From 5 December 2019 to 25 January 2020, a team made up of French scientists from the CNRS, the Grenoble Alpes University and Italian scientists from the CNR and INGV will travel 1318 km round trip in the middle of the Antarctic plateau, on a traverse organized by the French Polar Institute (IPEV) with the collaboration of the National Antarctic Research Program (PNRA), starting from the Italian-French station Concordia towards the South Pole. The main objectives of the EAIIST (East Antarctic International Ice Sheet Traverse) expedition, are those of being able to estimate the increase in sea level through the study of climate archives. The expedition is financed on the French side by the Agence nationale de la recherche and by the Fondation BNP Paribas, on the Italian side by the PNRA, financed by the MIUR (Ministry of Education, University and Research) and coordinated by the CNR (National Research Council) for the activities scientific research, and by ENEA (National Agency for new technologies, energy and sustainable economic development) for the operational implementation of shipments.
On the subject of climate change, one of the greatest unknowns concerns the impact of global warming in Antarctica. An accelerated melting of the polar cap has already been detected by the scientific community, especially in coastal areas, but according to some models of atmospheric circulation, the warming could also be accompanied by more intense rainfall on the white continent. If this hypothesis were true, the mass loss of the ice sheet could be limited and also the phenomenon of sea level rise would be moderate
Some French, Italian and Australian scientists will try to verify the reliability of this hypothesis by checking whether the accumulation of snow on the Antarctic plateau has really increased. For this reason the EAIIST traverse will explore for a few weeks one of the driest, inhospitable and unexplored parts of the planet, essential for regulating the Earth's climate.
In the region that will be crossed, and which is located halfway between the Concordia station and the South Pole, the very low rainfall and the wind regime lead to the formation of unique structures on Earth called 'megadunes': surfaces with a glassy appearance where the ice is smooth and bare with large-scale undulations, invisible to the naked eye, but detectable by satellite. Understanding their formation and observing how they record the composition of the atmosphere is essential for interpreting the data from the ice cores that make up the climate archives. These regions have characteristics similar to those existing during the Ice Ages, when rainfall was very scarce compared to warmer periods.
To face this challenge, various skills have been put together: snow physics, geophysics, geochemistry, atmospheric chemistry, meteorology. At each stage, scientists will take snow samples and ice cores and create radar profiles to study the overlap of the various layers of snow. Automated instruments (weather stations, GPS stations and seismic stations) will also be installed, in order to obtain a record of the seasonal trend of ice and precipitation in the various sites visited. These ground measurements will then be correlated with satellite data and complemented by laboratory studies.
The EAIIST expedition represents a logistical challenge, being totally autonomous. The 243-tonne convoy will travel 50 km in 1318 days at a rate of 8 km/h in temperatures ranging from -25 to -45 °C. If the movement of the vehicles from the coast is also counted, the total kilometers traveled will be around 4000.
All this is made possible thanks to the help and experience of the IPEV and the PNRA with the support of the Australian Antarctic Division. Of the 10 people making up the crew, four, including a doctor, are logisticians.
The project director is Joël Savarino, a French researcher from the CNRS. the Institut des géosciences de l'environnement (CNRS/Université Grenoble-Alpes/IRD/Grenoble INP), for Italy the project manager is Barbara Stenni of the Ca' Foscari University of Venice and Andrea Spolaor (CNR -ISP) and Graziano Larocca (INGV). In addition to the scientists participating in the expedition, there will be around 40 researchers from around fifteen Italian, French and Australian laboratories who will work on the collected data.
The cost of logistical support, including staff salaries, exceeds one million Euros. The French agency "Agence nationale de la recherche" and the BNP Paribas Foundation financed the enterprise with an additional 1,6 million euros.
Images from a former science cross, ASUMA (Improving the accuracy of the surface mass balance of Antarctica), conducted by French researchers from the CNRS and the University of Grenoble-Alpes, with the support of IPEV. © Bruno JOURDAIN / IGE / CNRS Phototheque
Left: caravan of the ASUMA crossbar. The EAIIST convoy will consist of a snowcat and 5 large Antarctic crawler tractors that will tow containers on sleds: hot and cold laboratories, life module, storage module, fuel
Right: an example of shallow drilling (50 -100 meters) through a trap door in the cold laboratory. In East Antarctica, these depths date back up to a thousand years.