June 20, 2017

Main ice core processing terminated

A guided tour of the incredible wind sledge that has travelled some 20,000 kilometers in Antarctica, Greenland and the polar regions. The ‘drivers’ sit on the two boxes and steer the sail/kite that is fixed in a 350 m long line. The other expedition members can rest in a tent on a second attached sledge. The sledge weighs 2 tons and it can move up to 400 km in 24 hours (record) or it can be stuck for days.

Today the science trench finished processing of the upper 100 m of the main core, whereby the main science trench activities are terminated for 2017. In total, the upper 350 m of the main core have been processed. All of the deeper core drilled this year will be stored in the core buffer to relax for next year.
The stored core includes the ‘brittle zone’ ice (some 500-1200 m depth) that easily breaks due to the high bubble pressure. At around 450 m depth the loggers are already noticing the first signs of brittle ice. The continuous isotope measurements and the physical property studies will continue until 350 m depth in the coming weeks.
The deep drilling and the firn gas drilling are in good progress. The swiss drilling is fighting an issue with the chips separator that will separate the ice cuttings from the drill liquid in order for the drill liquid to be reused and the ice analysed. The main attraction of the day was a guided tour of the wind sledge.

What we did today:

1. Deep drilling core length: 15.76 m.
2. Logging depth: 452.15 m.
3. Processing depth: 116.05 m
4. Water isotopes: 312.95 m
5. Firn gas sampling depth: 55 m
6. Worked in chips separator for RADIX drill
7. Water vapour, methane, aerosols, snow and boundary layer measurements
8. Reorganized ice cores in ice core buffer
9. Made inventory of cooks fresh food storage
10. Groomed skiway with tiller and apron with beam

Weather: Blue sky with thin high clouds all day. -10°C to -20°C. During the day wind 2-12 kt SW→NW→W.

FL, Anders Svensson

The final cut of main core this year.