FLORIDA GEOLOGICAL SURVEY
one should view it in the .... .statistical sense where we know S..more about its central tendency 2 than we do about the behavior of the lower foreshore (corresponding to MLW or MLLW) or higher foreshore (corresponding to MHW or MHHW). When we approach the extremes of the 4 -slope, exceptions due to physiographic irregularities can occur. Hence, one needs to view the surf base foreshore slope intersection as a focal point about which the foreshore rotates. In this context, the focal point is directly related to incoming force elements. Furthermore, it is conceptually not subject to variations to which the upper and lower parts of the foreshore are subject, since it is an origin both common and comparable to the focal point at other localities.
From a slightly different viewpoint, one argument
Figure 8. Semidiumal tide curves for 6 tidal days (from proffered by a colleague who Manner, 1951). took the "devil's advocate' position, is that the MHW intercept represents the most issue becomes particularly poignant from stable portion of the foreshore slope. While inspection of Figure 1 where the behavior of this may appear appropriate to the layman, low waters (i.e., MLW and MLLW) and high from the geological perspective it is not. It waters (i.e., MHW and MHHW) are anything is, in fact, the least stable in terms of but symmetrical in their relationship to MSL representing a normal slope. The most (or MTL), signifying a need for an average stable position of the foreshore is probably at surf base measure. Statistically extreme the MSL intercept (i.e., relative to other average point measures providing numerical submerged portions of the profile) since it is values of upper (i.e., MHW and MHHW) and reflective of average, ongoing force elements lower (i.e., MLW and MLLW) tidal datums to which it is modified as a response are robustly founded. Corresponding element. By comparison, the foreshore in extremes of such physiographic features as the vicinity of the MHW or MHHW intercepts the foreshore may not be so robustly is affected only during high tide stages and founded, since its formation and can be reflective of extremal impacts (e.g., maintenance has not been rigorously defined storm wave events). Extreme impacts in terms of forces and responses (e.g., Kraus affecting the MHW foreshore are likely to and others, 1991, p. 3). Given the manner result in relict features which persist until in which we currently define the foreshore, continual average force conditions finally
46