Seasonal variations in Greenland Ice Sheet motion

Inland extent and behaviour at higher elevations

I. D. Bartholomew, P. Nienow, A. Sole, D. Mair, T. Cowton, M. A. King, S. Palmer

Research output: Contribution to journalArticle

76 Citations (Scopus)
1 Downloads (Pure)

Abstract

We present global positioning system observations that capture the full inland extent of ice motion variations in 2009 along a transect in the west Greenland Ice sheet margin. In situ measurements of air temperature and surface ablation, and satellite monitoring of ice surface albedo and supraglacial lake drainage are used to investigate hydrological controls on ice velocity changes. We find a strong positive correlation between rates of annual ablation and changes in annual ice motion along the transect, with sites nearest the ice sheet margin experiencing greater annual variations in ice motion (15-18%) than those above 1000 m elevation (3-8%). Patterns in the timing and rate of meltwater delivery to the ice-bed interface provide key controls on the magnitude of hydrologically-forced velocity variations at each site. In the lower ablation zone, the overall contribution of variations in ice motion to annual flow rates is limited by evolution in the structure of the subglacial drainage system. At sites in the upper ablation zone, a shorter period of summer melting and delayed establishment of a hydraulic connection between the ice sheet surface and its bed limit the timeframe for velocity variations to occur. Our data suggest that land-terminating sections of the Greenland Ice Sheet will experience increased dynamic mass loss in a warmer climate, as the behaviour that we observe in the lower ablation zone propagates further inland. Findings from this study provide a conceptual framework to understand the impact of hydrologically-forced velocity variations on the future mass balance of land-terminating sections of the Greenland Ice Sheet. (C) 2011 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)271-278
Number of pages8
JournalEarth and Planetary Science Letters
Volume307
Issue number3-4
Early online date28 May 2011
DOIs
Publication statusPublished - 15 Jul 2011

Keywords

  • Greenland
  • GPS
  • ice dynamics
  • supraglacial lakes
  • subglacial hydrology
  • Haut Glacier Darolla
  • high-velocity event
  • subglacial drainage
  • melt season
  • acceleration
  • Switzerland
  • system
  • record
  • Albedo
  • uplift

Cite this

Bartholomew, I. D., Nienow, P., Sole, A., Mair, D., Cowton, T., King, M. A., & Palmer, S. (2011). Seasonal variations in Greenland Ice Sheet motion: Inland extent and behaviour at higher elevations. Earth and Planetary Science Letters, 307(3-4), 271-278. https://doi.org/10.1016/j.epsl.2011.04.014

Seasonal variations in Greenland Ice Sheet motion : Inland extent and behaviour at higher elevations. / Bartholomew, I. D.; Nienow, P.; Sole, A.; Mair, D.; Cowton, T.; King, M. A.; Palmer, S.

In: Earth and Planetary Science Letters, Vol. 307, No. 3-4, 15.07.2011, p. 271-278.

Research output: Contribution to journalArticle

Bartholomew, ID, Nienow, P, Sole, A, Mair, D, Cowton, T, King, MA & Palmer, S 2011, 'Seasonal variations in Greenland Ice Sheet motion: Inland extent and behaviour at higher elevations', Earth and Planetary Science Letters, vol. 307, no. 3-4, pp. 271-278. https://doi.org/10.1016/j.epsl.2011.04.014
Bartholomew, I. D. ; Nienow, P. ; Sole, A. ; Mair, D. ; Cowton, T. ; King, M. A. ; Palmer, S. / Seasonal variations in Greenland Ice Sheet motion : Inland extent and behaviour at higher elevations. In: Earth and Planetary Science Letters. 2011 ; Vol. 307, No. 3-4. pp. 271-278.
@article{9441d7ac52c340f896371e943a22dce8,
title = "Seasonal variations in Greenland Ice Sheet motion: Inland extent and behaviour at higher elevations",
abstract = "We present global positioning system observations that capture the full inland extent of ice motion variations in 2009 along a transect in the west Greenland Ice sheet margin. In situ measurements of air temperature and surface ablation, and satellite monitoring of ice surface albedo and supraglacial lake drainage are used to investigate hydrological controls on ice velocity changes. We find a strong positive correlation between rates of annual ablation and changes in annual ice motion along the transect, with sites nearest the ice sheet margin experiencing greater annual variations in ice motion (15-18{\%}) than those above 1000 m elevation (3-8{\%}). Patterns in the timing and rate of meltwater delivery to the ice-bed interface provide key controls on the magnitude of hydrologically-forced velocity variations at each site. In the lower ablation zone, the overall contribution of variations in ice motion to annual flow rates is limited by evolution in the structure of the subglacial drainage system. At sites in the upper ablation zone, a shorter period of summer melting and delayed establishment of a hydraulic connection between the ice sheet surface and its bed limit the timeframe for velocity variations to occur. Our data suggest that land-terminating sections of the Greenland Ice Sheet will experience increased dynamic mass loss in a warmer climate, as the behaviour that we observe in the lower ablation zone propagates further inland. Findings from this study provide a conceptual framework to understand the impact of hydrologically-forced velocity variations on the future mass balance of land-terminating sections of the Greenland Ice Sheet. (C) 2011 Elsevier B.V. All rights reserved.",
keywords = "Greenland, GPS, ice dynamics, supraglacial lakes, subglacial hydrology, Haut Glacier Darolla, high-velocity event, subglacial drainage, melt season, acceleration, Switzerland, system, record, Albedo, uplift",
author = "Bartholomew, {I. D.} and P. Nienow and A. Sole and D. Mair and T. Cowton and King, {M. A.} and S. Palmer",
year = "2011",
month = "7",
day = "15",
doi = "10.1016/j.epsl.2011.04.014",
language = "English",
volume = "307",
pages = "271--278",
journal = "Earth and Planetary Science Letters",
issn = "0012-821X",
publisher = "ELSEVIER SCIENCE BV",
number = "3-4",

