14 January 2025
Weather at 6pm: Temp −26°C; Wind 11 kn
We finished the day at a driller’s depth of 34.5 metres. Pilot drilling of the MYIC is officially underway!
Today:
- We descended into the deep trench and guided the Eclipse pilot drill into the ice sheet at 75.04220°S, 123.63120°E, Dome C North. 3064 m of ice and well over a million years of climate and atmospheric history lie ahead.
- We finished the day at drillers depth of 35.4 m, pulling up consistent cores of around one metre length. The Eclipse drill is running perfectly. Traverse crew came in to assist and celebrate the long-awaited start to drilling.
- Once the firn hardened, we changed to medium strength core dog springs at 20 metres depth.
- Our plastic lined and carefully levelled ice core v channel worked a treat, to move the core along an eight-metre-long logging and processing line, all expertly run by Chris and Chelsea. Cores are measured, cut to length, photographed, logged, weighed and sampled for water isotopes (for later measurement in lab). They are then bagged, placed in insulating core boxes with a temperature sensor, and then moved to a firn trench to keep cold until transport back with traverse later this month.
- We logged the borehole inclination, results to process tomorrow.
From tomorrow we will move to a shift pattern with two eight-hour shifts per day, five people per shift, with two operating the drill and three core logging. Traverse are keen to join in and help with the drilling and logging. Each shift includes three from the science team and two from the traverse team.
Kind of lost for words that we are now started drilling the MYIC. We’ll save the celebration until we finish the pilot hole.
15 January 2025
Weather at 5pm: Temp −23°C; Wind 3 kn
Pilot drilling is well underway. Some statistics for the past 24 hours:
- Drill runs: 28
- Core drilled: 34.11 m
- Current drill depth: 70.44 m
- Average core length: 1.22 m
Dr Liv and Chippy Dave joined the drilling and core logging team for this morning’s shift and did a stellar job. Our shifts run from 7am–3pm and from 3–11pm. Jack and Damien have joined the drilling and logging team for this evening’s shift.
The borehole inclination (straightness of the drill hole) from yesterday’s log was around 1.2 degrees, which is excellent. We are drilling cautiously and with minimal weight on the drill head, so that the borehole is as true as possible. American colleagues drilling in the Dome C area this season found that core quality and speed of drilling gets more challenging around 100 metres.
Meanwhile some of the traverse crew have put up another smaller tent and lined the floor with Geohex and ply. It’ll be put to use as a storage area.
16 January 2025
Weather at 5pm: Temp −20°C; Wind 3 kn
We are now over 100 m into the pilot drilling!
Stats for the past 24 hours:
- Drill runs: 34
- Core drilled: 33.6 m
- Current drill depth: 105.1 m
- Average core length: 1.05 m
Derryn recalibrated the borehole logger and we logged the borehole again every five metres, to 90 metres. The inclination (straightness of the borehole) is less than 0.3 degrees at all points. This is superb. Our careful drilling with minimal weight on the drill head is working to keep the pilot hole true.
Progress was more difficult between 70 and 90 metres. We swapped out the anti-torque springs on the drill to overcome problems with the drill spinning in the borehole and not cutting, and then spent a number of runs fine tuning the settings. Progress improved when we swapped from #5 to #3 heels on the cutters. This takes a smaller cut which means less force on the anti-torque.
The improvements coincided with passing Jesus Christ ice at 90 m (0 AD). and there were cheers and smiles on reaching 100 m (age approximately 2400 years).
On the drilling and logging shift this evening are Derryn, Chelsea and Daniel, with sparkies Ryan and Cookie joining them. The shift pattern is working well. The traverse crew are enjoying being a part of it and it lets us split the science-drilling crew between two shifts, so that we can operate the drill for 16 hours a day.
Meanwhile all the borehole casing was moved into the drill tent and the traverse crew continued with sorting cargo and jobs around camp.
17 January 2025
Weather at 5pm: Temp −20°C; Wind 3 kn
MYIC drilling in past 24 hours:
- Drill runs: 36
- Core drilled: 35.86 m
- Current drill depth: 141.78 m
- Average core length: 1.0 m
We are closing in on the pilot hole target depth of 150 m.
The ice is becoming more brittle, the ice density has reached around 0.9 kg/m3 and the air trapped in the firn is now occluded into bubbles in the ice (see pic).
