An atlas of Antarctica north of 72.1degreesS from GEOSAT radar altimeter data

Abstract

Although the importance of Antarctica in the global system has long been recognized and discussed in the literature, data as basic as topographic maps of a resolution amenable to geophysical analysis are still lacking for large parts of the continent. Mapping, surveying, and monitoring of the large expanses in remote areas are facilitated by remote-sensing technology. The best source for topographic mapping is satellite altimetry. It is often argued that satellite radar altimeter data over ice cannot be used to map ice surfaces with a slope exceeding 0.65degree. In the work presented in this paper, we extend the limits of altimeter data evaluation using ( a ) geostatistical methods, and ( b ) an atlas approach to mapping all of Antarctica north of 72.1degreesS at 3-km resolution. Ordinary Kriging is applied to altimeter data from the GEOSAT Geodetic Mission, selected for its denser coverage as compared to the Exact Repeat Mission. The resultant maps yield a wealth of new information, in particular along the margin of the East Antarctic Ice Sheet including location and topography of drainage systems of small glaciers and location of some of the ice shelves. The atlas sheets Riiser-Larsen Peninsula, Prince Olav Coast, Mawson Coast West (Kemp Coast), Lambert Glacier, Ingrid Christensen Coast, Pennell Coast, Napier Mountains, Knox Coast, Sabrina Coast, and Antarctic Peninsula (Graham Land) are presented and analyzed. Repeated mapping facilitates the monitoring of changes in surface elevation may indicate dynamically and climatically induced mass changes of the East Antarctic Ice Sheet.