Ice-dynamic conditions of Shirase Glacier, Antarctica, inferred from ERS SAR interferometry

• Published in: Journal of Glaciology
• Main Authors: Pattyn, Frank, De Rauw, Dominique
• Other Authors: Vrij Universiteit Brussels, CSL - Centre Spatial de Liège - ULiège
• Format: Article in Journal/Newspaper
• Language: English
• Published: Int Glaciol Soc 2002
• Subjects: Ice dynamics; SAR interferometry; Coherence tracking; Physical; chemical; mathematical & earth Sciences; Earth sciences & physical geography; Physique; chimie; mathématiques & sciences de la terre; Sciences de la terre & géographie physique; Antarc*; Antarctic; Antarctica; Ice Sheet; Journal of Glaciology; Shirase Glacier
• Online Access: https://orbi.uliege.be/handle/2268/143297; https://orbi.uliege.be/bitstream/2268/143297/1/Pattyn_Derauw2002_JGLAC.pdf; https://doi.org/10.3189/172756502781831115

peer reviewed The surface velocity field of Shirase Glacier, a fast-flowing East Antarctic outlet glacier, is determined from ERS synthetic aperture radar (SAR) images by means of speckle tracking using phase correlation, a technique which matches small image kernels of two complex SAR images by maximization of the local coherence. Velocity estimates are used to calculate surface strain rates, which are then used to calculate the large-scale, vertically integrated force balance and to determine the major stress components resisting the driving stress. For the whole glacier system, the driving stress is largely balanced by the basal drag, but with contributions from lateral drag up to 15% of the driving stress at the grounding line. Longitudinal stress gradients have only local importance to the balance of forces, limited to an area of a few square kilometers near the grounding line, where they resist the driving stress. In the grounded part of the glacier, >90% of the total ice velocity is due to basal sliding. Comparison with a balance-flux distribution of the Antarctic ice sheet suggests that the glacier in the downstream part of the Shirase drainage basin is close to equilibrium, showing a slight negative imbalance.