Modelling sand wave migration in shallow shelf seas


Nemeth, Attila A. and Hulscher, Suzanne J.M.H. and Vriend, Huib J. de (2002) Modelling sand wave migration in shallow shelf seas. Continental Shelf Research, 22 (18-19). pp. 2795-2806. ISSN 0278-4343

[img] PDF
Restricted to UT campus only
: Request a copy
Abstract:Sand waves form a prominent regular pattern in the offshore seabed of sandy shallow seas. The positions of sand-wave crests and troughs slowly change in time. Sand waves are usually assumed to migrate in the direction of the residual current. This paper considers the physical mechanisms that may cause sand waves to migrate and methods to quantify the associated migration rates. We carried out a theoretical study based on the assumption that sand waves evolve as free instabilities of the system. A linear stability analysis was then performed on a 2DV morphological model describing the interaction between the vertically varying water motion and an erodible bed in a shallow sea. Here, we disrupted the basic tidal symmetry by choosing a combination of a steady current (M0) and a sinusoidal tidal motion (M2) as the basic flow. We allowed for two different physical mechanisms to generate the steady current: a sea surface wind stress and a pressure gradient. The results show that similar sand waves develop for both flow conditions and that these sand waves migrate slowly in the direction of the residual flow. The rates of migration and wavelengths found in this work agree with theoretical and empirical values reported in the literature.
Item Type:Article
Copyright:© 2002 Elsevier Science Ltd.
Engineering Technology (CTW)
Research Group:
Link to this item:
Official URL:
Export this item as:BibTeX
HTML Citation
Reference Manager


Repository Staff Only: item control page

Metis ID: 124028