Velocities and flux of the Filchner Ice shelf and its tributaries determined from speckle tracking interferometry

• Published in: Canadian journal of remote sensing Vol. 27; no. 3; pp. 193 - 206
• Main Authors: GRAY, A. L, SHORT, N, MATTAR, K. E, JEZEK, K. C
• Format: Journal Article
• Language: English
• Published: Ottawa, ON Canadian Aeronautics and Space Institute 01.06.2001
• Subjects: Earth, ocean, space; Exact sciences and technology; External geophysics; Glaciers; Physics of the oceans; Remote sensing systems; Sea ice; Snow. Ice. Glaciers; Weddell Sea; Southern Ocean; Antarctica; PSW, Antarctica, Coats Land, Filchner Ice Shelf; Glacier; Satellite observation; Digital elevation model; Velocity distribution; Speckle interferometry; Floating ice; Ice stream; Sea ice
• ISSN: 0703-8992; 1712-7971
• DOI: 10.1080/07038992.2001.10854936

Velocities of the Filchner Ice Shelf and its tributary glaciers are derived using a variation of satellite radar interferometry known as speckle tracking. The method requires a coherent pair of SAR passes, a digital elevation model and, for floating ice, an estimate of the height difference due to the tide. Speckle tracking interferometry has the advantage that ice speed and direction can be estimated from one interferometric pair and, with adequate coherence, it is suitable for areas of high velocity and long repeat cycles. Fluxes are estimated using the ice velocities together with ice thickness data derived from a hydrostatic equilibrium model. They are given for gates downstream from the grounding lines of the input tributary glaciers, and for a gate close to the ice shelf edge. The calculations show that the flux close to the edge of the Filchner Ice Shelf ( similar to 75.3 km super(3)/a) is comparable to that estimated further upstream. However, the errors in the estimates ( similar to 10 km super(3)/a) preclude any firm conclusions concerning equilibrium of the ice shelf, or bottom surface melt or accretion. Assuming the upstream fluxes reflect the flow across the grounding lines, then the Recovery Glacier is the largest contributor to the ice shelf with 48% and the Slessor Glacier is the second largest with 33%. Support Force Glacier and Foundation Ice Stream both contribute similar to 7%. Ice Shelf accumulation accounts for the remaining 5%.