Saturday, October 26, 2013

The Plan

Map (c) 2013 Commonwealth of Australia.

Aurora Basin North (ABN) is a slightly catchier name for an old traverse waypoint called GC40. It is the site we have chosen for a new ice core record of climate extending back over 2000 years. There are relatively few such records in this sector of Antarctica, especially records with enough detail to observe at nearly year-by-year resolution. The only other comparable millennial length record is from Law Dome. The ice core record will contribute to the work of international projects, the IPICS2k Array and the PAGES Antarctica2k initiative.

ABN is located about 550km inland from Casey at 2700m elevation, so getting there and making it livable will be an adventure in itself! I'll talk a little more about the site and our plans for infrastructure in a future post.

The project is highly international, with researchers and drillers from Denmark, France, US, China as well as several Australian groups. The French Antarctic Programme is providing logistical support in the form of a traverse from the French station, Dumont d'Urville (DDU). We plan to leave DDU on the 1300km traverse in late November and arrive onsite at ABN around December 11. We will then prepare a skiway for light aircraft and the full team will join us by flying in from Casey.

The plan is to be onsite around 6 weeks. The traverse will leave sometime shortly after the skiway is prepared and the basic camp infrastructure is in place. We expect to change some personnel over in early January by aircraft, and the entire camp will be dismantled and returned by air in late January.

We will be drilling 3 ice cores to provide enough ice for a wide range of analyses. The main core will be up to 400m long and cover several thousand years. A second core, about 100m long will provide for extra analysis of the last 1000 years. The hole for this second core will also be used to extract large volumes of trapped air from the upper 60 metres or so of porous snow (firn). This trapped air will be put in clean flasks and returned from Antarctica for detailed analysis of changes in atmospheric composition in recent decades. A third core, also 100m deep will provide additional ice for French colleagues to undertake novel analysis of sulphur isotopes.

So that's it in a nutshell. I'm joining the traverse and will be leaving Hobart on around 8 November. I will be mostly responsible for drilling the core associated with the firn air pumping. This is scheduled to be completed by changeover and so I am expecting to be back from Antarctica in early January... we shall see!

[For some more background, see the AAD website]