TY - JOUR

T1 - Recurring dynamically induced thinning during 1985-2010 on Upernavik Isstrøm, West Greenland

AU - Khan, Shfaqat Abbas

AU - Kjær, Kurt H.

AU - Korsgaard, Niels Jákup

AU - Wahr, John

AU - Joughin, Ian R.

AU - Timm, Lars H.

AU - Bamber, Jonathan L

AU - van den Broeke, Michiel R.

AU - Stearns, Leigh A.

AU - Hamilton, Gordon S.

AU - Csatho, Bea M.

AU - Nielsen, Karina

AU - Hurkmans, Ruud

AU - Babonis, Greg

PY - 2013/3

Y1 - 2013/3

N2 - Many glaciers along the southeast and northwest coasts of Greenland have accelerated, increasing the ice sheet’s contribution to global sea-level rise.Here, we map elevation changes on Upernavik Isstrøm (UI), West Greenland, during 2003-2009 using high-resolution Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data supplemented with altimeter surveys from NASA’s Airborne Topographic Mapper (ATM) during 2002-2010. To assess thinning prior to 2002, we analyze aerial photographs from 1985. We document at least two distinct periods of dynamically-induced ice loss during 1985-2010 characterized by a rapid retreat of the calving front, increased ice speed and lowering of the ice surface. The first period occurred prior to 1991, while the latter occurred during 2005-2009. Analyses of air and sea surface temperature suggest a combination of relatively warm air and ocean water as a potential trigger for the dynamically-induced ice loss. We estimate a total catchment-wide ice mass loss of UI caused by the two events of 72.3 +/- 15.8 Giga-ton during 1985-2010, while the total melt induced ice mass loss during this same period is 19.8 +/ 2.8 Gt. Thus, 79 % of the total ice mass loss of the UI catchment was caused by ice dynamics, indicating the importance of including dynamically-induced ice loss in the total mass change budget of the Greenland ice sheet.

AB - Many glaciers along the southeast and northwest coasts of Greenland have accelerated, increasing the ice sheet’s contribution to global sea-level rise.Here, we map elevation changes on Upernavik Isstrøm (UI), West Greenland, during 2003-2009 using high-resolution Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data supplemented with altimeter surveys from NASA’s Airborne Topographic Mapper (ATM) during 2002-2010. To assess thinning prior to 2002, we analyze aerial photographs from 1985. We document at least two distinct periods of dynamically-induced ice loss during 1985-2010 characterized by a rapid retreat of the calving front, increased ice speed and lowering of the ice surface. The first period occurred prior to 1991, while the latter occurred during 2005-2009. Analyses of air and sea surface temperature suggest a combination of relatively warm air and ocean water as a potential trigger for the dynamically-induced ice loss. We estimate a total catchment-wide ice mass loss of UI caused by the two events of 72.3 +/- 15.8 Giga-ton during 1985-2010, while the total melt induced ice mass loss during this same period is 19.8 +/ 2.8 Gt. Thus, 79 % of the total ice mass loss of the UI catchment was caused by ice dynamics, indicating the importance of including dynamically-induced ice loss in the total mass change budget of the Greenland ice sheet.

U2 - 10.1029/2012JF002481

DO - 10.1029/2012JF002481

M3 - Journal article

VL - 118

SP - 111

EP - 121

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

SN - 0148-0227

IS - 1

ER -