Geophysical Survey at Talos Dome (East Antarctica)

Abstract

Talos Dome is an ice dome on the edge of the East Antarctic plateau (Fig. l), about 290 km from the Southern Ocean and 250 km from the Ross Sea. It is adjacent to the Victoria Land mountains and overlies the eastern margin of the Wilkes Subglacial Basin. To the West, an ice saddle (2260 m) divides the Dome from an ice ridge coming from Dome C. Ice flows southeastward from this ridge into outlet glaciers (Priestley, Reeves and David Glaciers) which drain into the Ross Sea, and north-westward into the Rennick and Matusevich Glaciers which drain into the Southern Ocean. Another ice ridge trends northward from the Dome, passing behind the USARP Mountain. As part of the ITASE project, two traverse surveys were carried out in the Talos Dome area in November 1996 (Frezzotti et al., 1998) and January 2002 (Frezzotti et al., this volume). Airborne radar surveys were conducted in 1997, 1999 and 2001. Research aimed to better understand the latitudinal (North-South) and longitudinal (East-West) gradient along two East-West (Talos Dome - D66) and North-South (GV7 - Talos Dome - Taylor Dome) transepts, documenting climatic, atmospheric and surface conditions in the Talos Dome area and northern Victoria Land throughout the last 200-1000 years. The study of the Talos Dome area aimed to find the best location to extract an ice core down to the bedrock. Six shallow snow-firn cores (two during 1996 and four during 2001-02), up to 90 m deep, were drilled in the Talos Dome area. An eight century-long record of volcanic signal and climatic change was obtained at Talos Dome through geochemical analysis of the deepest core (TD, 90 m deep), drilled in 1996 (Becagli et al., 2003; Narcisi et al., 2001; Stenni et al., 2002). The core was dated through seasonal variations in nss SO4 raised to the power of 2- concentrations coupled with the recognition of tritium marker level (1965-66) and the nss SO4 raised to the power of 2- spikes attributed to the most important historical volcanic events (Pinatubo 1991, Agung 1963, Krakatoa 1883, Tambora 1815, Kuwae 1452, Unknown 1259).