A systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling
Abstract The accuracy of electrical resistivity tomography (ERT) as a method for locating frozen‐to‐unfrozen interfaces in permafrost environments was investigated systematically for simplified scenarios using forward modeling. The impacts of varying the resistivity, thickness, and lateral continuit...
Published in: | Permafrost and Periglacial Processes |
---|---|
Main Authors: | , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2022
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1002/ppp.2141 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2141 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2141 |
id |
crwiley:10.1002/ppp.2141 |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1002/ppp.2141 2024-06-02T08:08:01+00:00 A systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling Herring, Teddi Lewkowicz, Antoni G. Natural Sciences and Engineering Research Council of Canada 2022 http://dx.doi.org/10.1002/ppp.2141 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2141 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2141 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Permafrost and Periglacial Processes volume 33, issue 2, page 134-146 ISSN 1045-6740 1099-1530 journal-article 2022 crwiley https://doi.org/10.1002/ppp.2141 2024-05-03T10:42:37Z Abstract The accuracy of electrical resistivity tomography (ERT) as a method for locating frozen‐to‐unfrozen interfaces in permafrost environments was investigated systematically for simplified scenarios using forward modeling. The impacts of varying the resistivity, thickness, and lateral continuity of the frozen region, altering the thickness of the surface thaw layer, and of differing array types were evaluated in relation to the detection and positioning of frozen–unfrozen interfaces. The results from these simple scenarios show that boundaries between frozen and unfrozen ground are more accurately indicated by maximum gradients rather than a fixed threshold value based on the resistivity at the base of the surface thawed layer. The resistivity of the frozen region plays a significant role in interpreted boundary locations, with high resistivity values causing a decrease in model sensitivity at depth and increased uncertainty in the interpreted base of the frozen zone, particularly in laterally continuous permafrost. Error in the interpreted base of the frozen zone also increases for thicker permafrost bodies, while thaw layer thickness plays a less significant role. In laterally discontinuous permafrost, wider frozen bodies cause the boundary at the base of the frozen region to become less distinct. Array type affected the appearance of the inverted resistivity models and the frozen–unfrozen boundaries located using the threshold method, but boundary locations were comparable among array types when the maximum gradient method was used. This synthetic modeling showed that the boundaries between unfrozen and frozen regions in ERT images should be interpreted with caution, particularly in ice‐rich, laterally continuous permafrost where sensitivity at depth is low. We conclude that forward modeling is a useful tool for permafrost investigations, both for assessing the likelihood of achieving ERT survey goals prior to fieldwork, and as an interpretive aid after field data have been acquired. Article in Journal/Newspaper Ice permafrost Permafrost and Periglacial Processes Wiley Online Library Permafrost and Periglacial Processes 33 2 134 146 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract The accuracy of electrical resistivity tomography (ERT) as a method for locating frozen‐to‐unfrozen interfaces in permafrost environments was investigated systematically for simplified scenarios using forward modeling. The impacts of varying the resistivity, thickness, and lateral continuity of the frozen region, altering the thickness of the surface thaw layer, and of differing array types were evaluated in relation to the detection and positioning of frozen–unfrozen interfaces. The results from these simple scenarios show that boundaries between frozen and unfrozen ground are more accurately indicated by maximum gradients rather than a fixed threshold value based on the resistivity at the base of the surface thawed layer. The resistivity of the frozen region plays a significant role in interpreted boundary locations, with high resistivity values causing a decrease in model sensitivity at depth and increased uncertainty in the interpreted base of the frozen zone, particularly in laterally continuous permafrost. Error in the interpreted base of the frozen zone also increases for thicker permafrost bodies, while thaw layer thickness plays a less significant role. In laterally discontinuous permafrost, wider frozen bodies cause the boundary at the base of the frozen region to become less distinct. Array type affected the appearance of the inverted resistivity models and the frozen–unfrozen boundaries located using the threshold method, but boundary locations were comparable among array types when the maximum gradient method was used. This synthetic modeling showed that the boundaries between unfrozen and frozen regions in ERT images should be interpreted with caution, particularly in ice‐rich, laterally continuous permafrost where sensitivity at depth is low. We conclude that forward modeling is a useful tool for permafrost investigations, both for assessing the likelihood of achieving ERT survey goals prior to fieldwork, and as an interpretive aid after field data have been acquired. |
author2 |
Natural Sciences and Engineering Research Council of Canada |
format |
Article in Journal/Newspaper |
author |
Herring, Teddi Lewkowicz, Antoni G. |
spellingShingle |
Herring, Teddi Lewkowicz, Antoni G. A systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling |
author_facet |
Herring, Teddi Lewkowicz, Antoni G. |
author_sort |
Herring, Teddi |
title |
A systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling |
title_short |
A systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling |
title_full |
A systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling |
title_fullStr |
A systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling |
title_full_unstemmed |
A systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling |
title_sort |
systematic evaluation of electrical resistivity tomography for permafrost interface detection using forward modeling |
publisher |
Wiley |
publishDate |
2022 |
url |
http://dx.doi.org/10.1002/ppp.2141 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2141 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ppp.2141 |
genre |
Ice permafrost Permafrost and Periglacial Processes |
genre_facet |
Ice permafrost Permafrost and Periglacial Processes |
op_source |
Permafrost and Periglacial Processes volume 33, issue 2, page 134-146 ISSN 1045-6740 1099-1530 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/ppp.2141 |
container_title |
Permafrost and Periglacial Processes |
container_volume |
33 |
container_issue |
2 |
container_start_page |
134 |
op_container_end_page |
146 |
_version_ |
1800753166346616832 |