A NEW DATA-BANK FOR TIDAL GRAVITY MEASUREMENTS (DB 92)

Tidal gravity parameters are now available in 352 permanent or temporary stations all over the world. Previous tentative interpretations of these data were made on the basis of a data bank created in 1980-1982 which contained all available results without any discrimination which could have appeared as arbitrary. These interpretations were criticized on the basis of the different qualities of instruments (null instruments or not), data, calibration and necessary corrections for ocean-continent interactions. As we agree that a careful re-examination of the basic data is needed before any geophysical discussion, we have built this new data bank which contains only those 211 stations where rigid control of every step in the observations, calibrations and reduction could be made either because the original data are stored in the World Data Center C, or because the published results give enough information to permit checks and revisions. As a result, the scattering in the tidal parameters is reduced by a factor of 2 with respect to the previous data while the mean values of the amplitude factors of the two main waves (O1 diurnal; M2 semi-diurnal) calculated continent by continent, agree with the best available earth model. It is expected that this new data bank will be used for renewed discussions of the results.