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Fig. 4.4.
The real and imaginary Wiese-Parkinson tippers over a near-surface rectangular inclusion
of higher conductivity. Model parameters:
/
=
1
/
16
,v/
h
1
=
8
,
h
2
/
h
1
=
21. Calculated
for
λ
1
/
h
1
=
30
,
45
,
60 (
S
1
−
interval), 100
,
150 (
h
−
interval);1-real tipper, 2- imaginary tipper
real tippers preserve their orientation, whereas the imaginary tippers turn towards
the center of conductive inclusion.
A spectacular practical example is given in Fig. 4.5. This map of the real Wiese-
Parkinson tippers has been constructed for the Carpathian region in the early 1970s
(Rokityansky, 1982). When crossing the mountains, we observe the reversal of
Re
W
plotted for
T
=1000-1500 s. The induction arrows point away from the
Carpathian arc. So, we can state with confidence that the Carpathian magnetovaria-
tional anomaly is formed by a narrow arc-shaped conductive zone in the deep roots
of the mountains.
4.2.2 The Vozoff Tipper Technique
Another vector representation has been suggested by Vozoff (1972). It separates
the amplitude and phase characteristics of the magnetovariational anomalies and
offers a simple three-dimensional generalization of the longitudinal and transverse
magnetic fields. We will describe this technique with some modifications proposed
by Berdichevsky and Nguen Tkhan Van (1991).
Let us introduce the
tipper ratio
as an amplitude characteristic of the magne-
tovariatonal anomaly:
