speeds, especially in the presence of benthic fauna.