1 June 2010

Now we are analyzing air from the last glacial period

NEEM main dome, rectangular generator hut and a red dome tent from above
NEEM main dome, our rectangular generator hut and a red dome tent from a new perspective. There are some snowmobiles parked in front of the main door. You may
wonder how this picture was taken - it was not a balloon. Explanation follows tomorrow.

Today the gas people of the CFA team passed into gases deposited in the ice from the
last glacial period 11713 years ago. The content of the greenhouse gas methane in the
air bubbles dropped as the analysis picked up the samples of the atmosphere from the
last glacial period.

The reason why we see the glacial air in CFA one day later (or 15 m deeper in the ice)
than we see glacial ice is a bit complicated; but here is a simple version: Up here at
NEEM the snow pack is 80 m deep. As long as it is snow, the air can pass through the snow pack and be exchanged with the atmosphere. At little deeper than 80 m the
pressure causes the air to be trapped in bubbles, so in principle the air in 85 m depth
is new, but the ice layers at this depth is 200 years old snow. This means that at any given layer the age difference between the air in the bubbles and the ice is around 200 years, here at NEEM. The age difference is different from site to site, depending on the annual snow fall.
Today the CFA people analysed ice from 200 years before the ice age ended and thus they ran into bubbles from the end of the glacial.

What we have done today:
1. Drilling and logging.
2. Processing brittle ice cores. Processed 37 bags, from 2202 to 2238.
3. Grooming skiway with tiller.
4. Measuring CFA. Today we measured 22 m. Last bag 2625, 1443.75 m.

Ad.1: Drillers report:
Mounting the old cutters again and opening the hallow shaft brought some stability to
drilling today. Seven runs produced between 2.5 and 3.5 meter cores each. We are using Pressure Tube "1" because Chip recovery was good. Packing of chips at the
central junction or in the pump itself seemed to create the shorter of the runs.
Cutting pitch is about 2.4 mm.

Drillers depth: 1904.57 m. Logging depth: 1920 m.

Weather: Overcast and snow. -20°C to -10°C, 10-20 knots from S, later SW.
Visibility: 1 mile to ¼ mile. Snow and blowing snow.

FL, J.P. Steffensen


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