J. Phys. IV France 107 (2003) 879
210Pb transport by sinking particles at a selected site of the Southern Adriatic SeaS. Miserocchi, M. Frignani, L. Langone and S. Albertazzi
Istituto di Geologia Marina, CNR, via Gobetti 101, 40129 Bologna, Italy
A mooring was deployed in the southem Adriatic basin (1030 m depth) between April 1994 and October 1995. The mooring was equipped with two time-series sediment traps placed at 500 and 35 m above the bottom, respectively. Mass fluxes at both depths are characterised by high variability (26-1577 mg cm -2 y -1), without a clear seasonal trend. Particulate 210Pb activities vary within a relatively limited range of values (13-74 dpm g -1) and do not show any evident relationship with water depth. Activities are higher in winter. The correlation between 210Pb activity and organic matter in the upper water column suggests that 210Pb scavenging may be controlled by carbon cycle. On the contrary, at the near-bottom trap 210Pb activity seems to be driven by the amount of particles, their residence time in the water column and the contribution of lateral advection. The mass balances of both particulate matter and 210Pb require a very significant lateral input between the lower trap and the sea bottom. This flux is mainly consisting of resuspended sediment and seems to be episodic.
© EDP Sciences 2003