1D and 2D Modelling of AMT and CSAMT Measurements from Swedish Lapland - A Case Study
Audiomagnetotelluric measurements with (CSAMT) and without (AMT) a controlled source were performed near Gällivare and Kiruna in Swedish Lapland in order to retrieve representative conductivity models of the subsurfaces. Magnetotelluric transfer functions were gained from processed time series’ and...
Main Author: | |
---|---|
Format: | Bachelor Thesis |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-364219 |
id |
ftuppsalauniv:oai:DiVA.org:uu-364219 |
---|---|
record_format |
openpolar |
spelling |
ftuppsalauniv:oai:DiVA.org:uu-364219 2023-05-15T16:19:31+02:00 1D and 2D Modelling of AMT and CSAMT Measurements from Swedish Lapland - A Case Study Dossow, Lisa 2018 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-364219 eng eng Examensarbete vid Institutionen för geovetenskaper, 1650-6553 444 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-364219 info:eu-repo/semantics/openAccess audiomagnetotellurics controlled source audiomagnetotellurics Gällivare Kiruna time series processing 1D and 2D inversion Geophysics Geofysik Student thesis info:eu-repo/semantics/bachelorThesis text 2018 ftuppsalauniv 2023-02-23T21:49:27Z Audiomagnetotelluric measurements with (CSAMT) and without (AMT) a controlled source were performed near Gällivare and Kiruna in Swedish Lapland in order to retrieve representative conductivity models of the subsurfaces. Magnetotelluric transfer functions were gained from processed time series’ and subsequently inverted to generate the sought models successfully. Additionally, a strike angle analysis was performed to determine the dimension of the ground structures. That information was used to justify the approaches of 1D and 2D inversions of the data sets and to judge their applicability. In Kiruna, two profiles were installed. One profile is considered to be in line with the strike direction, the other profile was oriented rather orthogonal to the strike direction. In Gällivare, only one profile was installed orthogonally with respect to the strike direction. The strike analysis showed a preferentially 2-dimensional structure for Kiruna’s parallel profile. For the orthogonal oriented profiles from Kiruna and Gällivare, the analysis revealed a 2D (with distortions) to 3D dimension of the ground structures. For the AMT method, it was possible to generate 1-dimensional and 2-dimensional models. Regarding the CSAMT data, it was only possible to generate a 1D conductivitymodel for the subsurface. Due to a significant transmitter overprint, no undistorted start model for the 2-dimensional CSAMT data inversion could be produced. The models from Kiruna had a sufficient data quality and thus resulted in reliable 2D AMT resistivity models with, locally, 2 to 3 layers. However, in combination with the 1D models for AMT and CSAMT, a 3-layer structure was predicted, where a resistive layer is covered by a thin conductive layer and underlaid by a rather conductive basement. For Gällivare’s profile, the data quality was good such that for all inversion methods good results were achieved. The predicted 2-layer models were resolved for for depths between 10m and 10,000m and coincide with the at hand geological maps and cross ... Bachelor Thesis Gällivare Kiruna Lapland Uppsala University: Publications (DiVA) Gällivare ENVELOPE(20.660,20.660,67.132,67.132) Kiruna |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
audiomagnetotellurics controlled source audiomagnetotellurics Gällivare Kiruna time series processing 1D and 2D inversion Geophysics Geofysik |
spellingShingle |
audiomagnetotellurics controlled source audiomagnetotellurics Gällivare Kiruna time series processing 1D and 2D inversion Geophysics Geofysik Dossow, Lisa 1D and 2D Modelling of AMT and CSAMT Measurements from Swedish Lapland - A Case Study |
topic_facet |
audiomagnetotellurics controlled source audiomagnetotellurics Gällivare Kiruna time series processing 1D and 2D inversion Geophysics Geofysik |
description |
Audiomagnetotelluric measurements with (CSAMT) and without (AMT) a controlled source were performed near Gällivare and Kiruna in Swedish Lapland in order to retrieve representative conductivity models of the subsurfaces. Magnetotelluric transfer functions were gained from processed time series’ and subsequently inverted to generate the sought models successfully. Additionally, a strike angle analysis was performed to determine the dimension of the ground structures. That information was used to justify the approaches of 1D and 2D inversions of the data sets and to judge their applicability. In Kiruna, two profiles were installed. One profile is considered to be in line with the strike direction, the other profile was oriented rather orthogonal to the strike direction. In Gällivare, only one profile was installed orthogonally with respect to the strike direction. The strike analysis showed a preferentially 2-dimensional structure for Kiruna’s parallel profile. For the orthogonal oriented profiles from Kiruna and Gällivare, the analysis revealed a 2D (with distortions) to 3D dimension of the ground structures. For the AMT method, it was possible to generate 1-dimensional and 2-dimensional models. Regarding the CSAMT data, it was only possible to generate a 1D conductivitymodel for the subsurface. Due to a significant transmitter overprint, no undistorted start model for the 2-dimensional CSAMT data inversion could be produced. The models from Kiruna had a sufficient data quality and thus resulted in reliable 2D AMT resistivity models with, locally, 2 to 3 layers. However, in combination with the 1D models for AMT and CSAMT, a 3-layer structure was predicted, where a resistive layer is covered by a thin conductive layer and underlaid by a rather conductive basement. For Gällivare’s profile, the data quality was good such that for all inversion methods good results were achieved. The predicted 2-layer models were resolved for for depths between 10m and 10,000m and coincide with the at hand geological maps and cross ... |
format |
Bachelor Thesis |
author |
Dossow, Lisa |
author_facet |
Dossow, Lisa |
author_sort |
Dossow, Lisa |
title |
1D and 2D Modelling of AMT and CSAMT Measurements from Swedish Lapland - A Case Study |
title_short |
1D and 2D Modelling of AMT and CSAMT Measurements from Swedish Lapland - A Case Study |
title_full |
1D and 2D Modelling of AMT and CSAMT Measurements from Swedish Lapland - A Case Study |
title_fullStr |
1D and 2D Modelling of AMT and CSAMT Measurements from Swedish Lapland - A Case Study |
title_full_unstemmed |
1D and 2D Modelling of AMT and CSAMT Measurements from Swedish Lapland - A Case Study |
title_sort |
1d and 2d modelling of amt and csamt measurements from swedish lapland - a case study |
publishDate |
2018 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-364219 |
long_lat |
ENVELOPE(20.660,20.660,67.132,67.132) |
geographic |
Gällivare Kiruna |
geographic_facet |
Gällivare Kiruna |
genre |
Gällivare Kiruna Lapland |
genre_facet |
Gällivare Kiruna Lapland |
op_relation |
Examensarbete vid Institutionen för geovetenskaper, 1650-6553 444 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-364219 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766005899138170880 |