Geoscience Reference
In-Depth Information
Figure 10.22.
(
cont.
)
Figure 10.23.
The shear-wave velocity structure of the upper mantle
beneath the western Alps obtained from the simultaneous inversion
of surface-wave-dispersion data. S-wave velocities are shown in
km s
−1
.M,Moho discontinuity; 'Lid', lower lithosphere; 'Channel',
asthenosphere; dark shading, uncertainty in boundaries. High
velocity beneath the Alps indicates that material may have been
subducted to about 200 km depth. (From Panza and Mueller (1979).)
Figure 10.23 shows the shear-wave velocity structure of the upper mantle on
a cross section through Switzerland and northern Italy obtained from inversion
of surface-wave data. The lithosphere on the northern side of the Alps is some-
what thicker than that beneath Italy. The high shear-wave velocities, extending
to
200 km depth beneath the Alps, are typical of the lithosphere, rather than
the asthenosphere, and suggest that lithosphere has been subducted to about that
depth.
∼
