The high density of geophysical data (gravity, bathymetry...) collected in the ANTPAC 97/98 cruise by the
Spanish BIO Hespérides allows us to obtain the crustal thickness of the areas near the intersection of the
Shackleton Fracture Zone and the West Scotia Ridge (Z1), and the P2 segment of the Phoenix-Antarctic
Ridge (Z2) by means of inversion methods. Data were merged with that of the Global Gravity Grid and the
Global Sea Floor Topography (Sandwell and Smith, 1997). The effect of the bathymetry on the Free Air
anomaly was eliminated previously. Differences in the crustal thickness in both areas are presented