July 28, 2017

Brittle ice cores

Ina preparing thin sections of the ice from the ice core and measuring the ice crystal rheology.

The depth is 750 m where the age of the ice is around 6500 years before present and we are in the zone where the ice is very brittle. It is one of the high priority goals of the EGRIP project to produce high quality ice cores from this zone as the ice is from the Climatic Optimum (5000-8000 years before present), a period of interest to study because the temperatures were as warm as those we have these years. The 1-2 m long ice cores are still very good and many are recovered unbroken. This is a great success and a result of a good setup and the hard and careful work of the drillers and loggers. Cross your fingers that we can continue in this mode.

What we did today:

1. Deep drilling core length at 19.00: 14.76 m.
2. Drillers depth at 19.00: 746.47 m.
3. Water vapour, methane, aerosols, snow and boundary layer measurements
4. Physical properties measurements.
5. Water isotope sampling for sublimation studies.
6. Checker Tobi filming and Asahi Shimbun reporting.
7. Troubleshouting the control boxes for the intermediate dill
8. Packing of the intermediate drill for retro to Copenhagen
9. GPS and Drone mission to the southern shear margin
10. Cryoegg and measurements of possible very low concentration biological material in the surface snow
11. Improving curtains in the trenches
12. Building pallets for mission tomorrow

Ad. 8. The intermediate drill is planned to drill a core at Mount Brown in Antarctica 2017/2018 in collaboration with the team of ice core researchers from Hobart, Australia.

Weather: Sunny winds from 2 to 7 m/s from W turning to SW and temperatures from -14°C to -4°C.

FL, Dorthe Dahl-Jensen

A 1.5 m brittle ice core in one piece.