Sedimentation and Sediment Accumulation Rates in a Low-Energy Embayment
Keywords:
Low-energy embayment, sediment accumulation rates, sediment traps, Pb-210, organic material, eel-grass, grain-size, Western BalticAbstract
This paper describes sedimentary conditions in a low-energy embayment in the Western Baltic. Water depths vary between 32m and 4m. The tidal range of 20 cm is less than the sea level fluctuations caused by strong winds. Sediment accumulation rates were examined by means of sediment trap sand the Pb·210 method. It is shown that the two methods give almost identical sediment accumulation rates. There are seasonal variations with low rates in Bummer (≈ 260 g/m2 * y) and high rates (≈ 2600 g/m2*y) in fall and winter. Sediment accumulation rates are positively correlated with strong winds from the south-west. Changes in the organic content is shown to reflect changes in the depth-limit of eel-grass (Zostera marina, L.). It is also shown that the sediment transport mode in the study area is suspension. A sediment transport model applied to the data predicts that sediments are transported from the outer to the inner part of the embayment.