THE ROLE OF GRAVITY IN THE WEGENER PROJECT

Variations in the gravity field are introduced by mass or density redi stribution in the vicinity of the measuring point as well as far held or global effects but also any crustal process which involves a height variation has a direct implication on the temporal variation of the g ravity field. The measuring techniques involved in the WEGENER project include absolute and high precision relative gravity measurements and stationary measurements with superconducting gravity meters. The stat e of the art for both techniques is discussed and shown that systemati c errors or the measurement of their changes can be detected by inter- comparison with other absolute gravimeters and frequently repeated mea surements at a reference station monitored by a superconducting gravim eter. In the combination of the available gravity techniques it is pos sible to achieve a precision at the micro-Gal level for secular trends and a higher accuracy for period events which enable improvements in the modelling of environmental effects induced by ocean, atmospheric a nd ground water loading effects from the long term processes. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.