Analysis of anomalous electrical conductivity and magnetic permeability effects using a frequency domain controlled-source electromagnetic method

2016 ◽  
Vol 204 (3) ◽  
pp. 1550-1564 ◽  
Author(s):  
Kyubo Noh ◽  
Seokmin Oh ◽  
Soon Jee Seol ◽  
Ki Ha Lee ◽  
Joongmoo Byun
Keyword(s):  
Electrical Conductivity ◽  
Frequency Domain ◽  
Magnetic Permeability ◽  
Electromagnetic Method ◽  
Controlled Source

Magnitude-phase Relationship behind Controlled-source Electromagnetic Field Revealed by Nyquist Diagrams

2017 ◽  
Vol 22 (4) ◽  
pp. 365-373
Author(s):  
Dajun Li ◽  
Aihua Weng ◽  
Yue Yang ◽  
Song Han ◽  
Yu Tang
Keyword(s):  
Electromagnetic Field ◽  
Data Processing ◽  
Frequency Domain ◽  
Electric Fields ◽  
Phase Relationship ◽  
Electromagnetic Method ◽  
Nyquist Diagram ◽  
Controlled Source ◽  
Data Inversion ◽  
D Model

We present a means of processing data from frequency-domain controlled-source electromagnetic method observations via a Nyquist diagram. For a controlled-source electromagnetic field in the frequency domain, the x component of the electric field and the y and z components of the magnetic fields were chosen for discussion. Typical 1-D models and a 3-D model, which have a single anomalous body embedded in a half space, have been used to calculate the complex electromagnetic fields. The corresponding Nyquist diagrams have been plotted and analyzed. The diagrams can reveal the magnitude-phase frequency characteristics of an electromagnetic field and can be used to guide data processing by considering the constraints of the intrinsic connection between amplitude and phase. The results further show that: (1) the Nyquist diagrams of both electric and magnetic responses, varying from low to high frequencies, are all characterized by continuous, single-direction, clockwise spiral curves; (2) for the magnetic field, the opening direction of the Nyquist curve is upward for the y and downward for the z components, regardless of the change in resistivity; (3) for the electric fields, the resistivity changes also lead the spiral structure to take on complicated shapes, such as a snail-like shape or a W, and the starting points of the Nyquist curves depend on the variations in the resistivity with depth. According to the aforementioned rules, we can obtain reliable and reasonably complex field data during the data processing of frequency-domain controlled-source electromagnetic method, which lays a foundation for 3-D frequency-domain data inversion.

scholarly journals Frequency Domain Electromagnetic Method (FDEM) as a Tool to Study Contamination at the Sub-Soil Layer

Geosciences ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 382
Author(s):  
Naftaly Goldshleger ◽  
Omer Shamir ◽  
Uri Basson ◽  
Eli Zaady
Keyword(s):  
Electrical Conductivity ◽  
Frequency Domain ◽  
Soil Analysis ◽  
Soil Layer ◽  
Conductivity Measurement ◽  
Laboratory Analysis ◽  
Electromagnetic Method ◽  
Soil Parameters ◽  
Forest Site ◽  
Soil Layers

