HR: 0800h
AN: C41B-0470    [Abstracts]
TI: Seasonal Acceleration of Inland ice via Along-Flow Coupling to Marginal ice
AU: * Price, S F
EM: S.F.Price@bristol.ac.uk
AF: Bristol Glaciology Centre, University of Bristol, Bristol, BS8 1SS, United Kingdom
AU: Payne, A J
EM: A.J.Payne@bristol.ac.uk
AF: Bristol Glaciology Centre, University of Bristol, Bristol, BS8 1SS, United Kingdom
AU: Catania, G A
EM: gcatania@utig.ig.utexas.edu
AF: Institute for Geophysics, University of Texas, Austin, TX 78758, United States
AU: Neumann, T A
EM: tneumann@uvm.edu
AF: Department of Geology, University of Vermont, Burlington, VT 05405, United States
AB: We use an ice flow model to demonstrate how flow variations initiated in the marginal zone of an ice sheet affect flow farther inland via along-flow coupling. Our findings allow for an alternate interpretation of seasonal accelerations observed near the equilibrium line of the Greenland ice sheet [Zwally et al., 2002]. We demonstrate that these observations can be explained by accelerations initiated up to 12 km closer to the margin where the ice is known (from field observations) to be 40 percent thinner, is heavily crevassed, experiences a seasonal doubling of velocity, and where the ablation rate, surface meltwater flux, and ice temperature are likely higher. Our modeling and observations suggest that conditions and processes normally found near ice sheet margins are adequate to explain the observations of Zwally et al. [2002]. In this case, we argue that seasonal acceleration may have a limited impact on ice-sheet mass balance even in the face of future climate warming.
DE: 0726 Ice sheets
DE: 0762 Mass balance (1218, 1223)
DE: 0774 Dynamics
DE: 0776 Glaciology (1621, 1827, 1863)
DE: 0798 Modeling
SC: Cryosphere [C]
MN: 2007 Fall Meeting