HR: 14:00h
AN: C43B-03 [Abstracts]
TI: Mass budgets of the Lambert, Mellor and Fisher glaciers and basal fluxes beneath their flowbands on Amery Ice Shelf
AU: * Wen, J
EM: wen.37@osu.edu
AF: Department of Geography, Shanghai Normal University, 100 Guilin Road, Shanghai, 200234 China
AU: * Wen, J
EM: wen.37@osu.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AU: Jezek, K C
EM: jezek@frosty.mps.ohio-state.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AU: Fricker, H A
EM: hafricker@ucsd.edu
AF: IGPP, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Dr, La
Jolla, CA 92093-0225 United States
AU: Csatho, B M
EM: Csatho.1@osu.edu
AF: Byrd Polar Research Center, The Ohio State University, 1090 Carmack Road, Columbus, OH 43210 United States
AU: Herzfeld, U C
EM: herzfeld@iceberg.colorado.edu
AF: CIRES/NSIDC, University of Colorado Boulder, 216 UCB, Boulder, CO 80309-0449 United States
AB:
We use RADARSAT InSAR velocity data, the RAMP image mosaic, OSU digital elevation model (DEM), GLAS laser altimeter data,
AIS-DEM (Fricker and others, 2000), ANTARCTIC ATLAS-DEM (Herzfeld, 2004), BEDMAP ice thickness, a new surface accumulation
data set (Giovinetto and Zwally (2000), modified by Giovinetto), and in situ measurements collected by ANARE and CHINARE to:
1) assess the mass budgets of the Lambert, Mellor and Fisher glaciers, upstream and downstream of the ANARE LGB traverse and
2) investigate melting and freezing beneath the Amery Ice Shelf (AIS) in the flowbands originating from those glaciers.
The total accumulation over the grounded part of the Lambert, Mellor and Fisher glaciers is 55.0±1.6 Gt ice a-1. The total ice flux into the AIS across the southern grounding line from these glaciers is 58.8±4.7 Gt ice a-1. Thus the grounded system as a whole could be in a slight negative budget. However, there are distinct mass budget differences for the higher and lower elevation parts of the grounded ice, and the three glaciers. The whole upstream region has a positive
imbalance of 6.4±3.1 Gt ice a-1, or 15.2±7.2% compared to its total accumulation, and the whole downstream
region has a significant negative imbalance of -10.3±7.1 Gt ice
a-1, or -21.2±14.6%. The mass budgets of the grounded Fisher, Mellor and Lambert glaciers are -1.0±0.9,
1.7±2.6, -4.5±2.9 Gt ice a-1, or -14.7±12.2
%, 7.0±10.4%, -19.4±12.6%, thus Fisher and Lambert glaciers are possibly in negative mass balance, whereas the
Mellor is in slight positive mass balance.
Beneath the AIS of the three flowbands, the mean melting rate is -23.2±4.6 m ice a-1 near the southern grounding
line (~530 km from the ice front), which decreases rapidly downstream, and transitions to refreezing at around 250 km
from the ice front. Mean freezing rates of the flowbands are around 0.5±0.2 to 1.5±0.4 m ice a-1. The total
basal melting is -50.4±5.0 Gt ice a-1 (which includes part of the refrozen marine ice). The total marine ice
accreted is 7.2±1.0 Gt ice a-1. The total loss of the ice from the interior of the three glaciers by basal melting
under the ice shelf is 80±5%.
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
SC: Cryosphere [C]
MN: 2005 Joint Assembly