Article
Geochemistry & Geophysics
Wei Zhou, Lichao Nie, Yongheng Zhang, Yonghao Pang, Zhao Dong, Zhimin An, Zhengyu Liu, Chuanyi Ma
Summary: Most existing electrical-resistivity-based tunnel prospecting methods are limited by the available space for electrodes, leading to less accurate imaging of water-bearing structures. The Chert and Bsert methods using borehole space have been proven effective in obtaining better images of deep anomalies. This study focused on the Tberi method in tunnels, optimizing the configuration to achieve more accurate detection of abnormal objects in the target area.
Article
Geochemistry & Geophysics
M. Shahriari, A. Hazra, D. Pardo
Summary: In this paper, a deep neural network-based iterative algorithm is used to design a borehole instrument and provide valuable insights for designing borehole-logging instruments based on a suitable subset of measurements for inversion purposes.
Article
Chemistry, Multidisciplinary
Raffaele Martorana, Patrizia Capizzi
Summary: Electrical resistivity tomography (ERT) is a widely used geophysical method for geological, hydrogeological, and geoenvironmental research. 2D ERT is more commonly used than 3D ERT due to its greater immediacy, survey speed, and simplicity in processing. However, the assumption of underground structures being two-dimensional can lead to errors when interpreting the effects of three-dimensional structures. This study aims to evaluate these effects through testing synthetic and experimental models.
APPLIED SCIENCES-BASEL
(2023)
Article
Geography, Physical
Rahmantara Trichandi, Klaus Bauer, Trond Ryberg, Dirk Scherler, Klaus Bataille, Charlotte M. Krawczyk
Summary: This study utilizes seismic methods to investigate the weathering structure in the Santa Gracia National Reserve. By calibrating with borehole results, the boundaries of different rock layers are determined, revealing a complex mechanism controlling the weathering front.
EARTH SURFACE PROCESSES AND LANDFORMS
(2022)
Review
Geography, Physical
Teddi Herring, Antoni G. Lewkowicz, Christian Hauck, Christin Hilbich, Coline Mollaret, Greg A. Oldenborger, Sebastian Uhlemann, Mohammad Farzamian, Fabrice Calmels, Riccardo Scandroglio
Summary: This paper reviews more than 300 scientific publications to identify the capabilities and limitations of ERT for permafrost applications and makes recommendations for ERT surveys of permafrost.
PERMAFROST AND PERIGLACIAL PROCESSES
(2023)
Article
Geochemistry & Geophysics
Tianqi Deng, Joaquin Ambia, Carlos Torres-Verdin
Summary: Well logs are geophysical measurements of rock properties acquired along a borehole, and their interpretation is often affected by tool design, layer boundaries, borehole conditions, and mud-filtrate invasion. Bayesian well-log inversion provides posterior probability distribution and quantifies uncertainty, but it requires a large number of forward simulations. This study introduces an efficient gradient-based Markov chain Monte Carlo method for Bayesian well-log inversion and demonstrates its superiority in computational cost reduction and accuracy improvement compared to conventional methods.
GEOPHYSICAL PROSPECTING
(2023)
Article
Environmental Sciences
Leonides Guireli Netto, Camila Camolesi Guimaraes, Alexandre Muselli Barbosa, Otavio Coaracy Brasil Gandolfo
Summary: Open dumping is a common waste disposal method in developing countries, which poses environmental and health risks. Electrical resistivity tomography (ERT) is an interesting alternative for studying the environmental impacts of dumpsites. In this study, ERT was used to delimit the waste mass and identify anomalies related to alterations in soil and groundwater properties in an abandoned dumpsite in Brazil. The results showed a good correlation between conductive anomalies and the extent of waste.
ENVIRONMENTAL EARTH SCIENCES
(2023)
Article
Computer Science, Interdisciplinary Applications
Teddi Herring, Lindsey J. Heagy, Adam Pidlisecky, Edwin Cey
Summary: In this study, a hybrid inversion algorithm that combines parametric and smooth inversion strategies was developed to improve the estimation of subsurface conductivity. Tested on synthetic models, the hybrid inversion showed better resolution of feature boundaries and magnitudes with fewer artifacts compared to the standard smooth inversion. The sensitivity analysis demonstrated successful recovery of subsurface features under different conditions, showcasing the potential of this hybrid inversion strategy in various applications.
