Mapping groundwater contamination using dc resistivity and VLF geophysical methods–A case study

Geophysics ◽  
1997 ◽  
Vol 62 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Alvin K. Benson ◽  
Kelly L. Payne ◽  
Melissa A. Stubben
Keyword(s):  
Electrical Resistivity ◽  
Cross Sections ◽  
Electromagnetic Induction ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Hydrocarbon Contamination ◽  
Monitoring Wells ◽  
Contour Maps ◽  
A Site

Geophysical methods can be helpful in mapping areas of contaminated soil and groundwater. Electrical resistivity and very low‐frequency electromagnetic induction (VLF) surveys were carried out at a site of shallow hydrocarbon contamination in Utah County, Utah. Previously installed monitoring wells facilitated analysis of water chemistry to enhance interpretation of the geophysical data. The electrical resistivity and VLF data correlate well, and vertical cross‐sections and contour maps generated from these data helped map the contaminant plume, which was delineated as an area of high interpreted resistivities.

scholarly journals Very Low Frequency Electromagnetic Induction Surveys in Hydrogeological Investigations; Case Study from Poland

2016 ◽  
Vol 64 (6) ◽  
pp. 2322-2336 ◽  
Author(s):  
Szymon Oryński ◽  
Marta Okoń ◽  
Wojciech Klityński
Keyword(s):  
Electromagnetic Induction ◽  
Low Frequency ◽  
Very Low Frequency

scholarly journals CRSP, numerical results for an electrical resistivity array to detect underground cavities

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Amin Amini ◽  
Hamidreza Ramazi
Keyword(s):  
Electrical Resistivity ◽  
Geophysical Methods ◽  
Electrode Array ◽  
Electrode Configuration ◽  
Electrode Arrays ◽  
Wide Range ◽  
Underground Cavities ◽  
Conventional Electrode

AbstractThis paper is devoted to the application of the Combined Resistivity Sounding and Profiling electrode configuration (CRSP) to detect underground cavities. Electrical resistivity surveying is among the most favorite geophysical methods due to its nondestructive and economical properties in a wide range of geosciences. Several types of the electrode arrays are applied to detect different certain objectives. In one hand, the electrode array plays an important role in determination of output resolution and depth of investigations in all resistivity surveys. On the other hand, they have their own merits and demerits in terms of depth of investigations, signal strength, and sensitivity to resistivity variations. In this article several synthetic models, simulating different conditions of cavity occurrence, were used to examine the responses of some conventional electrode arrays and also CRSP array. The results showed that CRSP electrode configuration can detect the desired objectives with a higher resolution rather than some other types of arrays. Also a field case study was discussed in which electrical resistivity approach was conducted in Abshenasan expressway (Tehran, Iran) U-turn bridge site for detecting potential cavities and/or filling loose materials. The results led to detect an aqueduct tunnel passing beneath the study area.

scholarly journals The use of Geoelectrical Methods for Delineation of Lead-Zinc Mineralization: A Case Study of Eziama Village, Abia State, South- East, Nigeria

2021 ◽  
pp. 16-22
Author(s):  
O. J. Airen ◽  
D. A. Babaiwa
Keyword(s):  
Electrical Resistivity ◽  
Cross Sections ◽  
Mineral Exploration ◽  
Ore Bodies ◽  
Anomalous Zone ◽  
Lateral Distance ◽  
Lead Zinc ◽  
Mineralized Zone ◽  
Geoelectrical Methods

2D Electrical Resistivity (ER) and Instantaneous Potential (IP) geophysical techniques were used at Eziama village in Abia state of Nigeria to investigate possible Pb-Zn mineralization. The dipole-dipole electrode configuration was employed for data acquisition and Earth Imager software was used for inversion of the acquired data. The analysis of the result of the study showed the presence of the Pb-Zn ore along traverses 1, 2 and 3 while traverses 4 and 5 appear barren. Along traverse 1, the mineralized zone falls within the fractured basement and is characterized by low resistivity (about 316 – 5623 ohm-m) and high chargeability (33.2 – 128 ns) at lateral distance of 73 – 103 m. On traverse two, the ore body was identified at lateral distance of about -18 to 53 m as delineated on the IP structure with resistivity and chargeability of the anomalous zone ranging from 4.6 – 677 ohm-m and 41.8 – 142 ns respectively at depth of about 21.4 m while on traverse three, two ore bodies labeled a, a’ and b, b’ on the ER and IP cross-sections were delineated at lateral distance of about -130 to -93 m and 78 to 98 m respectively with depth to the top of the suspected ore bodies ranging from about 7.1 m for body ‘a’ and about 14.3 m for ‘a’. Traverses four and five however showed no prospect for Pb-Zn mineralization. The result of this investigation has once again demonstrated the usefulness of combined electrical resistivity and induced polarization techniques in solid mineral exploration.

