RRS Charles Darwin Cruise 104 Leg 2, 21 Mar-19 Apr 1997. Geological processes in the Strait of Hormuz, Arabian Gulf: a contribution to the Scheherezade Programme

The second leg of the Scheherezade multidisciplinary environmental cruise to the entrance to the Arabian Gulf is concerned with superficial geology, geoacoustics and geotechnics. Preliminary interpretation of the digitally recorded sidescan sonar, seismic profiles and the 206 sediment samples showed that the area can be divided into two types, one where strong currents sweep the seafloor and the other where currents are weaker. In the strong current area, bed load transport paths have been determined from asymmetrical bedforms and a number of bedform zones have been identified. The sediments here are mainly shelly sands and gravels. In the weaker current areas there are large numbers of pockmarks, believed to be due to gas venting at the seabed. The sediments here are muddier but shelly sands are still present. Two very high resolution sidescan surveys of selected areas were made and at each survey area video photographs of the seabed and dredge samples were obtained. Measurements of shear waves were made with the newly developed SAPPA device at nine sites. Further work is needed before P waves can be measured.