| Abstract RADARSAT Interferometry for Antarctic Grounding Zone Mapping L. Gray N. Short B. Bindschadler I. Joughin L. Padman P. Vornberger A. Khananian Satellite Radar Interferometry (SRI) with RADARSAT has significantly improved our knowledge of ice motion in Antarctica and can also be used to map grounding zones. We use RADARSAT data from the 1997 Antarctic Mapping Mission to map the grounding zone in areas of the eastern Ross Ice Shelf and the Filchner Ice Shelf. The interferometric data show that the vertical displacement, between satellite passes, of the freely floating ice was consistent with tide model predictions. As most of the ice flexing occurs over a distance of 5 - 10 km from the grounding zone, the change in vertical position will lead to a relatively high phase fringe rate. The phase gradients in the along- and across-track directions, and images of coherence, have been used to estimate the position of the grounding zone. Results for the ‘ice plain’ area upstream of the Crary Ice Rise add to and improve the previous estimates based on field surveys and SPOT data. The results support the suggestion of increased ice grounding in this area, and show that a sub-ice shelf water channel around the southern end of the Crary Ice Rise is unlikely. Positional accuracy varies from ~1 - 2 km for those regions with a clear phase gradient to ~10 km in other areas where poor coherence and complicated phase variation make it more difficult to assign an accurate grounding zone position. Results for the Filchner Ice Shelf show that existing maps of the grounding zone can be refined. In particular, we have identified a large ice rise close to the mouth of the Bailey Ice Stream. |
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Gray for further information on this research. |