In the present contribution the presence of sand waves in the Messina Strait, Italy, is analysed, on the basis of unpublished data gathered during two different surveys carried out in 1991 and 1992. The study is carried out both from a sedimentological and morphological viewpoint, and in relation to the hydrodynamics in the Strait. Sand waves in two areas are examined: the first one lies just outside the northern part of the Strait, where the flow is rather complex, while the second one lies farther south in the Strait, where the tide characteristics force the flow essentially to oscillate along one direction. As a matter of fact, the dunes are made up with rather coarse sand; therefore, even where current direction varies significantly, only the highest currents are able to mobilise sediment. However, the differences in flow conditions play a significant role on the generation of smaller scale bed-forms (megaripples) in the first area, as obtained from a FFT analysis, and a likely sand bank in the second one.

A morphometric analysis showed that there is not a remarkable variability of these geometric characteristics at constant depth in the two areas. Steepness does not change much as well, and it appears always very low, thus suggesting a likely negligible effect of flow separation on these sand wave morphodynamics.

Time for the examined bed-forms to re-orient has been computed, on the basis of a defect dynamics theory, with the aim of partially investigating the risk for buried cables and pipelines to become exposed. Such time has been estimated as more than one century for both areas, thus implying that it does not play a significant role on problems concerning duct and cable cross design in the Messina Strait.

This content is only available as a PDF.
You do not currently have access to this content.