Details
| Original language | English |
|---|---|
| Pages (from-to) | F53-F64 |
| Journal | GEOPHYSICS |
| Volume | 85 |
| Issue number | 3 |
| Publication status | Published - 1 May 2020 |
| Externally published | Yes |
Abstract
Nuclear-magnetic resonance (NMR) is a powerful tool for groundwater system imaging. Ongoing developments in surface NMR, for example, multichannel devices, allow for investigations of increasingly complex subsurface structures. However, with the growing complexity of field cases, the availability of appropriate software to accomplish the in-depth data analysis becomes limited. The open-source Python toolbox coupled magnetic resonance and electrical resistivity tomography (COMET) provides the community with a software for modeling and inversion of complex surface NMR data. COMET allows the NMR parameters' water content and relaxation time to vary in one dimension or two dimensions and accounts for arbitrary electrical resistivity distributions. It offers a wide range of classes and functions to use the software via scripts without in-depth programming knowledge. We validated COMET to existing software for a simple 1D example. We discovered the potential of COMET by a complex 2D case, showing 2D inversions using different approximations for the resistivity, including a smooth distribution from electrical resistivity tomography (ERT). The use of ERT-based resistivity results in similar water content and relaxation time images compared with using the original synthetic block resistivity. We find that complex inversion may indicate incorrect resistivity by non-Gaussian data misfits, whereas amplitude inversion shows well-fitted data, but leading to erroneous NMR models.
Keywords
- 2D, inversion, surface nuclear magnetic resonance
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: GEOPHYSICS, Vol. 85, No. 3, 01.05.2020, p. F53-F64.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Coupled magnetic resonance and electrical resistivity tomography
T2 - An open-source toolbox for surface nuclear-magnetic resonance
AU - Skibbe, Nico
AU - Rochlitz, Raphael
AU - Günther, Thomas
AU - Müller-Petke, Mike
N1 - Funding information: This research was supported by the Deutsche Forschungsgemein-schaft (DFG, German Research Foundation) under grant MU 3318/ 3-1. We thank T. P. Irons and three anonymous reviewers as well as the associate editor F. Broggini for their extensive testing and care during the review process.
PY - 2020/5/1
Y1 - 2020/5/1
N2 - Nuclear-magnetic resonance (NMR) is a powerful tool for groundwater system imaging. Ongoing developments in surface NMR, for example, multichannel devices, allow for investigations of increasingly complex subsurface structures. However, with the growing complexity of field cases, the availability of appropriate software to accomplish the in-depth data analysis becomes limited. The open-source Python toolbox coupled magnetic resonance and electrical resistivity tomography (COMET) provides the community with a software for modeling and inversion of complex surface NMR data. COMET allows the NMR parameters' water content and relaxation time to vary in one dimension or two dimensions and accounts for arbitrary electrical resistivity distributions. It offers a wide range of classes and functions to use the software via scripts without in-depth programming knowledge. We validated COMET to existing software for a simple 1D example. We discovered the potential of COMET by a complex 2D case, showing 2D inversions using different approximations for the resistivity, including a smooth distribution from electrical resistivity tomography (ERT). The use of ERT-based resistivity results in similar water content and relaxation time images compared with using the original synthetic block resistivity. We find that complex inversion may indicate incorrect resistivity by non-Gaussian data misfits, whereas amplitude inversion shows well-fitted data, but leading to erroneous NMR models.
AB - Nuclear-magnetic resonance (NMR) is a powerful tool for groundwater system imaging. Ongoing developments in surface NMR, for example, multichannel devices, allow for investigations of increasingly complex subsurface structures. However, with the growing complexity of field cases, the availability of appropriate software to accomplish the in-depth data analysis becomes limited. The open-source Python toolbox coupled magnetic resonance and electrical resistivity tomography (COMET) provides the community with a software for modeling and inversion of complex surface NMR data. COMET allows the NMR parameters' water content and relaxation time to vary in one dimension or two dimensions and accounts for arbitrary electrical resistivity distributions. It offers a wide range of classes and functions to use the software via scripts without in-depth programming knowledge. We validated COMET to existing software for a simple 1D example. We discovered the potential of COMET by a complex 2D case, showing 2D inversions using different approximations for the resistivity, including a smooth distribution from electrical resistivity tomography (ERT). The use of ERT-based resistivity results in similar water content and relaxation time images compared with using the original synthetic block resistivity. We find that complex inversion may indicate incorrect resistivity by non-Gaussian data misfits, whereas amplitude inversion shows well-fitted data, but leading to erroneous NMR models.
KW - 2D
KW - inversion
KW - surface nuclear magnetic resonance
UR - http://www.scopus.com/inward/record.url?scp=85102996715&partnerID=8YFLogxK
U2 - 10.1190/geo2019-0484.1
DO - 10.1190/geo2019-0484.1
M3 - Article
AN - SCOPUS:85102996715
VL - 85
SP - F53-F64
JO - GEOPHYSICS
JF - GEOPHYSICS
SN - 0016-8033
IS - 3
ER -