Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams
<p>Ice streams are corridors of fast-flowing ice that control mass transfers from continental ice sheets to oceans. Their flow speeds are known to accelerate and decelerate, their activity can switch on and off, and even their locations can shift entirely. Our analogue physical experiments...
Main Authors: | , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2018-08-01
|
Series: | The Cryosphere |
Online Access: | https://www.the-cryosphere.net/12/2759/2018/tc-12-2759-2018.pdf |
_version_ | 1818913137581096960 |
---|---|
author | T. Lelandais É. Ravier S. Pochat O. Bourgeois C. Clark R. Mourgues P. Strzerzynski |
author_facet | T. Lelandais É. Ravier S. Pochat O. Bourgeois C. Clark R. Mourgues P. Strzerzynski |
author_sort | T. Lelandais |
collection | DOAJ |
description | <p>Ice streams are corridors of fast-flowing ice that control mass transfers
from continental ice sheets to oceans. Their flow speeds are known to
accelerate and decelerate, their activity can switch on and off, and even
their locations can shift entirely. Our analogue physical experiments reveal
that a life cycle incorporating evolving subglacial meltwater routing and bed
erosion can govern this complex transitory behaviour. The modelled ice
streams switch on and accelerate when subglacial water pockets drain as
marginal outburst floods (basal decoupling). Then they decelerate when the
lubricating water drainage system spontaneously organizes itself into
channels that create tunnel valleys (partial basal recoupling). The ice
streams surge or jump in location when these water drainage systems maintain
low discharge but they ultimately switch off when tunnel valleys have
expanded to develop efficient drainage systems. Beyond reconciling
previously disconnected observations of modern and ancient ice streams into
a single life cycle, the modelling suggests that tunnel valley development
may be crucial in stabilizing portions of ice sheets during periods of
climate change.</p> |
first_indexed | 2024-12-19T23:25:43Z |
format | Article |
id | doaj.art-80cce5937f1347daaeef3c111235782a |
institution | Directory Open Access Journal |
issn | 1994-0416 1994-0424 |
language | English |
last_indexed | 2024-12-19T23:25:43Z |
publishDate | 2018-08-01 |
publisher | Copernicus Publications |
record_format | Article |
series | The Cryosphere |
spelling | doaj.art-80cce5937f1347daaeef3c111235782a2022-12-21T20:01:52ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242018-08-01122759277210.5194/tc-12-2759-2018Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streamsT. Lelandais0É. Ravier1S. Pochat2O. Bourgeois3C. Clark4R. Mourgues5P. Strzerzynski6Laboratoire de Planétologie et Géodynamique, UMR 6112, CNRS, Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans CEDEX 9, FranceLaboratoire de Planétologie et Géodynamique, UMR 6112, CNRS, Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans CEDEX 9, FranceLaboratoire de Planétologie et Géodynamique, UMR 6112, CNRS, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322 Nantes CEDEX 3, FranceLaboratoire de Planétologie et Géodynamique, UMR 6112, CNRS, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322 Nantes CEDEX 3, FranceDepartment of Geography, University of Sheffield, Sheffield, UKLaboratoire de Planétologie et Géodynamique, UMR 6112, CNRS, Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans CEDEX 9, FranceLaboratoire de Planétologie et Géodynamique, UMR 6112, CNRS, Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans CEDEX 9, France<p>Ice streams are corridors of fast-flowing ice that control mass transfers from continental ice sheets to oceans. Their flow speeds are known to accelerate and decelerate, their activity can switch on and off, and even their locations can shift entirely. Our analogue physical experiments reveal that a life cycle incorporating evolving subglacial meltwater routing and bed erosion can govern this complex transitory behaviour. The modelled ice streams switch on and accelerate when subglacial water pockets drain as marginal outburst floods (basal decoupling). Then they decelerate when the lubricating water drainage system spontaneously organizes itself into channels that create tunnel valleys (partial basal recoupling). The ice streams surge or jump in location when these water drainage systems maintain low discharge but they ultimately switch off when tunnel valleys have expanded to develop efficient drainage systems. Beyond reconciling previously disconnected observations of modern and ancient ice streams into a single life cycle, the modelling suggests that tunnel valley development may be crucial in stabilizing portions of ice sheets during periods of climate change.</p>https://www.the-cryosphere.net/12/2759/2018/tc-12-2759-2018.pdf |
spellingShingle | T. Lelandais É. Ravier S. Pochat O. Bourgeois C. Clark R. Mourgues P. Strzerzynski Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams The Cryosphere |
title | Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams |
title_full | Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams |
title_fullStr | Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams |
title_full_unstemmed | Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams |
title_short | Modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams |
title_sort | modelled subglacial floods and tunnel valleys control the life cycle of transitory ice streams |
url | https://www.the-cryosphere.net/12/2759/2018/tc-12-2759-2018.pdf |
work_keys_str_mv | AT tlelandais modelledsubglacialfloodsandtunnelvalleyscontrolthelifecycleoftransitoryicestreams AT eravier modelledsubglacialfloodsandtunnelvalleyscontrolthelifecycleoftransitoryicestreams AT spochat modelledsubglacialfloodsandtunnelvalleyscontrolthelifecycleoftransitoryicestreams AT obourgeois modelledsubglacialfloodsandtunnelvalleyscontrolthelifecycleoftransitoryicestreams AT cclark modelledsubglacialfloodsandtunnelvalleyscontrolthelifecycleoftransitoryicestreams AT rmourgues modelledsubglacialfloodsandtunnelvalleyscontrolthelifecycleoftransitoryicestreams AT pstrzerzynski modelledsubglacialfloodsandtunnelvalleyscontrolthelifecycleoftransitoryicestreams |