NEARSHORE PROCESSES THESIS TOPICS

Thesis topics are involved with participation in a field experiment, analysis of the data, and/or modeling of wave, current, sediment transport and morphology processes in the nearshore. You are invited to assist in the analysis of data from the large scale SandyDuck nearshore experiment, which took place in July-November 1997. SandyDuck, conducted on a barred beach at Duck, North Carolina, was the largest nearshore field experiment ever with over 18 universities and institutions participating. This work was funded by the Office of Naval Research in support of the U.S. Navy's interest in special warfare, amphibious landings and mine countermeasures.

Tentative Thesis Topics:

1) Set-up/down

As waves shoal, eventually break and then propagate towards the shore, there is a change in the momentum of the waves which is balanced by mean hydrostatic pressure gradients (set-up/down). An extensive array of mean water and wave measurements were made during SandyDuck to record both cross-shore and alongshore pressure gradients. Thesis projects will focus on the analysis of data and comparing with models.

2) Undertow

There is an onshore mass transport associated with waves propagating towards the shore. In shallow water, this is balanced by an offshore flow which is the undertow. The undertow is forced primarily by wave set-up in the nearshore. The mean cross-shore vertical velocity profiles and wave set-up forcing were measured during SandyDuck. Thesis projects will focus on the analysis of data and comparing with models.

3) Wave Boundary Layers

Unique acoustic Doppler instrumentation have been developed to obtain highly temporally and spatially resolved 3-component vertical velocity profiles to study the boundary layer under waves. These unique measurements will form the basis for testing wave boundary layer models, which are essential for the understanding of sediment transport and wave dissipation. Thesis projects will focus on the analysis of data and comparing with models.

4) Small-scale morphology

Unique acoustic techniques are being used to study small-scale (less than 5 m) variations in the nearshore bottom allowing some of the first comprehensive measurements of these processes. Knowledge of the small-scale morphology is essential for prediction of sediment transport and nearshore hydrodynamics. Thesis projects will focus on the analysis of data.

5) Bubbles under breaking waves

Bubbles are injected into the water column during the passage of breaking waves. The vertical distribution of bubbles is inferred from readings of a vertical array of conductivity cells and acoustic backscatter techniques. Bubbles are used to determine the depth of turbulence penetration and to calibrate video measurements of wave breaking.


Special Requirements:

Students must have at least one year remaining prior to graduation in order to pursue one of these thesis topics. Familiarity with spectral analysis (OC3150), Matlab and nearshore processes (OC4213) is also required.

Time frame:

Flexible

Professors:

Edward B. Thornton, Spanagel 327, x2847

Timothy P. Stanton, Spanagel 329, x3144