Studies for Students: Density Currents as Agents for Transporting Sediments

Abstract

Density currents are defined, and their origin discussed. Their driving mechanism is identified, and their characteristic behavior explained. "Black blizzards," underflows of turbid water, and nuées ardentes are shown to have much in common. Attention is called to a marked difference in the coarseness of sediments transported by atmospheric and aqueous density currents, and some reasons for this difference are suggested. The effect of flocculation upon density currents is discussed briefly. Estimates are given as to the quantity of fine sediment transported by turbid density flows at Lake Mead, by major dust storms, and by the atmosphere following great volcanic eruptions.