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Fig. 11.6
Two-dimensional model of the
-effect
conversely, if the
values from the high-frequency ascending branch of apparent-
resistivity curves do not correlate with the
S
sed
−
−
A
values, then we can suppose that
they are distorted by the
effect.
Success of magnetotelluric soundings depends dramatically on the reliability of
the static-shift corrections. There is no standard universal remedy for static shift,
so the best result can be attained by combining different correction techniques.
Modern magnitotellurics offers a variety of methods for the static-shift correction
(Larsen, 1977; Bostick, 1984; Jones, 1988; Kaufman, 1988; Berdichevsky et al.,
1989b; Pellerin and Hohmann, 1990; Vozoff, 1991; Singer, 1992). These methods
use statistical averaging, filtering, fitting to a given reference, and mathematical
modeling.
−
11.1.2 Averaging Apparent Resistivities
A
effect has been suggested in
(Berdichevsky et al., 1980). Following this paper, we consider the magnitude of
the static shift as a random variable with lognormal distribution. Returning to the
model shown in Figs. 11.11 and 11.12, we write
simple
statistics
for
suppressing
the
−
(
i
)
(
i
)
(
i
)
(
i
)
xy
=
xy
N
yx
=
yx
N
i
=
1
,
2
, ...
22
(11
.
2)
