26 May 2010

Now most of the CFA analyses work

A close-up of the CFA melt head

CFA stands for Continuous Flow Analysis. It means that we measure the layers in the ice core as a section of it melts from top to bottom. Today’s picture shows the CFA melt head. The bottom end of a square rod of ice core (33mm x 33mm) is seen in the square hole of the white plate. The ice rod is 1.10 m long. In the square hole is a golden hot plate with a drain in the middle and a drain along the edge. As the ice melts, the clean water from the center is analyzed chemically, the concentration of micro particles is measured, and the isotopic composition of the ice is determined. Also during melting, bubbles of trapped atmospheric air from the ancient atmosphere burst and the air is analyzed for green house gases. The water from the drain along the edge is used for analyses, which are insensitive to contamination from handling the core section.

What we have done today:

  1. Adjusting drill and drilling.
  2. Running in equipment in gas laboratory. DK-methane measurements now work.
  3. Processing ice cores.
  4. Moving empty boxes to cargo line and removing snow drifts from storage garage.
  5. Measuring CFA. Today we measured 22 m. Last bag 2433, 1338.15 m
  6. Water vapour sampling. Tests with kite and atmospheric logger.

Ad.1: Drillers report:

From 25th may:
Reaming operation finished today to the bottom at 1823.44 meters cable depth.  The final push also produced 0.75 meters of ice core. The rest of the day was dedicated to filtering the chips produced. Four filter runs from 1000 to the bottom yielded 37 kg of chips.  The drill is mounted and we will make a run first thing in the morning.
Six completed runs and one in progress at the time of this publication since reaming and filtering have produced more than 12 meters of ice.  We are currently seeking a stable mode that produces coarse enough chips for efficient transport and packing in the chip chamber while at the same time allowing for drilling below the motor’s current limitation.  This is apparently a fine balance. The new cutters produced for this year are installed on the drill head and we will tune our operation to accommodate these.

Driller’s depth 1836 meters.  Logging depth 1836.95 meters

Ad.3: Processed 16 bags, last bag 3353, 1844.15 m.

Weather: Thin overcast and fog/haze all day. -18°C to - 7°C, 12-20 knots from S. Visibility: Between 1 mile and ½ mile.

FL, J.P. Steffensen

In the drillers workshop Steff is making adjustments to the drill.


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