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Using Very-Low-Frequency Electromagnetics (VLF-EM) for geophysical exploration at Albertine Graben, Uganda : a new CAD approach for 3D data blending

Eggert, David LU (2019) In Dissertations in Geology at Lund University GEOR02 20192
Department of Geology
Abstract (Swedish)
Elektromagnetiska vågor, även kända som radiovågor, är vågor som sprider sig med låga frekvenser från 3 till 30 kHz. Dessa lågfrekventa vågor används vanligtvis när man önskar kommunicera med ubåtar. De kan emellertid också användas på land för att mäta skillnader i jord– och bergarters elektriska konduktivitet. Denna mätteknik kallas Very-Low-Frequency Electromagnetics (VLF-EM) och har framgångsrikt använts för att få en inblick i underlagets geologiska egenskaper.
I detta projektarbete utfördes VLF-EM-mätningar i en aktiv riftdal (Albertine graben) i Uganda i Afrika för att lokalisera misstänkta avvikelser i form av järnrika malmer. Datan bearbetades och visas i ett antal tredimensionella sektioner för att åskådliggöra potentiellt... (More)
Elektromagnetiska vågor, även kända som radiovågor, är vågor som sprider sig med låga frekvenser från 3 till 30 kHz. Dessa lågfrekventa vågor används vanligtvis när man önskar kommunicera med ubåtar. De kan emellertid också användas på land för att mäta skillnader i jord– och bergarters elektriska konduktivitet. Denna mätteknik kallas Very-Low-Frequency Electromagnetics (VLF-EM) och har framgångsrikt använts för att få en inblick i underlagets geologiska egenskaper.
I detta projektarbete utfördes VLF-EM-mätningar i en aktiv riftdal (Albertine graben) i Uganda i Afrika för att lokalisera misstänkta avvikelser i form av järnrika malmer. Datan bearbetades och visas i ett antal tredimensionella sektioner för att åskådliggöra potentiellt intressanta zoner. För att validera dessa kompletterades VLF-EM datan med annan geologisk information, såsom fjärranalys och geokemisk bergartsanalys. Därmed kunde potentiellt intressanta zoner hittas, identifierade såsom anomalier. VLF-EM-metodiken har visat sig vara en kostnadseffektiv metod jämfört med andra geofysiska undersökningsmetoder. (Less)
Abstract
Electromagnetic waves, also known as radio waves, which propagate at low frequencies of only 3 kHz to 30 kHz, are usually used for communication with submarines. However, these waves can also be used on land to measure differences in the electrical conductivity of the subsurface. This technique is called Very-Low-Frequency Electromagnetics (VLF-EM) and has been successfully used to gain an insight into the geological properties of the subsurface.
In the present work, these VLF-EM measurements were performed in an active rift valley in Uganda, East-Africa (Albertine graben) to locate suspected anomalies in the form of ore deposits. The data were processed and displayed in a three-dimensional space and thus made it possible to visualize... (More)
Electromagnetic waves, also known as radio waves, which propagate at low frequencies of only 3 kHz to 30 kHz, are usually used for communication with submarines. However, these waves can also be used on land to measure differences in the electrical conductivity of the subsurface. This technique is called Very-Low-Frequency Electromagnetics (VLF-EM) and has been successfully used to gain an insight into the geological properties of the subsurface.
In the present work, these VLF-EM measurements were performed in an active rift valley in Uganda, East-Africa (Albertine graben) to locate suspected anomalies in the form of ore deposits. The data were processed and displayed in a three-dimensional space and thus made it possible to visualize distinctive areas. To validate these striking areas, additional geological data such as remote sensing and geochemical rock analysis and geological maps were blended with VLF-EM results in 3D space. Thereby promising zones could be found, which indicate anomalies by different data. The VLF-EM methodology has proven to be quite cost effective compared to other geophysical exploration methods, but it does harbor a number of peculiarities that should be considered in advance. (Less)
Please use this url to cite or link to this publication:
author
Eggert, David LU
supervisor
organization
course
GEOR02 20192
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Albertine Graben, EAR, East-African-Rift, Exploration, Geology, Geophysics, Ore, Uganda, Very Low Frequency, VLF-EM
publication/series
Dissertations in Geology at Lund University
report number
579
language
English
additional info
External supervisor: Dr. Rouwen Lehné (Technische Universität Darmstadt)
id
8998826
date added to LUP
2019-12-18 11:17:28
date last changed
2021-12-24 03:40:20
@misc{8998826,
  abstract     = {{Electromagnetic waves, also known as radio waves, which propagate at low frequencies of only 3 kHz to 30 kHz, are usually used for communication with submarines. However, these waves can also be used on land to measure differences in the electrical conductivity of the subsurface. This technique is called Very-Low-Frequency Electromagnetics (VLF-EM) and has been successfully used to gain an insight into the geological properties of the subsurface. 
In the present work, these VLF-EM measurements were performed in an active rift valley in Uganda, East-Africa (Albertine graben) to locate suspected anomalies in the form of ore deposits. The data were processed and displayed in a three-dimensional space and thus made it possible to visualize distinctive areas. To validate these striking areas, additional geological data such as remote sensing and geochemical rock analysis and geological maps were blended with VLF-EM results in 3D space. Thereby promising zones could be found, which indicate anomalies by different data. The VLF-EM methodology has proven to be quite cost effective compared to other geophysical exploration methods, but it does harbor a number of peculiarities that should be considered in advance.}},
  author       = {{Eggert, David}},
  language     = {{eng}},
  note         = {{Student Paper}},
  series       = {{Dissertations in Geology at Lund University}},
  title        = {{Using Very-Low-Frequency Electromagnetics (VLF-EM) for geophysical exploration at Albertine Graben, Uganda : a new CAD approach for 3D data blending}},
  year         = {{2019}},
}