Determination of land elevation changes using tidal data

Abstract

Abstract : The purpose of this thesis is to study the temporal pattern of vertical land movements at selected Pacific Coast tide stations. The relative motion of the land at these stations is indicated by the relationship between monthly mean sea levels measured at pairs of stations. Examination of historical monthly mean sea level data by means of graphical and spectral analysis led to the use of an anomaly filter which adjusts for mean monthly differences. A cumulative analysis procedure of Wyss (1977) was adopted to the study of the relative movement of seven tide stations. Determination of the type of vertical movement between pairs of stations, the date of sudden movement, and the station responsible can be determined from analysis of the cumulative curve of monthly sea level difference. Results of the cumulative analysis show that tide stations, whether separated by short or long distances, experience frequent changes in relative elevation. Whether these are caused by land movements or changes in station datum, or both, is not known. (Author)