Use of electric potential difference in audio magnetotelluric (AMT) geophysics for groundwater exploration

Gomo, M.

doi:10.1016/j.gsd.2022.100864

Cited by 8 publications

(11 citation statements)

References 6 publications

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“…An inter-data point interval of 2m was used for the acquired EM data in this study. A two-probe M and N are placed on the ground at point 0 and 10 m [36] and [37], the probes were connected to the EM console via cable which reads the EM impulse generated by those points. The subsurface natural electric current is produced through electrochemical processes among various conductive minerals being in contact with one another, and the fluid contents in porous media within the subsurface [24].…”

Section: Nef Field Measurementmentioning

confidence: 99%

Investigation of leachate infiltration on groundwater using georesistivity and natural electric field method around Ojoou-Olayanju’s dumpsite, Ada, southwestern Nigeria

Adeniji,

Ajani,

Adagunodo

et al. 2024

Nig. J. Tech.

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The investigation of groundwater within the dumpsite environment is highly important in geophysical study. This is because the extent of interaction between the aquiferous medium and the contaminated zone could pose a serious threat to the end users especially humans when consumed. This research aimed at investigating leachate infiltration and its potential influence on groundwater at Ojoou Olayanju's Dumpsite using combining geo-resistivity and natural electric field (NEF) methods. In this study, five dipole-dipole and five NEF measurements were obtained using the Omega resistivity meters and PQWT-150 equipment respectively. The dipole-dipole method was deployed to obtain a 2D near-surface pseudo-section, and the NEF method was used to obtain the frequency curve and profile maps of electric potential difference. The dipoledipole results revealed the lateral variation in the resistivity along the traverses, suggesting that the materials within this near-surface are heterogeneous, and the closely spaced contours' varying gradients indicate fracture, which would facilitate potential leachate filtration. The NEF results revealed curves, and a subsurface image with respect to depth and profile distance. The points of convergence signals on the frequency model correspond to a medium with low resistivity on the profile map. The conductive medium is seen as being saturated with leachate, which suggests that very large portion of the study area around the dumpsite has been contaminated by leachate. Conclusively, it was revealed that leachate filtration is evidence especially at the topsoil and due to the presence of fractured zones, the groundwater quality is at risk of contamination by continuous filtration of leachate

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Section: Nef Field Measurementmentioning

confidence: 99%

Investigation of leachate infiltration on groundwater using georesistivity and natural electric field method around Ojoou-Olayanju’s dumpsite, Ada, southwestern Nigeria

Adeniji,

Ajani,

Adagunodo

et al. 2024

Nig. J. Tech.

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“…Another geophysical survey method used in this current study includes the ground magnetotelluric techniques, which use electrical potential difference (mV) as the main parameter for groundwater exploration [23,24]. This method has recently been favoured and has gained attraction in the groundwater exploration field in Africa.…”

Section: Introductionmentioning

confidence: 99%

“…This method has recently been favoured and has gained attraction in the groundwater exploration field in Africa. Gomo [24] suggests the need to extensively understand the ground magnetotelluric geophysical application in groundwater exploration. The magnetotelluric method is a passive surface geophysical technique that uses the earth's natural electromagnetic fields to investigate the electric resistivity structure of the subsurface from depths of tens of meters to tens of kilometres [24].…”

Section: Introductionmentioning

confidence: 99%

“…Gomo [24] suggests the need to extensively understand the ground magnetotelluric geophysical application in groundwater exploration. The magnetotelluric method is a passive surface geophysical technique that uses the earth's natural electromagnetic fields to investigate the electric resistivity structure of the subsurface from depths of tens of meters to tens of kilometres [24]. It is particularly useful in delineating deep structures due to its deep penetration, which is not achievable with other conventional geophysics equipment methods [25].…”

Section: Introductionmentioning

confidence: 99%

“…It is particularly useful in delineating deep structures due to its deep penetration, which is not achievable with other conventional geophysics equipment methods [25]. Fewer studies have recently used this technology, exclusively as a complementary method in combination with any of the traditional commonly used methods such as electrical resistivity (ER) as suggested in Gomo., [24]. This method, measures and records the natural variations of the earth's magnetic and electric fields at each ground magnetotelluric station for specified fixed depths with a 2D tomography model being produced from a system inbuilt inverse model [25].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Application of Aquifer Delineation and Hydrogeophysical Techniques in Estimating Groundwater Recharge to Enhance Water Allocation in Groundwater-Dependent Areas, Northern Cape, South Africa