OIL AND GAS EXPLORATION IN ALABAMA, GEORGIA, AND FLORIDA

Geophysics ◽  
1953 ◽  
Vol 18 (2) ◽  
pp. 340-359 ◽  
Author(s):  
Robert B. Baum
Keyword(s):  
Cross Sections ◽  
Oil And Gas ◽  
Geophysical Methods ◽  
Oil Field ◽  
Oil Fields ◽  
Seismic Events ◽  
Oil And Gas Exploration ◽  
Contour Maps ◽  
Reflection Seismic ◽  
Southern Florida

The discovery of the Pollard oil field in southern Alabama early in 1952 sparked a campaign of leasing and exploration which spread quickly into Georgia and Florida. Three fields in southwestern Alabama and one in southern Florida account for all the oil production in the three states. Some aspects of the general geology and geophysics of the area, illustrated with maps, cross sections, and correlation charts, suggest the presence of geologic conditions favorable for the possible trapping and accumulation of oil and gas. Early seismograph exploration in much of the area was not effective, but in recent months the tempo of seismic activity has been accelerating, and improvements in instrumental and interpretive techniques are being achieved through current experimental work. The use of the various geophysical methods contributed to the discovery of the four oil fields located in the area. The structural traps indicated by the contour maps of the four fields are of the type sought by the reflection seismic method. Examples of representative reflection records indicate the presence of usable and correlatable seismic events. A seismic cross section prepared from data of this type shows the fault zone associated with the Pollard field. The existence of favorable geologic conditions in the southeastern states and the recent oil field successes at Pollard and South Carlton indicate the continuing of active development and exploration throughout the area.

The self‐potential method in the geothermal exploration of Greece

Geophysics ◽  
1997 ◽  
Vol 62 (6) ◽  
pp. 1715-1723 ◽  
Author(s):  
George Apostolopoulos ◽  
Ioannis Louis ◽  
Evangelos Lagios
Keyword(s):  
Surrounding Medium ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Potential Method ◽  
Geothermal System ◽  
Electrode Polarization ◽  
Geothermal Exploration ◽  
Contour Maps ◽  
Tectonic Features ◽  
Self Potential

Self‐potential (SP) anomalies are generated by flows of fluid, heat, and ions in the earth. SP investigations have been used to locate and delineate sources associated with such flows in three areas of geothermal interest in Greece—Lesvos Island, Loutra Hypatis (central Greece), and Nisyros Island. A combination of geophysical methods, with SP being the primary method, has been applied in these areas. The SP method is adversely influenced by various sources of noise. Field procedures have been suggested to minimize their effects by monitoring electrode polarization and telluric activity. The interpretation of SP contour maps is preferred to using profile data. A procedure was adopted for SP interpretation, and the results were satisfactory. However, this model is based on thermoelectric sources only and is not related directly to hot fluid movement. In all three survey areas, the geothermal zones delimited by the SP interpretation in combination with data acquired by other geophysical methods result in an integrated interpretation of the geothermal system. Since SP and very‐low‐frequency (VLF) anomalies can be generated by the same geological source (i.e., geothermal, highly conductive zone), the corresponding results are compared to provide a strong indication of the presence of geothermal zones. The activity of geothermal zones affects the conductivity of the surrounding medium, which also can be detected by dc resistivity and audio‐magnetotelluric (AMT) methods. In addition, geothermal zones can be related to various interfaces or tectonic features that can be detected by gravity or seismic methods.

scholarly journals Detection of Cover Collapse Doline and Other Epikarst Features by Multiple Geophysical Techniques, Case Study of Tarimba Cave, Brazil

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2835
Author(s):  
Yawar Hussain ◽  
Rogerio Uagoda ◽  
Welitom Borges ◽  
Renato Prado ◽  
Omar Hamza ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Least Square ◽  
P Wave ◽  
Positive Anomaly ◽  
Refraction Tomography ◽  
Collapse Doline

