June 20, 2018

Terminating the firn gas program

Celebrating the firn gas program. The Team: Ji-woong, Thomas Röckmann, Johannes, Thomas Blunier, Camilla, and Kevin F.

The firn gas program is now in its very final phase. At 66 m depth the flow of the gas pumping in the borehole is very slow, meaning that the gas in the firn is no longer in contact with the atmosphere. A little deeper it will be impossible to suck any air out of the firn as all air is converted in to bubbles. After the gas sampling part of the program is finalized, the ice core will be extended to some 140 m depth in order to investigate the densification process of firn into ice. The deep drilling has been obtaining short cores as the drill head has been replaced and adjustments are being made. The positive side of this is that the loggers have been able to log previously drilled cores without being interrupted by too many new cores. Together with our colleagues in Kangerlussuaq, we now started planning next week’s flight missions. How many passengers go to and from camp, how much fuel, drill liquid, and cargo does camp need, how many ice core boxes can be shipped out etc.
It’s a question of optimizing the precious payload without compromising the program.

What we did today:

1. Deep drilling 6.95 m. Drillers’ depth 1184.69 m.
2. Firn gas drilling sampling to depth 65.84 m
3. Firn gas core DEP, final depth 62 m
4. Measurements in isotope laboratory, final depth: 680.90 m
5. Measurements in physical properties laboratory, final depth 873.40 m
6. Logging and cutting of this years’ brittle ice 1055.48-1096.30 m
7. Water vapour sampling and measuring. 

Weather: Mostly blue sky and some snow drift. Temp. -8 ºC to -16 ºC. Wind: 10-16 kt from SW. Visibility: unrestricted.

FL, Anders Svensson

The gas sampling setup in a tent at the drilling site.

Drilling the shallow ice core before a bladder goes into the borehole to suck the firn air out.