4:15 PM - 4:30 PM
[ACC29-16] Investigation on candidate area for new deep ice coring at Dome Fuji, East Antarctica, and its future prospect
Keywords:ice core, ice sheet, Antarctica, radar
Outline of the surveys: The survey team departed Japan in late October, 2017. They arrived at Syowa Station, Antarctica in early November through air routes. From the Syowa Station, the team moved to the Dome Fuji region by tracked vehicles. After arrival at Dome Fuji in early December, the team investigated the ice sheet using radars mounted on the two tracked vehicles, during a total period of 24 days. Total distance for driving for the radar survey near Dome Fuji was about 2,990 km. A major spacing of the survey lines was 5 km. Total area covered by this survey was as large as 20,000 km2.
Main results and future prospect: We succeeded to detect a few major internal layers within the deepest ~500 m of the ice sheet in the vicinity of "New Dome Fuji" (hereinafter, NDF) area. In this NDF area, because of presence of the subglacial mountains, ice thickness is at most of locations as thin as 2,300 m or thinner. Dating these very deep internal layers is one of very important study subjects in the near future. Such deep layers tend to become unclear, folded or absent being away from the NDF area. In contrast, at locations where ice is thicker than ~2,800m, we verified that there was basically no detectable internal layers; the power of the radio echo from internal layers has a sharp drop at a depth ~500 m above the bed. Overall, we succeeded to obtain observational data to make detailed maps of bed elevation map and distribution map of the internal layers. In future, we will use such maps for modelling studies of the ice sheet in this region. In addition, analyzing the new data, we will narrow down candidate areas for future drilling. We plan to perform additional radar surveys in such narrower areas in the fiscal year 2018. We plan to collect further information and analyze it.