Open AccessSolid tidal tilting observed in the West Australian goldfields
Author(s) -
Blair D. P.
Publication year - 1981
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1981.tb02751.x
Subject(s) - tilt (camera) , sidereal time , geology , geodesy , bedrock , amplitude , fourier analysis , coupling (piping) , fourier transform , fourier series , deformation (meteorology) , seismology , geometry , mineralogy , geomorphology , optics , physics , mathematics , materials science , mathematical analysis , oceanography , astrophysics , metallurgy
Summary Experimental tidal tilts were obtained in the Eastern Goldfields region of Western Australia. Spectral data are given for the total tilt in one direction only and the results compared with the theory. The main semidiurnal (M2) component is extracted by Fourier techniques and it is shown that analysis of a data length 57 periods of the M2 wave (or 29.50 sidereal day) yields less uncertainty in the estimation of the M2 amplitude than does analysis of a longer data length of 70 M2 periods (or 36.23 sidereal day). Furthermore it is shown that use of a simple rectangular gate time window yields less uncertainty in the Fourier estimation of the M2 amplitude than that obtained using the well‐known Hanning and Hamming windows. Phasor plots of the M2 tilt tide are also given for two distinct methods of tilt meter mounting to the bedrock. In the present investigation tilt‐strain coupling due to both the cavity effect and local topography is considered negligible, however tilt‐strain coupling due to the geological effect is not necessarily negligible and is evaluated using a boundary integral method.