26 June 2009

The NEEM production line

Table soccer on the first floor of the main dome

Table soccer is a popular after-dinner sport.

The drilling, processing, and analysis routines are now up and running after the 2/3 crew change last Tuesday. The work flow is as follows:

First the ice core is drilled by the long NEEM drill and the drilling team consisting of seven persons. The ice core length is then determined precisely, it is fitted to the previously drilled ice core, and cut into 1.65 m long sections by a two person logging team. Subsequently, the core is "processed" by a nine person team: The electrical properties of the ice are determined (used to identify acid volcanic layers) and the visual stratigraphy of the ice is mapped. Each 1.65 m ice core section is then split into 80 pieces in seven band saws. The different ice core pieces are used to sample the water isotopic composition (climate), the gas concentrations and gas isotopic composition (greenhouse gases), and the Beryllium-10 concentration (solar activity). A 3x3 cm2 cross-section of the ice core is melted and used for Continuous Flow Analysis (CFA) in which the concentration of dust and more than ten different chemical spices is measured in high temporal resolution by the six person CFA team. Finally, there are sampling programs for volcanic ash particles and pollen, and analysis of the crystalline structure of the ice (three persons). The remaining ice is packed into plastic bags and ice core boxes before leaving camp.

What we have done today:

  1. Drilling with the NEEM long drill. Drillers depth: 648.80 m.
  2. Ice core processing. Depth: 408.65 m.
  3. CFA analysis. Depth: 111.65 m.
  4. Continued BAS radar measurements.
  5. Finished Korean pit sampling.

Ad.1: Very good progress, but poor core quality for the last runs. More details tomorrow.

Ad. 3: The CFA team passed 100 m depth twice over the last 24 h: first time in the shallow ice core that was drilled for the pilot hole in 2008. Second time in the main core drilled in 2009 that has a depth overlap with the shallow core because the drill deviated from last year’s bore hole. A rare occasion for a double celebration.

Weather: High thin cloud cover, wind speed 10-16 knots from S, temperatures day -8°C, night -20°C, slight snow drift.

Field leader, Anders Svensson

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