The dominant processes of sediment distribution and focusing in a small, eutrophic, monomictic lake

Abstract

There is evidence for 10 mechanisms of sediment distribution in small lakes. The sediment accumulation rates measured from a common horizon in cores from 64 sites on Esthwaite Water, U.K., were used to determine the relative importance of these mechanisms on the distribution of sediment in the lake. River inflows generally produced localized effects but there were indications of periodic turbidity flows to the deepest point of the lake from the major inflow. Active sediment focusing processes were the dominant distribution mechanisms, a major resuspension of sediment at autumn overturn probably being the most important. The remaining variance was much greater than observed in similar work elsewhere, suggesting that redistribution of sediment by direct and indirect wave action may be taking place all over the lakebed during isothermal periods. The relative contributions of the different processes were corroborated by analysis of previously published sediment trap data.