}

TY - JOUR

T1 - Seasonal variations in Greenland Ice Sheet motion

T2 - Inland extent and behaviour at higher elevations

AU - Bartholomew, I. D.

AU - Nienow, P.

AU - Sole, A.

AU - Mair, D.

AU - Cowton, T.

AU - King, M. A.

AU - Palmer, S.

PY - 2011/7/15

Y1 - 2011/7/15

N2 - We present global positioning system observations that capture the full inland extent of ice motion variations in 2009 along a transect in the west Greenland Ice sheet margin. In situ measurements of air temperature and surface ablation, and satellite monitoring of ice surface albedo and supraglacial lake drainage are used to investigate hydrological controls on ice velocity changes. We find a strong positive correlation between rates of annual ablation and changes in annual ice motion along the transect, with sites nearest the ice sheet margin experiencing greater annual variations in ice motion (15-18%) than those above 1000 m elevation (3-8%). Patterns in the timing and rate of meltwater delivery to the ice-bed interface provide key controls on the magnitude of hydrologically-forced velocity variations at each site. In the lower ablation zone, the overall contribution of variations in ice motion to annual flow rates is limited by evolution in the structure of the subglacial drainage system. At sites in the upper ablation zone, a shorter period of summer melting and delayed establishment of a hydraulic connection between the ice sheet surface and its bed limit the timeframe for velocity variations to occur. Our data suggest that land-terminating sections of the Greenland Ice Sheet will experience increased dynamic mass loss in a warmer climate, as the behaviour that we observe in the lower ablation zone propagates further inland. Findings from this study provide a conceptual framework to understand the impact of hydrologically-forced velocity variations on the future mass balance of land-terminating sections of the Greenland Ice Sheet. (C) 2011 Elsevier B.V. All rights reserved.

AB - We present global positioning system observations that capture the full inland extent of ice motion variations in 2009 along a transect in the west Greenland Ice sheet margin. In situ measurements of air temperature and surface ablation, and satellite monitoring of ice surface albedo and supraglacial lake drainage are used to investigate hydrological controls on ice velocity changes. We find a strong positive correlation between rates of annual ablation and changes in annual ice motion along the transect, with sites nearest the ice sheet margin experiencing greater annual variations in ice motion (15-18%) than those above 1000 m elevation (3-8%). Patterns in the timing and rate of meltwater delivery to the ice-bed interface provide key controls on the magnitude of hydrologically-forced velocity variations at each site. In the lower ablation zone, the overall contribution of variations in ice motion to annual flow rates is limited by evolution in the structure of the subglacial drainage system. At sites in the upper ablation zone, a shorter period of summer melting and delayed establishment of a hydraulic connection between the ice sheet surface and its bed limit the timeframe for velocity variations to occur. Our data suggest that land-terminating sections of the Greenland Ice Sheet will experience increased dynamic mass loss in a warmer climate, as the behaviour that we observe in the lower ablation zone propagates further inland. Findings from this study provide a conceptual framework to understand the impact of hydrologically-forced velocity variations on the future mass balance of land-terminating sections of the Greenland Ice Sheet. (C) 2011 Elsevier B.V. All rights reserved.

KW - Greenland

KW - GPS

KW - ice dynamics

KW - supraglacial lakes

KW - subglacial hydrology

KW - Haut Glacier Darolla

KW - high-velocity event

KW - subglacial drainage

KW - melt season

KW - acceleration

KW - Switzerland

KW - system

KW - record

KW - Albedo

KW - uplift

U2 - 10.1016/j.epsl.2011.04.014

DO - 10.1016/j.epsl.2011.04.014

M3 - Article

VL - 307

SP - 271

EP - 278

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

SN - 0012-821X

IS - 3-4

ER -