Diurnal fluctuations in glacier ice deformation

Haut Glacier d'Arolla, Switzerland

Douglas Mair, Bryn Hubbard, Peter Nienow, Ian Willis, Urs H. Fischer

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Measurements of surface velocity, ice deformation (at 42 and 89% ice depth) and proglacial stream discharge were made at Haut Glacier d'Arolla, Switzerland, to determine diurnal patterns of variation in each. Data are analysed in order to understand better the relationship between hydraulically induced basal motion and glacier ice deformation over short timescales. The data suggest that hydraulically induced localized basal 'slippery' spots are created over diurnal cycles, causing enhanced basal motion and spatially variable glacier speed-up. Our data indicate that daily glacier speed-up is associated with reduced internal deformation over areas previously identified as slippery spots and increased deformation in areas located adjacent to or down-glacier from slippery spots. We interpret this pattern in terms of a transfer of mechanical support for basal shear stress away from slippery spots to adjacent sticky areas, where the resulting stronger ice-bed coupling causes increased ice deformation near the bed. These patterns indicate that basal ice is subjected to stress regimes that are variable at a high spatial and temporal resolution. Such variations may be central to the creation of anomalous vertical velocity profiles measured above and downglacier of basal slippery zones, which have shown evidence for 'plug flow' and extrusion flow over annual timescales. Copyright (C) 2007 John Wiley & Sons, Ltd.

Original languageEnglish
Pages (from-to)1272-1284
Number of pages13
JournalEarth Surface Processes and Landforms
Volume33
Issue number8
Early online date1 Oct 2007
DOIs
Publication statusPublished - Jul 2008

Keywords

  • glacier dynamics
  • hydrology
  • ice deformation
  • temperate valley glacier
  • basal motion
  • seasonal-variations
  • surface velocity
  • drainage system
  • borehole
  • patterns

Cite this

Diurnal fluctuations in glacier ice deformation : Haut Glacier d'Arolla, Switzerland. / Mair, Douglas; Hubbard, Bryn; Nienow, Peter; Willis, Ian; Fischer, Urs H.

In: Earth Surface Processes and Landforms, Vol. 33, No. 8, 07.2008, p. 1272-1284.

Research output: Contribution to journalArticle

Mair, Douglas ; Hubbard, Bryn ; Nienow, Peter ; Willis, Ian ; Fischer, Urs H. / Diurnal fluctuations in glacier ice deformation : Haut Glacier d'Arolla, Switzerland. In: Earth Surface Processes and Landforms. 2008 ; Vol. 33, No. 8. pp. 1272-1284.
@article{153dd58dbd6f46b3b7b3807098c9e093,
title = "Diurnal fluctuations in glacier ice deformation: Haut Glacier d'Arolla, Switzerland",
abstract = "Measurements of surface velocity, ice deformation (at 42 and 89{\%} ice depth) and proglacial stream discharge were made at Haut Glacier d'Arolla, Switzerland, to determine diurnal patterns of variation in each. Data are analysed in order to understand better the relationship between hydraulically induced basal motion and glacier ice deformation over short timescales. The data suggest that hydraulically induced localized basal 'slippery' spots are created over diurnal cycles, causing enhanced basal motion and spatially variable glacier speed-up. Our data indicate that daily glacier speed-up is associated with reduced internal deformation over areas previously identified as slippery spots and increased deformation in areas located adjacent to or down-glacier from slippery spots. We interpret this pattern in terms of a transfer of mechanical support for basal shear stress away from slippery spots to adjacent sticky areas, where the resulting stronger ice-bed coupling causes increased ice deformation near the bed. These patterns indicate that basal ice is subjected to stress regimes that are variable at a high spatial and temporal resolution. Such variations may be central to the creation of anomalous vertical velocity profiles measured above and downglacier of basal slippery zones, which have shown evidence for 'plug flow' and extrusion flow over annual timescales. Copyright (C) 2007 John Wiley & Sons, Ltd.",
keywords = "glacier dynamics, hydrology, ice deformation, temperate valley glacier, basal motion, seasonal-variations, surface velocity, drainage system, borehole, patterns",
author = "Douglas Mair and Bryn Hubbard and Peter Nienow and Ian Willis and Fischer, {Urs H.}",
year = "2008",
month = "7",
doi = "10.1002/esp.1612",
language = "English",
volume = "33",
pages = "1272--1284",
journal = "Earth Surface Processes and Landforms",
issn = "0197-9337",
publisher = "John Wiley and Sons Ltd",
number = "8",

