Sensitivity analysis of inverted model parameters from transient electromagnetic measurements affected by induced polarization effects (2024)

Aigner, L., Werthmüller, D., & Flores Orozco, A. (2024). Sensitivity analysis of inverted model parameters from transient electromagnetic measurements affected by induced polarization effects. Journal of Applied Geophysics, 223, Article 105334. https://doi.org/10.1016/j.jappgeo.2024.105334

Aigner, Lukas ; Werthmüller, Dieter ; Flores Orozco, Adrián. / Sensitivity analysis of inverted model parameters from transient electromagnetic measurements affected by induced polarization effects. In: Journal of Applied Geophysics. 2024 ; Vol. 223.

@article{aca9114b26414c21be193f7ad782cfcb,

title = "Sensitivity analysis of inverted model parameters from transient electromagnetic measurements affected by induced polarization effects",

abstract = "We investigate the application of the distance-based global sensitivity analysis (DGSA) to evaluate the sensitivity of electrical model parameters obtained from transient electromagnetic (TEM) data including induced polarization (IP) effects. We propose novel open-source forward modeling and inversion routines for single-loop TEM data including IP effects with the maximum phase angle model to model the frequency dependence of the complex resistivity. In a first step, we evaluate the accuracy of our forward modeling and inversion routines using numerical studies, where the actual variations of layer thicknesses and resistivities, as well as the frequency dependence of the complex resistivity is known. In a second step, we extend our investigation to field data and apply our approach to three distinct case studies in layered media: 1) a confined aquifer corresponding to conductive non-polarizable media, 2) a graphite deposit corresponding to highly conductive and polarizable anomalies in a resistive host rock and 3) an ice glacier corresponding to highly resistive polarizable media. Our DGSA results reveal that standard depth of investigation (DOI) approaches may overestimate the true sensitivity of the model obtained from the inversion. TEM data collected in conductive layered media without IP effects show reduced sensitivity above the predicted DOI. The case studies in polarizable media demonstrate that the maximum phase angle is more influential on the TEM model response than the relaxation time and dispersion coefficient. Our DGSA results for polarizable media reveal that TEM field data collected at the graphite deposit and at the ice glacier are sensitive to the geometry of the polarizable layer.",

keywords = "Distance-based global sensitivity analysis, Forward modeling and inversion of transient electromagnetic method, Frozen ground and graphite ores, Induced polarization effect",

author = "Lukas Aigner and Dieter Werthm{\"u}ller and {Flores Orozco}, Adri{\'a}n",

note = "Green Open Access added to TU Delft Institutional Repository {\textquoteleft}You share, we take care!{\textquoteright} – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. ",

year = "2024",

doi = "10.1016/j.jappgeo.2024.105334",

language = "English",

volume = "223",

journal = "Journal of Applied Geophysics",

issn = "0926-9851",

publisher = "Elsevier",

}

Aigner, L, Werthmüller, D & Flores Orozco, A 2024, 'Sensitivity analysis of inverted model parameters from transient electromagnetic measurements affected by induced polarization effects', Journal of Applied Geophysics, vol. 223, 105334. https://doi.org/10.1016/j.jappgeo.2024.105334

Sensitivity analysis of inverted model parameters from transient electromagnetic measurements affected by induced polarization effects. / Aigner, Lukas; Werthmüller, Dieter; Flores Orozco, Adrián.
In: Journal of Applied Geophysics, Vol. 223, 105334, 2024.

Research output: Contribution to journal › Article › Scientific › peer-review

TY - JOUR

T1 - Sensitivity analysis of inverted model parameters from transient electromagnetic measurements affected by induced polarization effects

AU - Aigner, Lukas

AU - Werthmüller, Dieter

AU - Flores Orozco, Adrián

N1 - Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

PY - 2024

Y1 - 2024

N2 - We investigate the application of the distance-based global sensitivity analysis (DGSA) to evaluate the sensitivity of electrical model parameters obtained from transient electromagnetic (TEM) data including induced polarization (IP) effects. We propose novel open-source forward modeling and inversion routines for single-loop TEM data including IP effects with the maximum phase angle model to model the frequency dependence of the complex resistivity. In a first step, we evaluate the accuracy of our forward modeling and inversion routines using numerical studies, where the actual variations of layer thicknesses and resistivities, as well as the frequency dependence of the complex resistivity is known. In a second step, we extend our investigation to field data and apply our approach to three distinct case studies in layered media: 1) a confined aquifer corresponding to conductive non-polarizable media, 2) a graphite deposit corresponding to highly conductive and polarizable anomalies in a resistive host rock and 3) an ice glacier corresponding to highly resistive polarizable media. Our DGSA results reveal that standard depth of investigation (DOI) approaches may overestimate the true sensitivity of the model obtained from the inversion. TEM data collected in conductive layered media without IP effects show reduced sensitivity above the predicted DOI. The case studies in polarizable media demonstrate that the maximum phase angle is more influential on the TEM model response than the relaxation time and dispersion coefficient. Our DGSA results for polarizable media reveal that TEM field data collected at the graphite deposit and at the ice glacier are sensitive to the geometry of the polarizable layer.

AB - We investigate the application of the distance-based global sensitivity analysis (DGSA) to evaluate the sensitivity of electrical model parameters obtained from transient electromagnetic (TEM) data including induced polarization (IP) effects. We propose novel open-source forward modeling and inversion routines for single-loop TEM data including IP effects with the maximum phase angle model to model the frequency dependence of the complex resistivity. In a first step, we evaluate the accuracy of our forward modeling and inversion routines using numerical studies, where the actual variations of layer thicknesses and resistivities, as well as the frequency dependence of the complex resistivity is known. In a second step, we extend our investigation to field data and apply our approach to three distinct case studies in layered media: 1) a confined aquifer corresponding to conductive non-polarizable media, 2) a graphite deposit corresponding to highly conductive and polarizable anomalies in a resistive host rock and 3) an ice glacier corresponding to highly resistive polarizable media. Our DGSA results reveal that standard depth of investigation (DOI) approaches may overestimate the true sensitivity of the model obtained from the inversion. TEM data collected in conductive layered media without IP effects show reduced sensitivity above the predicted DOI. The case studies in polarizable media demonstrate that the maximum phase angle is more influential on the TEM model response than the relaxation time and dispersion coefficient. Our DGSA results for polarizable media reveal that TEM field data collected at the graphite deposit and at the ice glacier are sensitive to the geometry of the polarizable layer.

KW - Distance-based global sensitivity analysis

KW - Forward modeling and inversion of transient electromagnetic method

KW - Frozen ground and graphite ores

KW - Induced polarization effect

UR - http://www.scopus.com/inward/record.url?scp=85188706880&partnerID=8YFLogxK

U2 - 10.1016/j.jappgeo.2024.105334

DO - 10.1016/j.jappgeo.2024.105334

M3 - Article

AN - SCOPUS:85188706880

SN - 0926-9851

VL - 223

JO - Journal of Applied Geophysics

JF - Journal of Applied Geophysics

M1 - 105334

ER -

Aigner L, Werthmüller D, Flores Orozco A. Sensitivity analysis of inverted model parameters from transient electromagnetic measurements affected by induced polarization effects. Journal of Applied Geophysics. 2024;223:105334. doi: 10.1016/j.jappgeo.2024.105334