British Antarctic Survey Radar measurements

The mobile BAS radar setup in action.

British Antarctic Survey (BAS) is running an associated project at NEEM, i.e. a project not directly related to the ice core drilling. Fabien Gillet and Timothy Burton have spent the last week driving skidoo to various points in the surroundings with their radar, GPS, radio, and a tent for the case of sudden change of weather. They use a phase sensitive radar for precise measurements of the displacement of internal layers of the ice sheet. Two lines perpendicular to the ice divide (10 km upstream and down stream of the camp) were surveyed last year, each line consisting of 33 points of measurements. Two bamboos were left at each point for precise repositioning of the instrument. This year’s measurements show good resemblance with those of last year and vertical velocity profiles of the ice down to 1000 m depth are obtained by comparing the two sets of measurements. Furthermore, GPS measurements have been made on one line for comparison with the radar measurements. The results are important for a detailed understanding of the flow of ice.

What we have done today:

1. Drilling with the NEEM long drill: 33.56 m. Drillers depth: 829.56 m.
   
2. Ice core processing: 21.45 m. Depth: 527.45 m.
   
3. CFA analysis: 18.70 m. Depth: 208.45 m.
   
4. Preparing rain gutters for protecting brittle ice in the core buffer.
   
5. Filling in ramp to drill trench.
   
6. Feeding camp bird ‘David’ with sardines in tomato sauce.
   

Ad.1: Drillers Report July 1
"Thirty four meters of ice core was recovered today, finishing at a depth of 796m. The new plastic plate cracked during the first run of the day and a large loose piece was luckily trapped in the anti-torque springs when the drill returned to the surface so a fishing trip was not required. The plate was re-clamped and drilling continued. This plastic becomes brittle with the present combination of cold temperature, drill fluid and pressure in the hole. Another part of different design and different plastic material has been made ready for backup."

Weather: Several snow showers during the day and winds up to 14 knots. Clearing up and becoming quiet in the evening, temperatures from -8 to -20 °C, almost no wind.

Field Leader, Anders Svensson