Hi again from Adam, blogging from Finse station!
Happy to report that the sunny conditions which greeted us on Saturday have remained, and we’ve benefitted from amazing conditions for surveying. Great visibility, calm wind and no precipitation risk is a great recipe for a pleasant glaciological campaign!
Yesterday was our first full day on Midtdlasbreen and Benny and I spent the day on the glacier margins, testing our ground-penetrating radar (GPR) system and setting up a few survey grids to target ice conditions beneath our feet. Grid set-up can be a bit of a guessing game: while Benny knows that he wants to work around the glacier margin, last time he saw it (August 2013), it wasn’t buried beneath several metres of snow. Add to this the fact that the glacier will have retreated a few metres since August, knowing that we’re exactly where we want to be can be problematic and his disorientation is entirely forgivable! Fortunately, we have the GPR. If Benny gives me a ball-park guess of where the glacier margin is, I can quickly use the radar to zero in on exactly where we should be working. This is one of the great things about GPR: its display is almost real-time, so you can quickly make an initial assessment of what is buried beneath you.
Surveying is pretty efficient – which is good, because walking under the weight of the equipment is a great way to keep warm! Our GPR system – made by Mala Geoscience – is robust enough just to be dragged along the floor behind us as we walk over the glacier. We simply connect it to a control console, secured in a rucksack, and tow it along. Informally, this system is called ‘The Snake‘ – the photo below, in which Benny is operating the system, should suggest why! The system triggers a recording every 0.5 seconds meaning that, at a typical walking pace over snow, we get a measurement of the glacier every 30 cm.
Where we have a particularly long line to survey, we can also attach The Snake to the back of our snowmobile. Compared to walking, this approach makes geophysical survey feel like a piece of cake…! In this video link, you can come for a snowmobile cruise along the top of Midtdalsbreen with me and Benny! However, we still have to survey quite slowly to get the detail we require, and snowmobile engines quickly overheat if they are driven at walking pace for too long. As such, the main mode of surveying is still pedestrian-powered. Still, it leaves the glacier nice and peaceful, for us and the ski-mountaineers who pass us by through the day.
All in all, it’s been a great kick-off to the fieldwork and we think we’re starting to get some really great data. I’ll share some with you in the next few days; right now, it’s time to watch the snow turn pink in the sunset.