28 June 2009

THE Christmas snow processed

The Christmas ice in the processing line.

Four snap-shots of the Christmas ice as it passed through the processing line (left to right): 1) in the Swiss horizontal saw, 2) the ECM signal across the transition, 3) the visual stratigraphy of the ice (white spots are air bubbles), and 4) the packed core ready to enter a box and be shipped out of camp.

This Sunday morning some of the ice that went through the saws of the science trench was exactly 2009 years old. We thus passed the transition from year 1 AD (+1) to year 1 BC (-1), including the snow that fell on Christmas Eve 1 AD (there is per definition no year zero).

Although one person from the science trench team felt that she could vaguely identify the contours of a cross in the bubble pattern of the visual stratigraphy of the ice core, the Christmas ice didn’t appear much different from the surrounding ice. We localized the Christmas ice in a depth of 424 m from interpolating between the depths of the Vesuvius eruption identified yesterday and a large volcanic eruption of unknown origin that appeared in 52 BC (which was identified from the non-destructive Dielectrical Property measurement (DEP) that runs a few days ahead of the main processing line).

There were several suggestions for how best to celebrate this special event including playing Bach in the science trench, decorating with Danish flags (Danes tend to celebrate all birthdays with lots of flags), or sharing a sample beaker of Gammel Dansk (rejected by FL).

What we have done today:

  1. Drilling with the NEEM long drill. Drillers depth: 702.40 m.
  2. Ice core processing. Depth: 443.30 m.
  3. CFA analysis. Depth: 134.75 m.
  4. Setting up wind sock between skiway and apron.
  5. A double pit for inspecting firn stratigraphy was "dug" by Timothy and the snow blower.
  6. The seismic station was inspected and levelled.

Ad.1: Drillers report June 27:
"Saturday was a shortened work day and the two shifts recovered in total 20.48 m of core finishing at 677.46 m. A successful fishing expedition down hole added a little bit of excitement to the last shift and recovered the 60cm errant fish (core) and a further 70 cm of core."

Ad. 3: The CFA lab had several minor problems that are all solved by now.

Weather: Mostly overcast, temperatures form -8°C to -12°C, low winds <10 knots from S-SE.

Field leader, Anders Svensson

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