foreshore and inshore zone occurred at elevation -0.2 foot, the lower 
limit of backrush. The boundary between the inshore and offshore zones 
is defined for these profiles at -0.6-foot elevation, which was always 
seaward of the breaker and represented a break in the profile topography. 
A definition sketch of the profile zones is shown in Figure 12. Pro- 
files in experiment 72B-06 (Fig. 12,a) had a steep foreshore, a short 
inshore zone with a longshore bar, and a gently sloping, concave-upward 
offshore. Early profiles in experiment 72B-10 (solid line in Fig. 12,b) 
had a steep foreshore, a short inshore zone with a rolling shape, and a 
gently sloping offshore zone with a bar near station 11 (elevation -1.0 
foot). Later profiles (dashline in Fig. 12,b) also had a steep fore- 
shore and a short inshore zone with a rolling shape, but the offshore 
zone had two bars, one near station 10 (elevation -0.8 foot) and the 
other near station 18 (elevation -1.5 feet) and a convex-upward shape. 
Profile development is shown by contour movement plots (Figs. 13 to 
20) of the seawardmost contour intercepts for elevations at 0.1-foot 
depth increments from +0.7 to -2.2 feet. Figures 13, 14, and 15 are for 
ranges 1, 3, and 5 in experiment 72B-06; Figures 16 to 20 are for ranges 
1, 3, 5, 7, and 9 in experiment 72B-10. The heavier lines for the -0.2- 
and -0.6-foot contours distinguish the three profile zones. In the fore- 
shore zone and on the seaward face of bars, the contour lines are close 
together indicating relatively steep slopes; on the shoreward side of 
the bar crests, the lines are spaced farther apart indicating a flatter 
slope or a trough. 
(1) Foreshore Zone. Within the first 5 hours of each experiment 
the foreshore developed as shown in the contour movement plots of the 
foreshore zone for the first 10 hours of experiments 72B-06 and 72B-10 
(Figs. 21 and 22). The foreshore maintained basically the same shape 
throughout the experiments, as shown by the roughly parallel lines in the 
foreshore zone in Figures 13 to 20. The foreshore was at equilibrium in 
position in experiment 72B-06 after 10 hours (indicated by the horizontal 
lines in Figs. 13, 14, and 15), but not in experiment 72B-10 (indicated 
by the upward-sloping lines in Figs. 16 to 20). 
The values for the tangent of the foreshore slope at the SWL inter- 
cept in both experiments are given in Table 8. In experiment 72B-06, the 
steepest slope was 0.46, the flattest slope was 0.10, and the average 
slope was 0.18; in experiment 72B-10, the steepest was 0.54, the flattest 
was 0.10, and the average was 0.20. 
The lateral variations in the slope of the foreshore developed as a 
result of concentrations of backwash, which created gullies or flatter 
slopes. The shape of the foreshore at 130 hours in experiment 72B-10 
(Fig. 23) is typical of the foreshore shape throughout both experiments. 
Figure 24 compares the shoreline (0 contour) movement along the 
several ranges of the two experiments. The shoreline (and foreshore zone) 
prograded about 1 foot during the first 10 hours in experiment 72B-06 and 
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