Estimation of sedimentation rate in the Middle and South Adriatic Sea using 137Cs.

137Cs activity concentrations were studied in the sediment profiles collected at five locations in the Middle and South Adriatic. In the sediment profiles collected from the South Adriatic Pit, the deepest part of the Adriatic Sea, two 137Cs peaks were identified. The peak in the deeper layer was attributed to the period of intensive atmospheric nuclear weapon tests (early 1960s), and the other to the Chernobyl nuclear accident (1986). Those peaks could be used to estimate sedimentation rates by relating them to the respective time periods. Grain-size analysis showed no changes in vertical distribution through the depth of the sediment profile, and these results indicate uniform sedimentation, as is expected in deeper marine environments. It was not possible to identify respective peaks on more shallow locations due to disturbance of the seabed either by trawlers (locations Palagruža and Jabuka) or by river sediment (location Albania). The highest sedimentation rates were found in Albania (∼4 mm y−1) and Jabuka (3.1 mm y−1). For Palagruža, the sedimentation rate was estimated to be 1.8 mm y−1, similar to the South Adriatic Pit where the sedimentation rate was estimated to be 1.8±0.5 mm y−1. Low sedimentation rates found for the Middle and South Adriatic Sea are consistent with previously reported results for the rest of the Mediterranean. [ABSTRACT FROM AUTHOR]