Date of Award
Master of Science in Oceanography
The orientations and changes of orientation of the straightened secondary shorelines of Cape Cod Bay were studied in order to determine whether they were controlled by the direction of approach of the largest waves to reach them or by the direction or amount of the littoral drift.
A comparison of coastal surveys made over the past approximately one hundred years indicated that although short beaches bounded by barriers to littoral drift tend to “face” the direction of minimum drift, longer uninterrupted shorelines tend to “face” the direction of maximum fetch which is interpreted to be the direction of approach of the largest waves. In particular, the shoreline between Cape Cod Canal and Barnstable Harbor was found to possess a stable orientation toward the direction of maximum fetch despite a net littoral drift toward the east.
It is suggested that the erosive action of storm waves is responsible for maintaining coastal orientations toward the direction of maximum fetch on both erosional and accretional shorelines. It is also suggested that some spits may be formed by a process of “natural selection” whereby those accretional features are preserved which are normal to the approach of the large storm waves.
Changes of wave exposure were found to have changed the orientation of some equilibrium shorelines, to have destroyed others, and to have formed still others. It is concluded that there is a strong interdependence between coastal forms of equilibrium and that their study can be extremely useful in solving problems of past and future coastal changes.
Giese, Graham Sherwood, "Coastal Orientation of Cape Cod Bay" (1964). Open Access Master's Theses. Paper 2067.