Tidal and spatial variability of flow speed and seismicity near the grounding zone of Beardmore Glacier, Antarctica
ABSTRACT GPS measurements of tidal modulation of ice flow and seismicity within the grounding zone of Beardmore Glacier show that tidally induced fluctuations of horizontal flow are largest near the grounding line and decrease downstream. Seismic activity is continuous, but peaks occur on falling an...
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crcambridgeupr:10.1017/aog.2019.14 2024-06-09T07:38:29+00:00 Tidal and spatial variability of flow speed and seismicity near the grounding zone of Beardmore Glacier, Antarctica Cooley, Jade Winberry, Paul Koutnik, Michelle Conway, Howard 2019 http://dx.doi.org/10.1017/aog.2019.14 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305519000144 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by-nc-nd/4.0/ Annals of Glaciology volume 60, issue 79, page 37-44 ISSN 0260-3055 1727-5644 journal-article 2019 crcambridgeupr https://doi.org/10.1017/aog.2019.14 2024-05-15T13:14:51Z ABSTRACT GPS measurements of tidal modulation of ice flow and seismicity within the grounding zone of Beardmore Glacier show that tidally induced fluctuations of horizontal flow are largest near the grounding line and decrease downstream. Seismic activity is continuous, but peaks occur on falling and rising tides. Beamforming methods reveal that most seismic events originate from two distinct locations, one on the grid-north side of the grounding zone, and one on the grid-south side. The broad pattern of deformation generated as Beardmore Glacier merges with the Ross Ice Shelf results in net extension along the grid-north side of the grounding zone and net compression along the grid-south side. During falling tides, seismic activity peaks on both sides because of increased vertical flexure across the grounding line. During rising tides, seismic activity in the region of extension on the grid-north side is relatively low because the tidal influence on both horizontal strain rate and vertical flexure is small. On the grid-south side during rising tides, however, tidally induced horizontal strain rates promote increased seismicity in regions of long-term compressional flow paths. Our study highlights how concurrent geodetic and seismic measurements provide insight into grounding-zone mechanics and their influence on ice-shelf buttressing. Article in Journal/Newspaper Annals of Glaciology Antarc* Antarctica Beardmore Glacier Ice Shelf Ross Ice Shelf Cambridge University Press Beardmore ENVELOPE(174.900,174.900,-83.350,-83.350) Beardmore Glacier ENVELOPE(170.000,170.000,-84.500,-84.500) Ross Ice Shelf Annals of Glaciology 60 79 37 44 |
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Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
ABSTRACT GPS measurements of tidal modulation of ice flow and seismicity within the grounding zone of Beardmore Glacier show that tidally induced fluctuations of horizontal flow are largest near the grounding line and decrease downstream. Seismic activity is continuous, but peaks occur on falling and rising tides. Beamforming methods reveal that most seismic events originate from two distinct locations, one on the grid-north side of the grounding zone, and one on the grid-south side. The broad pattern of deformation generated as Beardmore Glacier merges with the Ross Ice Shelf results in net extension along the grid-north side of the grounding zone and net compression along the grid-south side. During falling tides, seismic activity peaks on both sides because of increased vertical flexure across the grounding line. During rising tides, seismic activity in the region of extension on the grid-north side is relatively low because the tidal influence on both horizontal strain rate and vertical flexure is small. On the grid-south side during rising tides, however, tidally induced horizontal strain rates promote increased seismicity in regions of long-term compressional flow paths. Our study highlights how concurrent geodetic and seismic measurements provide insight into grounding-zone mechanics and their influence on ice-shelf buttressing. |
format |
Article in Journal/Newspaper |
author |
Cooley, Jade Winberry, Paul Koutnik, Michelle Conway, Howard |
spellingShingle |
Cooley, Jade Winberry, Paul Koutnik, Michelle Conway, Howard Tidal and spatial variability of flow speed and seismicity near the grounding zone of Beardmore Glacier, Antarctica |
author_facet |
Cooley, Jade Winberry, Paul Koutnik, Michelle Conway, Howard |
author_sort |
Cooley, Jade |
title |
Tidal and spatial variability of flow speed and seismicity near the grounding zone of Beardmore Glacier, Antarctica |
title_short |
Tidal and spatial variability of flow speed and seismicity near the grounding zone of Beardmore Glacier, Antarctica |
title_full |
Tidal and spatial variability of flow speed and seismicity near the grounding zone of Beardmore Glacier, Antarctica |
title_fullStr |
Tidal and spatial variability of flow speed and seismicity near the grounding zone of Beardmore Glacier, Antarctica |
title_full_unstemmed |
Tidal and spatial variability of flow speed and seismicity near the grounding zone of Beardmore Glacier, Antarctica |
title_sort |
tidal and spatial variability of flow speed and seismicity near the grounding zone of beardmore glacier, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
2019 |
url |
http://dx.doi.org/10.1017/aog.2019.14 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0260305519000144 |
long_lat |
ENVELOPE(174.900,174.900,-83.350,-83.350) ENVELOPE(170.000,170.000,-84.500,-84.500) |
geographic |
Beardmore Beardmore Glacier Ross Ice Shelf |
geographic_facet |
Beardmore Beardmore Glacier Ross Ice Shelf |
genre |
Annals of Glaciology Antarc* Antarctica Beardmore Glacier Ice Shelf Ross Ice Shelf |
genre_facet |
Annals of Glaciology Antarc* Antarctica Beardmore Glacier Ice Shelf Ross Ice Shelf |
op_source |
Annals of Glaciology volume 60, issue 79, page 37-44 ISSN 0260-3055 1727-5644 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.1017/aog.2019.14 |
container_title |
Annals of Glaciology |
container_volume |
60 |
container_issue |
79 |
container_start_page |
37 |
op_container_end_page |
44 |
_version_ |
1801373187227779072 |