Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability?
We present 1 and 100 MHz ground-based radar data from the onset region of Rutford Ice Stream, West Antarctica, which indicate the form and internal structure of isochrones. In the flow-parallel lines, modelled isochrone patterns reproduce the gross pattern of the imaged near-surface layers, assuming...
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International Glaciological Society
2009
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ftnerc:oai:nora.nerc.ac.uk:11379 2023-05-15T13:29:43+02:00 Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? Woodward, John King, Edward C. 2009 text http://nora.nerc.ac.uk/id/eprint/11379/ https://nora.nerc.ac.uk/id/eprint/11379/1/s8.pdf http://www.igsoc.org/annals/V50/51/a51a100.pdf en eng International Glaciological Society https://nora.nerc.ac.uk/id/eprint/11379/1/s8.pdf Woodward, John; King, Edward C. orcid:0000-0003-3793-3915 . 2009 Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? Annals of Glaciology, 50 (51). 57-62. https://doi.org/10.3189/172756409789097469 <https://doi.org/10.3189/172756409789097469> Glaciology Publication - Article PeerReviewed 2009 ftnerc 2023-02-04T19:27:17Z We present 1 and 100 MHz ground-based radar data from the onset region of Rutford Ice Stream, West Antarctica, which indicate the form and internal structure of isochrones. In the flow-parallel lines, modelled isochrone patterns reproduce the gross pattern of the imaged near-surface layers, assuming steady-state flow velocity from GPS records and the current accumulation rate for the last 200 years. We interpret this as indicating overall stability in flow in the onset region of Rutford Ice Stream throughout this period. However, in the cross-flow lines some local variability in accumulation is seen in areas close to the ice-stream margin where a number of tributaries converge towards the ice-stream onset zone. Episodic surface lowering events are observed followed by rapid fill episodes. The fill events indicate deposition towards the northwest, most likely generated by storm winds, which blow at an oblique angle to ice flow. More problematic is explaining the generation of episodic surface lowering in this area. We speculate this may be due 10: changing ice-flow direction in the complex tributary area of the onset zone; a change in basal sediments or sedimentary landforms; a change in basal melt rates or water supply; or episodic lake drainage events in the fjord systems of the Ellsworth Subglacial Highlands. The study highlights the difficulty of assessing flow stability in the complex onset regions of West Antarctic ice streams. Article in Journal/Newspaper Annals of Glaciology Antarc* Antarctic Antarctica Rutford Ice Stream West Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic Ellsworth Subglacial Highlands ENVELOPE(-94.000,-94.000,-80.500,-80.500) Rutford ENVELOPE(-85.300,-85.300,-78.600,-78.600) Rutford Ice Stream ENVELOPE(-80.000,-80.000,-79.167,-79.167) West Antarctica Annals of Glaciology 50 51 57 62 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
topic |
Glaciology |
spellingShingle |
Glaciology Woodward, John King, Edward C. Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? |
topic_facet |
Glaciology |
description |
We present 1 and 100 MHz ground-based radar data from the onset region of Rutford Ice Stream, West Antarctica, which indicate the form and internal structure of isochrones. In the flow-parallel lines, modelled isochrone patterns reproduce the gross pattern of the imaged near-surface layers, assuming steady-state flow velocity from GPS records and the current accumulation rate for the last 200 years. We interpret this as indicating overall stability in flow in the onset region of Rutford Ice Stream throughout this period. However, in the cross-flow lines some local variability in accumulation is seen in areas close to the ice-stream margin where a number of tributaries converge towards the ice-stream onset zone. Episodic surface lowering events are observed followed by rapid fill episodes. The fill events indicate deposition towards the northwest, most likely generated by storm winds, which blow at an oblique angle to ice flow. More problematic is explaining the generation of episodic surface lowering in this area. We speculate this may be due 10: changing ice-flow direction in the complex tributary area of the onset zone; a change in basal sediments or sedimentary landforms; a change in basal melt rates or water supply; or episodic lake drainage events in the fjord systems of the Ellsworth Subglacial Highlands. The study highlights the difficulty of assessing flow stability in the complex onset regions of West Antarctic ice streams. |
format |
Article in Journal/Newspaper |
author |
Woodward, John King, Edward C. |
author_facet |
Woodward, John King, Edward C. |
author_sort |
Woodward, John |
title |
Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? |
title_short |
Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? |
title_full |
Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? |
title_fullStr |
Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? |
title_full_unstemmed |
Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? |
title_sort |
radar surveys of the rutford ice stream onset zone, west antarctica: indications of flow (in)stability? |
publisher |
International Glaciological Society |
publishDate |
2009 |
url |
http://nora.nerc.ac.uk/id/eprint/11379/ https://nora.nerc.ac.uk/id/eprint/11379/1/s8.pdf http://www.igsoc.org/annals/V50/51/a51a100.pdf |
long_lat |
ENVELOPE(-94.000,-94.000,-80.500,-80.500) ENVELOPE(-85.300,-85.300,-78.600,-78.600) ENVELOPE(-80.000,-80.000,-79.167,-79.167) |
geographic |
Antarctic Ellsworth Subglacial Highlands Rutford Rutford Ice Stream West Antarctica |
geographic_facet |
Antarctic Ellsworth Subglacial Highlands Rutford Rutford Ice Stream West Antarctica |
genre |
Annals of Glaciology Antarc* Antarctic Antarctica Rutford Ice Stream West Antarctica |
genre_facet |
Annals of Glaciology Antarc* Antarctic Antarctica Rutford Ice Stream West Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/11379/1/s8.pdf Woodward, John; King, Edward C. orcid:0000-0003-3793-3915 . 2009 Radar surveys of the Rutford Ice Stream onset zone, West Antarctica: indications of flow (in)stability? Annals of Glaciology, 50 (51). 57-62. https://doi.org/10.3189/172756409789097469 <https://doi.org/10.3189/172756409789097469> |
container_title |
Annals of Glaciology |
container_volume |
50 |
container_issue |
51 |
container_start_page |
57 |
op_container_end_page |
62 |
_version_ |
1766002345548709888 |