Rights statement: © 2014 American Geophysical Union
Final published version, 3.58 MB, PDF document
Available under license: CC BY: Creative Commons Attribution 4.0 International License
Final published version
Licence: CC BY: Creative Commons Attribution 4.0 International License
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Rapid dynamic activation of a marine-based Arctic ice cap
AU - McMillan, Malcolm
AU - Shepherd, Andrew
AU - Gourmelen, Noel
AU - Dehecq, Amaury
AU - Leeson, Amber
AU - Ridout, Andrew
AU - Flament, Thomas
AU - Hogg, Anna
AU - Gilbert, Lin
AU - Benham, Toby
AU - Van Den Broeke, Michiel
AU - Dowdeswell, Julian A.
AU - Fettweis, Xavier
AU - Noël, Brice
AU - Strozzi, Tazio
N1 - © 2016 American Geophysical Union
PY - 2015/1/27
Y1 - 2015/1/27
N2 - We use satellite observations to document rapid acceleration and ice loss from a formerly slow-flowing, marine-based sector of Austfonna, the largest ice cap in the Eurasian Arctic. During the past two decades, the sector ice discharge has increased 45-fold, the velocity regime has switched from predominantly slow (~ 101 m/yr) to fast (~ 103 m/yr) flow, and rates of ice thinning have exceeded 25 m/yr. At the time of widespread dynamic activation, parts of the terminus may have been near floatation. Subsequently, the imbalance has propagated 50 km inland to within 8 km of the ice cap summit. Our observations demonstrate the ability of slow-flowing ice to mobilize and quickly transmit the dynamic imbalance inland; a process that we show has initiated rapid ice loss to the ocean and redistribution of ice mass to locations more susceptible to melt, yet which remains poorly understood. Key Points Recent dynamic activation of a formerly slow-flowing marine Arctic ice capImbalance has spread 50 km inland to within 8 km of the ice cap summitIce discharge has increased 45-fold, and thinning rates have exceeded 25 m/yr
AB - We use satellite observations to document rapid acceleration and ice loss from a formerly slow-flowing, marine-based sector of Austfonna, the largest ice cap in the Eurasian Arctic. During the past two decades, the sector ice discharge has increased 45-fold, the velocity regime has switched from predominantly slow (~ 101 m/yr) to fast (~ 103 m/yr) flow, and rates of ice thinning have exceeded 25 m/yr. At the time of widespread dynamic activation, parts of the terminus may have been near floatation. Subsequently, the imbalance has propagated 50 km inland to within 8 km of the ice cap summit. Our observations demonstrate the ability of slow-flowing ice to mobilize and quickly transmit the dynamic imbalance inland; a process that we show has initiated rapid ice loss to the ocean and redistribution of ice mass to locations more susceptible to melt, yet which remains poorly understood. Key Points Recent dynamic activation of a formerly slow-flowing marine Arctic ice capImbalance has spread 50 km inland to within 8 km of the ice cap summitIce discharge has increased 45-fold, and thinning rates have exceeded 25 m/yr
KW - altimetry
KW - Austfonna
KW - dynamic instability
KW - ice cap
KW - InSAR
KW - mass balance
U2 - 10.1002/2014GL062255
DO - 10.1002/2014GL062255
M3 - Journal article
AN - SCOPUS:84921844855
VL - 41
SP - 8902
EP - 8909
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 24
ER -