What Is MT / Magnetotellurics?

Definition of Magnetotellurics

  • A geophysical technique measuring changes in earth’s natural electromagnetic fields
  • These electromagnetic fields fields are constantly changing
  • Measures changes in Electric (E) and magnetic (H) as a function of time
  • Frequency range 10kHz to .001 Hz
  • Used to derive the resistivity structure of the subsurface

What is Magnetotellurics used for?

  • Exploration for almost any natural resource
  • This includes oil, gas, minerals, water, geothermal
  • Also used for deep crustal studies (plate boundaries, etc.)
  • Images from the very-near surface to depths of over 10,000 meters
  • Requires resistivity contrast between target and surrounding rock
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What Is Electromagnetic Geophysics?

Definition of Electromagnetic Geophysics

  • A geophysical technique measuring changes in electromagnetic fields induced in the earth
  • Measurements can be made as a function of time or frequency
  • Measurements can be done on ground, in air, or at sea
  • Used to derive the resistivity structure of the subsurface
  • Limited depth of investigation, normally musch less than 1 km

What is Time-Domain Electromagnetics used for?

  • Exploration for almost any resource
  • Shallow targets with resistivity contrast
  • Also for MT statics corrections
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