Model for the formation of longshore sand ridges on the continental shelf

Technical Report · Wed Jan 05 04:00:00 EST 1994

DOI:https://doi.org/10.2172/205053· OSTI ID:205053

Restrepo, J M ^[1]; Bona, J L ^[2]

---

1. Argonne National Lab., IL (United States)
2. Pennsylvania State Univ., University Park, PA (United States). Dept. of Mathematics

A model is proposed for the formation and evolution of three- dimensional sedimentary structures such as longshore sand ridges on the continental shelf in water deeper than that of the shoaling region. Owing to the striking similarity between the bar spacing and the length scales in which interactions among the most energetic modes of shallow water waves take place, we argue that these bars are formed slowly by flows in the turbulent boundary layer generated by weakly nonlinear, dispersive waves. Hence the model is based on the interaction between surficial, weakly nonlinear shallow water waves, having weak spanwise spatial dependence, and the bottom topography. While such underwater structures are not the result of a single formative agent, it is argued that the mechanism proposed in this study does contribute significantly to their generation and evolution. Comparisons of this model with oceanographic data must wait for sufficient data to become available. In conjunction with developing the sand ridge model, this study proposes new mathematical equations of interest in their own right.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); Pennsylvania State Univ., University Park, PA (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 205053
• Report Number(s): MCS--P406-1293; ON: DE96007628
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
BOUNDARY LAYERS
CONTINENTAL SHELF
HAMILTONIAN FUNCTION
HYDRODYNAMICS
MATHEMATICAL MODELS
SEA BED
SEDIMENTS
TOPOGRAPHY
WATER WAVES