COMPUTERS & GEOSCIENCES
(2022)
Article
Geochemistry & Geophysics
Yinchu Li, Dikun Yang
Summary: This study demonstrates the potential of using steel-cased wells as long electrodes for real-time monitoring of fracturing fluid flow and explores the feasibility of electric fluid imaging. Deep learning framework is adopted to address the challenging imaging problem in conventional regularized inversions.
Article
Geochemistry & Geophysics
Gang Yu, Fangjing Hu, Liangcheng Tu, Guo Zhao, Juan Chen
Summary: A micro-electro-mechanical-based 3-C borehole gravimeter with high precision has been developed in China for mineral and hydrocarbon exploration. The gravimeter consists of a three-axis gravity sensor chip based on deep silicon etching, capacitive displacement sensing, and weak signal detection circuitry. The prototype tool, which has an outer diameter of 50 mm, was tested in a borehole up to 850 m depth and showed good adaptability to the down instrument environment.
GEOPHYSICAL PROSPECTING
(2023)
Article
Geochemistry & Geophysics
David L. Alumbaugh, Evan Schankee Um, G. Michael Hoversten, Kerry Key
Summary: Over the past decade, rapid development in distributed optical fibre sensing technologies has provided a new way to continuously record geophysical data, reducing data acquisition costs. This paper explores the theoretical feasibility of using an electromagnetic sensing optical fibre in geophysical applications, analyzing the sensitivity and applicability of such fibre in oilfield environments through numerical simulations.
GEOPHYSICAL PROSPECTING
(2022)
Article
Geochemistry & Geophysics
Mattia Aleardi, Alessandro Vinciguerra, Eusebio Stucchi, Azadeh Hojat
Summary: By utilizing a trained residual neural network as the forward operator in probabilistic inversions of electrical resistivity tomography data, this study provides a faster and more accurate approach compared to traditional methods, reducing computational workload. The method properly incorporates modelling errors and propagates them onto estimated model uncertainties, allowing for solving electrical resistivity tomography with limited hardware resources.
GEOPHYSICAL PROSPECTING
(2022)
Article
Geosciences, Multidisciplinary
M. F. Ishak, M. F. Zolkepli, E. M. H. Masyhur, N. Z. M. Yunus, A. S. A. Rashid, M. A. Hezmi, D. Z. A. Hasbollah, A. R. Yusoff
Summary: Electrical Resistivity Tomography (ERT) is an important and efficient tool for early prediction of subsurface mapping. The results obtained from ERT can be accurately verified with the results from borehole lithology.
PHYSICS AND CHEMISTRY OF THE EARTH
(2022)
Article
Metallurgy & Metallurgical Engineering
Hector M. Lizama
Summary: In-situ leaching assisted by geophysical techniques were used to exploit previously leached and long-abandoned copper sulphide heaps. The technology was first piloted for five months at the 59 kt scale with up to three in-jection wells. This was followed by a 14-month industrial pilot at the 1.2 Mt. scale with 97 injection wells. Geophysical surveys were used to visualize the movement of the injected leaching solutions in-situ. Geophysical imaging was also used to avoid flooding and prevent geotechnical instability. The imaging indicated the injection wells had a radius of influence of 11 to 13 m, and that well injection flows should not exceed 1.5 L/s. Oxidative conditions were facilitated in-situ by encouraging air entry from the heap drainage system and alternating periods of injection with rest periods that allowed air entry through the injection wells. This work introduces some concepts and terms related to in-situ leaching operations.
Article
Geochemistry & Geophysics
Qingxin Meng, Wenli Gao, Zheng Niu, Jianghao Chang, Shida Sun, Haibo Zhang
Summary: Identification of time spectrum is a crucial issue in time-domain induced polarization (IP) method, which helps in distinguishing different polarized rocks. A key step in spectrum identification is fitting the IP data using a forward model and obtaining optimized model parameters. However, the appropriate forward model needs to consider observation conditions such as charging time and time window. Time spectrum identification can be challenging due to the lack of objective reference for the optimal solution. Thus, the purpose of this study is to improve the forward model and implement spectrum identification for IP data.
