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Fig. 7.22
Longitudinal and transverse apparent-resistivity and impedance-phase curves over
the central conductive segment in the model from Fig. 7.16;
y
-distance to the centre of the
model; ˜
⊥
,
⊥
-analytical solution,
⊥
,
⊥
and
,
-numerical solution by the finite elements
˜
1
,
1
method, ˙
n
,
n
-locally normal solution. Model parameters:
˙
=
100 Ohm
·
m
,
h
1
=
1km
=
100 Ohm
·
m
,v
=
10 km
,
2
=
10000 Ohm
·
m
,
h
2
=
99 km
,
3
=
0
⊥
-curves. These curves have no
ascending branch and their descending branch is shifted deeply down. Here the
the strong
S-
effect that dramatically distorts the
-
- curves are much less distorted.
Figure 7.23 presents the tipper curves. Here over the side segments bordering the
conductive central segment we observe rather large tippers at distances
and
|
−
v
about 30 km. Comparing Fig. 7.23 with Fig. 7.20, we see that conductive struc-
tures cause more vigorous magnetovariational anomalies than resistive structures.
Note also that in this model low-frequency tippers show the same property as in
the model with the resistive central segment: the tipper phases,
=
|
y
y
=
arg
W
zy
or
W
