Integrated geodetic, geophysic and remote sensing observations for the study of David Glacier Cauldron icefall and the floating Drygalski ice-tongue
Project The David Glacier is the largest outlet glacier in Northern Victoria Land, which collects a catchment area of
approximately 4% of the East Antarctic ice sheet (Rignot, 2002). The David Glacier basin extends to Dome C and
Talos Dome and produces a floating ice tongue about 140 km long from the grounding zone and a width of about 20 km, with 90 km of extension not confined into the Ross Sea. The David-Drygalski glacial system affects local ocean circulation and Polynya persistence within Terra Nova Bay. Since this area is the terminal part of a large basin it is important to monitor it, collecting quantitative data not yet available and necessary to interpret the flow velocity trend and the interaction between bedrock and ice (Danesi et al 2022, Lindzey et al 2021, Moon et al 2021). With this project it is proposed to set up 13 GNSS stations, located astride the David Cauldron icefall and along the Drygalski ice-tongue. Four of these stations will be installed in the same positions as the GPS points measured in 1992-2006 (Frezzotti et al 1998, Danesi et al 2008), to be able to highlight signs of changes in the flow velocity. Furthermore, the installation of 3 seismic stations in the surrounding area and an overall study is planned to use the Synthetic Aperture Radar (SAR) from satellite for the extension of the information collected punctually by the GNSS to the glacial body (Moon et al 2021, Lugli & Vittuari 2017). From this study it is expected to clarify the influence of the tidal forcing on ice movements (Vittuari et al 2020) and to measure eventual seasonal effects and non-periodic trend within the 3D positions time series. Furthermore, this study will better clarify the effect at the grounding line of possible massive injections of subglacial water from the David Cauldron icefall on the ice-stream dynamics and interaction with thermohaline circulation driven by latent polynya in the large cavity beneath the floating glacier (Frezzotti et al. 2000).