Electrical resistivity imaging

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Electrical resistivity imaging
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What is resistivity imaging?

• We want to image the subsurface by reconstructing
  a 2D or 3D electrical resistivity distribution
  from electrical potential measurements (DC)
• Usually this corresponds to a tomogaphy problem
  Electrical Resistivity Tomography (ERT)

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pseudosection
Inversion ( imaging)
Resistivity model
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The greater flexibility in electrode positioning
allows efficient use of inversion techniques
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The ability to use subsurface electrodes (both
for potential and current) increases greatly the
number of independent measurements available for
inversion This results in better sampling of the
potential field.
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Current Source
Voltmeter
Ammeter
Borehole
Electrodes
Schematic of boreholeERT acquisition
system (pole-dipole)
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Abandoned Mines
Coal Seam
Gallery
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Abandoned Mines
Galleries
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Chihuahua
Trunk of Mezquite ???
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Example of resistivity surveysEl Fresnal
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