}

TY - JOUR

T1 - Diurnal fluctuations in glacier ice deformation

T2 - Haut Glacier d'Arolla, Switzerland

AU - Mair, Douglas

AU - Hubbard, Bryn

AU - Nienow, Peter

AU - Willis, Ian

AU - Fischer, Urs H.

PY - 2008/7

Y1 - 2008/7

N2 - Measurements of surface velocity, ice deformation (at 42 and 89% ice depth) and proglacial stream discharge were made at Haut Glacier d'Arolla, Switzerland, to determine diurnal patterns of variation in each. Data are analysed in order to understand better the relationship between hydraulically induced basal motion and glacier ice deformation over short timescales. The data suggest that hydraulically induced localized basal 'slippery' spots are created over diurnal cycles, causing enhanced basal motion and spatially variable glacier speed-up. Our data indicate that daily glacier speed-up is associated with reduced internal deformation over areas previously identified as slippery spots and increased deformation in areas located adjacent to or down-glacier from slippery spots. We interpret this pattern in terms of a transfer of mechanical support for basal shear stress away from slippery spots to adjacent sticky areas, where the resulting stronger ice-bed coupling causes increased ice deformation near the bed. These patterns indicate that basal ice is subjected to stress regimes that are variable at a high spatial and temporal resolution. Such variations may be central to the creation of anomalous vertical velocity profiles measured above and downglacier of basal slippery zones, which have shown evidence for 'plug flow' and extrusion flow over annual timescales. Copyright (C) 2007 John Wiley & Sons, Ltd.

AB - Measurements of surface velocity, ice deformation (at 42 and 89% ice depth) and proglacial stream discharge were made at Haut Glacier d'Arolla, Switzerland, to determine diurnal patterns of variation in each. Data are analysed in order to understand better the relationship between hydraulically induced basal motion and glacier ice deformation over short timescales. The data suggest that hydraulically induced localized basal 'slippery' spots are created over diurnal cycles, causing enhanced basal motion and spatially variable glacier speed-up. Our data indicate that daily glacier speed-up is associated with reduced internal deformation over areas previously identified as slippery spots and increased deformation in areas located adjacent to or down-glacier from slippery spots. We interpret this pattern in terms of a transfer of mechanical support for basal shear stress away from slippery spots to adjacent sticky areas, where the resulting stronger ice-bed coupling causes increased ice deformation near the bed. These patterns indicate that basal ice is subjected to stress regimes that are variable at a high spatial and temporal resolution. Such variations may be central to the creation of anomalous vertical velocity profiles measured above and downglacier of basal slippery zones, which have shown evidence for 'plug flow' and extrusion flow over annual timescales. Copyright (C) 2007 John Wiley & Sons, Ltd.

KW - glacier dynamics

KW - hydrology

KW - ice deformation

KW - temperate valley glacier

KW - basal motion

KW - seasonal-variations

KW - surface velocity

KW - drainage system

KW - borehole

KW - patterns

U2 - 10.1002/esp.1612

DO - 10.1002/esp.1612

M3 - Article

VL - 33

SP - 1272

EP - 1284

JO - Earth Surface Processes and Landforms

JF - Earth Surface Processes and Landforms

SN - 0197-9337

IS - 8

ER -