Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling

Nioghalvfjerdsfjorden glacier is a >60 km long and 20 km wide floating outlet glacier located at 79°30'N, 22° W, draining a large area of the northeast Greenland ice sheet. Climate, mass-balance and dynamics studies were carried out on the glacier in three field seasons in 1996, 1997 and 199...

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Main Authors: Reeh, N., Mayer, Christoph, Olesen, O. B., Christensen, E. L., Thomsen, H. H.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2000
Subjects:
Online Access:https://epic.awi.de/id/eprint/9752/
https://hdl.handle.net/10013/epic.20250
id ftawi:oai:epic.awi.de:9752
record_format openpolar
spelling ftawi:oai:epic.awi.de:9752 2023-09-05T13:12:04+02:00 Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling Reeh, N. Mayer, Christoph Olesen, O. B. Christensen, E. L. Thomsen, H. H. 2000 https://epic.awi.de/id/eprint/9752/ https://hdl.handle.net/10013/epic.20250 unknown Reeh, N. , Mayer, C. , Olesen, O. B. , Christensen, E. L. and Thomsen, H. H. (2000) Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling , Annals of Glaciology, 31 , pp. 111-117 . hdl:10013/epic.20250 EPIC3Annals of Glaciology, 31, pp. 111-117 Article isiRev 2000 ftawi 2023-08-22T19:48:15Z Nioghalvfjerdsfjorden glacier is a >60 km long and 20 km wide floating outlet glacier located at 79°30'N, 22° W, draining a large area of the northeast Greenland ice sheet. Climate, mass-balance and dynamics studies were carried out on the glacier in three field seasons in 1996, 1997 and 1998. As part of this work, tidal-movement observations were carried out by simultaneous differential global positioning system (GPS) measurements at several locations distributed on the glacier surface. The GPS observations were performed continously over several tidal cycles. At the same time, tiltmeter measurements were carried out in the grounding zones along the glaciers margins and upstream, where the glacier leaves the main ice sheet. A tide gauge installed in the sea immediately in front of the glacier front recorded the tide in the open sea during the field seasons. The observations show that the main part of the glacier tongue responds as a freely floating plate to the phase and amplitude of the local tide in the sea. However, kilometre-wide flexure zones exist along the marginal and upstream grounding lines. Attempts to model the observed tidal defectionand tilt patterns in the flexure zone by elastic-beam theory are unsuccessful, in contrast to previous findings by other investigators. The strongest disagreement between our measurements and results derived from elastic-beam theory is a significant variation of the phase of the tidal records with distance from the grounding line (most clearly displayed by the tilt records). We suggest that the viscous properties of glacier ice must be taken into account, and consequently that a viscoelastic-beam model must be used to adequately describe tidal bending of floating glaciers. Article in Journal/Newspaper Annals of Glaciology glacier Greenland Ice Sheet Nioghalvfjerdsfjorden Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Greenland Nioghalvfjerdsfjorden ENVELOPE(-21.500,-21.500,79.500,79.500)
institution Open Polar
collection Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
op_collection_id ftawi
language unknown
description Nioghalvfjerdsfjorden glacier is a >60 km long and 20 km wide floating outlet glacier located at 79°30'N, 22° W, draining a large area of the northeast Greenland ice sheet. Climate, mass-balance and dynamics studies were carried out on the glacier in three field seasons in 1996, 1997 and 1998. As part of this work, tidal-movement observations were carried out by simultaneous differential global positioning system (GPS) measurements at several locations distributed on the glacier surface. The GPS observations were performed continously over several tidal cycles. At the same time, tiltmeter measurements were carried out in the grounding zones along the glaciers margins and upstream, where the glacier leaves the main ice sheet. A tide gauge installed in the sea immediately in front of the glacier front recorded the tide in the open sea during the field seasons. The observations show that the main part of the glacier tongue responds as a freely floating plate to the phase and amplitude of the local tide in the sea. However, kilometre-wide flexure zones exist along the marginal and upstream grounding lines. Attempts to model the observed tidal defectionand tilt patterns in the flexure zone by elastic-beam theory are unsuccessful, in contrast to previous findings by other investigators. The strongest disagreement between our measurements and results derived from elastic-beam theory is a significant variation of the phase of the tidal records with distance from the grounding line (most clearly displayed by the tilt records). We suggest that the viscous properties of glacier ice must be taken into account, and consequently that a viscoelastic-beam model must be used to adequately describe tidal bending of floating glaciers.
format Article in Journal/Newspaper
author Reeh, N.
Mayer, Christoph
Olesen, O. B.
Christensen, E. L.
Thomsen, H. H.
spellingShingle Reeh, N.
Mayer, Christoph
Olesen, O. B.
Christensen, E. L.
Thomsen, H. H.
Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling
author_facet Reeh, N.
Mayer, Christoph
Olesen, O. B.
Christensen, E. L.
Thomsen, H. H.
author_sort Reeh, N.
title Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling
title_short Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling
title_full Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling
title_fullStr Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling
title_full_unstemmed Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling
title_sort tidal movement of nioghalvfjerdsfjorden glacier, northeast greenland: observations and modelling
publishDate 2000
url https://epic.awi.de/id/eprint/9752/
https://hdl.handle.net/10013/epic.20250
long_lat ENVELOPE(-21.500,-21.500,79.500,79.500)
geographic Greenland
Nioghalvfjerdsfjorden
geographic_facet Greenland
Nioghalvfjerdsfjorden
genre Annals of Glaciology
glacier
Greenland
Ice Sheet
Nioghalvfjerdsfjorden
genre_facet Annals of Glaciology
glacier
Greenland
Ice Sheet
Nioghalvfjerdsfjorden
op_source EPIC3Annals of Glaciology, 31, pp. 111-117
op_relation Reeh, N. , Mayer, C. , Olesen, O. B. , Christensen, E. L. and Thomsen, H. H. (2000) Tidal movement of Nioghalvfjerdsfjorden glacier, northeast Greenland: observations and modelling , Annals of Glaciology, 31 , pp. 111-117 . hdl:10013/epic.20250
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