Location: Recovery Lake B and surroundings, about 82º 30’ S, 19-20º E
Weather: All clear, -27 C, wind 18 kts

A common feature of the larger subglacial lakes is a dip in the surface on the upstream side of the lake.  The ice will flow slightly faster across the lake, and this creates stresses in the ice layers that tend to form a trough where the speed increases – the beginnings of a gap if you like.  The trough will collect more snow than the surrounding areas, thus creating a zone with thicker snow layers.  As the ice moves further downstream over the years and more snow accumulates on the surface, this zone of thicker layers moves deeper down in the snowpack. This is exactly where we would like to place our next drill site.  The plan is to drill a 120 meter core, and ideally we should have the ice layers as wide apart as possible towards the bottom of the core, where the ice approaches 1000 years of age.  “Thick” layers makes it easier to discern and date the variations in the chemical and physical properties of the ice – i.e. better resolution to the historic climate data.  The idea is that this will give us data that better lets us compare the climate processes of the last period of global warming, before 1300 AD, to those of today.  Are there similarities, or are there entirely different processes behind the recorded climate changes?  There are important questions awaiting answers here, and we will touch upon them again tomorrow.

The site we are searching for is affectionately labelled “Joe Dip” after Joe McConnell of the Desert Research Institute, one of the PIs of the traverse. During one of our planning meetings last year, Joe noticed the trough in satellite images. ‘If we drill in this dip here’, he urged, ‘we’ll get the highest accumulation in the region’. Instantly a phrase was coined: ‘the Joe-Dip’, or, now, Joe Dip. To pinpoint it we have conducted this two day survey of the area of interest, driving a total of 113 km to get our radar profiles.  This is more than we can do in a day, so we picked a nice spot to pitch our tent and stay overnight.  Not too difficult, really – all spots on Lake B look exactly the same, and white and clean they all are.

So what is it like to go camping in –25C?  Well, out of the wind, with the sun baking the tent round the clock – and with modern equipment – it is really quite cosy.  Personally I woke up in the middle of the night because I was too warm.  Half consciously I tried to compensate by putting a naked arm out of the sleeping  bag – but of course this doesn’t really work in minus 25.  Quickly enough I pulled the arm back in, found a better solution by opening the zipper a bit, dozed off again and woke up totally refreshed some hours later to hot morning coffee and sandwiches; glorious sunshine and endless visibility.  Camping life isn’t all that bad after all, not even at 82º S.

Radar image from the margin of Lake D.  The ‘dip’ is visible towards the right, and the red line indicates where we would find the thicker layers towards the bottom of our core. Image: Tom Neumann

Ted, Kirsty and Anna discussing radar results at the field office – in our tent. Photo: Stein Tronstad/NPI