The role of gravity in the WEGENER project

Variations in the gravity field are introduced by mass or density redistribution in the vicinity of the measuring point as well as far field or global effects but also any crustal process which involves a height variation has a direct implication on the temporal variation of the gravity 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 state of the art for both techniques is discussed and shown that systematic errors or the measurement of their changes can be detected by inter-comparison with other absolute gravimeters and frequently repeated measurements at a reference station monitored by a superconducting gravimeter. In the combination of the available gravity techniques it is possible 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 and ground water loading effects from the long term processes.