During the first week of September 1976, a distant tropical storm created 

 a new breach in the dune line, just south (approximately 300 meters) of Nauset 

 Coast Guard Beach parking lot. Large swells arrived during a spring high tide 

 on a sunny, windless day, producing a breach at the position of a blowout and 

 pedestrian-created path in the dune line. Water ponded on the backshore, 

 draining marshward through the dune breach. A channel meandered through the 

 dune line, and overwash sand was deposited on the adjacent marsh, creating a 

 small washover fan. Very little of the living vegetation was displaced in the 

 dunes since the throat crossed an old blowout; therefore, few living plant 

 fragments were deposited with overwash sediments. Spring tides from the bay 

 side did not reach the lip of the new washover fan; thus, no drift lines were 

 deposited. 



A small northeaster resulted in overwash during 12 and 13 November 1976, 

 according to National Park Service rangers, adding an insignificant amount of 

 sand to earlier washovers on Nauset Spit-Eastham. There were no significant 

 overwashes recorded during the winter of 1977. Two small overwash events, 

 10 May and 10 June 1977, occurred in the spring. Although these events were 

 sedimentologically insignificant, saltwater flooding during the growing season 

 killed dune vegetation (.see Sec. 111). 



On 9 January 1978 a northeaster passed to the west and north of Cape Cod, 

 generating large waves in Cape Cod Bay and causing extensive flooding in 

 Provincetown. During the final stages, the storm developed a southeast 

 airflow along Outer Cape Cod, which resulted in overwash at spring high 

 tide. Because of the peculiar storm path and morphology, overwash was not 

 anticipated so no measurements were taken. This northeaster resulted in the 

 formation of a new wasnover located only 100 meters south of the southern end 

 of the Coast Guard Beach parking lot. 



(2) Large-Scale Event . The 6 and 7 February 1978 northeaster may 

 have been the most significant extratropical storm to strike the Cape Cod 

 shoreline in the last 50 to 100 years. This northeaster affected the entire 

 New England coastline. The National Park Service parking lot at Coast Guard 

 Beach was destroyed, and property losses for several Massachusetts towns 

 located on barrier beaches totaled about $200 million (Piatt and KcMullen, 

 1930). Using the Bretschneider technique (U.S. Army, Corps of Engineers, 

 Coastal Engineering Research Center, 1977), this storm was hir.dcasted to have 

 a significant deepwater wave height of 5 meters and a probable return interval 

 of 75 years. Nearshore breaker heights approached 3 meters. Based on tide 

 gage data (Boston, Massachusetts) and field surveys, the maximum Storm surge 

 was approximately 1.2 meters. 



On 6 February 1978 an electromagnetic current meter was used to measure 

 Gurge velocities during the first overwash-producing high tide (Fig. 7); 1 

 hour and 45 minutes of data (10:00 to 11:45 a.m.) was recorded on a strip 

 chart. Instrumentation was set up at Nauset Spit-Eastham in the throat of the 

 washover created by the January 1978 storm. Measurements during the height 

 of the storm (10:20 p.m. high tide) and the following morning were not taken 

 since access to the spit was impossible; the Coast Guard Beach parking lot was 

 underwater and in the process of being destroyed (Fig. 8). Destruction of 

 the parking lot also resulted in the generation of large quantities of rubble 

 which would have damaged instruments if measurements had been attempted. 



33 



