17 July 2010

Borehole logging, 2500 m logger depth, 2200 m CFA depth, and a great Mexican dinner

On Saturday evening it is time to relax and play
Nerilie clearly spent too much time in the CFA hut over the last months; here she’s gone mad with a big stick. No! We play the Mexican children’s game of Pinata in the workshop: the puppet is filled with candy, but to get it, you have to hit the puppet blindfold.

Last night, a second borehole logging was carried out in order to measure the temperature and the pressure at the bottom of the hole. Those values are needed to adjust the liquid pressure with the basal pressure in the borehole. If, namely, there is melt at the base, we would like the basal water to enter the drill hole rather than to drill liquid to flow below the ice. On the other hand, we also would like the basal water not to rise too high into the borehole as it will block the borehole when it freezes.

Due to the many logging activities todays drilling production is somewhat lower than the previous days. Nevertheless, the drilling passed 2500 m logger’s depth this afternoon!
What a great achievement! The result of the seismic logging last evening was not definitive, but it suggests that bedrock may be some 20 m deeper than the radar prediction of 2545 m.

The CFA team reached their goal of 2200 m depth last night. This depth is in interstadial 24 in the earliest part of the last glacial. The deeper ice and the Holocene brittle ice will be stored at NEEM for CFA processing next season. Altogether, the CFA team has had a very successful season with processing of more than 930 m of Holocene and glacial ice! This implies that there has literally been ice on the CFA melt head some 500 hours over the last months. Congratulations with the impressive production and the great results!

Julia, Lizzie, Tim, and Gunnar prepared a full Mexican Saturday evening treat: Nachos at 7, then Pinata in the workshop (see picture), and three types of enchiladas for main course. Dorthe made a tasty ice cream core for dessert. Que rico!

Drilling: 5.03 m, drillers depth: 2485.53 m
Logging: 4.86 m, loggers depth: 2501.19 m
Processing: bag 4367-4404 (20.90 m) 2422.20 m
CFA: bag 3982-4001 (11.00 m), CFA depth 2200.55 m. Brittle zone bags 2116-2119 also processed.

What we have done today:
1. Drilling and core logging ice.
2. Processed deep ice.
3. CFA measurements.
4. Temperature logging of borehole.
5. Enjoying Mexican dinner.

Weather: Unfortunately, the warm windy overcast conditions continue. Wind has been 10-15 knots from SW. Temperatures between -6°C  and -8°C.
Occational snow showers. These are not ideal conditions for preparing a skiway.

FL’s Dorthe Dahl-Jensen and Anders Svensson

 

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