Little Dome C - Beyond EPICA Oldest Ice Drilling Site (75.29917 °S, 122.44516 °E) – Season 2022/23

Situation Report #46; Tuesday 17th January 2023

Personnel @LDC: Saverio Panichi (ENEA, Camp Leader), Frank Wilhelms (AWI, Chief Driller), Robert Mulvaney (BAS, Chief Scientist), Markus Grimmer (UNIBE), Romilly Harris Stuart (LSCE), Matthias Hüther (AWI), Gunther Lawer (AWI), Johannes Lemburg (AWI), Florian Krauss (UNIBE), Martin Leonhardt (AWI), Michele Scalet (ENEA), Julien Westhoff (NBI), Andrea de Vito (ENEA)

Personnel @DC: Giuditta Celli (UNIVE, ISP)

Weather at LDC 5 pm: sunny, 10 knots, 640 hPa

Meteo at DC 5 pm: T = −35°C, Wind = W 10 knots, Wind Chill T = −50°C (wind chill warning)

First Basler lands at Little Dome C; some more drilling problems – all solved

In a first for Little Dome C, a Basler aircraft flew from Casey today, and landed at the prepared skiway close by the BE-OIC camp. Twin Otters have landed in previous seasons at earlier camps on Little Dome C during the survey phase of the BE-OI project, but this is the first time for the larger Basler.

Overnight, the AWI motor system was switched for a few hours to the second system with enhanced electronics which allowed us to log some parameters of the borehole, particularly the inclination. After logging the hole, we switched back to the better of the two AWI motors. Drilling started without problems in the first few runs of the day but in the late afternoon, after a short 1.58 m run which ended with high current on the drill motor, we found the German motor had seized, and would no longer turn either under power, or by trying to rotate the motor manually. A change to the newly refurbished Danish motor and control section had us drilling again by late evening, with a final run of the day with the new motor of nearly 3.5 m. Earlier in the season, the Danish motor had failed on us with a broken harmonic drive (the reduction gear between the motor and the drill shaft), but over the Christmas period, our colleagues in Denmark had managed to courier a spare harmonic drive to Christchurch, and early in the new year, this had made its way out via McMurdo, Mario Zuchelli, and Concordia to us. We were very grateful to the effort everyone had made as both of our German motor sections now had problems. In practice, we found later that once warmed up the German motor section worked again, and the conclusion was that ice had built up in one of the bearings.

End of day statistics:

Individual runs of the drill were recorded as: 3.01, 2.94, 2.92, 3.01, 1.58, 3.44 m

  • Drillers’ depth: 782.92 m; daily total 17.18 m
  • Loggers’ depth: 786.42 m; daily total 17.28 m

Rob Mulvaney & Frank Wilhelms - LDC, 19 Jan 2023