Surficial sediment distribution and net sediment transport pattern in İzmir Bay, western Turkey

Abstract

İzmir Bay, a microtidal bay in the eastern Aegean Sea, is an area of fine-grained sediment. The surficial sediments may be subdivided into seven zones based on their grain size. The western part of the outer bay is covered by silty and muddy sand, whilst the eastern part of the outer bay is covered with silt and mud. Most of the central bay is covered with sandy silt containing up to 50% carbonate and the area between the central and inner bay is floored by silt. Total organic carbon concentrations of the surface sediments vary between 0.40% and 3.12%, and increase in proportion to silt content. Accumulation of organic matter in the inner bay is probably produced by the inflow from raw sewage outfalls. The grain size trends are analyzed in conjunction with information on hydrodynamics, mineralogy and geochemistry, to derive sediment movement patterns. The pattern gives a preliminary idea of sediment transport directions together with the main areas of deposition and the possible dispersal patterns of contaminants in the İzmir Bay environment.