June 11, 2019

1900 m depth reached

Sarah and Maaike ready with very tasty sushi for dinner. Several others helped preparing the delicious little rolls.

Today, 1900 m depth was passed and drilling continues in a good mode, although several issues require the driller’s attention. Firstly, the inclination of the borehole needs to be monitored as it has to be kept low. Drilling is done with negative cutter load, i.e. the drill is held back in the cable while the cutters attack the ice. This approach normally causes the drilling to converge towards vertical. Yet, it may be a good idea to log the borehole over the weekend, to be sure about what the inclination is. Secondly, the hard core breaks that appear to become more common is a concern. Possibly, the hardness of the ice is linked to the ‘type’ of ice we are penetrating. We are currently close to the onset of Dansgaard-Oeschger event 8, 38.000 years before present.
The ice will thus very soon change from being very clean to containing higher amounts of impurities as we enter the cold stadial 9. Such changes of the ice properties may affect the breaking strength of the ice. Many other conditions, such as the amount of fine chips in the borehole or the configuration of the drill head, may, however, also play a role here. For dinner, Sarah prepared sushi(!) with good help from MAGPIE and other helpful participants.

What we did today:

  1. Drilling continues in a good mode, while hard breaks and inclination require attention.
  2. Ice core logging depth: 1912.70 m (length: 15.6 m).
  3. Station for atmospheric moisture sampling and isotopic measurement is active.
  4. The isotope CFA laboratory bag 3029 to bag 3061 (length 17.60 m).
  5. MAGPIE set up one station 50 km S of EGRIP and maintained the station near camp.
  6. Working on and possibly repairing C-axis fabric analyser.
  7. Setting up three passive seismic stations for deep drill seismic detection.
  8. Continued excavation above logging cabin in trenches.

EGRIP population is 24. EGRIP average age is 37 years.

Weather: Clear blue sky and windy all day. Almost no snow drift as there is no loose snow to move. Temp. -6 °C to -16 °C. Wind: 2 kt to 16 kt from W and SW.

FL, Anders Svensson

Despite fast internet and an endless number of movies available, ‘old-fashioned’ entertainment, such as cards and board games, are very popular in the evening.