Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica
ABSTRACT. Basal radar reflectivity is the most important measurement for the detection of subglacial water. However, dielectric loss in the overlying ice column complicates the determination of basal reflectivity. Dielectric attenuation is a function of ice temperature and impurity concentration. Te...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.430.1128 2023-05-15T13:43:47+02:00 Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica Sasha Peter Carter Donald D. Blankenship Duncan A. Young John W. Holt The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.430.1128 http://www.igsoc.org/journal/55/194/j08j110.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.430.1128 http://www.igsoc.org/journal/55/194/j08j110.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.igsoc.org/journal/55/194/j08j110.pdf text ftciteseerx 2016-01-08T04:36:47Z ABSTRACT. Basal radar reflectivity is the most important measurement for the detection of subglacial water. However, dielectric loss in the overlying ice column complicates the determination of basal reflectivity. Dielectric attenuation is a function of ice temperature and impurity concentration. Temperature distribution is a function of climate history, basal heat flow and vertical strain rate, all of which can be partially inferred from the structure of dated internal layers. Using 11 dated layers, isotope records from Dome C, East Antarctica, and a model of the spatial variation of geothermal flux, we calculate the vertical strain rate and accumulation-rate history, allowing identification of areas where the basal melt rate exceeds 1.5 mm a –1. The accumulation-rate history and vertical strain rates are then used as inputs for a transient temperature model. The model outputs for the present-day temperature distribution are then combined with depth-dependent ionic concentrations to model dielectric loss and infer basal reflectivity. The resulting reflection coefficients are consistent (�–5 dB) across a variety of subglacial water bodies. We also identify a high reflectivity>–15 dB in Concordia Trench and along suspected subglacial water-flow routes in Vincennes Basin. Highland areas tend to have highly variable reflection coefficients near –30 dB, consistent with an ice–bedrock interface. This combined model also identifies three areas of enhanced basal melting along Concordia Ridge, Concordia Subglacial Lake and Text Antarc* Antarctica East Antarctica Unknown Concordia Subglacial Lake ENVELOPE(125.150,125.150,-74.100,-74.100) East Antarctica |
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Open Polar |
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ftciteseerx |
language |
English |
description |
ABSTRACT. Basal radar reflectivity is the most important measurement for the detection of subglacial water. However, dielectric loss in the overlying ice column complicates the determination of basal reflectivity. Dielectric attenuation is a function of ice temperature and impurity concentration. Temperature distribution is a function of climate history, basal heat flow and vertical strain rate, all of which can be partially inferred from the structure of dated internal layers. Using 11 dated layers, isotope records from Dome C, East Antarctica, and a model of the spatial variation of geothermal flux, we calculate the vertical strain rate and accumulation-rate history, allowing identification of areas where the basal melt rate exceeds 1.5 mm a –1. The accumulation-rate history and vertical strain rates are then used as inputs for a transient temperature model. The model outputs for the present-day temperature distribution are then combined with depth-dependent ionic concentrations to model dielectric loss and infer basal reflectivity. The resulting reflection coefficients are consistent (�–5 dB) across a variety of subglacial water bodies. We also identify a high reflectivity>–15 dB in Concordia Trench and along suspected subglacial water-flow routes in Vincennes Basin. Highland areas tend to have highly variable reflection coefficients near –30 dB, consistent with an ice–bedrock interface. This combined model also identifies three areas of enhanced basal melting along Concordia Ridge, Concordia Subglacial Lake and |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Sasha Peter Carter Donald D. Blankenship Duncan A. Young John W. Holt |
spellingShingle |
Sasha Peter Carter Donald D. Blankenship Duncan A. Young John W. Holt Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica |
author_facet |
Sasha Peter Carter Donald D. Blankenship Duncan A. Young John W. Holt |
author_sort |
Sasha Peter Carter |
title |
Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica |
title_short |
Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica |
title_full |
Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica |
title_fullStr |
Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica |
title_full_unstemmed |
Using radar-sounding data to identify the distribution and sources of subglacial water: application to Dome C, East Antarctica |
title_sort |
using radar-sounding data to identify the distribution and sources of subglacial water: application to dome c, east antarctica |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.430.1128 http://www.igsoc.org/journal/55/194/j08j110.pdf |
long_lat |
ENVELOPE(125.150,125.150,-74.100,-74.100) |
geographic |
Concordia Subglacial Lake East Antarctica |
geographic_facet |
Concordia Subglacial Lake East Antarctica |
genre |
Antarc* Antarctica East Antarctica |
genre_facet |
Antarc* Antarctica East Antarctica |
op_source |
http://www.igsoc.org/journal/55/194/j08j110.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.430.1128 http://www.igsoc.org/journal/55/194/j08j110.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766193209223938048 |