A Geophysical Study: Desert Hot Springs, CA

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A Geophysical Study Desert Hot Springs, CA

• Electric and Electromagnetic Response of the
  Mission Creek Fault
• Undergraduate research project
• Brad Coffey, Ben Drenth, Amber Harris, Shannon
  Kobs, Mellisa Le, Doug Moore

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Introduction

• Purpose
• Location
• Geology
• Methods

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Purpose

• Use of electrical and electromagnetic geophysical
  methods to assess the properties of the Mission
  Creek Fault and determine the usefulness of these
  methods in similar areas.

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Location
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Aerial Photo
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Geology
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Geophysical Methods

• Electrical
• Resistivity
• Electromagnetic
• Very Low Frequency (VLF)
• VLF resistivity (VLF-R)
• Horizontal Loop Electromagnetics (HLEM)

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Resistivity

• Previous Work
• Location
• Methods
• Results
• Interpretation
• Multielectrode Resistivity 2002

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Locations of soundings taken by Chad Lukkarila
and Dr. Diehl
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Resistivity methods

• Schlumberger Arrays
• 250 meter maximum spacing
• Originally interpreted using Resist3
• New interpretation using Zhody program

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Resistivity Cross-section Line
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Zhody Layered Model Results
N-NE
S-SW
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Multielectrode Resistivity
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Electromagnetics

• Very Low Frequency (VLF)
• VLF-Resistivity
• Horizontal Loop EM (HLEM)

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VLF and VLF-R
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VLF
VLF tilt-angle response
Horizontal Conductor
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VLF
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VLF-R
N-NE
S-SW
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HLEM
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HLEM Field Data
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HLEM Models
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Model Summary
S-SW
N-NE
30-50 m
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Conclusions

• Successful identification of fault location
  through electrical and electromagnetic methods
• Future Work
• Resistive or conductive fault gouge
• Interaction of fault and groundwater

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Acknowledgements
Thanks to Dr. Alex Mayer for his informative talk
on the hydrogeology of the Desert Hot Springs
Area. A special thanks to Dr. Young for
arranging the field trip, leading us in the
interpretation of the data, and feeding us at
that awesome steak place.
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References

• ________, 1988. Emix-mm Users Manual, Interpex
  Limited, Golden, Colorado, USA.
• Karous, M., and S. E. Hjelt (1983) Linear
  Filtering of VLF Dip-Angle measurements,
  Geophysical Prospecting, 31 782-794.
• Lukkarila, Chad R., 1999, Refinement of a
  groundwater flow model Upper Coachella Valley,
  Riverside County, California, MS Thesis,
  Department of Geological Engineering and
  Sciences, Michigan Technological University
• McNeil, J.D. 1988 Advances in Electromagnetic
  Methods for Groundwater Studies. SAGEEP 1988,
  252-348.
• Proctor, R. J. 1968. Geology of the Desert Hot
  Springs-Upper Coachella Valley Area, California.
  Special Report 94 California Division of Mines
  and Geology, San Fransisco, 50 p.
• Reynolds, J. M. 1997. An Introduction to Applied
  and Environmental Geophysics. John Wiley Sons,
  Inc. New York.

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Questions?
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Photos Nap Time
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Photos Fun Time
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Photos Miscellaneous
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Photos - Miscellaneous
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Photos Miscellaneous