Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica
Interferometric radar images collected by ERS-1, ERS-2 and RADARSAT-1 are used to observe the rupture tip of rifts that propagate along Hemmen Ice Rise on the Ronne Ice Shelf, Antarctica. Interferograms generated in 1992 and 1997 allow for the observation of ice deformation accumulated over 9 and 24...
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ftcdlib:qt70k0t7zg 2023-05-15T14:04:14+02:00 Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica Larour, E Rignot, E Aubry, D 329 - 340 2004-12-01 application/pdf http://www.escholarship.org/uc/item/70k0t7zg english eng eScholarship, University of California qt70k0t7zg http://www.escholarship.org/uc/item/70k0t7zg Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ CC-BY Larour, E; Rignot, E; & Aubry, D. (2004). Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica. Journal of Glaciology, 50(170), 329 - 340. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/70k0t7zg article 2004 ftcdlib 2018-07-06T22:51:35Z Interferometric radar images collected by ERS-1, ERS-2 and RADARSAT-1 are used to observe the rupture tip of rifts that propagate along Hemmen Ice Rise on the Ronne Ice Shelf, Antarctica. Interferograms generated in 1992 and 1997 allow for the observation of ice deformation accumulated over 9 and 24 days respectively. These interferograms are combined, in order to separate the continuous process of creep deformation from the more cyclic motion caused by variations in ocean tide. An examination of local gradients in creep deformation reveals the pattern of ice deformation around and near the rupture tips and rifts with great precision (up to 10 cm a-1). We compare the observations with a deformation model for ice and obtain the following results: (1) The tidal oscillation of the Ronne Ice Shelf only yields small deformations along the rifts and near the rupture tips. (2) Along the ice front, the rifts and at the rupture tips, vertical bending is observed which is well explained by a model of viscous deformation of ice. Furthermore, the model indicates that the deformation pattern observed at the rupture tips is a sensitive indicator of the propagation state of the rifts (i.e. active vs inactive). (3) The viscous adjustment of ice is the dominant mode of deformation, masking the deformation pattern predicted by linear elastic fracture mechanics (LEFM). (4) Yet, at a spatial scale equivalent to the length of a rift, the propagation rate is well predicted by LEFM. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal Ice Shelf Journal of Glaciology Ronne Ice Shelf University of California: eScholarship Hemmen Ice Rise ENVELOPE(-49.767,-49.767,-77.950,-77.950) Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
description |
Interferometric radar images collected by ERS-1, ERS-2 and RADARSAT-1 are used to observe the rupture tip of rifts that propagate along Hemmen Ice Rise on the Ronne Ice Shelf, Antarctica. Interferograms generated in 1992 and 1997 allow for the observation of ice deformation accumulated over 9 and 24 days respectively. These interferograms are combined, in order to separate the continuous process of creep deformation from the more cyclic motion caused by variations in ocean tide. An examination of local gradients in creep deformation reveals the pattern of ice deformation around and near the rupture tips and rifts with great precision (up to 10 cm a-1). We compare the observations with a deformation model for ice and obtain the following results: (1) The tidal oscillation of the Ronne Ice Shelf only yields small deformations along the rifts and near the rupture tips. (2) Along the ice front, the rifts and at the rupture tips, vertical bending is observed which is well explained by a model of viscous deformation of ice. Furthermore, the model indicates that the deformation pattern observed at the rupture tips is a sensitive indicator of the propagation state of the rifts (i.e. active vs inactive). (3) The viscous adjustment of ice is the dominant mode of deformation, masking the deformation pattern predicted by linear elastic fracture mechanics (LEFM). (4) Yet, at a spatial scale equivalent to the length of a rift, the propagation rate is well predicted by LEFM. |
format |
Article in Journal/Newspaper |
author |
Larour, E Rignot, E Aubry, D |
spellingShingle |
Larour, E Rignot, E Aubry, D Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica |
author_facet |
Larour, E Rignot, E Aubry, D |
author_sort |
Larour, E |
title |
Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica |
title_short |
Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica |
title_full |
Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica |
title_fullStr |
Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica |
title_full_unstemmed |
Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica |
title_sort |
processes involved in the propagation of rifts near hemmen ice rise, ronne ice shelf, antarctica |
publisher |
eScholarship, University of California |
publishDate |
2004 |
url |
http://www.escholarship.org/uc/item/70k0t7zg |
op_coverage |
329 - 340 |
long_lat |
ENVELOPE(-49.767,-49.767,-77.950,-77.950) ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
geographic |
Hemmen Ice Rise Ronne Ice Shelf |
geographic_facet |
Hemmen Ice Rise Ronne Ice Shelf |
genre |
Antarc* Antarctica Antarctica Journal Ice Shelf Journal of Glaciology Ronne Ice Shelf |
genre_facet |
Antarc* Antarctica Antarctica Journal Ice Shelf Journal of Glaciology Ronne Ice Shelf |
op_source |
Larour, E; Rignot, E; & Aubry, D. (2004). Processes involved in the propagation of rifts near Hemmen Ice Rise, Ronne Ice Shelf, Antarctica. Journal of Glaciology, 50(170), 329 - 340. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/70k0t7zg |
op_relation |
qt70k0t7zg http://www.escholarship.org/uc/item/70k0t7zg |
op_rights |
Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
_version_ |
1766275265562935296 |