Law Dome summer traverse
In recent weeks we have had a small team of eight traverse to Law Dome to undertake a 30 metre ice core drill sampling program along with obtaining samples to measure Beryllium (Be10) traces.
Our small team involved three Casey personnel Billy (FTO), Wato (plumber) and Rick (mechanic) supporting the science team of Mark, Adam, Jason (research scientists), Zac (glaciologist) and Chelsea (science student).
After two days of packing all field support and drilling equipment into two Häggs and Sheer sleds, our team of eight left station bound for the summit of Law Dome some 120 kilometres to the east and 1340 metres above sea level from Casey. The trip from station took around 10 hours of driving with an average speed of 15 kph, and once we arrived at our destination we were met with a lovely ground blizzard to make our tent city all the more interesting to erect and get settled for the following three days of the drilling program.
The deep ice core from near the summit of Law Dome is the premiere high-resolution ice core from East Antarctica. It contains a record of local temperature, snowfall and atmospheric gases (such as carbon dioxide). Furthermore, recent work has linked records from this ice core to south-west Western Australian and eastern Australian rainfall and eastern Australia droughts. This linkage allows us to extend our knowledge of Australian rainfall beyond the limited instrumental period.
Drilling of the main Law Dome ice core finished in the mid 1990s and we frequently revisit the site to drill short (8–40 metre) ice cores to bring the record up–to–date, which also increases the amount of overlap we have with observations which in turn increases our skill at predicting what happened in Australia's past.
During the initial assembly and testing of the ice core drill the team experienced issues with the drive gear for the winch drum slipping on the winch shaft, after consultations with our plumber Wato, he quickly had the problem rectified by manufacturing some shims out of a butter tin which at the time was being used by Billy to prepare lunch for that day. Once the shims were manufactured and installed the drilling team recommenced operations obtaining their 30 metre core target without further setbacks.
During our time at Law Dome once the drilling crew were setup, it gave Billy and Wato an opportunity to dash across to the automatic weather station (AWS) located approximately three kilometres from the drill site to investigate the condition of the unit and see if they could see why the wind speed anemometer hadn’t been transmitting wind speeds back to station. With no obvious signs of ice accumulation and the anemometer spinning freely a quick satellite phone hook-up back to our wintering Met Tech Mark at Casey, had the diagnosis of a faulty sensor as the likely cause and a fault that will have to be further investigated during the winter traverse to service the AWS.
After two days of reasonably favourable weather conditions which helped all scientists obtain their targeted samples, we got to experience science first hand helping Andrew collect ice samples and bagging them up for transportation back to Australia for testing as well Wato and myself digging trenches in the snow to house the samples until our departure. We all worked on disassembling the ice core drill and packing up the camp as much as we could under the direction of Billy to reduce our work load on the last evening as weather conditions for the following day for our return to station were expected to deteriorate progressively during the day.
During the return trip we experienced white out conditions for the middle leg of our trip with winds reaching approximately 40 knots which made for an interesting return trip, at times only navigating by the on board GPS system.
It was a welcome site for all as we descended in Casey station with the picturesque backdrop of the iceberg filled bay and calm seas marked a successful science trip and one that all involved worked tirelessly to achieve in a short timeframe. Once we had the ice core samples safely secure in the −18° C freezer back on station we all looked forward for a well deserved shower and refreshing drink with our team on station reflecting on a successful program.
Wato and Rick, thanks to Jason