NJDEP - NJGS - Bulletin 66, Mapping Digest for New Jersey, 1965

level. However, the elevation of this bench from the geodetic level not(based upon the 1876-1881 epoch) is 7.27 feet above mean sea level.In the time interval of 78 years from 1881 to 1959, the relationshipbetween the sea a_d the land at Sandy Hook has changed hy 0.58 foot. 8Considering the evidence given above, it must be concluded without qualificationthat any references to local mean high water, local mean lowwater, half tide level, etc. and/or mean sea level must specify the epochused to determine the datum(s).REFERENCESCITEDI. U.S. Department of Commerce, Tidal Datum Planes, Special PublicationNo. 135, Revised (1951) Edition (Washington: GoverninentPrinting Office, 1951), chap. v, p. 63.2. U.S. Department of Commerce, Tide and Current Glossary, SpecialPublication No. 228 (Washington: Government Printing Office,1941), p. 24.3. U.S. Department of Commerce, h.lanual o] Harmonic Analysisand Prediction o/Tides, Special Publication No. 98 (Washington: GovernmentPrinting Office, 1958), p. 17.4. U. S. Department of Commerce, Shore and Sea Boundaries,Publication 10-1, Vol. 1 (Washington: Government Printing Office,1962), Appendix A, p. 304.5. U.S. Department of Commerce, Tidal Datum Planes, chap. v, p. 58.6. Personal communication, United States Coast and Geodetic Survey,Geodesy Division.7. Ibid.8. Ibid.SELECTEDREFERENCE1. Defant, Al,bert, Ebb and Flow, The Tides of Earth, Air and Water,(Ann Arbor, Michigan: The University of Michigan Press, 1958).2ONEW JERSEY GEOLOGICAL SURVEY