The inversion of 2-D and 3-D resistivity data from surveys in aquatic areas
(2019) EAGE-GSM 2nd Asia Pacific Meeting on Near Surface Geoscience and Engineering- Abstract
Resistivity surveys are now also carried in areas covered by water. The surveys involve electrodes planted on the water bottom or on a streamer towed by a boat. As the water layer has a large effect on resistivity measurements, its effect must be accurately modelled. The water resistivity and depth to the bottom are usually independently measured with a conductivity meter and depth sounder. The upper part of a finite-element grid is used to model the water layer, including possible variations in the water resistivity with depth. We show the results from a 2-D survey in Stockholm with electrodes planted on the sea bottom. The sediment thickness from the inverse model agrees well with drilling results and a possible weak zone in the... (More)
Resistivity surveys are now also carried in areas covered by water. The surveys involve electrodes planted on the water bottom or on a streamer towed by a boat. As the water layer has a large effect on resistivity measurements, its effect must be accurately modelled. The water resistivity and depth to the bottom are usually independently measured with a conductivity meter and depth sounder. The upper part of a finite-element grid is used to model the water layer, including possible variations in the water resistivity with depth. We show the results from a 2-D survey in Stockholm with electrodes planted on the sea bottom. The sediment thickness from the inverse model agrees well with drilling results and a possible weak zone in the bedrock was detected. Surveys with floating electrodes do not follow a straight line due to water currents and a 3-D inversion approach is required. An example is shown from a survey in the Panama Canal where the data from 19 sub-parallel lines are collated into a 3-D data set. The inverse model shows a conductive bottom with weathered marine sedimentary rocks and a remnant of an old river channel filled with more resistive sands and gravels.
(Less)
- author
- Loke, M. H. ; Dahlin, T. LU and Rucker, D.
- organization
- publishing date
- 2019
- type
- Chapter in Book/Report/Conference proceeding
- publication status
- published
- subject
- host publication
- EAGE-GSM 2nd Asia Pacific Meeting on Near Surface Geoscience and Engineering
- publisher
- European Association of Geoscientists and Engineers
- conference name
- EAGE-GSM 2nd Asia Pacific Meeting on Near Surface Geoscience and Engineering
- conference location
- Kuala Lumpur, Malaysia
- conference dates
- 2019-04-22 - 2019-04-26
- external identifiers
-
- scopus:85088774445
- ISBN
- 9789462822740
- DOI
- 10.3997/2214-4609.201900401
- project
- Geoelectrical Imaging for Site Investigation for Urban Underground Infrastructure
- language
- English
- LU publication?
- yes
- id
- 35d58dee-be2f-442f-ba79-6850e52d4ada
- date added to LUP
- 2019-07-09 13:16:59
- date last changed
- 2022-04-26 03:04:58
@inproceedings{35d58dee-be2f-442f-ba79-6850e52d4ada,
abstract = {{<p>Resistivity surveys are now also carried in areas covered by water. The surveys involve electrodes planted on the water bottom or on a streamer towed by a boat. As the water layer has a large effect on resistivity measurements, its effect must be accurately modelled. The water resistivity and depth to the bottom are usually independently measured with a conductivity meter and depth sounder. The upper part of a finite-element grid is used to model the water layer, including possible variations in the water resistivity with depth. We show the results from a 2-D survey in Stockholm with electrodes planted on the sea bottom. The sediment thickness from the inverse model agrees well with drilling results and a possible weak zone in the bedrock was detected. Surveys with floating electrodes do not follow a straight line due to water currents and a 3-D inversion approach is required. An example is shown from a survey in the Panama Canal where the data from 19 sub-parallel lines are collated into a 3-D data set. The inverse model shows a conductive bottom with weathered marine sedimentary rocks and a remnant of an old river channel filled with more resistive sands and gravels.</p>}},
author = {{Loke, M. H. and Dahlin, T. and Rucker, D.}},
booktitle = {{EAGE-GSM 2nd Asia Pacific Meeting on Near Surface Geoscience and Engineering}},
isbn = {{9789462822740}},
language = {{eng}},
publisher = {{European Association of Geoscientists and Engineers}},
title = {{The inversion of 2-D and 3-D resistivity data from surveys in aquatic areas}},
url = {{http://dx.doi.org/10.3997/2214-4609.201900401}},
doi = {{10.3997/2214-4609.201900401}},
year = {{2019}},
}