A method of calculating ice-shelf surface velocity using ICESat altimetry

• Published in: Polar Record
• Main Authors: Marsh, O.J., Rack, W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2011
• Subjects: General Earth and Planetary Sciences; Ecology; Geography, Planning and Development; Ross Ice Shelf; Beardmore; Beardmore Glacier; Antarc*; Antarctica; Ice Shelf; Polar Record
• Online Access: http://dx.doi.org/10.1017/s0032247411000362; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0032247411000362

ABSTRACT Very high precision satellite altimeter measurements from the Geoscience Laser Altimeter System onboard NASA's Ice, Cloud and Land Elevation Satellite (ICESat) have allowed a method of feature tracking to be developed for floating ice which relies on recording the movement of large surface undulations. This method is applied to a section of the Ross Ice Shelf downstream of the grounding line of the Beardmore Glacier, Antarctica. The altimetry method has benefits over established optical and interferometric remote sensing techniques due to high pointing accuracy for geo-location, ability to deal with tidal fluctuations and to measure velocity where visible surface features are absent. Initial processing of a single sequence of ICESat tracks gives encouraging results for unidirectional ice flow with correlations between surface profiles in consecutive years exceeding 90% and producing high internal consistency in velocity between independent tracks. Velocities of 331 ± 28 m a −1 near to the grounding line are also consistent with available ground measurements for the area.