In this morning’s drilling shift we start to encounter more cores with breaks and shards, often emanating from where the core dogs have applied force to the core during the core break. To improve core quality, we tried sharpening the cutters, lowering the depth of cut and changing to a drill head with 3 rather than 6 core dogs. None of this seemed to make a lot of difference. The ice is under pressure and the stress of the cutters and core breaks causes the fractures. All this is expected, at these depths in this cold ice.
Once we reach over 150 m we will start reaming the borehole from the current 130 mm borehole diameter, out to 260 mm diameter. With delays earlier in the season we did not think we would have time to get to reaming this summer – but the team here are super-efficient and have won back precious days.
Our pilot drilling and reaming are in order to install the 255 mm diameter bore casing, which is essential for deep drilling next season.
We got a friendly visit today from the French/Italian traverse team, who pass a few kilometres away on their resupply traverse from Dumont D’urville to Concordia. They were interested to check out our ice drilling.
Great traverse help with the drilling today from field leader Chris ‘Psycho’ Gallagher on the logging table and Dieso Tim Harris drill offsiding.
18 January 2025
Weather at 5pm: Temp −18°C; Wind 11 kn
Pilot drilling of MYIC DCN is complete!
MYIC drilling in past 24 hours:
- Drill runs: 36
- Core drilled: 35.86 m
- Current drill depth: 150 m
- Average core length: 1.0 m
Eighteen days ago only a bamboo cane marked the borehole location. Since then the combined efforts of the traverse and science teams have built the drill shelter, dug the deep incline trench and completed pilot drilling. It’s been a super team effort!
The last 10 m of drilling and logging were challenging. We tried more and less aggressive cutters and oversize cutters. Some runs of a few meters of good core interspersed with broken and fractured core and binding of fine chips in the barrel. In the end a return to the #3 cutters got us over the line the to the target pilot hole depth of 150 m.
For one of the most remote places on earth it’s surprisingly busy around here. Yesterday we had the French/Italian traverse team visit and today, as we completed the pilot drilling, a team of six American and French ice core scientists working out of Concordia arrived. We had some good discussion about reaming and casing and shared a nice lunch together (thanks Liv!).
A final borehole survey was done and confirmed the inclination over the 150 m is less than 0.3 degrees.
In the afternoon we started readying the drill to start reaming and made the first reaming run with the 176 mm reamer. We have around seven days left on site and will see how far we can get with the reaming.
19 January 2025
Weather at 6pm: Temp −20°C; Wind 4 kn
A couple of hours were spent this morning chasing an electrical fault that turned out to be a shorted wire close to the cable termination into the drill. With that fault corrected we were back into reaming. As of writing we are at 67 metres with the smallest (158.75 mm) diameter reamer. The target depth for this smallest reamer is 130 metres. A simple weight on a rope lowered down the borehole indicates not more than a metre or two of chips has been lost to the bottom of the borehole. We can recover these later with the drill.
We installed the site surface reference marker (a pole buried to 4.2) at 75.04295°S, 123.63130°E (80 metres south of the borehole) in the undisturbed clean snow area. This marker is used to register our drill depth against the undisturbed snow surface away from the drill tent and to monitor change in snow surface.
We're looking forward tomorrow to a visit from our Beyond EPICA friends who have closed their camp and moved back Concordia, before their flights home.
20 January 2025
Weather at 6pm: Temp −23°C; Wind 11 kn
The first of the three main reaming steps was completed to 130 metres. At the end of reaming we measured six metres of ice chips had been lost during reaming to the bottom of the borehole. To fish these out we changed back to the drill and simply drilled over them to collect a ‘chip core’. We were a little anxious about whether the chips would be sintered together enough to come up in the drill and not just fall out of the barrel. Our US colleagues advised that they should come up easily like this, and indeed they did.
The Beyond EPICA team arrived in the afternoon, piling out the back of a PistenBulley. We gave them a tour of our drilling set up, shared some rad nachos and toasted their successful drilling to bedrock at Little Dome C.
Chippy Dave had secretly fashioned an ice cream bar earlier in the day and we enjoyed the best ice cream south of the polar circle, if not the equator. It was great to return the hospitality that Beyond EPICA have always shown us at Little Dome C.
Meanwhile we kept the drill shift going, and have just a couple of metres still of chips to collect tomorrow before we can switch to the second of the three main reaming steps.
