Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography
The porosity of a sea ice pressure ridge keel is an important but poorly known variable relevant for determining the mass budget and evolution of the Arctic sea ice cover. Determination of keel porosity from drillholes is time-intensive and only yields limited information because of their limited la...
Main Authors: | , , , , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
INT GLACIOL SOC
2013
|
Subjects: | |
Online Access: | https://epic.awi.de/id/eprint/31770/ https://hdl.handle.net/10013/epic.42226 |
id |
ftawi:oai:epic.awi.de:31770 |
---|---|
record_format |
openpolar |
spelling |
ftawi:oai:epic.awi.de:31770 2024-09-15T17:39:58+00:00 Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography Nuber, Andre Rabenstein, Lasse Lehmann-Horn, Jochen Hertrich, Marian Hendricks, Stefan Mahoney, Andrew Eicken, Hajo 2013 https://epic.awi.de/id/eprint/31770/ https://hdl.handle.net/10013/epic.42226 unknown INT GLACIOL SOC Nuber, A. , Rabenstein, L. , Lehmann-Horn, J. , Hertrich, M. , Hendricks, S. orcid:0000-0002-1412-3146 , Mahoney, A. and Eicken, H. (2013) Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography , Annals of Glaciology, 54 (64) . hdl:10013/epic.42226 EPIC3Annals of Glaciology, INT GLACIOL SOC, 54(64), ISSN: 0260-3055 Article isiRev 2013 ftawi 2024-06-24T04:06:16Z The porosity of a sea ice pressure ridge keel is an important but poorly known variable relevant for determining the mass budget and evolution of the Arctic sea ice cover. Determination of keel porosity from drillholes is time-intensive and only yields limited information because of their limited lateral extent. Since the porosity within a keel equals its liquid water content, surface-nuclear magnetic resonance (surface-NMR) methods can be used to estimate porosity within such features. Surface-NMR tomography measurements were made in April 2011 using seven surface coil positions across a first-year pressure ridge on landfast sea ice near Barrow, Alaska. The inversion results indicate water contents of 30 ± 7 % and 40 ± 10 % in the ridge's shallow and deep parts, respectively. These values are much higher than those obtained from drillholes, which are ~10 % and ~27 %, respectively. In contrast to drilling, surface-NMR tomography yields average porosity values for the entire subsurface volume. However, the inversion process is sensitive to the electrical conductivity distribution; uncertain conductivity estimates limit the reliability of the inverted water contents. Nevertheless, the results suggest that ridge porosities obtained from invasive measurements such as drilling may lead to substantially overestimated sea ice volume. Article in Journal/Newspaper Annals of Glaciology Barrow Sea ice Alaska Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
The porosity of a sea ice pressure ridge keel is an important but poorly known variable relevant for determining the mass budget and evolution of the Arctic sea ice cover. Determination of keel porosity from drillholes is time-intensive and only yields limited information because of their limited lateral extent. Since the porosity within a keel equals its liquid water content, surface-nuclear magnetic resonance (surface-NMR) methods can be used to estimate porosity within such features. Surface-NMR tomography measurements were made in April 2011 using seven surface coil positions across a first-year pressure ridge on landfast sea ice near Barrow, Alaska. The inversion results indicate water contents of 30 ± 7 % and 40 ± 10 % in the ridge's shallow and deep parts, respectively. These values are much higher than those obtained from drillholes, which are ~10 % and ~27 %, respectively. In contrast to drilling, surface-NMR tomography yields average porosity values for the entire subsurface volume. However, the inversion process is sensitive to the electrical conductivity distribution; uncertain conductivity estimates limit the reliability of the inverted water contents. Nevertheless, the results suggest that ridge porosities obtained from invasive measurements such as drilling may lead to substantially overestimated sea ice volume. |
format |
Article in Journal/Newspaper |
author |
Nuber, Andre Rabenstein, Lasse Lehmann-Horn, Jochen Hertrich, Marian Hendricks, Stefan Mahoney, Andrew Eicken, Hajo |
spellingShingle |
Nuber, Andre Rabenstein, Lasse Lehmann-Horn, Jochen Hertrich, Marian Hendricks, Stefan Mahoney, Andrew Eicken, Hajo Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography |
author_facet |
Nuber, Andre Rabenstein, Lasse Lehmann-Horn, Jochen Hertrich, Marian Hendricks, Stefan Mahoney, Andrew Eicken, Hajo |
author_sort |
Nuber, Andre |
title |
Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography |
title_short |
Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography |
title_full |
Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography |
title_fullStr |
Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography |
title_full_unstemmed |
Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography |
title_sort |
water content estimates of a first-year sea ice pressure ridge keel from surface nuclear magnetic resonance tomography |
publisher |
INT GLACIOL SOC |
publishDate |
2013 |
url |
https://epic.awi.de/id/eprint/31770/ https://hdl.handle.net/10013/epic.42226 |
genre |
Annals of Glaciology Barrow Sea ice Alaska |
genre_facet |
Annals of Glaciology Barrow Sea ice Alaska |
op_source |
EPIC3Annals of Glaciology, INT GLACIOL SOC, 54(64), ISSN: 0260-3055 |
op_relation |
Nuber, A. , Rabenstein, L. , Lehmann-Horn, J. , Hertrich, M. , Hendricks, S. orcid:0000-0002-1412-3146 , Mahoney, A. and Eicken, H. (2013) Water Content Estimates of a First-Year Sea Ice Pressure Ridge Keel from Surface Nuclear Magnetic Resonance Tomography , Annals of Glaciology, 54 (64) . hdl:10013/epic.42226 |
_version_ |
1810483786407739392 |