Date of Award

Spring 1976

Document Type


Degree Name

Master of Science (MS)


Ocean & Earth Sciences



Committee Director

Jogn C. Ludwick

Committee Member

Chester E. Grosch

Committee Member

Peter Fleischer

Committee Member

Phylis Nagel

Committee Member

Victor Goldsmith

Call Number for Print

Special Collections LD4331.O35G635


The historical, hydrodynamic, and sedimentological development of Inner Middle Ground - Nine Foot Shoal indicates that it is presently in quasi-equilibrium with mutually evasive ebb and flood tidal currents. Bathymetric comparisons among six surveys taken during the past 122 years depict development of the shoal from two linear sand bodies to its present double parabolic morphology. Circulation paths are proposed for each survey.

Information from eight current meter stations on and adjacent to Inner Middle Ground - Nine Foot Shoal were used to determine near-surface and near-bottom tidal current asymmetries and directions. The concepts of bathymetrically diverted currents and mutual evasion are well illustrated. Pseudo-synoptic vertical velocity profiles were drawn from which boundary shear stress and sediment transport were calculated. Determined sediment transport paths were in close agreement with proposed paths.

Cluster analysis was employed to determine the optimum natural grouping of the sediments over Inner Middle Ground - Nine Foot Shoal. This categorization, based on the weight percent of material from each 1/4 ϕ sieve fraction, was found to be in agreement with determined and proposed sediment transport paths. The procedure of differentiating the sediments into geographically intact groups is objective. Neither arbitrary limits nor a priori knowledge were required. The groups found are sedimentologically significant.


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