Specifications

University of Pretoria etd – Combrinck, M (2006)
Channels are scaled so that channel 1 corresponds with the top of the section and channel
20 to the bottom. Note the half space (-2.5) decay that is observed on all models at some
stage. Although conductors are present the conductive nature of the half space itself
causes the dominant decay to be that of -2.5 as mentioned by Singh (1973) and discussed in
2.3.4. Only the high contrast horizontal plate shows finite conductor decay in the late time.
Automated decay constant analyses should be applied with great care if the half space
response has not been removed from data in a conductive host rock environment. It is
clear that under these conditions the S-layer differential transform is a more effective way
of determining the presence and locality of conductive
bodies
Figure 4-62: Same models as in Figure 4-63. Red dots indicate half space decay behaviour and
blue dots indicate conductor in “free air” decay.
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