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The shallow ice core drilling setup at Site D last night. The plywood and shower curtains are to create shadow for the ice and the drill that tends to ice in if heated in the Sun. To the right the logging setup where the ice cores are fitted together, the length is measured and the cores are being cut into pieces that fit into the boxes. Best not to turn the ice cores upside down.

July 2: An early morning arrival and fishing in the borehole

The airborne visit to the Site D that started yesterday afternoon and ended this morning when the Basler returned to camp at 4:30 in the morning was a great success. The combined forces of the ICELINK team and the Polar 6 crew managed drilling to 45.27m depth and thus secured depth and age overlap with the previous Site D ice core. The ice sheet had been so kind to store the well-ordered climate information in a safe and cold place for us to come and pick it up. To be dropped off in the ice desert in the middle of nowhere to drill an ice core all night is a very special experience. The pictures say it all.

 

Deep drilling report: Today has been a day of ups and downs. In total we removed two large pieces of fiberglass from the hole. Yet, in the progress, we paid the price and broke two centralizing drill bits of the hole drill, which disappeared downhole. Later, we used a 20mm snow auger mounted to the drill which managed to penetrate the blockage at the bottom. We can now confirm that the blockage is 18cm thick. Yet, during retraction the auger dismounted. Rescue attempts with a magnet have failed so far and now it stands 4:2 for the borehole.

 

In the evening, camp was invited for a drink to the mega trench in the clean snow area that has now been deepened to 3.7 m. It was a beautiful sunny and calm evening and we were fascinated by the complexity of the firn stratigraphy that is visible in the trench wall. One may start to wonder how representative the climate signal in a 10 cm wide ice core is when one sees the great lateral variability of the firn layering. To investigate this and many other aspects of the firnification process, two of the world leading experts in the field, HC and Sonja, are sampling 13 snow profiles in 2 cm depth resolution across the snow wall, if possible, to 5 m depth. That’s a lot of samples…

 

What we did this Thursday:

 

  1. Lost and received items in the deep borehole
  2. Received Polar 6 at 4:30 in the morning
  3. Worked on entrance to large storage trench
  4. Deepened the mega trench to 3.7 m depth
  5. Made pit sampling at PFAS site
  6. Experimented with geophones along skiway
  7. Enjoyed evening sun and snow wall in mega trench

 

Weather: Calm and sunny day, except in the early morning when the Basler returned to camp and a ground fog appeared. Wind 0-10 kt from SE and later SSE, temp -18C to -10C.

FL, Anders Svensson

Celebrating the second piece (third in total) of fiberglass that has been removed from the borehole. The hole saw has really worked well!
The ice sheet is hiding little hints and secrets for us: Johannes, Iben and Maria are holding an ice core section from 10.6 m depth that most likely dates from 2012 - an extremely warm summer in Greenland that resulted in melting over large parts of the ice sheet. The evidence of this event is found over much of the ice sheet as those clearly visible melt layers.
That airplane better bring us home or it’s a very long walk. Thanks to all the tricks and experience of the Basler crew the ski-equipped Basler got everyone home safely, despite very long working hours, sticky snow and teasing ground fog.
Nora, Gill and Mimi are digging for gold at Site D. ‘Climate gold’ that is.