Helheim 2006: Integrated Geophysical Observations of Glacier Flow
During the summer field season, 2006, we undertook a pilot geophysical experiment at Helheim Glacier, East Greenland, in which we deployed a network of GPS instruments on and around the glacier to measure the ice deformation field as a function of time. The experiment was motivated by the discovery...
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ftdtupubl:oai:pure.atira.dk:publications/c0ff4779-f10e-4d97-be2a-5a79a8344255 2023-05-15T13:54:38+02:00 Helheim 2006: Integrated Geophysical Observations of Glacier Flow Nettles, M. Ahlstrøm, A. Elosegui, P. Hamilton, G. Kahn, S. Langer, M. Stearns, L. Stenseng, Lars Davis, J. Rkström, G. Forsberg, René Jørgensen, T. Larsen, T. 2006 application/pdf https://orbit.dtu.dk/en/publications/c0ff4779-f10e-4d97-be2a-5a79a8344255 https://backend.orbit.dtu.dk/ws/files/87943786/FM06-S44A-08.pdf http://abstractsearch.agu.org/meetings/2006/FM/sections/S/sessions/S44A/abstracts/S44A-08.html eng eng info:eu-repo/semantics/openAccess Nettles , M , Ahlstrøm , A , Elosegui , P , Hamilton , G , Kahn , S , Langer , M , Stearns , L , Stenseng , L , Davis , J , Rkström , G , Forsberg , R , Jørgensen , T & Larsen , T 2006 , ' Helheim 2006: Integrated Geophysical Observations of Glacier Flow ' , American Geophysical Union Fall Meeting 2006 , San Francisco,CA , United States , 01/01/2006 . < http://abstractsearch.agu.org/meetings/2006/FM/sections/S/sessions/S44A/abstracts/S44A-08.html > conferenceObject 2006 ftdtupubl 2022-08-14T08:17:41Z During the summer field season, 2006, we undertook a pilot geophysical experiment at Helheim Glacier, East Greenland, in which we deployed a network of GPS instruments on and around the glacier to measure the ice deformation field as a function of time. The experiment was motivated by the discovery of a new class of earthquakes occurring at glaciers in Alaska, Antarctica, and Greenland (Ekström, Nettles, and Abers, 2003). Teleseismic analysis indicates that these glacial earthquakes may result from the rapid sliding of the glacial ice over the glacier bed, and recent evidence (Ekström, Nettles, and Tsai, 2006) suggests a link to the hydrological cycle. However, little is understood about the mechanism by which the earthquakes occur. We installed sixteen GPS receivers on Helheim glacier, in a network spanning an upglacier distance of ~25~km from a point ~10~km behind the calving front. We also installed three GPS receivers at nearby rock sites to help define a stable reference frame. The stations were deployed in late June, 2006, and retrieved in late August, 2006. The GPS receivers recorded at a rate of at least 5~samples/sec. In addition, we operated several receivers for a few days each just behind the calving front during field visits in late June, late July, and late August, and we recorded the tidal stage using a pressure sensor near the end of Helheim Fjord for ~3~weeks during the experiment. Initial results show a variation in flow speed from about 25~m/day near the calving front to about 6~m/day at a location ~35~km behind the front. The horizontal flow speeds are tidally modulated, and an abrupt spatial change in vertical displacements due to the water tide gives the probable location of the glacier grounding line. We will present our geodetic results, and combine these results with seismological and glaciological observations to place constraints on the conditions under which glacial earthquakes are generated. Conference Object Antarc* Antarctica East Greenland glacier glacier glaciers Greenland Alaska Technical University of Denmark: DTU Orbit Greenland |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
description |
