## 2 Study Area  
The Adriatic Sea is a mostly shallow semi-enclosed basin connected to the Mediterranean Sea (Figure 1) and is commonly divided into three sectors (i.e., northern, central and southern). The northernmost sector is very shallow (i.e., 100 m). The central part of the Adriatic Sea represents the transition zone between the northern shallower and the southern deeper sub-basins and is limited by the 100 m isobath to the north and the Palagruza (Pelagosa) sil to the south. In this sector, a depression, the Mid Adriatic Depression (MAD), is present and subdivides the basins into three adjacent sub-basins. The western pit has a depth of ca. 255 m, whereas the central and eastern pits are ca. 270 m and 240 m deep, respectively [35]. The southern sector, between the Palagruza sill and the Otranto Strati, presents a wide depression, the Southern Adriatic Depression (SAD, >1200 m).  
The circulation of the Northern and Central Adriatic Sea (Figure 1) is represented by anticlockwise currents parallel to the coasts in winter [36], whereas in summer, the hydrodynamic pattern slows down and involves clockwise and counter-clockwise gyres. The circulation is also influenced by dense waters forming in the northern part of the Adriatic Sea that reach the MAD and partly flow further south [37].  
The main circulation pattern in the Adriatic Sea is represented by the inflow of Mediterranean Sea waters along the eastern part of the Otranto Strati and the outflow across the western side of it [38]. During summer, the riverine waters and the associated fine sediments predominantly flow in the centre of the basin, which are instead limited near the coast in winter [39]. Strong winter and autumn storms occur in the northern and central Adriatic Sea, causing a marked bottom sediment resuspension up to a sediment thickness  
Figure 1: Bathymetric map of the Adriatic Sea showing the general circulation (from [PERSON] et al. [35]). Western Adriatic Current (WAC), Eastern Adriatic Current (EAC), North Adriatic Gyre (NAdG), Mid Adriatic Gyre (MAdG), South Adriatic Gyre (SAdG), Adriatic Dense Water (AdDW) North Adriatic AdW (NAdDW), Levantine Intermediate Water (LIW), Adriatic-Ionian bimodal oscillating system (BIOS).  
of 5-10 cm [40]. Overall, the current and wave actions control the distribution of sediments to the south and, partly, in the open sea [41].  
The principal inputs of sediment are placed along the western side of the Adriatic Sea, which is primarily due to the Po River [42; 43; 44], and secondarily, by the Italian rivers.  
The changes in sea-level in the recent past have markedly shaped the present bottom sea in the northern and central sectors of the Adriatic Sea as well as the shelves in the southern one. The last fast transgression formed an accretionary sedimentary wedge parallel to the Italian coastline over an erosional unconformity [45; 46; 47; 48]. The thickness of the pelitic wedge reduces in the centre of the basin between the MAD and the Italian coast [49]. The bottom is marked by a belt of coastal sands and by a finer grain size area and again by coarser sediments offshore in the southern sector [47]. The grain size of sediment is silt and clay in the SAD.