To investigate the influence of inherited inhomogeneity in a lithosphere un
der extension, we studied the deep structure of Corsica, an island in the M
editerranean sea, at the boundary of the extensional Tyrrhenian basin, usin
g: a temporary array of eight broad-band seismographs. Between the stations
in the western Hercynian part of the island and the stations in eastern Al
pine Corsica, an average static station delay of 0.4 s was observed for P w
aves, and 0.7 s for S waves. The crustal structure is obtained through seis
mic data, gravity modeling and the receiver function method. The difference
in crustal structure between the west and east of Corsica can explain only
about half of the anomaly. Consequently we postulate a sharp increment in
the thickness of the lithosphere to account for the remaining 0.2 s of P an
omaly.