What’s cooler: snow pits or soil pits? Among the IGERT group, that could be a bit of a loaded question. I may be just a tad biased, so I will diplomatically bow out of answering that question directly, and instead present the facts that I’ve gathered about snow and soil and what we can learn from them.
Creating the pit
Digging is digging is digging. If you want a hole in the ground, you’ve found the right group! We love it so much that we have even created a dance move to celebrate digging.
Layers and Horizons
One feature shared between both soils and snow is their tendency to form stratigraphic layers. In snow, these layers can be seasonal or from particular storm events. As more snow accumulates every year, and the layers remain frozen even through the summer, the layers continuously build on top of one another. In soils, the layers are referred to as “horizons.” The uppermost horizon is known as the O-horizon, which is an organic rich layer, followed by the A, B and C horizons. Proceeding downwards, the horizons become decreasingly organic and increasingly mineral rich until you reach the parent material beneath the soil.
In both soil and snow pits, isotopes can be used to estimate the age of the horizon. In high snow accumulation areas, the snow layers show seasonal trends in oxygen isotopes. Counting back from the surface allows researchers to determine the age of layers. In soils, any remaining organic material in the soils can be dated by analyzing the isotopes of carbon. Histories can be unraveled in both snow and soil by tying the age of the horizons to other properties. In soils, this could be an investigation of what types of plants were growing at a time in the past. In snow, this could be a study of how carbon dioxide in the atmosphere has changed over time. In either case, the story needs a timeline and isotopes provide the tick marks for us.
In seems that across many disciplines, density measurements are used as a simple way to characterize a material. We found ourselves measuring density along snow pit walls at Summit and in deflation zone scarps in Kangerlussuaq. Not surprisingly, the least dense loess sample in our soil studies was far denser than even the ice samples that we measured at Summit.
Little known perks
We’ve also managed to explore some of the lesser known perks of soil and snow pits. We have found that covered snow pits create a perfect venue for puppet shows. And though it’s a bit of an acquired taste, Zak has found sandy soils to be quite a delicacy!