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:
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.
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.
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.
Edward B. Thornton, Spanagel 327, x2847
Timothy P. Stanton, Spanagel 329, x3144