Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland
Marine-terminating outlet glaciers of the Greenland ice sheet make significant contributions to global sea level rise, yet the conditions that facilitate their fast flow remain poorly constrained owing to a paucity of data. We drilled and instrumented seven boreholes on Store Glacier, Greenland, to...
Published in: | Journal of Geophysical Research: Earth Surface |
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Online Access: | https://epic.awi.de/id/eprint/46814/ https://epic.awi.de/id/eprint/46814/1/Doyle_et_al-2018-Journal_of_Geophysical_Research3A_Earth_Surface.pdf https://hdl.handle.net/10013/epic.1b69e6b7-67fd-4bc0-b27a-4f5a19a23744 https://hdl.handle.net/ |
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ftawi:oai:epic.awi.de:46814 2023-05-15T13:45:21+02:00 Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland Doyle, Samuel H. Hubbard, Bryn Christoffersen, Poul Young, Tun J. Hofstede, Coen Bougamont, Marion Box, Jason Hubbard, Alun 2018 application/pdf https://epic.awi.de/id/eprint/46814/ https://epic.awi.de/id/eprint/46814/1/Doyle_et_al-2018-Journal_of_Geophysical_Research3A_Earth_Surface.pdf https://hdl.handle.net/10013/epic.1b69e6b7-67fd-4bc0-b27a-4f5a19a23744 https://hdl.handle.net/ unknown Wiley https://epic.awi.de/id/eprint/46814/1/Doyle_et_al-2018-Journal_of_Geophysical_Research3A_Earth_Surface.pdf https://hdl.handle.net/ Doyle, S. H. , Hubbard, B. , Christoffersen, P. , Young, T. J. , Hofstede, C. orcid:0000-0002-6015-6918 , Bougamont, M. , Box, J. and Hubbard, A. (2018) Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland , Journal of Geophysical Research: Earth Surface, 123 , pp. 324-348 . doi:10.1002/2017JF004529 <https://doi.org/10.1002/2017JF004529> , hdl:10013/epic.1b69e6b7-67fd-4bc0-b27a-4f5a19a23744 EPIC3Journal of Geophysical Research: Earth Surface, Wiley, 123, pp. 324-348 Article isiRev 2018 ftawi https://doi.org/10.1002/2017JF004529 2021-12-24T15:43:44Z Marine-terminating outlet glaciers of the Greenland ice sheet make significant contributions to global sea level rise, yet the conditions that facilitate their fast flow remain poorly constrained owing to a paucity of data. We drilled and instrumented seven boreholes on Store Glacier, Greenland, to monitor subglacial water pressure, temperature, electrical conductivity and turbidity along with englacial ice temperature and deformation. These observations were supplemented by surface velocity and meteorological measurements to gain insight into the conditions and mechanisms of fast glacier flow. Located 30km from the calving front, each borehole drained rapidly on attaining ∼600m depth indicating a direct connection with an active subglacial hydrological system. Persistently high subglacial water pressures indicate low effective pressure (180 − 280 kPa), with small amplitude variations correlated with notable peaks in surface velocity driven by the diurnal melt cycle and longer periods of melt and rainfall. The englacial deformation profile determined from borehole tilt measurements indicates that 63-71% of total ice motion occurred at the bed, with the remaining 29-37% predominantly attributed to enhanced deformation in the lowermost 50-100 m of the ice column. We interpret this lowermost 100m to be formed of warmer, pre-Holocene ice overlying a thin (0 − 8 m) layer of temperate basal ice. Our observations are consistent with a spatially-extensive and persistently-inefficient subglacial drainage system that we hypothesize comprises drainage both at the ice-sediment interface and through subglacial sediments. This configuration has similarities to that interpreted beneath dynamically-analogous Antarctic ice streams, Alaskan tidewater glaciers, and glaciers in surge. Article in Journal/Newspaper Antarc* Antarctic glacier Greenland Ice Sheet Tidewater Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Greenland Journal of Geophysical Research: Earth Surface 123 2 324 348 |
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 |
