3-D joint inversion of the magnetotelluric phase tensor and vertical magnetic transfer functions Public Deposited

http://ir.library.oregonstate.edu/concern/articles/0g354h029

This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Oxford University Press on behalf of The Royal Astronomical Society. The published article can be found at:  http://gji.oxfordjournals.org/content/203/2/1128

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • With advancing computational resources, 3-D inversion techniques have become feasible in recent years and are now a more widely used tool for magnetotelluric (MT) data interpretation. Galvanic distortion caused by small-scale near-surface inhomogeneities remains an obstacle for 3-D MT inversion which so far has experienced little attention. If not considered properly, the effect on 3-D inversion can be immense and result in erroneous subsurface models and interpretations. To tackle the problem we implemented inversion of the distortion-free phase tensor into the ModEM inversion package. The dimensionless phase tensor components describe only variations of the conductivity structure. When inverting these data, particular care has to be taken of the conductivity structure in the a priori model, which provides the reference frame when transferring the information from phase tensors into absolute conductivity values. Our results obtained with synthetic data show that phase tensor inversion can recover the regional conductivity structure in presence of galvanic distortion if the a priori model provides a reasonable assumption for the regional resistivity average. Joint inversion of phase tensor data and vertical magnetic transfer functions improves recovery of the absolute resistivity structure and is less dependent on the prior model. We also used phase tensor inversion for a data set of more than 250 MT sites from the central San Andreas fault, California, where a number of sites showed significant galvanic distortion. We find the regional structure of the phase tensor inversion results compatible with previously obtained models from impedance inversion. In the vicinity of distorted sites, phase tensor inversion models exhibit more homogeneous/smoother conductivity structures.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Tietze, K., Ritter, O., & Egbert, G. D. (2015). 3-D joint inversion of the magnetotelluric phase tensor and vertical magnetic transfer functions. Geophysical Journal International, 203(2), 1128-1148. doi:10.1093/gji/ggv347
Series
Keyword
Rights Statement
Funding Statement (additional comments about funding)
Publisher
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Made available in DSpace on 2016-01-21T15:54:06Z (GMT). No. of bitstreams: 1 EgbertGaryCEOAS3DJointInversion.pdf: 11571334 bytes, checksum: 55dcd86b6a7c796556211da97974a502 (MD5) Previous issue date: 2015-11
  • description.provenance : Submitted by Patricia Black (patricia.black@oregonstate.edu) on 2016-01-21T15:53:32Z No. of bitstreams: 1 EgbertGaryCEOAS3DJointInversion.pdf: 11571334 bytes, checksum: 55dcd86b6a7c796556211da97974a502 (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2016-01-21T15:54:06Z (GMT) No. of bitstreams: 1 EgbertGaryCEOAS3DJointInversion.pdf: 11571334 bytes, checksum: 55dcd86b6a7c796556211da97974a502 (MD5)

Relationships

Parents:

This work has no parents.

Last modified

Downloadable Content

Download PDF

Items