Toward improved understanding of changes in Greenland outlet glacier shear margin dynamics in a warming climate

Derrick J. Lampkin, Byron Parizek, Eric Y. Larour, Hélène Seroussi, Casey Joseph, John P. Cavanagh

Research output: Contribution to journalArticle

Abstract

The Greenland Ice Sheet has experienced accelerated mass loss over the last couple decades, in part due to destabilization of marine-terminating outlet glaciers. Retreat and acceleration of outlet glaciers coincides with atmospheric and oceanic warming resulting in a significant contribution to sea-level rise. The relative role of surface meltwater production, runoff and infiltration on the dynamics of these systems is not well-understood. To assess how surface meltwater impacts shear margin dynamics and regional ice flow of outlet glaciers, we investigate the impact of basal lubrication of Jakobshavn Isbræ shear margins due to drainage from water-filled crevasses. We map the areal extent of inundated crevasses during summer (May–August) from 2000 to 2012 using satellite imagery and determined an increasing trend in the total areal extent over this time interval. We use a numerical ice flow model to quantify the potential impact of weakened shear margins due to surface melt derived basal lubrication on regional flow velocities. Ice flow velocities 10km from the lateral margins of Jakobshavn were amplified by as much as 20%, resulting in an increase of ∼0.6 Gt yr−1 in ice-mass discharge through the shearmargins into the ice stream. Under future warming scenarios with increased surface melt ponding, simulations indicate up to a 30% increase in extra-marginal ice flow. We conclude that surface meltwater will likely play an important role in the evolving dynamics of glacier shear margins and the future mass flux through Greenland’s major marine-terminating outlet glaciers.

Original languageEnglish (US)
Article number156
JournalFrontiers in Earth Science
Volume6
DOIs
StatePublished - Nov 13 2018

Fingerprint

ice flow
glacier
warming
meltwater
climate
crevasse
flow velocity
melt
ice stream
satellite imagery
ice sheet
infiltration
drainage
runoff
ice
summer
simulation
water

All Science Journal Classification (ASJC) codes

  • Earth and Planetary Sciences(all)

Cite this

Lampkin, Derrick J. ; Parizek, Byron ; Larour, Eric Y. ; Seroussi, Hélène ; Joseph, Casey ; Cavanagh, John P. / Toward improved understanding of changes in Greenland outlet glacier shear margin dynamics in a warming climate. In: Frontiers in Earth Science. 2018 ; Vol. 6.
@article{476038f6a5a343a89f14c2ba495880e5,
title = "Toward improved understanding of changes in Greenland outlet glacier shear margin dynamics in a warming climate",
abstract = "The Greenland Ice Sheet has experienced accelerated mass loss over the last couple decades, in part due to destabilization of marine-terminating outlet glaciers. Retreat and acceleration of outlet glaciers coincides with atmospheric and oceanic warming resulting in a significant contribution to sea-level rise. The relative role of surface meltwater production, runoff and infiltration on the dynamics of these systems is not well-understood. To assess how surface meltwater impacts shear margin dynamics and regional ice flow of outlet glaciers, we investigate the impact of basal lubrication of Jakobshavn Isbr{\ae} shear margins due to drainage from water-filled crevasses. We map the areal extent of inundated crevasses during summer (May–August) from 2000 to 2012 using satellite imagery and determined an increasing trend in the total areal extent over this time interval. We use a numerical ice flow model to quantify the potential impact of weakened shear margins due to surface melt derived basal lubrication on regional flow velocities. Ice flow velocities 10km from the lateral margins of Jakobshavn were amplified by as much as 20{\%}, resulting in an increase of ∼0.6 Gt yr−1 in ice-mass discharge through the shearmargins into the ice stream. Under future warming scenarios with increased surface melt ponding, simulations indicate up to a 30{\%} increase in extra-marginal ice flow. We conclude that surface meltwater will likely play an important role in the evolving dynamics of glacier shear margins and the future mass flux through Greenland’s major marine-terminating outlet glaciers.",
author = "Lampkin, {Derrick J.} and Byron Parizek and Larour, {Eric Y.} and H{\'e}l{\`e}ne Seroussi and Casey Joseph and Cavanagh, {John P.}",
year = "2018",
month = "11",
day = "13",
doi = "10.3389/feart.2018.00156",
language = "English (US)",
volume = "6",
journal = "Frontiers in Earth Science",
issn = "2296-6463",
publisher = "Frontiers Research Foundation",

}

Toward improved understanding of changes in Greenland outlet glacier shear margin dynamics in a warming climate. / Lampkin, Derrick J.; Parizek, Byron; Larour, Eric Y.; Seroussi, Hélène; Joseph, Casey; Cavanagh, John P.