Marine-terminating outlet glaciers of the Greenland ice sheet make significant contributions to global sea level rise, yet the conditions that facilitate their fast flow remain poorly constrained owing to a paucity of data. We drilled and instrumented seven boreholes on Store Glacier, Greenland, to monitor subglacial water pressure, temperature, electrical conductivity and turbidity along with englacial ice temperature and deformation. These observations were supplemented by surface velocity and meteorological measurements to gain insight into the conditions and mechanisms of fast glacier flow. Located 30km from the calving front, each borehole drained rapidly on attaining ∼600m depth indicating a direct connection with an active subglacial hydrological system. Persistently high subglacial water pressures indicate low effective pressure (180 − 280 kPa), with small amplitude variations correlated with notable peaks in surface velocity driven by the diurnal melt cycle and longer periods of melt and rainfall. The englacial deformation profile determined from borehole tilt measurements indicates that 63-71% of total ice motion occurred at the bed, with the remaining 29-37% predominantly attributed to enhanced deformation in the lowermost 50-100 m of the ice column. We interpret this lowermost 100m to be formed of warmer, pre-Holocene ice overlying a thin (0 − 8 m) layer of temperate basal ice. Our observations are consistent with a spatially-extensive and persistently-inefficient subglacial drainage system that we hypothesize comprises drainage both at the ice-sediment interface and through subglacial sediments. This configuration has similarities to that interpreted beneath dynamically-analogous Antarctic ice streams, Alaskan tidewater glaciers, and glaciers in surge. |
format |
Article in Journal/Newspaper |
author |
Doyle, Samuel H. Hubbard, Bryn Christoffersen, Poul Young, Tun J. Hofstede, Coen Bougamont, Marion Box, Jason Hubbard, Alun |
spellingShingle |
Doyle, Samuel H. Hubbard, Bryn Christoffersen, Poul Young, Tun J. Hofstede, Coen Bougamont, Marion Box, Jason Hubbard, Alun Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland |
author_facet |
Doyle, Samuel H. Hubbard, Bryn Christoffersen, Poul Young, Tun J. Hofstede, Coen Bougamont, Marion Box, Jason Hubbard, Alun |
author_sort |
Doyle, Samuel H. |
title |
Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland |
title_short |
Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland |
title_full |
Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland |
title_fullStr |
Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland |
title_full_unstemmed |
Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland |
title_sort |
physical conditions of fast glacier flow: 1. measurements from boreholes drilled to the bed of store glacier, west greenland |
publisher |
Wiley |
publishDate |
2018 |
url |
https://epic.awi.de/id/eprint/46814/ https://epic.awi.de/id/eprint/46814/1/Doyle_et_al-2018-Journal_of_Geophysical_Research3A_Earth_Surface.pdf https://hdl.handle.net/10013/epic.1b69e6b7-67fd-4bc0-b27a-4f5a19a23744 https://hdl.handle.net/ |
geographic |
Antarctic Greenland |
geographic_facet |
Antarctic Greenland |
genre |
Antarc* Antarctic glacier Greenland Ice Sheet Tidewater |
genre_facet |
Antarc* Antarctic glacier Greenland Ice Sheet Tidewater |
op_source |
EPIC3Journal of Geophysical Research: Earth Surface, Wiley, 123, pp. 324-348 |
op_relation |
https://epic.awi.de/id/eprint/46814/1/Doyle_et_al-2018-Journal_of_Geophysical_Research3A_Earth_Surface.pdf https://hdl.handle.net/ Doyle, S. H. , Hubbard, B. , Christoffersen, P. , Young, T. J. , Hofstede, C. orcid:0000-0002-6015-6918 , Bougamont, M. , Box, J. and Hubbard, A. (2018) Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland , Journal of Geophysical Research: Earth Surface, 123 , pp. 324-348 . doi:10.1002/2017JF004529 <https://doi.org/10.1002/2017JF004529> , hdl:10013/epic.1b69e6b7-67fd-4bc0-b27a-4f5a19a23744 |
op_doi |
https://doi.org/10.1002/2017JF004529 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
123 |
container_issue |
2 |
container_start_page |
324 |
op_container_end_page |
348 |
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1766221173872394240 |