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is exceeded. In addition, it was found that Savage (1989a, 1989b), and Schmidt and linear interpolation led to results that simply others (1993) consistently used MHW as do not reflect the natural behavior of coastal their vertical reference from which processes. Hence, in 1987, a non-linear nth- volumetric beach changes were measured, order polynomial numerical methodology Komar (1998) used NGVD (it is assumed was introduced and utilized to determine that this is NGVD of 1929, although such is quantitatively open ocean tidal datums for a not stated) but stated that for his site NGVD significant portion of Florida's ocean-fronting "... is approximately equal to mean sea level coasts (Balsillie and others, 1987a, 1987b, ...". Lee and others (1998) used NGVD at a 1987c). Updated results (Balsillie and North Carolina coastal location; they did not others, 1998) are plotted in Figures 1, 2, and state, however, how NGVD departs from 3. MSL at their site. These exemplify instances in which tidal datums referencing
This work is a companion paper to tidal can introduce significantly compounded datums listings for Florida originally error. One illustrates other cases where no published by Balsillie and others (1987a, explanation detailing how tidal datums are 1987b, and 1987c) and updated by Balsillie applied is given, and one cannot be sure if and others (1998). It was determined he or she can have confidence in final necessary to undertake the present results. compilation because of an increasing number
of misapplications of tidal datums appearing To one extent or another, misapplication in the coastal engineering literature. For of tidal datums may be due to a lack of example, Foster (1989, 1991), Foster and understanding as to how they have been
North South
4
-.- 1.5
a 0 0 150 20 25 30 35 0
0 2. I I
0.5
> 0J
Uj r0S7 i
0 0 100 150 200 250 300 350 400 Alongshore Distance (statute miles)
Figure 1. Relationship between open coast dial datums and National Geodetic Vertical Datum of 1929 for the Florida East Coast. Alongshore distance is measured from the center line of St. Mary's Entrance Channel proceeding south to Cape Florida. (Updated in 1992 after Balsillie and others, 1987a).
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