In: Frontiers in Earth Science, Vol. 6, 156, 13.11.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Toward improved understanding of changes in Greenland outlet glacier shear margin dynamics in a warming climate

AU - Lampkin, Derrick J.

AU - Parizek, Byron

AU - Larour, Eric Y.

AU - Seroussi, Hélène

AU - Joseph, Casey

AU - Cavanagh, John P.

PY - 2018/11/13

Y1 - 2018/11/13

N2 - The Greenland Ice Sheet has experienced accelerated mass loss over the last couple decades, in part due to destabilization of marine-terminating outlet glaciers. Retreat and acceleration of outlet glaciers coincides with atmospheric and oceanic warming resulting in a significant contribution to sea-level rise. The relative role of surface meltwater production, runoff and infiltration on the dynamics of these systems is not well-understood. To assess how surface meltwater impacts shear margin dynamics and regional ice flow of outlet glaciers, we investigate the impact of basal lubrication of Jakobshavn Isbræ shear margins due to drainage from water-filled crevasses. We map the areal extent of inundated crevasses during summer (May–August) from 2000 to 2012 using satellite imagery and determined an increasing trend in the total areal extent over this time interval. We use a numerical ice flow model to quantify the potential impact of weakened shear margins due to surface melt derived basal lubrication on regional flow velocities. Ice flow velocities 10km from the lateral margins of Jakobshavn were amplified by as much as 20%, resulting in an increase of ∼0.6 Gt yr−1 in ice-mass discharge through the shearmargins into the ice stream. Under future warming scenarios with increased surface melt ponding, simulations indicate up to a 30% increase in extra-marginal ice flow. We conclude that surface meltwater will likely play an important role in the evolving dynamics of glacier shear margins and the future mass flux through Greenland’s major marine-terminating outlet glaciers.

AB - The Greenland Ice Sheet has experienced accelerated mass loss over the last couple decades, in part due to destabilization of marine-terminating outlet glaciers. Retreat and acceleration of outlet glaciers coincides with atmospheric and oceanic warming resulting in a significant contribution to sea-level rise. The relative role of surface meltwater production, runoff and infiltration on the dynamics of these systems is not well-understood. To assess how surface meltwater impacts shear margin dynamics and regional ice flow of outlet glaciers, we investigate the impact of basal lubrication of Jakobshavn Isbræ shear margins due to drainage from water-filled crevasses. We map the areal extent of inundated crevasses during summer (May–August) from 2000 to 2012 using satellite imagery and determined an increasing trend in the total areal extent over this time interval. We use a numerical ice flow model to quantify the potential impact of weakened shear margins due to surface melt derived basal lubrication on regional flow velocities. Ice flow velocities 10km from the lateral margins of Jakobshavn were amplified by as much as 20%, resulting in an increase of ∼0.6 Gt yr−1 in ice-mass discharge through the shearmargins into the ice stream. Under future warming scenarios with increased surface melt ponding, simulations indicate up to a 30% increase in extra-marginal ice flow. We conclude that surface meltwater will likely play an important role in the evolving dynamics of glacier shear margins and the future mass flux through Greenland’s major marine-terminating outlet glaciers.

UR - http://www.scopus.com/inward/record.url?scp=85057082720&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85057082720&partnerID=8YFLogxK

U2 - 10.3389/feart.2018.00156

DO - 10.3389/feart.2018.00156

M3 - Article

AN - SCOPUS:85057082720

VL - 6

JO - Frontiers in Earth Science

JF - Frontiers in Earth Science

SN - 2296-6463

M1 - 156

ER -