Open AccessA microgravimetric network for secular gravity studies in Scotland
Author(s) -
Hipkin R. G.
Publication year - 1978
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.1978.tb04239.x
Subject(s) - geodesy , gravimeter , geology , residual , secular variation , geophysics , mathematics , casing , algorithm
Summary. Tests with the LaCoste and Romberg gravity meter G‐275 show that random reading errors generate a standard deviation of less than 0.02 gu (2 μgal) under typical microseismic conditions. Reproducible, systematic errors are commonly an order of magnitude larger, due mainly to residual tidal effects and drift induced by clamping. The latter, possibly related to thermal gradients in the oven, can be eliminated by observing along‐enough section of the drift curve at each field station so that equilibrium is reached there. A measurement of the gravity difference between the NGRN (73) sites at Edinburgh and Linlithgow, giving 5.565 5 ± 0.018 (se) gu, is described as an example of the method. A loop of eight gravity stations associated with Ordnance Survey Fundamental Bench Marks, east—west between Dunbar and Bowling (Dumbartons) and northwards to Crubenmore (Inverness) is being measured as the basis of a secular gravity study by a calibrated small‐difference method. The uses of such a network are discussed.