iSTAR is a collaborative scientific programme, funded by the Natural Environment Research Council (NERC) and co-ordinated by the British Antarctic Survey (BAS). It aims to improve our understanding of the stability of the West Antarctic Ice Sheet, which could potentially undergo rapid retreat in the coming centuries. It is divided into two halves – half the programme is ocean focused, looking at how relatively warm Circumpolar Deep Water intrusions onto the continental shelf interact with the ice shelves in the Amundsen Sea. The University of Bristol is involved in the second half of the programme, which is concerned with the ice sheet dynamics and mass balance, particularly the changes happening to Pine Island Glacier (PIG). In order to study these changes, two traverses of PIG have been made, over two consecutive seasons (2013-14 and 2014-15). The 800 km traverse, took in 22 sites across the ice stream and its tributaries, where various scientific techniques were used to determine the properties of the ice, glacier bed and firn layer (compacted snow).
During this season, despite some strong winds, we successfully completed all the science we set out to do, included seven seismic surveys, ten shallow ice cores, 22 neutron probe snow density profiles and ten phase-sensitive radar profiles. For me, as a PhD student, it was a great experience to work with senior scientists in the field, and to be involved in such a wide range of field techniques.
The scientific goals of the iSTAR traverse could not been achieved without the use of the traverse logistics, which involved using Pisten Bully snow tractors to tow the caboose (a converted container that acts as kitchen and living space), equipment and fuel from site to site. This is a new way of field operation for BAS and is likely to feature in many more scientific programmes in the future, given the success of the two iSTAR traverses. Of course, there are some old-school field scientists who joke that we are the Caravan Club of Antarctica, but I think they are just jealous – eating pancakes for breakfast in the caboose has to beat sitting in a pyramid tent eating rehydrated rations!
|On the move! Image credit: Isabel Nias|
Despite the perhaps more luxurious living conditions than the average field party, living in the deep field on the ice was not without its challenges. We were still sleeping in tents and my standard answer to the question, “but how did you wash?” has been, “I didn’t”. At the beginning of the field season we had temperatures as cold as -35°C (plus wind chill), which froze your breath inside your nostrils. However, I preferred the cold to the “warm” temperatures we had towards the end of the field season (it hit 0°C at one point!), which made our boots and gloves all damp. The work was also physically hard. Each seismic survey was 7 km long, and involved a team of us drilling 30 hot water drill holes, which were then loaded with explosives, and digging over 700 holes to place the geophone sensors in the snow. Although it was worth it for the end product: an idea of the type of bedrock PIG is flowing over.
Before I arrived, I had heard from Steph Cornford, who was on the first iSTAR traverse, that the weather had been exceptionally pleasant last year, with plenty of blue skies and low winds. So much so that they ate their Christmas dinner outside! This year, the weather was more like what you would expect from Antarctica – we certainly had our fair share of strong winds, which hindered progress at times, especially due to the sensitivity of the seismic work to wind speed. I got very good at estimating the wind speed based on how much my tent was shaking, or by looking at the Union Jack flying from the caboose!
|Emma Smith and Alex Brisbourne (BAS) making their way to the |
safety of the caboose on New Year’s Day. Image credit: Alex Taylor.
New Year on PIG was certainly one to remember. We spent the evening doing a pub quiz in the caboose and seeing in the New Year with a whisky and a poor rendition of Auld Lang Syne. By 1:30 am, however, the winds had picked up to 50 knots with gusts of up to 65 knots, creating extreme white out conditions from all the blowing snow. Many of us who were still up decided to sleep in the caboose that night. I’m glad I did because I doubt I would have slept at all in my tent (from the noise and the fear that the tent would be ripped from its pitch!). The strong winds persisted well into New Year’s Day, but we were able to assess the damage. Rather than blowing away, my tent was actually half buried by a huge drift. However, it could have been worse – James’ tent was destroyed and completely filled with snow! It took the whole of the next day to get camp cleared again – is “shovelling snow” a worthy thing to put on my CV?
Looking back, it is not working until 3 am to finish a seismic line that I remember. Rather, it is the people, as well as all the amazing experiences I had, which stick in my mind. It’s not every day that you co-pilot a plane across West Antarctica or bake a Christmas cake on 1800 m thick ice.
I would like to thank iSTAR, BAS and all the guys at the Rothera Research Station for such an awesome experience. The real work starts now – we have a lot of data to work on! Have a look on the iSTAR website for more blog posts written while we were in the field.
|The second iSTAR traverse team at Christmas, complete with a ratchet strap Christmas tree. Image credit: Alex Taylor|
Cabot Institute member Isabel Nias is a PhD student in the Bristol Glaciology Centre, School of Geographical Sciences at the University of Bristol. Her PhD, which is funded through the NERC iSTAR programme, aims to use ice flow modelling to understand the sensitivity of the Amundsen Sea ice streams, and their potential impact on future sea level rise.