We can now drill 2 m ice cores each run – University of Copenhagen

NEEM > Field diaries folder > UK diaries 2009 > We can now drill 2 m i...

23 May 2009

We can now drill 2 m ice cores each run

Saturday night barbecue in front of the main dome. The grill is an old oil
sump from one of the tracked vehicles.

Saturday night barbecue in front of the main dome. The grill is an old oil sump from one of the tracked vehicles.

With the drill trench fully operational, the drillers have turned their attention to learning to handle the drill fluid, to observe how the drill fluid interacts with the drill, and to tuning the various components of the drill. The drillers are satisfied with the progress. Construction work has now moved into the science trench. In the CFA cabin, tables and shelves have been mounted as well as the setup for the CFA melt head. The plan of where the various workstations will be has been finalized, and we are now setting up and adjusting the tables and saw positions. The beautiful day allowed for activities on the surface. Construction of the staircase and elevator is progressing. Then it was Saturday night. Sarah had an afternoon off while H.C. and Peter made supper, grilled steaks, and Lone and Marianne made desert.

What we have done today:

  1. Drilling.
  2. Setting up ECM bench and measuring ECM to establish the starting point for NEEM 2009 Main core.
  3. Excavating a cave for physical properties cabin.
  4. Making a CFA buffer.
  5. Setting up Barbecue.
  6. Removed large snow drifts in camp.
  7. Setting up tables and shelves in CFA lab.
  8. Adjusting table for O18 cutting.

Ad.1: This is how the drillers report looks today:

“The morning was spent improving liquid handling procedures and protection and improving the set up in the driller’s cabin. Afterwards, three cutter/shoe combinations were used for drilling to tune in the EPICA drill; using 3 mm pitch shoes, 4.5 mm pitch shoes, and adding a 0.2 mm shims to the 4.5 mm pitch shoes. Each configuration gives stable drilling, full core lengths, and a full chip chamber, but the best results so far come from the 4.5 mm pitch shoes. With this configuration we get the best negative cutter load and we get the best chips, while the smaller pitches give very fine chips. However, the pitch we measure on the core is less than 4.5 mm. While the cable is shorter we can control the mean pitch by holding back slack, which will not work when the cable gets longer. A few runs resulted in antitorque rotation. The ‘pilehøjde’ of the antitorque blades has been increased to 38 mm to account for the larger diameter borehole. Driller’s depth is 125.75 meters.”

Weather: Clear all day, - 22 °C to -11 °C, 4-14 knots mainly from S and SSW.
Visibility: Unrestricted. Beautiful.

FL, J.P. Steffensen

← Previous entry   Next entry →