Baloyi,

Kanyerere,

Muchingami

et al. 2024

Preprint

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The aquifer delineation using a hydrogeophysical survey was carried out in De Aar, a small town in the eastern part of the Karoo supergroup, Northern Cape, South Africa. In this re-gion, the current approach for estimating recharge, water allocation plans, and water monitoring does not consider the existence of different types of aquifers. Instead, it assumes there is one aquifer system and therefore the area might have one value of recharge. This study aimed to delineate aquifers into unconfined and confined aquifers for estimating recharge and demonstrate the use of geophysics techniques in delineating aquifer systems. Six VES stations and seven profile lines were measured using a Wenner array configuration and ground magnetotelluric method, respectively. VES data was processed using IPI2win software while electric potential difference curve was in-terpreted together with lithological data. Four significant layers of low (0.9-8.1 Ωm), moderate (22.4-125 Ωm), and high 68-177 Ωm) resistivity values were delineated suggestive of the different lithological formations. The subsurface profile mapping using ground magentotelluric methods did not suggest groundwater accumulations below 50 m, instead supported shallow groundwater potentials boreholes. These results have provided a double layer aquifer system thereby suggesting that recharge estimation need to be carried out in two different aquifer systems to enhance water allocation plans, and water monitoring in groundwater-dependent areas similar to prevailing conditions in the current study area.

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Groundwater exploration in a granite aquifer using the telluric electric frequency selection method (TEFSM) in Eswatini, Southern Africa

Gomo,

Ngobe

2024

Sustain. Water Resour. Manag.

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Recent technology development has enabled the use of electric potential difference (EPD) in the telluric electric frequency selection method (TEFSM) geophysical approach for groundwater exploration. As a new approach, there is a need to build knowledge and experience in the application of the TEFSM geophysical approach in groundwater exploration in different hydrogeological settings. Hard rock granite aquifers are one of those aquifers where the TEFSM geophysical approach to exploring groundwater is yet to be investigated. In this study, a geophysical survey to identify four drilling sites for community boreholes was first conducted using the TEFSM approach. Vertical electrical profiles (VEP) of EPD up to 120 m per station were analyzed and interpreted to identify the depths of potential aquifers prior to drilling. The EPD VEP was then corroborated with borehole lithology data collected from the drilling to provide hydrogeophysical meaning to the data. The results show that groundwater occurs in the weathered granite layers. However, the water strikes appear to occur at the contact plane between the overlying weathered granite and the underlying fresh amphibolite. This suggests that the groundwater is stored in the weathered granite while the contact plane at fresh amphibolite is a preferential flow path. The granite aquifer at the study site is characterized by the EPD ranging from 0.018 to 0.068 mV. However, not all geological materials in this EPD range had water, some were just a reflection of weathering. The TEFSM geophysical approach was able to delineate layers of weathered granite aquifers and impermeable amphibolite based on low and high EPD contrasts, respectively. The findings assist in improving the practical understanding of the application of TEFSM to delineate aquifers and site boreholes in granite aquifers.

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Use of electric potential difference in audio magnetotelluric (AMT) geophysics for groundwater exploration

Cited by 8 publications

References 6 publications

Investigation of leachate infiltration on groundwater using georesistivity and natural electric field method around Ojoou-Olayanju’s dumpsite, Ada, southwestern Nigeria

Investigation of leachate infiltration on groundwater using georesistivity and natural electric field method around Ojoou-Olayanju’s dumpsite, Ada, southwestern Nigeria

Application of Aquifer Delineation and Hydrogeophysical Techniques in Estimating Groundwater Recharge to Enhance Water Allocation in Groundwater-Dependent Areas, Northern Cape, South Africa

Groundwater exploration in a granite aquifer using the telluric electric frequency selection method (TEFSM) in Eswatini, Southern Africa

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