Subglacial deformation at sub-freezing temperatures? Evidence from Hagafellsjökull-Eystri, Iceland

Matthew R. Bennett, Richard I. Waller, Nicholas G. Midgley, David Huddart, Silvia Gonzalez, Simon J. Cook, Alexandre Tomio

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

We report evidence of deformation at sub-freezing temperatures beneath Hagafellsjökull-Eystri, an Icelandic surge-type glacier. The bed of a piedmont lobe that advanced during the 1999 surge comprises deformed blocks of glacier ice set within frozen sediment. This material has also been injected through overlying ice to form a network of crevasse-squeeze ridges. This layer contains evidence for two phases of deformation under contrasting theological conditions: (1) deformation under relatively warm conditions, when the blocks of glacier ice acted as competent clasts within an unfrozen deforming matrix and (2) subsequent deformation at sub-freezing temperatures when the ice blocks were attenuated into the surrounding frozen matrix along fractures and planar shears enriched with excess ice. This suggests that the basal thermal regime of the advancing ice margin changed from warm-based to cold-based during the surge event. The persistence and potential prevalence of subglacial sediment deformation at sub-freezing temperatures has fundamental implications for our understanding of the dynamic behaviour, sediment flux and geomorphic ability of cold-based glaciers.

Original languageEnglish
Pages (from-to)915-923
Number of pages9
JournalQuaternary Science Reviews
Volume22
Issue number8-9
DOIs
Publication statusPublished - 2003

Fingerprint

Iceland
freezing point
freezing
ice
glaciers
glacier
evidence
persistence
temperature
sediments
event
sediment
ability
crevasse
matrix
ice margin
thermal regime
piedmont
clast
shear stress

Cite this

Bennett, Matthew R. ; Waller, Richard I. ; Midgley, Nicholas G. ; Huddart, David ; Gonzalez, Silvia ; Cook, Simon J. ; Tomio, Alexandre. / Subglacial deformation at sub-freezing temperatures? Evidence from Hagafellsjökull-Eystri, Iceland. In: Quaternary Science Reviews. 2003 ; Vol. 22, No. 8-9. pp. 915-923.
@article{649a8d3601664e8ea836cdd4d8f3997d,
title = "Subglacial deformation at sub-freezing temperatures? Evidence from Hagafellsj{\"o}kull-Eystri, Iceland",
abstract = "We report evidence of deformation at sub-freezing temperatures beneath Hagafellsj{\"o}kull-Eystri, an Icelandic surge-type glacier. The bed of a piedmont lobe that advanced during the 1999 surge comprises deformed blocks of glacier ice set within frozen sediment. This material has also been injected through overlying ice to form a network of crevasse-squeeze ridges. This layer contains evidence for two phases of deformation under contrasting theological conditions: (1) deformation under relatively warm conditions, when the blocks of glacier ice acted as competent clasts within an unfrozen deforming matrix and (2) subsequent deformation at sub-freezing temperatures when the ice blocks were attenuated into the surrounding frozen matrix along fractures and planar shears enriched with excess ice. This suggests that the basal thermal regime of the advancing ice margin changed from warm-based to cold-based during the surge event. The persistence and potential prevalence of subglacial sediment deformation at sub-freezing temperatures has fundamental implications for our understanding of the dynamic behaviour, sediment flux and geomorphic ability of cold-based glaciers.",
author = "Bennett, {Matthew R.} and Waller, {Richard I.} and Midgley, {Nicholas G.} and David Huddart and Silvia Gonzalez and Cook, {Simon J.} and Alexandre Tomio",
year = "2003",
doi = "10.1016/S0277-3791(03)00007-6",
language = "English",
volume = "22",
pages = "915--923",
journal = "Quaternary Science Reviews",
issn = "0277-3791",
publisher = "Elsevier",
number = "8-9",

}

Subglacial deformation at sub-freezing temperatures? Evidence from Hagafellsjökull-Eystri, Iceland. / Bennett, Matthew R.; Waller, Richard I.; Midgley, Nicholas G.; Huddart, David; Gonzalez, Silvia; Cook, Simon J.; Tomio, Alexandre.

In: Quaternary Science Reviews, Vol. 22, No. 8-9, 2003, p. 915-923.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Subglacial deformation at sub-freezing temperatures? Evidence from Hagafellsjökull-Eystri, Iceland

AU - Bennett, Matthew R.

AU - Waller, Richard I.

AU - Midgley, Nicholas G.

AU - Huddart, David

AU - Gonzalez, Silvia

AU - Cook, Simon J.

AU - Tomio, Alexandre

PY - 2003

Y1 - 2003

N2 - We report evidence of deformation at sub-freezing temperatures beneath Hagafellsjökull-Eystri, an Icelandic surge-type glacier. The bed of a piedmont lobe that advanced during the 1999 surge comprises deformed blocks of glacier ice set within frozen sediment. This material has also been injected through overlying ice to form a network of crevasse-squeeze ridges. This layer contains evidence for two phases of deformation under contrasting theological conditions: (1) deformation under relatively warm conditions, when the blocks of glacier ice acted as competent clasts within an unfrozen deforming matrix and (2) subsequent deformation at sub-freezing temperatures when the ice blocks were attenuated into the surrounding frozen matrix along fractures and planar shears enriched with excess ice. This suggests that the basal thermal regime of the advancing ice margin changed from warm-based to cold-based during the surge event. The persistence and potential prevalence of subglacial sediment deformation at sub-freezing temperatures has fundamental implications for our understanding of the dynamic behaviour, sediment flux and geomorphic ability of cold-based glaciers.

AB - We report evidence of deformation at sub-freezing temperatures beneath Hagafellsjökull-Eystri, an Icelandic surge-type glacier. The bed of a piedmont lobe that advanced during the 1999 surge comprises deformed blocks of glacier ice set within frozen sediment. This material has also been injected through overlying ice to form a network of crevasse-squeeze ridges. This layer contains evidence for two phases of deformation under contrasting theological conditions: (1) deformation under relatively warm conditions, when the blocks of glacier ice acted as competent clasts within an unfrozen deforming matrix and (2) subsequent deformation at sub-freezing temperatures when the ice blocks were attenuated into the surrounding frozen matrix along fractures and planar shears enriched with excess ice. This suggests that the basal thermal regime of the advancing ice margin changed from warm-based to cold-based during the surge event. The persistence and potential prevalence of subglacial sediment deformation at sub-freezing temperatures has fundamental implications for our understanding of the dynamic behaviour, sediment flux and geomorphic ability of cold-based glaciers.

UR - http://www.scopus.com/inward/record.url?scp=0038745437&partnerID=8YFLogxK

U2 - 10.1016/S0277-3791(03)00007-6

DO - 10.1016/S0277-3791(03)00007-6

M3 - Article

AN - SCOPUS:0038745437

VL - 22

SP - 915

EP - 923

JO - Quaternary Science Reviews

JF - Quaternary Science Reviews

SN - 0277-3791

IS - 8-9

ER -