Article
Engineering, Geological
K. Sattler, D. Elwood, M. T. Hendry, D. Huntley, J. Holmes, P. B. Wilkinson, J. Chambers, S. Donohue, P. I. Meldrum, R. Macciotta, P. T. Bobrowsky
Summary: The study found that seasonal and multiyear changes in atmospheric factors cause fluctuations in matric suction in the vadose zone, with moisture ingress contributing to increasing landslide displacement rates. Water content in the unsaturated zone is particularly important, especially in semi-arid to arid climates.
Article
Engineering, Geological
J. S. Whiteley, A. Watlet, S. Uhlemann, P. Wilkinson, J. P. Boyd, C. Jordan, J. M. Kendall, J. E. Chambers
Summary: The study demonstrates the rapid construction of a landslide subsurface model by integrating multiple geophysical data sources and utilizing machine learning techniques, showing the feasibility of application in time-critical situations.
ENGINEERING GEOLOGY
(2021)
Article
Environmental Sciences
Paul McLachlan, Guillaume Blanchy, Jonathan Chambers, James Sorensen, Sebastian Uhlemann, Paul Wilkinson, Andrew Binley
Summary: The study utilized EMI methods to measure the electrical conductivities of a riparian wetland and evaluated methods to obtain structural information from EMI data and inverted models. It was found that EMI data were mainly influenced by the thickness of peaty alluvial soils. Through the use of multi-linear regression methods, improved accuracy in predicting the thickness of alluvial soils was achieved.
WATER RESOURCES RESEARCH
(2021)
Article
Water Resources
E. Zarate, D. Hobley, A. M. MacDonald, R. T. Swift, J. Chambers, J. J. Kashaigili, E. Mutayoba, R. G. Taylor, M. O. Cuthbert
Summary: This study in central semi-arid Tanzania focused on the role of superficial geology in controlling groundwater recharge. It found that superficial sand deposits act as collectors and stores, feeding recharge into fault zones and allowing permeable pathways for increased recharge. Additionally, 'windows' within clay layers may provide pathways for focused recharge, and overbank flooding during heavy precipitation events enhances the activation of permeable pathways.
JOURNAL OF HYDROLOGY-REGIONAL STUDIES
(2021)
Article
Geosciences, Multidisciplinary
M. H. Loke, P. B. Wilkinson, J. E. Chambers, S. Uhlemann, T. Dijkstra, T. Dahlin
Summary: This study uses the 4-D resistivity smoothness-constrained inversion method to monitor time-lapse resistivity and proposes barrier function and transformation methods to reduce artifacts. The hybrid technique proves to completely eliminate residual artifacts left by the barrier method and produces inversion results closer to the true model.
JOURNAL OF APPLIED GEOPHYSICS
(2022)
Article
Geography, Physical
Simon Blondel, Sebastian Uhlemann, Cornelia Inauen, Arnaud Watlet, Hansruedi Maurer, Colm Jordan, Jonathan Lee, Jonathan Chambers
Summary: This study combines geological fieldwork and geophysical data to investigate the parameters influencing the morphology and behavior of a retreating coastal cliff. The findings contribute to the development of a 3D geological and geophysical model, providing important input for coastal recession and erosion models.
EARTH SURFACE PROCESSES AND LANDFORMS
(2022)
Article
Engineering, Geological
Jessica Holmes, Jonathan Chambers, Paul Wilkinson, Philip Meldrum, Mihai Cimpoiasu, James Boyd, David Huntley, Paul Williamson, David Gunn, Ben Dashwood, Jim Whiteley, Arnaud Watlet, Matthew Kirkham, Kelvin Sattler, David Elwood, Vinayagamoothy Sivakumar, Shane Donohue
Summary: This study focuses on monitoring a landslide in the Thompson River Valley transportation corridor using a novel Electrical Resistivity Tomography (ERT) monitoring system, providing insights into the impact of moisture on slope stability.
ENGINEERING GEOLOGY
(2022)
Review
Geochemistry & Geophysics
Adrien Dimech, LiZhen Cheng, Michel Chouteau, Jonathan Chambers, Sebastian Uhlemann, Paul Wilkinson, Philip Meldrum, Benjamin Mary, Gabriel Fabien-Ouellet, Anne Isabelle
Summary: Mining operations generate large amounts of wastes that require monitoring to manage environmental risks. Time-lapse electrical resistivity tomography (TL-ERT) is a promising non-invasive monitoring technique that provides large-scale subsurface information. The purpose of this review is to understand the current state of research on TL-ERT, create a reference library, and identify future research needs. The review describes the theoretical basis and applications of TL-ERT for mining waste characterization and monitoring. It also discusses potential challenges and future research perspectives.
