Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica
Crary Ice Rise formed after the Ross Ice Shelf re-grounded ~1 kyr BP. We present new ice-penetrating radar data from two systems operating at center frequencies of 7 and 750 MHz that confirm the ice rise is composed of a former ice shelf buried by subsequent accumulation. Stacks of englacial diffrac...
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ftcwashingtonuni:oai:digitalcommons.cwu.edu:geological_sciences-1153 2023-05-15T13:47:32+02:00 Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica Hillebrand, Trevor R. Conway, Howard Koutnik, Michelle Martin, Carlos Paden, John Winberry, J. Paul 2021-03-05T08:00:00Z application/pdf https://digitalcommons.cwu.edu/geological_sciences/153 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1153&context=geological_sciences unknown ScholarWorks@CWU https://digitalcommons.cwu.edu/geological_sciences/153 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1153&context=geological_sciences © The Author(s), 2021. http://creativecommons.org/licenses/by/4.0/ CC-BY Geological Sciences Faculty Scholarship Antarctic glaciology crevasses ice rise ice shelves radio-echo sounding Glaciology text 2021 ftcwashingtonuni 2022-10-20T20:31:05Z Crary Ice Rise formed after the Ross Ice Shelf re-grounded ~1 kyr BP. We present new ice-penetrating radar data from two systems operating at center frequencies of 7 and 750 MHz that confirm the ice rise is composed of a former ice shelf buried by subsequent accumulation. Stacks of englacial diffraction hyperbolas are present almost everywhere across the central ice rise and extend up to ~350 m above the bed. In many cases, bed reflections beneath the diffraction hyperbolas are obscured for distances up to 1 km. Waveform modeling indicates that the diffraction hyperbolas are likely caused by marine ice deposits in former basal crevasses and rifts. The in-filling of rifts and basal crevasses may have strengthened the connection between the ice rise and the surrounding ice shelf, which could have influenced local and regional ice dynamics. Three internal reflection horizons mark the upper limit of disturbed ice and diffraction hyperbolas in different sections of the ice rise, indicating at least three stages of flow stabilization across the ice rise. A surface lineation visible in MODIS imagery corresponds spatially to deepening and strong deformation of these layers, consistent with the characteristics of former grounding lines observed elsewhere in Antarctica. Text Antarc* Antarctic Antarctica Ice Shelf Ice Shelves Ross Ice Shelf Central Washington University: ScholarWorks Antarctic Crary Ice Rise ENVELOPE(-172.500,-172.500,-82.933,-82.933) Ross Ice Shelf |
institution |
Open Polar |
collection |
Central Washington University: ScholarWorks |
op_collection_id |
ftcwashingtonuni |
language |
unknown |
topic |
Antarctic glaciology crevasses ice rise ice shelves radio-echo sounding Glaciology |
spellingShingle |
Antarctic glaciology crevasses ice rise ice shelves radio-echo sounding Glaciology Hillebrand, Trevor R. Conway, Howard Koutnik, Michelle Martin, Carlos Paden, John Winberry, J. Paul Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica |
topic_facet |
Antarctic glaciology crevasses ice rise ice shelves radio-echo sounding Glaciology |
description |
Crary Ice Rise formed after the Ross Ice Shelf re-grounded ~1 kyr BP. We present new ice-penetrating radar data from two systems operating at center frequencies of 7 and 750 MHz that confirm the ice rise is composed of a former ice shelf buried by subsequent accumulation. Stacks of englacial diffraction hyperbolas are present almost everywhere across the central ice rise and extend up to ~350 m above the bed. In many cases, bed reflections beneath the diffraction hyperbolas are obscured for distances up to 1 km. Waveform modeling indicates that the diffraction hyperbolas are likely caused by marine ice deposits in former basal crevasses and rifts. The in-filling of rifts and basal crevasses may have strengthened the connection between the ice rise and the surrounding ice shelf, which could have influenced local and regional ice dynamics. Three internal reflection horizons mark the upper limit of disturbed ice and diffraction hyperbolas in different sections of the ice rise, indicating at least three stages of flow stabilization across the ice rise. A surface lineation visible in MODIS imagery corresponds spatially to deepening and strong deformation of these layers, consistent with the characteristics of former grounding lines observed elsewhere in Antarctica. |
format |
Text |
author |
Hillebrand, Trevor R. Conway, Howard Koutnik, Michelle Martin, Carlos Paden, John Winberry, J. Paul |
author_facet |
Hillebrand, Trevor R. Conway, Howard Koutnik, Michelle Martin, Carlos Paden, John Winberry, J. Paul |
author_sort |
Hillebrand, Trevor R. |
title |
Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica |
title_short |
Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica |
title_full |
Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica |
title_fullStr |
Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica |
title_full_unstemmed |
Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica |
title_sort |
radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within crary ice rise, antarctica |
publisher |
ScholarWorks@CWU |
publishDate |
2021 |
url |
https://digitalcommons.cwu.edu/geological_sciences/153 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1153&context=geological_sciences |
long_lat |
ENVELOPE(-172.500,-172.500,-82.933,-82.933) |
geographic |
Antarctic Crary Ice Rise Ross Ice Shelf |
geographic_facet |
Antarctic Crary Ice Rise Ross Ice Shelf |
genre |
Antarc* Antarctic Antarctica Ice Shelf Ice Shelves Ross Ice Shelf |
genre_facet |
Antarc* Antarctic Antarctica Ice Shelf Ice Shelves Ross Ice Shelf |
op_source |
Geological Sciences Faculty Scholarship |
op_relation |
https://digitalcommons.cwu.edu/geological_sciences/153 https://digitalcommons.cwu.edu/cgi/viewcontent.cgi?article=1153&context=geological_sciences |
op_rights |
© The Author(s), 2021. http://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
_version_ |
1766247276864339968 |