Spatial distribution and temporal variability of lithogenic particles in first-year sea ice and conditions responsible for particle entrainment

Abstract

Processes controlling the spatial and temporal variability of sea ice sediment inclusions in the shallow-marine environment of Elson Lagoon near Barrow, Alaska, were studied by modeling the potential for sediment resuspension during the 1998, 1999 and 2000 fall freeze-up events and examining sea ice cores from the post-freeze-up ice cover. Resuspension potential was controlled spatially by the local bathymetry and interannually by wind speed and fetch. Increases in resuspension potential corresponded to greater sea ice sediment content. Sediments occurred exclusively as aggregates confined to brine inclusions in the ice and exhibited a tendency toward a clustered spatial distribution, because of their exclusion from growing frazil ice crystals. Sea ice sediment concentrations ranged from 24 mg/l to 1474 mg/l and were positively correlated with the cross-sectional area of aggregates and negatively correlated with the minimum distance between neighboring aggregates, implying that sediment aggregation occurred during the solidification of the ice cover.