In early June, the Beyond EPICA Oldest Ice Core cutting campaign began at the Alfred Wegener Institute in Bremerhaven, Germany. This collaborative project involves European teams working together to reconstruct the climate of the past 1.5 million years using ice samples extracted from the Antarctic ice sheet.
The ice, obtained from East Antarctica (Little Dome C) earlier this year, needs to be distributed to institutions in countries including Denmark, Norway, Switzerland, Germany, Italy and France, such as the LSCE, for various analyses. Priority was given to samples for gas measurements for logistic reasons since the ice samples have to be stored at –50°C to preserve the properties of the gases. The ice was, therefore, divided following the B-cut scheme. Individual metres were selected along the core beginning from 1632 m depth, moving upwards through different depths intervals and avoiding the brittle zone due to fragile ice conditions complicating the cutting process.
In the second week, the team started A-cuts dividing the ice into pieces for physical properties, discrete stable isotope and continuous flow analysis from the uppermost part of the ice core, reaching a depth of 149m by the end of the week. Before the ice is shared between the laboratories, electrical conductivity measurements and line scan images were performed for each bag, if permitted by the ice density. For the LSCE, low- and high-resolution samples were prepared to analyse the composition of stable water isotopes used as a temperature proxy with special interest to interglacial periods that are as warm as or warmer than today.
The cutting and processing will continue over the summer with more people from LSCE going to Bremerhaven and be repeated next year when older ice arrives from Antarctica after the upcoming field season.