Abstract During the last ice age, icebergs transported Ice‐Rafted Debris (IRD) more than 3,000 km across the North Atlantic. However, their effect on the deterioration of icebergs and thus where the deposits form is poorly understood. Laboratory experiments and a predictive model (with no fitting parameters) investigating the effects of sediment on iceberg deterioration found that IRD increase the melt rate in three ways. First, the melt rate of the sediment layer is 1/1−ϕs $1/left(1-{phi }{s}right)$ larger because there is less ice to melt, where ϕs ${phi }{s}$ is the sediment volume fraction. Second, the melt rate of the sediment layer and ice layer below is almost three times larger due to a sediment plume which enhances the turbulent heat flux toward the ice. Third, a sediment layer can cause an iceberg to break into two pieces, increasing the total surface area and causing the overall melt rate to increase as much as 50%–60%.