Antarctica: Seeking oldest ice to capture Earth’s climate history

ENEA glaciologist Massimo Frezzotti and Robert Mulvaney of the British Antarctic Survey hoisted the European flag at Little Dome C in Antarctica, where the second phase of the mission Beyond Epica Oldest Ice, born with the objective of identifying a drill site allowing to extract and analyze an ice core going back over one million years, has set out. Ice cores provide exceptional archives of past climate since the tiny air bubbles trapped in the ice, dating back to the time of their formation, preserve the ancient atmosphere’s composition and can shed light on how the atmosphere has changed. Once analyzed in laboratory, ice cores will add to researchers understanding on the chemical, physical and isotopic composition of the atmosphere of the past, allowing them to understand how climate will evolve, with reliable quantitative data useful for establishing more targeted climate mitigation and adaption strategies.

The survey, conducted in Anctarctica by Massimo Frezzotti, is part of a three-year European project funded by the EU with 2.2 million euro, involving glaciogists and climatologists from 10 European countries in the quest for the oldest continuous ice record on earth. Thanks to ice cores it will be possible to go back even further in time, almost double the lenght as compared to the samples currently available (800 thousand years).

The field, located at an altitude of 3.228 and 1.200 km from the coast, is characterized by average annual temperatures of -55°C, with winter lows falling down to -84°C and by an ice layer approximately 2.640 m thick. This year, scientists are engaged in the search for the optimal spot within the boundary identified last year. In-depth surveys of the rocky bottom are under way to retrieve this information through geophysical surveys conducted with radars and GPS, that will end with a fast drilling (RAID) at a depth of 600 m with objective of estimating the temperature of the interface ice/rock.

The first phase of the project concerned a preliminary survey of the drilling site. At the end of last year a suitable location was found, an area covering 7x5 km identified as Dome C, approximately 40 km south-west of the Italian-French station Concordia.

“The choice of the precise spot to drill - Massimo Frezzotti at ENEA explained – is critical to this type of study, since the deeper it goes, the more the ice loses its resolution, its stratification becomes denser and thinner, and can be subject to deformation due to glacial dynamics, making it more difficult to study it.

When going deeper, the time frame enclosed in a few centimetres of ice becomes increasingly wider, going from 2 centimeters of ice per year in the surface layer, up to 10-15 thousand years per meter of ice, reaching a depth of  2500 m. That’s why it’s important to find drilling spots where this process is mitigated by specific characteristics of the dynamics of the ice and the rocky bottom. This three-year period is the preliminary survey phase. If we find a suitable site, the actual drilling will start in 2020 and end in 2025. Also this second phase will be co-funded by  Horizon 2020 and the 10 european nations involved”.

The field work, part of the Horizon 2020 Beyond EPICA Oldest Ice Project (BE-OI), was made possible ENEA and IPEV, which co-run the Station Concordia. The European team is composed by Massimo Frezzotti (ENEA), Saverio Panichi (ENEA), Michele Scalet (PNRA), Rob Mulvaney e Julius Rix (British Antarctic Survey), Catherine Ritz (Centre National de la Recherche Scientifique)

For more information please contact:

Massimo Frezzotti, ENEA massimo.frezzotti@enea.it

http://www.italiantartide.it/video-intervista-a-massimo-frezzotti/

http://www.italiantartide.it/camp-at-little-dome-c-arrived-on-site-on-november-22nd-2017/