Sensitivity study of TEM data at La Bajada Fault

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Sensitivity study of TEM data at La Bajada Fault

• Tobyn W. VanVeghten
• University of Missouri-Rolla
• July 11, 2004

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Outline

• Objective
• Methodology with example 1-D results
• TEM Cross-section constrained by sensitivity
  analysis WinGLink
• EMMA and results from EMMA
• Conclusion

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Objective

• Sensitivity analysis
• Constrain TEM data at Canyon Site
• Qualitatively in WinGLink
• Quantitatively using EMMA

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Examples of Raw Data
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Sensitivity Test
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Sensitivity Test Contd
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Inverse Models with Error Bars
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TEM Cross-Section
W
E
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EMMA

• Electromagnetic Model Analysis (EMMA) Program
• Developed by the HydroGeophysics Group,
  University of Aarhus, Denmark
• 1-D modeling program for most TEM, FDEM,
  Resistivity, MT, and borehole methods
• Includes model sensitivity analysis

From Auken, Nebel, Sorensen, Breiner, Pellerin,
and Christensen, June 2002
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EMMA Screenshot
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Example of EMMA Results
Earlier Results for Comparison
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TEM Cross-Section after EMMA
E
W
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Conclusion

• Cant resolve top and bottom resistive layers
• Change in character between LB600 and LB650
• Possible fault here