On the origin, nature and uses of Antarctic ice-sheet radio-echo layering
Airborne radio-echo sounding (RES) data display layering within the Antarctic ice sheet. At ice depths below 1000m these layers are caused by horizons of ice with relatively high acidity which were originally deposited on the ice surface after large volcanic events. Layering which is less than 1000...
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Online Access: | http://dx.doi.org/10.1177/030913339902300201 https://journals.sagepub.com/doi/pdf/10.1177/030913339902300201 |
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crsagepubl:10.1177/030913339902300201 2024-10-13T14:03:19+00:00 On the origin, nature and uses of Antarctic ice-sheet radio-echo layering Siegert, Martin J. 1999 http://dx.doi.org/10.1177/030913339902300201 https://journals.sagepub.com/doi/pdf/10.1177/030913339902300201 en eng SAGE Publications https://journals.sagepub.com/page/policies/text-and-data-mining-license Progress in Physical Geography: Earth and Environment volume 23, issue 2, page 159-179 ISSN 0309-1333 1477-0296 journal-article 1999 crsagepubl https://doi.org/10.1177/030913339902300201 2024-09-24T04:11:34Z Airborne radio-echo sounding (RES) data display layering within the Antarctic ice sheet. At ice depths below 1000m these layers are caused by horizons of ice with relatively high acidity which were originally deposited on the ice surface after large volcanic events. Layering which is less than 1000 m from the ice surface can also be due to variation in ice density. Theoretically, therefore, internal RES layering below 1000 m should represent isochronous planes. This theory is upheld under examination of existing RES data where internal layers have been observed to follow the rules of superposition. For example, RES layers are deposited as discrete bands, fold and fault in a manner analogous to geological features, never cross over each other and, in an undisturbed deposit, have a depth-age relationship which means that the oldest layers are located at the lowest level. Moreover, the location of internal layering is independent of radiowave receiver altitude, the frequency of the radiowave does not affect layer depth, and the pulse width of the e/m wave does not affect identification of layers. Thus, RES reflects actual dielectric layering within the ice sheet. Glaciologists use RES layering for a number of reasons, including: (1) correlating ice cores; (2) as boundary conditions for numerical models to help determine the direction of ice flow; and (3) as a means of identifying the three-dimensional ice-sheet geometry and architecture. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet SAGE Publications Antarctic The Antarctic Progress in Physical Geography: Earth and Environment 23 2 159 179 |
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English |
description |
Airborne radio-echo sounding (RES) data display layering within the Antarctic ice sheet. At ice depths below 1000m these layers are caused by horizons of ice with relatively high acidity which were originally deposited on the ice surface after large volcanic events. Layering which is less than 1000 m from the ice surface can also be due to variation in ice density. Theoretically, therefore, internal RES layering below 1000 m should represent isochronous planes. This theory is upheld under examination of existing RES data where internal layers have been observed to follow the rules of superposition. For example, RES layers are deposited as discrete bands, fold and fault in a manner analogous to geological features, never cross over each other and, in an undisturbed deposit, have a depth-age relationship which means that the oldest layers are located at the lowest level. Moreover, the location of internal layering is independent of radiowave receiver altitude, the frequency of the radiowave does not affect layer depth, and the pulse width of the e/m wave does not affect identification of layers. Thus, RES reflects actual dielectric layering within the ice sheet. Glaciologists use RES layering for a number of reasons, including: (1) correlating ice cores; (2) as boundary conditions for numerical models to help determine the direction of ice flow; and (3) as a means of identifying the three-dimensional ice-sheet geometry and architecture. |
format |
Article in Journal/Newspaper |
author |
Siegert, Martin J. |
spellingShingle |
Siegert, Martin J. On the origin, nature and uses of Antarctic ice-sheet radio-echo layering |
author_facet |
Siegert, Martin J. |
author_sort |
Siegert, Martin J. |
title |
On the origin, nature and uses of Antarctic ice-sheet radio-echo layering |
title_short |
On the origin, nature and uses of Antarctic ice-sheet radio-echo layering |
title_full |
On the origin, nature and uses of Antarctic ice-sheet radio-echo layering |
title_fullStr |
On the origin, nature and uses of Antarctic ice-sheet radio-echo layering |
title_full_unstemmed |
On the origin, nature and uses of Antarctic ice-sheet radio-echo layering |
title_sort |
on the origin, nature and uses of antarctic ice-sheet radio-echo layering |
publisher |
SAGE Publications |
publishDate |
1999 |
url |
http://dx.doi.org/10.1177/030913339902300201 https://journals.sagepub.com/doi/pdf/10.1177/030913339902300201 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_source |
Progress in Physical Geography: Earth and Environment volume 23, issue 2, page 159-179 ISSN 0309-1333 1477-0296 |
op_rights |
https://journals.sagepub.com/page/policies/text-and-data-mining-license |
op_doi |
https://doi.org/10.1177/030913339902300201 |
container_title |
Progress in Physical Geography: Earth and Environment |
container_volume |
23 |
container_issue |
2 |
container_start_page |
159 |
op_container_end_page |
179 |
_version_ |
1812819760816062464 |