Geoscience Reference
In-Depth Information
Figure 5.21.
The uplift
one, three, six, eleven
(circles) and ∞ (crosses)
thousand years after the
removal of a 2.5-km-thick
model Wisconsin ice
sheet from an elastic
lithospheric plate
overlying a viscosity
mantle of uniform
10
21
Pa s. Note that, for
clarity, the vertical scale at
distances greater than 25
◦
(1
◦
=
800
11
6
600
3
400
110 km) is magnified
by a factor of ten. (From
Cathles (1975).)
1
200
20
Radial distance
0
10
o
LOAD
20
o
30
o
40
o
50
o
60
o
1
∞
11
6
3
−
200
−
20
10
22
10
21
1
2
3
4
10
20
0
1000 2000
Depth (km)
Figure 5.22.
Estimates of the viscosity structure of the mantle: 1, based on relative
sea level in northwest Europe; 2, based on relative sea level in Fennoscandia and
Hudson Bay together with upper- and lower-mantle seismic tomography; 3, based
on a mantle-flow model and lower-mantle seismic tomography; and 4, based on a
spectral study of the gravity field over Hudson Bay. (Reprinted with permission from
Nature
(Simons and Hager,
Nature
,
390
, 500-4) Copyright 1997 Macmillan
Magazines Ltd.)
