Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica
In order to better understand the spatial distribution of subglacial environments, ground-based radar profiling data were analyzed for a total distance of ~ 3300 km across Dronning Maud Land, East Antarctica. The relationship between geometrically corrected bed returned power [Pcbed]dB in decibels a...
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Copernicus Publications
2012
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fttriple:oai:gotriple.eu:oai:doaj.org/article:b80a704681544c2481223ab138d1876d 2023-05-15T13:53:30+02:00 Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica S. Fujita P. Holmlund K. Matsuoka H. Enomoto K. Fukui F. Nakazawa S. Sugiyama S. Surdyk 2012-10-01 https://doi.org/10.5194/tc-6-1203-2012 http://www.the-cryosphere.net/6/1203/2012/tc-6-1203-2012.pdf https://doaj.org/article/b80a704681544c2481223ab138d1876d en eng Copernicus Publications doi:10.5194/tc-6-1203-2012 1994-0416 1994-0424 http://www.the-cryosphere.net/6/1203/2012/tc-6-1203-2012.pdf https://doaj.org/article/b80a704681544c2481223ab138d1876d undefined The Cryosphere, Vol 6, Iss 5, Pp 1203-1219 (2012) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2012 fttriple https://doi.org/10.5194/tc-6-1203-2012 2023-01-22T18:47:30Z In order to better understand the spatial distribution of subglacial environments, ground-based radar profiling data were analyzed for a total distance of ~ 3300 km across Dronning Maud Land, East Antarctica. The relationship between geometrically corrected bed returned power [Pcbed]dB in decibels and ice thickness H was examined. When H is smaller than a~critical value that varies according to location, [Pcbed]dB tends to decrease relatively smoothly with increasing H, which is explicable primarily by the cumulative effect of dielectric attenuation within the ice. However, at locations where H is larger than the critical H values, anomalous increases and fluctuations in [Pcbed]dB were observed, regardless of the choice of radar frequency or radar-pulse width. In addition, the amplitude of the fluctuations often range 10 ~ 20 dB. We argue that the anomalous increases are caused by higher bed reflectivity associated with the existence of subglacial water. We used these features to delineate frozen and temperate beds. Approximately two-thirds of the investigated area was found to have a temperate bed. The beds of the inland part of the ice sheet tend to be temperate, with the exception of subglacial high mountains. In contrast, the beds of coastal areas tend to be frozen, with the exception of fast-flowing ice on the subglacial lowland or troughs. We argue that this new analytical method can be applied to other regions. Article in Journal/Newspaper Antarc* Antarctica Dronning Maud Land East Antarctica Ice Sheet The Cryosphere Unknown Dronning Maud Land East Antarctica The Cryosphere 6 5 1203 1219 |
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language |
English |
topic |
geo envir |
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geo envir S. Fujita P. Holmlund K. Matsuoka H. Enomoto K. Fukui F. Nakazawa S. Sugiyama S. Surdyk Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica |
topic_facet |
geo envir |
description |
In order to better understand the spatial distribution of subglacial environments, ground-based radar profiling data were analyzed for a total distance of ~ 3300 km across Dronning Maud Land, East Antarctica. The relationship between geometrically corrected bed returned power [Pcbed]dB in decibels and ice thickness H was examined. When H is smaller than a~critical value that varies according to location, [Pcbed]dB tends to decrease relatively smoothly with increasing H, which is explicable primarily by the cumulative effect of dielectric attenuation within the ice. However, at locations where H is larger than the critical H values, anomalous increases and fluctuations in [Pcbed]dB were observed, regardless of the choice of radar frequency or radar-pulse width. In addition, the amplitude of the fluctuations often range 10 ~ 20 dB. We argue that the anomalous increases are caused by higher bed reflectivity associated with the existence of subglacial water. We used these features to delineate frozen and temperate beds. Approximately two-thirds of the investigated area was found to have a temperate bed. The beds of the inland part of the ice sheet tend to be temperate, with the exception of subglacial high mountains. In contrast, the beds of coastal areas tend to be frozen, with the exception of fast-flowing ice on the subglacial lowland or troughs. We argue that this new analytical method can be applied to other regions. |
format |
Article in Journal/Newspaper |
author |
S. Fujita P. Holmlund K. Matsuoka H. Enomoto K. Fukui F. Nakazawa S. Sugiyama S. Surdyk |
author_facet |
S. Fujita P. Holmlund K. Matsuoka H. Enomoto K. Fukui F. Nakazawa S. Sugiyama S. Surdyk |
author_sort |
S. Fujita |
title |
Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica |
title_short |
Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica |
title_full |
Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica |
title_fullStr |
Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica |
title_full_unstemmed |
Radar diagnosis of the subglacial conditions in Dronning Maud Land, East Antarctica |
title_sort |
radar diagnosis of the subglacial conditions in dronning maud land, east antarctica |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/tc-6-1203-2012 http://www.the-cryosphere.net/6/1203/2012/tc-6-1203-2012.pdf https://doaj.org/article/b80a704681544c2481223ab138d1876d |
geographic |
Dronning Maud Land East Antarctica |
geographic_facet |
Dronning Maud Land East Antarctica |
genre |
Antarc* Antarctica Dronning Maud Land East Antarctica Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctica Dronning Maud Land East Antarctica Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 6, Iss 5, Pp 1203-1219 (2012) |
op_relation |
doi:10.5194/tc-6-1203-2012 1994-0416 1994-0424 http://www.the-cryosphere.net/6/1203/2012/tc-6-1203-2012.pdf https://doaj.org/article/b80a704681544c2481223ab138d1876d |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-6-1203-2012 |
container_title |
The Cryosphere |
container_volume |
6 |
container_issue |
5 |
container_start_page |
1203 |
op_container_end_page |
1219 |
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1766258669436010496 |