Airborne radar survey above Vostok region, east-central Antarctica: ice thickness and Lake Vostok geometry

Abstract

During the 1999^2000 Italian Expedition, an airborne radar survey was performed along12 transects across LakeVostok, Antarctica, and its western and eastern margins. Ice thickness, subglacial elevation and the precise location of lake boundaries were determined. Radar data confirm the geometry derived from previous surveys, but with some slight differences. We measured a length of up to 260 km, a maximum width of 81km and an area of roughly 14 000 km 2 . Along the major axis, from north to south, the ice thickness varies from 3800 to 4250 m, with a decreasing gradient. From west to east the ice thickness is fairly constant, except for two narrow strips located on the western and eastern margins, where it increases with high thickening rate. Over the lake the surface elevation increases from 3476 m a.s.l. (south) to 3525 (north), with a decreasing gradient, while the lake surface elevation decreases from^315 to^750 m a.s.l., with a decreasing gradient (absolute value). The icesurface and lake-ceiling slopes suggest that the lake is in a state of hydrostatic equilibrium.

Refined analysis of radar altimetry data applied to the region of the subglacial Lake Vostok/Antarctica

“…For this purpose, we use ICESat data as independent information. We show that our DEMs derived by the refined methods are significant improvements compared to previous satellite RA-based models and also to models derived from local airborne surveys (Studinger et al, 2002(Studinger et al, , 2003Tabacco & Bianchi, 2002).…”

A 60-year international history of Antarctic subglacial lake exploration

“…First, Italian geophysicists made the first airborne RES survey of Lake Vostok for twenty years (Tabacco et al, 2002). In the Austral summer of 1999-2000, 12 new RES transects were collected, including a continuous line along the 240 km axis of the lake, which confirmed the conclusion of Kapitsa et al (1996) of a large, continuous lake, with margins defined by the satellite-derived flat ice surface.…”

Glacio RADAR system and results

“…The aim was to define the morphological characteristics of the Aurora Trench and to improve the subglacial lakes exploration ( fig. 4 shows the Vostok lake radar signal) [10]. The radar data allowed to determine the ice thickness and the bedrock topography (the red line in fig.…”