58 



STETSON 



The following locations were chosen for this study. CJn the Atlantic side of Cape Cod 

 traverses have been maintained at the following places; Nauset Coast Guard Station, the aban- 

 doned Highland Light Coast Guard Station, and about three-quarters of a mile west of the Race 

 Point Coast Guard Station. The first site is a traverse off the southward growing spit which 

 protects the Eastham-Orleans shore, the second is off a cliff section which is shedding debris 

 of all types, and the third is off the north side of the Provincelands section where the shore is 

 being prograded by a succession of beach ridges and offshore bars. The exposure to onshore 

 gales is severe and is about the same on all three, although the tidal currents run stronger off 

 the Race Point traverse. Wave action is as violent as you can find anywhere on the Atlantic 

 coast. On the Cape Cod Bay side, two traverses have been maintained: one at Sandy Neck, 

 Barnstable, and the other at Duxbury Beach. On neither of these beaches is wave action as 

 . violent as on the outer Cape, although wind velocities are probably as high and dunes have been 

 extensively developed, especially at Barnstable. Geologically, both are wave-built spits. In the 

 case of Sandy Neck, the source of the sand is the cliffs north of the Cape Cod Canal, but at Dux- 

 bury the source is not apparent, possibly coming from the bottom off shore. Both seem rela- 

 tively stable and have exhibited little topographic change from year to year. They present a 

 marked contrast to the outer Cape where every storm brings marked alterations in width of 

 the backshore and in the position and height of the berms, as well as shifts in the offshore bars 

 of the seaward portion (Fig. 2). 



For any given set of environmental controls, 



Figure 2. The outer beach of Cape Cod looking 

 north. Note the marked variations in width and 

 the position of the offshore bars as marked by 

 the line of breakers. 



looked at in the large, there is a correspond- 

 ing form which any given beach tends to 

 assume, although it may change tempo- 

 rarily and in response to seasonal altera- 

 tions in the environment. The profile will 

 not be permanently altered unless the 

 controls, such as supply, also change per- 

 manently. The more rigorous conditions 

 of winter cause the most rapid fluctuations, 

 and it was for the purpose of charting these 

 shifts and the return to equilibrium condi- 

 tions that a twelve-months' period was de- 

 cided upon for the observations. There is 

 a strong possibility that any given beach 

 will tend to develop what might be termed 

 seasonal characteristics, which may be 

 repeated in response to changing weather 

 conditions as the seasons succeed each 

 other. It may well be that conditions ob- 

 served in one winter may be used as pre- 

 dictions for what may be expected in 

 subsequent winters. 



Field work has been carried out in 

 the following manner. The form of the 

 emerged portions of the beach, that is the 

 backshore and the foreshore, is surveyed 

 with a transit and the offshore portion is 

 sounded from a dory with a hand lead and 

 a marked bamboo pole. A permanent base- 

 line of 600 to 1000 feet has been staked out 

 depending on the curve of the shoreline. 

 The seaward portion of the traverse is 

 about 1500 to 2000 feet long, and the boat's 

 position upon it is cut in with the transit up 

 to 60°. Every time a sounding is taken 

 flag signals are made by the boat's crew 

 and acknowledged by the instrumentman. 

 On the Race Point and Highland traverses, 

 parallel profiles 400 feet away are being 

 run this winter [Feb. 1954], as the position 