Traditional sheep and cattle grazing in natural semiarid Mediterranean, Asian and African regions is based on night corrals, where animal secretions accumulate. Lack of management and disregard for the long-term effects of using the same sites for corrals on underground soil characters may negatively affect soil values. This locally increases the content of organic matter and nutrients such as nitrogen, potassium, phosphorus and others that are stockpiled in the corrals. As these activities are long-lasting, they affect the soil parameters, leading to nutrient leakage and contamination of the upper and sub-soil surface. This alarming situation demands a technique to reveal and estimate sub-soil contamination in corrals by using the frequency domain electromagnetic method (FDEM) for measuring soil salinity. The aim of this study is to correlate electrical conductivity measurement with the FDEM to study the influence of sheep corrals on the changes within the sub-soils of corrals in the semiarid region of the northern Negev desert. The results show that a correlation was found between the laboratory soil analysis and the electromagnetic analysis in all sites. Plugot forest site results found to be anomalous indicated sub-surface conductivity resulting from the presence of the corral, with a higher conductivity value of about 230 mS/m, while no differences were found between the soil layers outside the active corral and the corral edge. High values were found in the center of the active corral: 960 mS/m by the laboratory analysis and 200 mS/m by the FDEM. The values obtained in the abandoned corral in the laboratory were about 10 times lower than those obtained from the active corral and six times lower that those found with the FDEM. At the Beit Nir site, high values were found in the center of the active corral: 300 mS/m by the laboratory analysis and 130 mS/m by the FDEM. With different sources of manure, cattle and sheep have shown similar patterns of electrical conductivity (EC) obtained in the sub-soil layers between active and abandoned corrals: high in the center and low at the edge and outside the corral and decreased with depth.

scholarly journals БЕЗКОНТАКТНИЙ МЕТОД ТРИПАРАМЕТРОВОГО ВИМІРЮВАЛЬНОГО КОНТРОЛЮ ФІЗИКО-ХІМІЧНИХ ХАРАКТЕРИСТИК ЗРАЗКА ФЕРОМАГНІТНОЇ РІДИНИ

2018 ◽  
Vol 124 (4) ◽  
pp. 77-84
Author(s):  
В. В. Себко ◽  
В. Г. Здоренко
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Permeability ◽  
Electromagnetic Method ◽  
Specific Electrical Conductivity ◽  
Parameter Method ◽  
Chemical Characteristics ◽  
Parameter Control ◽  
Relative Magnetic Permeability ◽  
Physical And Chemical ◽  
Measuring Control

The aim of the article is to investigate the method of three-parameter control of a sample of a ferromagnetic liquid, the realization of which is carried out on the basis of a noncontact transformer electromagnetic converter (TEC) with samples of ferromagnetic liquids in a longitudinal magnetic field.We used a technique for studying samples of a ferromagnetic liquid for the realization of a three-parameter electromagnetic method for measuring the physical and chemical characteristics of ferromagnetic liquids based on thermal TEC. The three-parameter method of measuring control of the relative magnetic permeability mr, the specific electrical conductivity σ, and the temperature t of a sample of a ferromagnetic liquid, which is monitored on the basis of measurements and analysis of signals of a thermal contactless three-parameter TEC, is studied. The theoretical principles of the operation of a contactless thermal TEC with a sample of a ferromagnetic liquid are based on the realization of a three-parameter method for measuring the monitoring of magnetic, electrical, and temperature parameters.

Delineating ore-forming rock using a frequency domain controlled-source electromagnetic method

2019 ◽  
Vol 115 ◽  
pp. 103167
Author(s):  
Wen Chen ◽  
Guoqiang Xue ◽  
Nannan Zhou ◽  
Dongmei Tang ◽  
Dongyang Hou ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Electromagnetic Method ◽  
Controlled Source

Prediction of double stacking hydrocarbon using Marine Controlled Source Electromagnetic method

2014 ◽  
Author(s):  
Muhammad Rauf ◽  
Noorhana Yahya ◽  
Tadiwa Elisha Nyamasvisva ◽  
Adeel Ansari ◽  
Afza Shafie ◽  
...  
Keyword(s):  
Electromagnetic Method ◽  
Controlled Source

Inversion of frequency-domain marine-controlled-source electromagnetic data using genetic algorithm

2017 ◽  
Author(s):  
Mohit Ayani ◽  
Subhashis Mallick ◽  
Jürg Hunziker ◽  
Lucy MacGregor
Keyword(s):  
Genetic Algorithm ◽  
Frequency Domain ◽  
Controlled Source ◽  
Electromagnetic Data
Sign in / Sign up

Export Citation Format

Share Document