The study of the solid Earth and its fluid envelopes by space geodesy techniques

Satellite geodesy uses a variety of technologies developed for space resear ch to study the Earth as a planet. Scientific investigations concern the sh ape of the Earth, its gravity field, rotational motions and deformations of the Earth's crust, dynamics of the liquid core, global mean sea level chan ge, temporal variations of gravity related to mass transfers among the surf ace fluid envelopes in response to global change. In this paper, we review the most outstanding results obtained by space geodesy during the past few years on these various topics are discussed. (C) 2000 Academie des sciences /Editions scientifiques et medicales Elsevier SAS.