During the summer field season, 2006, we undertook a pilot geophysical experiment at Helheim Glacier, East Greenland, in which we deployed a network of GPS instruments on and around the glacier to measure the ice deformation field as a function of time. The experiment was motivated by the discovery of a new class of earthquakes occurring at glaciers in Alaska, Antarctica, and Greenland (Ekström, Nettles, and Abers, 2003). Teleseismic analysis indicates that these glacial earthquakes may result from the rapid sliding of the glacial ice over the glacier bed, and recent evidence (Ekström, Nettles, and Tsai, 2006) suggests a link to the hydrological cycle. However, little is understood about the mechanism by which the earthquakes occur. We installed sixteen GPS receivers on Helheim glacier, in a network spanning an upglacier distance of ~25~km from a point ~10~km behind the calving front. We also installed three GPS receivers at nearby rock sites to help define a stable reference frame. The stations were deployed in late June, 2006, and retrieved in late August, 2006. The GPS receivers recorded at a rate of at least 5~samples/sec. In addition, we operated several receivers for a few days each just behind the calving front during field visits in late June, late July, and late August, and we recorded the tidal stage using a pressure sensor near the end of Helheim Fjord for ~3~weeks during the experiment. Initial results show a variation in flow speed from about 25~m/day near the calving front to about 6~m/day at a location ~35~km behind the front. The horizontal flow speeds are tidally modulated, and an abrupt spatial change in vertical displacements due to the water tide gives the probable location of the glacier grounding line. We will present our geodetic results, and combine these results with seismological and glaciological observations to place constraints on the conditions under which glacial earthquakes are generated. |
format |
Conference Object |
author |
Nettles, M. Ahlstrøm, A. Elosegui, P. Hamilton, G. Kahn, S. Langer, M. Stearns, L. Stenseng, Lars Davis, J. Rkström, G. Forsberg, René Jørgensen, T. Larsen, T. |
spellingShingle |
Nettles, M. Ahlstrøm, A. Elosegui, P. Hamilton, G. Kahn, S. Langer, M. Stearns, L. Stenseng, Lars Davis, J. Rkström, G. Forsberg, René Jørgensen, T. Larsen, T. Helheim 2006: Integrated Geophysical Observations of Glacier Flow |
author_facet |
Nettles, M. Ahlstrøm, A. Elosegui, P. Hamilton, G. Kahn, S. Langer, M. Stearns, L. Stenseng, Lars Davis, J. Rkström, G. Forsberg, René Jørgensen, T. Larsen, T. |
author_sort |
Nettles, M. |
title |
Helheim 2006: Integrated Geophysical Observations of Glacier Flow |
title_short |
Helheim 2006: Integrated Geophysical Observations of Glacier Flow |
title_full |
Helheim 2006: Integrated Geophysical Observations of Glacier Flow |
title_fullStr |
Helheim 2006: Integrated Geophysical Observations of Glacier Flow |
title_full_unstemmed |
Helheim 2006: Integrated Geophysical Observations of Glacier Flow |
title_sort |
helheim 2006: integrated geophysical observations of glacier flow |
publishDate |
2006 |
url |
https://orbit.dtu.dk/en/publications/c0ff4779-f10e-4d97-be2a-5a79a8344255 https://backend.orbit.dtu.dk/ws/files/87943786/FM06-S44A-08.pdf http://abstractsearch.agu.org/meetings/2006/FM/sections/S/sessions/S44A/abstracts/S44A-08.html |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Antarc* Antarctica East Greenland glacier glacier glaciers Greenland Alaska |
genre_facet |
Antarc* Antarctica East Greenland glacier glacier glaciers Greenland Alaska |
op_source |
Nettles , M , Ahlstrøm , A , Elosegui , P , Hamilton , G , Kahn , S , Langer , M , Stearns , L , Stenseng , L , Davis , J , Rkström , G , Forsberg , R , Jørgensen , T & Larsen , T 2006 , ' Helheim 2006: Integrated Geophysical Observations of Glacier Flow ' , American Geophysical Union Fall Meeting 2006 , San Francisco,CA , United States , 01/01/2006 . < http://abstractsearch.agu.org/meetings/2006/FM/sections/S/sessions/S44A/abstracts/S44A-08.html > |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766260698059374592 |