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| isbn = 0-89181-602-X
| isbn = 0-89181-602-X
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Magnetotellurics (MT) is a method of surveying the subsurface from the surface. Although MT cannot provide the resolution of [[Seismic data|seismic surveys]], it is less expensive and, more importantly, can be used in places where seismic data collection is impractical or gives poor results.
Magnetotellurics (MT) is an electrical geophysical technique that measures the resistivity of the subsurface. Although MT cannot provide the resolution of [[Seismic data|seismic surveys]], it is less expensive and, more importantly, can be used in places where seismic data collection is impractical or gives poor results. This is the same physical parameter that is measured in a borehole resis- tivity log.
==How MT differs from electric logs==
MT differs from an inductive electric log in three major ways:
{|
| class = "wikitable"
|-
! Magnetotellurics Measurements || Electric Log Measurements
|-
| Made from the surface || Made subsurface from inside a borehole
|-
| Depth of investigation is a function of both frequency at which the measurement is taken and the average resistivity of the subsurface || Depth of investigation is the depth of the borehole measuring device below the surface
|-
| Respond only to changes in average bulk resistivity || Respond to individual rock layers along the wall of the borehole
|}
==See also==
==See also==