Seismic and radar observations of subglacial bedforms beneath the onset zone of Rutford Ice Stream, Antarctica
ABSTRACT. We present seismic and radar data from the onset region of Rutford Ice Stream, West Antarctica, which show the form and internal structure of a variety of bed forms beneath an active ice stream. The ice flow in the area of our survey accelerates from 72 to>200ma–1, the ice is 2200–3200m...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.634.3418 2023-05-15T13:37:43+02:00 Seismic and radar observations of subglacial bedforms beneath the onset zone of Rutford Ice Stream, Antarctica Edward C. King John Woodward Andy M. Smith The Pennsylvania State University CiteSeerX Archives 2007 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.634.3418 http://www.igsoc.org/journal/53/183/j07j009.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.634.3418 http://www.igsoc.org/journal/53/183/j07j009.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.igsoc.org/journal/53/183/j07j009.pdf text 2007 ftciteseerx 2016-01-08T15:37:28Z ABSTRACT. We present seismic and radar data from the onset region of Rutford Ice Stream, West Antarctica, which show the form and internal structure of a variety of bed forms beneath an active ice stream. The ice flow in the area of our survey accelerates from 72 to>200ma–1, the ice is 2200–3200m thick, and the bed of the ice stream lies up to 2000m below present sea level. We have imaged the internal structure of the bed forms with seismic reflection techniques and also observed radar reflections from below the bed in some circumstances. We observed a transverse moraine 2 km wide and 1.5 km long beneath the slower-flowing part of the ice stream, which we interpret to be composed of unconsolidated sediment undergoing active deformation near the ice–sediment interface. We observed drumlins of classical form with elongation ratios of between 1: 1.5 and 1: 4.0 where the surface flow speed exceeded 95ma–1. The conformity of the internal structure of the bed forms with the ice base suggests that the bed forms are active depositional features in congruence with the observation of a contemporary drumlin-forming episode in the distal part of the same ice stream. These observations provide the first direct evidence of the association between ice-stream flow speed and bed-form shape. Text Antarc* Antarctica Rutford Ice Stream West Antarctica Unknown Rutford ENVELOPE(-85.300,-85.300,-78.600,-78.600) Rutford Ice Stream ENVELOPE(-80.000,-80.000,-79.167,-79.167) West Antarctica |
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Open Polar |
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Unknown |
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ftciteseerx |
language |
English |
description |
ABSTRACT. We present seismic and radar data from the onset region of Rutford Ice Stream, West Antarctica, which show the form and internal structure of a variety of bed forms beneath an active ice stream. The ice flow in the area of our survey accelerates from 72 to>200ma–1, the ice is 2200–3200m thick, and the bed of the ice stream lies up to 2000m below present sea level. We have imaged the internal structure of the bed forms with seismic reflection techniques and also observed radar reflections from below the bed in some circumstances. We observed a transverse moraine 2 km wide and 1.5 km long beneath the slower-flowing part of the ice stream, which we interpret to be composed of unconsolidated sediment undergoing active deformation near the ice–sediment interface. We observed drumlins of classical form with elongation ratios of between 1: 1.5 and 1: 4.0 where the surface flow speed exceeded 95ma–1. The conformity of the internal structure of the bed forms with the ice base suggests that the bed forms are active depositional features in congruence with the observation of a contemporary drumlin-forming episode in the distal part of the same ice stream. These observations provide the first direct evidence of the association between ice-stream flow speed and bed-form shape. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Edward C. King John Woodward Andy M. Smith |
spellingShingle |
Edward C. King John Woodward Andy M. Smith Seismic and radar observations of subglacial bedforms beneath the onset zone of Rutford Ice Stream, Antarctica |
author_facet |
Edward C. King John Woodward Andy M. Smith |
author_sort |
Edward C. King |
title |
Seismic and radar observations of subglacial bedforms beneath the onset zone of Rutford Ice Stream, Antarctica |
title_short |
Seismic and radar observations of subglacial bedforms beneath the onset zone of Rutford Ice Stream, Antarctica |
title_full |
Seismic and radar observations of subglacial bedforms beneath the onset zone of Rutford Ice Stream, Antarctica |
title_fullStr |
Seismic and radar observations of subglacial bedforms beneath the onset zone of Rutford Ice Stream, Antarctica |
title_full_unstemmed |
Seismic and radar observations of subglacial bedforms beneath the onset zone of Rutford Ice Stream, Antarctica |
title_sort |
seismic and radar observations of subglacial bedforms beneath the onset zone of rutford ice stream, antarctica |
publishDate |
2007 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.634.3418 http://www.igsoc.org/journal/53/183/j07j009.pdf |
long_lat |
ENVELOPE(-85.300,-85.300,-78.600,-78.600) ENVELOPE(-80.000,-80.000,-79.167,-79.167) |
geographic |
Rutford Rutford Ice Stream West Antarctica |
geographic_facet |
Rutford Rutford Ice Stream West Antarctica |
genre |
Antarc* Antarctica Rutford Ice Stream West Antarctica |
genre_facet |
Antarc* Antarctica Rutford Ice Stream West Antarctica |
op_source |
http://www.igsoc.org/journal/53/183/j07j009.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.634.3418 http://www.igsoc.org/journal/53/183/j07j009.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766097017350651904 |