Go with the Floe: Tuesday, July 10, 2012

PERMAFROST!!!! (And Soil Profiling)

We went out with Julia and Ruth (from Dartmouth University) again today! They visited us in the morning to share atmospheric carbon dioxide data from our last encounter and to teach us about gelisols ("ice soils"). We traveled up to an area near Lake Fergusson and discussed remote sensing techniques (the use of satellites, cameras, or other methods of observation to perform preliminary surveys on a landscape), vegetation classification, and the purpose of soil pits. Julia and Ruth have been using soil pits (deep holes dug to reveal a soil profile) to analyze fluctuations in the depth of the active layer in relation to that of the permafrost layer. Each group was assigned an area in which we dug our own soil pit. We measured the depth of the permafrost layer at various locations and compared the results. My group dug our pit on a north-facing hill slope covered primarily in grasses and small shrubs. The top 8 centimeters of our profile was moss! That layer was followed by a 4-5 cm layer of organic soil (dark, nutrient-rich peat) beneath which was a layer of mixed sand and silty clay. Our pit was comparatively shallow - only 28 cm of active soil on top of the permafrost (other groups' pits ranged from ~40 cm deep to ~55 cm deep). We hypothesized that this is largely due to the orientation of the slope to the sun. Because the hill is north-facing, the slope is less exposed to the sun than the surrounding area, and the permafrost layer can exist at a shallower depth because the ground is cooler. This activity gave me a different perspective on the ground beneath our feet - and a chance to play with some permafrost! It was so much fun!

This doesn't have a lot to do with what we did today, but I thought it might be worth mentioning; relative to its level the day we took discharge measurements (July 3), the Watson River has risen considerably and is flowing at a seemingly greater capacity than before. It's extremely formidable!
Tomorrow will be our last day in Kangerlussuaq. I'm so sad to be leaving, but I've definitely got the Polar Bug, and I'll be looking for any chance I could possibly get to return to Greenland! For now, I'll just have to enjoy the time I have left.