Reliable characterization of the karst system is essential for risk assessment where many associated hazards (e.g., cover-collapse dolines and groundwater pollution) can affect natural and built environments, threatening public safety. The use of multiple geophysical approaches may offer an improved way to investigate such cover-collapse sinkholes and aid in geohazard risk assessments. In this paper, covered karst, which has two types of shallow caves (vadose and fluvial) located in Tarimba (Goias, Brazil), was investigated using various geophysical methods to evaluate their efficiency in the delineation of the geometry of sediments filled sinkhole. The methods used for the investigation were Electrical Resistivity Tomography (ERT), Seismic Refraction Survey (SRS), Seismic Refraction Tomography (SRT) and the Very Low Frequency Electromagnetic (VLF-EM) method. The study developed several (2D) sections of the measured physical properties, including P-wave velocity and electrical resistivity, as well as the induced current (because of local bodies). For the analysis and processing of the data obtained from these methods, the following approaches were adopted: ERT inversion using a least-square scheme, Karous-Hjelt filter for VLF-EM data and time-distance curves and Vp cross-sections for the SRS. The refraction data analysis showed three-layered stratigraphy topsoil, claystone and carbonate bedrock, respectively. The findings obtained from ERT (three-layered stratigraphy and sediment-filled doline), as well as VLF-EM (fractured or filled caves as a positive anomaly), were found to be consistent with the actual field conditions. However, the SRS and SRT methods did not show the collapsed material and reached the limited the depth because of shorter profile lengths. The study provides a reasonable basis for the development of an integrated geophysical approach for site characterization of karst systems, particularly the perched tank and collapse doline.

scholarly journals Determining geophysical responses from burials in graveyards and cemeteries

Geophysics ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. B245-B255 ◽  
Author(s):  
Henry C. Dick ◽  
Jamie K. Pringle ◽  
Kristopher D. Wisniewski ◽  
Jon Goodwin ◽  
Robert van der Putten ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Target Detection ◽  
High Frequency ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Coarse Sand ◽  
Detection Methods ◽  
Surface Data ◽  
Ground Penetrating

Graveyards and cemeteries around the world are increasingly designated as full. Therefore, there is a requirement to identify vacant spaces for new burials or to identify existing ones to exhume and then reinter if necessary. Geophysical methods offer a potentially noninvasive target detection solution; however, there has been limited research to identify optimal geophysical detection methods against burial age. We have collected multifrequency (225–900 MHz) ground-penetrating radar (GPR), electrical resistivity, and magnetic susceptibility surface data over known graves with different burial ages and soil types in three UK church graveyards. Results indicate that progressively older burials are more difficult to detect, but this decrease is not linear and is site specific. Medium- to high-frequency GPR and magnetic susceptibility was optimal in clay-rich soils, medium- to high-frequency GPR and electrical resistivity in sandy soils, and electrical resistivity and low-frequency GPR in coarse sand and pebbly soils, respectively. A multigeophysical technique approach should be used by survey practitioners where grave locations are not known to maximize target detection success. Grave soil and grave cuts are important grave position indicators. Grave headstones were not always located where burials were located. We have determined the value of these techniques in grave detection and could potentially date burials from their geophysical responses.

scholarly journals The Potential Use of Geophysical Methods to Identify Cavities, Sinkholes and Pathways for Water Infiltration

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2289 ◽  
Author(s):  
Yawar Hussain ◽  
Rogerio Uagoda ◽  
Welitom Borges ◽  
José Nunes ◽  
Omar Hamza ◽  
...  
Keyword(s):  
Cross Sections ◽  
Current Density ◽  
Geophysical Methods ◽  
Low Frequency ◽  
Water Infiltration ◽  
Non Invasive ◽  
Geophysical Techniques ◽  
Karst Systems ◽  
Ground Penetrating

The use of geophysical characterization of karst systems can provide an economical and non-invasive alternative for extracting information about cavities, sinkholes, pathways for water infiltration as well as the degree of karstification of underlying carbonate rocks. In the present study, three geophysical techniques, namely, Ground Penetrating Radar (GPR), Electrical Resistivity Tomography (ERT) and Very Low Frequency Electromagnetic (VLFEM) methods were applied at three different locations in relation to fluvial karst, which is listed as an environmentally sensitive area in Rio Vermelho, Mambaí, Goiás, Brazil. In the data acquisition phase, the GPR, direct-current (DC) resistivity and VLFEM profiles were obtained at the three locations in the area. Data were analyzed using commonly adopted processing workflows. The GPR results showed a well-defined lithology of the site based on the amplitude of the signal and radar typologies. On the other hand, the inverted resistivity cross-sections showed a three-layered stratigraphy, pathways of water infiltration and the weathered structures in carbonate (Bambui group). The interpretation of VLFEM as contours of current density resulted from Fraser and Karous–Hjelt filters, indicated the presence of conductive structures (high apparent current density) that might be linked to the weathered carbonate and other conductive and resistive anomalies associated with the water-filled and dry cavities (cave), respectively. The results encourage the integrated application of geophysical techniques such as the reconnaissance for further detailed characterization of the karst areas.

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