La surcharge hydrologique en géodésie terrestre

Nicolas Florsch (1) , Laurent Longuevergne (1) , Muriel Llubes (2) , Jacques Hinderer (3) , M. Amalvict (3)

1 SISYPHE - Structure et fonctionnement des systèmes hydriques continentaux
2 LEGOS - Laboratoire d'études en Géophysique et océanographie spatiales
3 IPGS - Institut de physique du globe de Strasbourg

We investigate the possible influence of underground waters on gravity and radial displacement. One actual challenge is to manage the validation of dedicated satellites like GRACE from ground based gravimetric measurements. Actually, the local hydrologic variations dominate the ground signal. We can estimate the direct Newtonian attraction plus the loading effect due to theoretical aquifer variations, but a realistic modelling needs an accurate study of the hydrological background. By taking as an example the J9 superconducting gravimeter station close to Strasbourg (France), we argue that it is necessary to characterize as well as possible the aquifer systems, and the water mobility from the shallow soil to the water table, in order to predict the gravity variations at the signal level available today from current instruments. The expected variation range agree with the observed one.

Domaines: Interfaces continentales, environnement; Milieux et Changements globaux

Nicolas Florsch, Laurent Longuevergne, Muriel Llubes, Jacques Hinderer, M. Amalvict. La surcharge hydrologique en géodésie terrestre. 2003. ⟨hal-00708079⟩