Specifications

University of Pretoria etd – Combrinck, M (2006)
σ
Layer
= 0.2 S/m
d
Layer
= 150 m
h
Layer
= 15 m
Conductive layer in
half space (varying
σ contrast)
σ
HS
= 0.02 S/m
σ
Layer
= 2 S/m
and
σ
Layer
= 10 S/m
d
Layer
= 150 m
h
Layer
= 15 m
Decreasing depths with
increasing times
Layer depth overestimated
proportional to contrast;
initial decrease of
conductivity before
increasing to sometimes
erroneously high values.
High contrast
Conductive layer in
half space (varying
thickness)
σ
HS
= 0.02 S/m
σ
Layer
=0. 2 S/m
d
Layer
= 150 m
h
Layer
= 2 m, 5 m, 10
m, 15 m, 20 m, 50 m
and 100 m
Change in curve
characteristic for 50m
and 100m thickness.
2m to 20m see similar
graphs except for increase in
maximum conductivity
values with well defined top
of layer; 50m and 100m
thickness gives
overestimation of depth
proportional to thickness.
Low contrast behaviour
(increasing depths
mapped with increasing
time) remains even if
conductivity-thickness
product becomes very
large
Conductive layer in
half space (varying
thickness)
σ
HS
= 0.02 S/m
σ
Layer
= 2 S/m
d
Layer
= 150 m
h
Layer
= 2 m, 5 m, 10
m, 15 m, 20 m
Thicknesses more than
2m exhibit decreasing
depths with increasing
time.
Overestimation of depths
for 10m and thicker
proportional to thickness.
High contrast. The
thicker the layer becomes,
the closer the curves
resemble the two layer
case with very little or no
influence from the earth
below the conductive
layer contributing to the
signal.
Conductive layer in
half space (varying
depth)
σ
HS
= 0.02 S/m
σ
Layer
= 0.2 S/m
d
Layer
= 50 m, 150 m,
Smoothly increasing
with depth. 50m shows
anomalous behaviour
(see comment)
Width of the anomaly
increases proportional to
depth while the amplitude
decreases. Maxima slightly
deeper than layer top
boundary.
Low contrast.
Conductive layers
shallower than “first
channel expected depth
for host rock” maps at
correct depth but with
slightly distorted curves –
97