scholarly journals 2D Electrical Resistivity Imaging of Bedrock Fissures in Ogbomoso, Southwestern Nigeria

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
I. A. Akinlabi ◽  
O. G. Bayowa
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Electrical Resistivity Imaging ◽  
Expansion Factor ◽  
Southwestern Nigeria ◽  
Resistivity Tomography ◽  
Resistivity Inversion ◽  
Potential Failure ◽  
2D Resistivity ◽  
Tomography Data

2D electrical resistivity surveys were conducted around the site of the failed proposed Ogbomoso North Secretariat building with a view to examining the trend of suspected bedrock fissures and assessing the vulnerability of structures in the vicinity to potential failure. Electrical Resistivity Tomography data were acquired along ten traverses 80-200 m long each, using the dipole-dipole electrode configuration with station interval of 5 m and expansion factor, n, varied from 1 to 6. The data were processed by using 2D resistivity inversion technique in the DipproTM software package to generate 2D resistivity sections beneath the traverses. The 2D resistivity sections delineated 2-19 m thick typically clay overburden underlain by bedrock with resistivity ranging from 103 to 59767 Ωm, and anomalously low resistivity zones suspected to be fissures within the bedrock. The bedrock fissures are generally 5-20 m wide and occur at depths ranging from 5 m to ˃25 m beneath the traverses. The fissures trend southward toward the roundabout and front of the College of Health Sciences premises. The incessant road failures and groundwater seepages observed within the study area are attributable to the network of bedrock fissure.

scholarly journals Evaluation of petroleum hydrocarbons contamination in soils and groundwater using electrical resistivity and hydrochemical methods-Case study: Ayetoro, Osogbo southwestern Nigeria

2021 ◽  
Vol 47 (2) ◽  
pp. 597-608
Author(s):  
Mutiu A Fakunle ◽  
Muhydeen A Ibraheem ◽  
Wasiu B Agbaje ◽  
Luqman A Abidoye
Keyword(s):  
Electrical Resistivity ◽  
Petroleum Hydrocarbons ◽  
Electrical Resistivity Tomography ◽  
Silty Clay ◽  
Southwestern Nigeria ◽  
Resistivity Tomography ◽  
Porosity And Permeability ◽  
Dug Wells ◽  
2D Resistivity ◽  
Dug Well

The presence of Petroleum Hydrocarbons (PHCs) in hand-dug wells has become a concern to the residents of Ayetoro area, Osogbo. Consequently, the detection of PHCs was evaluated using, nine Vertical Electrical Soundings (VES) and 2D electrical resistivity tomography surveys. Soil samples collected were analyzed for porosity and permeability. Hand-dug well water samples were screened for PHCs. VES revealed that second layer had high apparent resistivity of 14415.0 Ωm, indicating presence of PHCs that had penetrated to maximum depth of 19.1 m. The highest resistivity of the control points was 48.0 Ωm, indicating absence of PHCs. The 2D resistivity revealed highest value of 3622 Ωm and had migrated to a depth of 10.0 m. The porosity (0.40) and permeability (6.87516 x 10–4 cm/s) were typical of silty clay which allowed passage of PHCs. Hydro-chemical analysis indicated presence of PHCs (0.50–11.00 mg/L). The study has established presence of PHCs in soils and hand-dug wells. Keywords: Petroleum Hydrocarbons, Soil, Groundwater, Electrical resistivity tomography

scholarly journals Electrical resistivity tomography applied to geologic, hydrogeologic, and engineering investigations at a former waste-disposal site

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. B231-B239 ◽  
Author(s):  
Jonathan E. Chambers ◽  
Oliver Kuras ◽  
Philip I. Meldrum ◽  
Richard D. Ogilvy ◽  
Jonathan Hollands
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Site Investigation ◽  
High Resistivity ◽  
Potential Zone ◽  
Resistivity Tomography ◽  
L2 Norm ◽  
Resistivity Model ◽  
2D And 3D ◽  
2D Resistivity

A former dolerite quarry and landfill site was investigated using 2D and 3D electrical resistivity tomography (ERT), with the aims of determining buried quarry geometry, mapping bedrock contamination arising from the landfill, and characterizing site geology. Resistivity data were collected from a network of intersecting survey lines using a Wenner-based array configuration. Inversion of the data was carried out using 2D and 3D regularized least-squares optimization methods with robust (L1-norm) model constraints. For this site, where high resistivity contrasts were present, robust model constraints produced a more accurate recovery of subsurface structures when compared to the use of smooth (L2-norm) constraints. Integrated 3D spatial analysis of the ERT and conventional site investigation data proved in this case a highly effective means of characterizing the landfill and its environs. The 3D resistivity model was successfully used to confirm the position of the landfill boundaries, which appeared as electrically well-defined features that corresponded extremely closely to both historic maps and intrusive site investigation data. A potential zone of leachate migration from the landfill was identified from the electrical models; the location of this zone was consistent with the predicted direction of groundwater flow across the site. Unquarried areas of a dolerite sill were imaged as a resistive sheet-like feature, while the fault zone appeared in the 2D resistivity model as a dipping structure defined by contrasting bedrock resistivities.

