GRAVIMETER OBSERVATIONS COMPARING PENDULUM STATIONS AT CAMBRIDGE, YORK, NEWCASTLE-UPON-TYNE, EDINBURGH AND ABERDEEN

Abstract

Summary An extensive network of gravimeter stations has been observed by the Geological Survey of Great Britain using a Frost gravimeter. In the course of this survey gravimeter observations were made at recent pendulum stations in York, Newcastle-upon-Tyne, Edinburgh and Aberdeen. At these stations the gravimeter determinations gave values for differences in gravity from Pendulum House, Cambridge, which were consistent with the pendulum observations of Browne, Cook, McCarthy and Parasnis (1950). If the value of gravity at Pendulum House, Cambridge, is assumed to be 981.26500 cm/s2 the values at the other stations are found by combining the pendulum and gravimeter observations as:– York, Minster Crypt 981.41474 cm/s2± 0.00011 Newcastle, King's College 981.50608 cm/s2± 0.00012 Edinburgh, Royal Observatory 981.58014 cm/s2± 0.00013 Aberdeen, Marischal College 981.69597 cm/s2± 0.00014 From the observations at these pendulum stations an accurate calibration factor was obtained for the Frost gravimeter and this was found to differ significantly from the calibration factor determined from observations in the tower of Westminster Cathedral. Further measurements at Westminster Cathedral showed that the vertical variation in gravity is not linear but is distorted near the base of the tower, probably due to local terrain effects.