SCHOLARSHIP DAY 55: Lake Bathymetry Fieldwork (in minus 20 degree C)

It was to be another early start for me, and after the excitement of Chena Hot Springs yesterday, I was by no means surprised by my fatigue this morning. Today was set to be another field trip to a lake, but with a different purpose. I've done some fieldwork in my time, but never I don't think in -20 degree C temperatures. How best to describe how cold -20 degrees C is? Well, if you touch bare metal with wet hands, you're stuck there. If you pour water over your jacket, it will freeze almost immediately. Oh, and if you've just had a shower and your hair is still wet upon going outside, your hair starts to turn white. The truth, and I should know, as the latter in that list happened to me as I was waiting for my bus this morning.

I arrived at the university to meet Allen; the professor that I would be assisting today and Jacob (another volunteer who I met the other day). I was also introduced to a pair of Bunny Boots; don't laugh, this is serious stuff! Bunny Boots make all the difference between freezing cold wet feet and nice dry and toasty feet. So, it turned out my hiking boots got a day off today, whilst the Bunny Boots were put in full service.

Well, our first job was to get the equipment out of this large storage tin; about a garage size tin, with a combination padlock for security. Normally, one would put the combination in and away you go, but this is Alaska, and life isn't that simple. It seemed like the padlock was frozen, and so we were left to figure out how to get the tin open. Hammers didn't work. A metal pole didn't work. We eventually tried using a blowtorch, and after consistent heating, we eventually melted the padlock, and accessed our equipment.


The lake (when we finally arrived) was much the same in comparison to the one we studied last week. It was a thermokarst lake, with split trees on the shore, and much the same vegetation; Spruce and Firs. If anything was different, it was the thickness of the ice. In other words, it was much safer to walk on, with at least 2cm of white ice and a further 12cm of black ice.

 

 

So, the task today was to study lake bathymetry. Basically for those who are unsure, we want to form a 3D model of the lake; how deep it is, and the topography of the bed. To do this, individual holes had to be drilled with an auger, the location of the hole had to be defined by DGPS (Differential Global Positioning System) and then the depth of the lake would be measured using a tape measure held down on the bed by an iron weight. (The mix of sophisticated and particularly amateur equipment never ceases to amaze me!)

I had a go with the auger, but believe me, this is hard work. Very hard work! It's a hand one, and drilling through thick ice became weary on the arm, to the extent where your arm becomes dead. Why we put ourselves to all that effort when we had a petrol one in the van, I will never know! If anything positive was to become of it all, it was the fact that you instantly became nice and warm, although after a few holes, you start to produce a sweat which instantly turns cold. Fortunately, Allen and Jacob saw how difficult I was finding it, and we switched roles after lunch.

We worked until the Sun was starting to set, and the light was starting to dim. By that time, we had drilled and measured 120 holes; not bad going for three people! My coat and trousers were covered in ice which had formed quickly after water from the drill had splashed up on me, and so I defrosted in the truck on the way back to the university. When I returned, this scene caught my eye. It's not smoke from a fire; it's water vapour. After drilling through ice and measuring depths of lakes, to see such a dramatic scene formed from water vapour, really does show you the immense diversity of water. No more than 24 hours ago, I was bathing in water heated by the Earth; today I was walking on frozen water, and now I was seeing it leaving the Earth- once again, how wonderfully dynamic the planet is.