scholarly journals Two-dimensional Electrical Resistivity Tomography of Bitumen Occurrence in Agbabu, Southwest Nigeria

2019 ◽  
pp. 1-9
Author(s):  
O. F. Ogunlana ◽  
O. M. Alile ◽  
O. J. Airen
Keyword(s):  
Electrical Resistivity ◽  
Apparent Resistivity ◽  
Electrical Resistivity Tomography ◽  
Electrode Spacing ◽  
Southwestern Nigeria ◽  
Resistivity Tomography ◽  
2D Inversion ◽  
Earth Resistivity ◽  
Southwest Nigeria ◽  
Resistivity Meter

The Electrical Resistivity Tomography (ERT) data was acquired within the area suspected to have high potential for bitumen occurrence using the Wenner-Schlumberger configuration in Agbabu, southwestern Nigeria. PASI 16GL-N Earth resistivity meter instrument was used to acquire data along five (5) traverses with 5m electrode spacing and traverses length of 150m. The apparent resistivity values obtained was processed using RES2DINV software which helped to automatically obtain the 2D inversion model of the subsurface. This study has shown the occurrence of bitumen between the depth of 13.4m and 9.93m for Traverses 1, 2, 3 and Traverses 4, 5 respectively in a 2-Dimensional electrical resistivity images for boreholes with a depth of about 18m. The results indicate that the bitumen is characterized by good lateral continuity and is sufficiently thick for commercial exploitation.

scholarly journals Cross-Section Resistivity Detection of Tree (Swietenia Magahoni and Gmelina) Using ERT Method

2022 ◽  
Vol 8 (1) ◽  
pp. 39-44
Author(s):  
Evi Fazriati ◽  
Asep Purnama ◽  
Gian Agistian Algifari ◽  
Irene Siti Amilah Muslimah ◽  
Fitria Hapsari Puteri Sumanto ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Cross Section ◽  
Electrical Resistivity Tomography ◽  
Nondestructive Method ◽  
Resistivity Tomography ◽  
Living Tree ◽  
Value Range ◽  
2D Resistivity ◽  
Swietenia Mahagoni ◽  
Monitoring Activity

The existence of trees is very beneficial for humans’ life. There are utilizations of tree such as urban planning and reforestation. However, the tree can be dangerous when the tree is aged and decay because of several factors that might be cause fallen tree. Furthermore, the monitoring activity is needed to know the condition of the tree. One of the methods that can be used to detect hollow in living tree is Electrical Resistivity Tomography (ERT). The ERT is an efficient and nondestructive method that can be potential to estimate resistivity cross section. The measurement of ERT conducted on Swietenia mahagoni and Gmelina with unhealthy and healthy condition visually. The data processed using Res2Dinv and reconstructed for obtaining 2D resistivity cross section. The results shows that the unhealthy Swietenia mahagoni has logarithmic resistivity value range between 0.1-1 Ωm and the healthy Swietenia mahagoni has 1-4 Ωm. Meanwhile, the unhealthy and healthy Gmelina has logarithmic resistivity value range between 0.5-4.5 Ωm and 0.5-3 Ωm, respectively. It is shows that the tree indicated health visually from biological view does not mean the tree is decay. It might be influenced by phenology factor and/or the species of the tree.

scholarly journals Inter-borehole electrical resistivity imaging of englacial drainage

1998 ◽  
Vol 44 (147) ◽  
pp. 429-435 ◽  
Author(s):  
Bryn Hubbard ◽  
Andrew Binley ◽  
Lee Slater ◽  
Roy Middleton ◽  
Bernd Kulessa
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Electrical Resistivity Imaging ◽  
Glacier Surface ◽  
Resistivity Tomography ◽  
Resistivity Imaging ◽  
Low Resistivity ◽  
Glacier Ice ◽  
First Time ◽  
Englacial Drainage

AbstractBorehole-based electrical resistivity surveys have the capacity to enhance our understanding of the structure of englacial drainage pathways in temperate ice. We summarize inter-borehole electrical resistivity tomography (ERT) as currently used in hydrogeological investigations and as adapted for imaging englacial drainage. ERT connections were successfully made for the first time in glacier ice, following artificial mineralization of borehole waters at Haut Glacier d’Arolla, Switzerland. Here, two types of electrical connection were made between boreholes spaced up to 10 m apart and drilled to depths of between 20 and 60 m. Most tests indicated the presence of resistively homogeneous ice with uniform bulk resistivities of ~108- 109Ω m. However, ERT was also successfully used to identify and characterize a hydraulically conductive englacial fracture that intersected two boreholes at a depth of ~ 13 m below the glacier surface. The presence of this connecting void was suggested by drilling records and verified by dual borehole-impulse testing. The reconstructed tomogram for these boreholes is characterized by a background ice-resistivity field of ~109Ω m that is disrupted at a depth of ~13 m by a sharp, sub-horizontal low-resistivity zone (~104Ω m). Inter-borehole ERT, therefore, has the capacity to image both uniform and fractured temperate glacier ice.

Sign in / Sign up

Export Citation Format

Share Document