SURVEYS IN GEOPHYSICS
(2022)
Article
Environmental Sciences
Krisztina Kelevitz, Alessandro Novellino, Arnaud Watlet, James Boyd, James Whiteley, Jonathan Chambers, Colm Jordan, Tim Wright, Andrew Hooper, Juliet Biggs
Summary: This paper presents a case study of using ESA's Sentinel-1 InSAR data to study the behavior and seasonal variations of the Hollin Hill landslide in the UK. The study shows that InSAR data provides valuable information about landslide movement and behavior. The installation of corner reflectors improves the accuracy of InSAR measurements and allows tracking of the most recent landslide movement.
Article
Engineering, Geological
Jessica Holmes, Jonathan Chambers, Paul Wilkinson, Ben Dashwood, David Gunn, Mihai Cimpoiasu, Matthew Kirkham, Sebastian Uhlemann, Philip Meldrum, Oliver Kuras, David Huntley, Simon Abbott, Vinayagamoothy Sivakumar, Shane Donohue
Summary: The instability of slopes, embankments, and cuttings on railway networks is increasingly common worldwide. This study examines the use of a novel near-real-time Electrical Resistivity Tomography (ERT) monitoring system to assess the stability of a railway cutting in Leicestershire, UK. The findings show that seasonal changes in subsurface moisture content and soil suction, exacerbated by the presence of trees, can lead to shrink-swell behavior and reduced shear strength, resulting in instability. It is suggested that grassed slopes are beneficial for stability on slopes with expansive soils.
ENGINEERING GEOLOGY
(2022)
Article
Geochemistry & Geophysics
John Ball, Jonathan Chambers, Paul Wilkinson, Andrew Binley
Summary: Electrical resistivity tomography (ERT) is widely used in monitoring river embankment conditions, but 2D surveys are sensitive to anomalous resistivity features near the survey line, leading to 3D effects. This study found that changing water levels and salinities in tidal environments can cause 3D effects in ERT monitoring. Synthetic modeling showed that these effects are enhanced in brackish waters and with larger electrode spacing. Proper geoelectrical measurement design is crucial to minimize artifacts in ERT data for tidal embankment characterization.
NEAR SURFACE GEOPHYSICS
(2023)
Article
Geosciences, Multidisciplinary
P. B. Wilkinson, J. E. Chambers, P. I. Meldrum, O. Kuras, C. M. Inauen, R. T. Swift, G. Curioni, S. Uhlemann, J. Graham, N. Atherton
Summary: This study tests and compares different methods for regularizing the time-lapse geoelectrical inverse problem, and finds that 4D inversion of the full data set performs the best, while windowed 4D inversion is also applicable in near real-time applications.
FRONTIERS IN EARTH SCIENCE
(2022)
Editorial Material
Geosciences, Multidisciplinary
Christof Kneisel, Sebastian Uhlemann, Jonathan Chambers
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Engineering, Civil
Jim Whiteley, Cornelia Inauen, Paul Wilkinson, Philip Meldrum, Russell Swift, Oliver Kuras, Jonathan Chambers
Summary: Electrical resistivity tomography (ERT) monitoring was used to assess spatiotemporal variation in moisture content on a risk-prone slope above a highway. Results showed complex subsurface moisture dynamics in the partially slipped area as compared to the stable slope. ERT data was used to evaluate the volume of unstable ground and was validated using other data analysis techniques. This study highlights the importance of understanding subsurface processes at the slope-scale for long-term slope management.
TRANSPORTATION GEOTECHNICS
(2023)
Article
Geochemistry & Geophysics
Chak-Hau Michael Tso, Marco Iglesias, Paul Wilkinson, Oliver Kuras, Jonathan Chambers, Andrew Binley
Summary: Electrical resistivity tomography (ERT) is widely used in imaging the Earth's subsurface, but traditional smoothness-constrained inversion may not effectively resolve sharp interfaces. The proposed EM-based framework offers a computationally efficient alternative for estimating resistivity models and uncertainty.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
