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| Titel |
Three-dimensional magnetotelluric inversion with distortion correction, practical experience and solution recipes |
| VerfasserIn |
Max Moorkamp, Anna Avdeeva |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250133187
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| Publikation (Nr.) |
 EGU/EGU2016-13769.pdf |
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| Zusammenfassung |
| The static distortion of magnetotelluric (MT) impedances is a common problem that can
prevent detailed imaging of the subsurface. The effect of distortion on the undistorted
impedance Z can be described as a multiplication with an unknown, real-valued
matrix C. Inverting the observed impedance Zobs = C ⋅ Z without any consideration
of distortion can result in strong artefacts, particularly in the near-surface. As a
consequence, a variety of approaches have been developed to remove as much of the
distortion effects as possible or compensate for them in the inversion. However, these
either reduce the number of data and thus potentially reduce resolution, or make
assumptions about the properties of the matrices C and Z which might not be generally
valid.
Recently we developed a new 3D inversion approach that includes the four unknown
elements of C as parameters in the inversion and showed encouraging result with different
synthetic test cases. In this presentation we will focus on the practical aspects of inverting real
data with this approach. We will use a combined MT and transient electromagnetic (TEM)
dataset acquired over the Kemaliye geothermal field in Turkey. We will demonstrate the
improvements in imaging that can be obtained by incorporating distortion in the inversion.
Having TEM data at each site, gives us some indication of the amount of distortion
and we will compare our recovered distortion values with these measurements.
Finally, we will also show in how far the inversion approach is robust in the presence
of noise and present recipes for successful inversion with distortion correction. |
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