the bar completely eroded and thereafter the inner inshore (between -0.2- 

 and -0.5-foot elevations) remained fairly steep, as indicated by the 

 shoreward movement of the -0.2- to -0.5-foot contours. This material 

 was deposited at elevations -0.7, -0.8, and -0.9 foot. During the first 

 5 hours, the shoreward movement of the -0.5-foot contour and the seaward 

 movement of the -0.8-foot contour indicate fairly rapid development of a 

 long, flat shelf in the outer part of the inshore zone. 



Between 5 and 100 hours the seaward edge of the shelf (and inner in- 

 shore zone) remained stationary and the shelf grew as the shoreward edge 

 (-0.5-foot contour) moved shoreward. During this period some lateral 

 variations occurred in the positions of the -0.5- and -0.6-foot contours; 

 however, these variations were not significant. 



Between 75 and 95 hours the -0.7-foot contour retreated about 10 feet 

 (3 meters) along range 3 (Fig. 14), indicating significant erosion at that 

 depth. The same erosion occurred along the other ranges (Figs. 13 

 and 15) . 



After 100 hours, material deposited at the seaward edge of the shelf 

 (inshore zone) at depths of 0.7 and 0.8 foot advanced the inshore zone 

 8.5 feet (2.6 meters) in 20 hours. The shelf (-0.8-foot contour) con- 

 tinued to advance seaward for the remainder of the experiment. No sig- 

 nificant lateral variations occurred at the -0.8-foot elevation. After 

 135 hours the -0.7-foot contour retreated 23.0 feet (7.0 meters) as the 

 seaward part of the shelf flattened. The erosion of the -0.7-foot 

 contour along ranges 1 and 5 occurred 5 hours sooner. 



At 105 hours the area between stations 8 and 10 began eroding, which 

 eventually became a large trough with a bottom elevation of -1.3 feet 

 at station 10 at 175 hours (shown by heavy lines in Fig. 14). 



(3) Offshore Zone . The movement of contours in the offshore zone 

 is shown in Figures 7, 8 and 9 for ranges 1, 3, and 5. The offshore zone 

 developed from the initial 0.05 slope to a relatively steep slope as a 

 result of the deposition of material seaward of the breaker. 



During the first 5 hours, most of the material was deposited at 

 elevations -0.9 and -1.0 foot. Between 5 and 85 hours there was slight 

 deposition at various depths. After 85 hours significant amounts of 

 material were deposited in the offshore zone, beginning first at a depth 

 of 1.2 feet, then at a depth of 1.1 feet at 90 hours, 1.0 foot at 95 

 hours, and 0.9 foot at 100 hours. This deposition created a relatively 

 steep offshore slope, which subsequently became steeper as more material 

 was deposited offshore. 



Movements of the -1.0- , -1.4-, and -2.1-foot contours along the three 

 ranges are compared in Figure 17. The only lateral variation in contour 

 movement occurred at the -1.4-foot elevation near 50 hours, when the 

 deposition started first along range 1 and last along range 5. 



36 



