Earth gravity up to second order in topography and density

Frédéric Chambat (1) , Bernard Valette (2)

1 LST - Laboratoire de Sciences de la Terre
2 LGIT - Laboratoire de Géophysique Interne et Tectonophysique

he gravity potential of a planet is usually expanded up to first order only as a linear function of topography and lateral variations of density. In this article, we extend these expressions up to second order and we estimate the magnitude of the new non-linear terms. We find that they are not negligible when compared to observed values: tens of metres for height anomalies and tens of milligals for gravity anomalies. Therefore, second-order expressions should be taken into account when inverting global gravity data.

Mots clés: Gravity; Potential; Density; Topography; Perturbation

Frédéric Chambat, Bernard Valette. Earth gravity up to second order in topography and density. Physics of the Earth and Planetary Interiors, 2005, 151 (1-2), pp.89-106. ⟨10.1016/j.pepi.2005.01.002⟩. ⟨insu-00271517⟩