Saturday, May 12, 2012

Reflections on the Tundra

Written by Alessio Gusmeroli (UAF)

It is really flat up here. No matter where you look, there are no hills and there are no mountains. The topography is as boring as it gets. This is noticeable if you are a glaciologist (as am I) - used to working narrow valley field sites that are filled by ice and surrounded by rugged peaks and spectacular mountains.
The flat Arctic Coastal Plain
The glory of the Arctic coastal plain does not come right away. It comes with careful inspection. One must stop, listen and look very carefully. If you do that, you hear the sound of the wind, you hear a myriad of snow granules constantly in motion. You notice the role of the wind in creating snow sculptures on the surface. You see beautiful moving snow dunes that resemble their sand relatives. 

The way snow fills the coastal plain is indeed one of the first things we have been learning about in this fieldwork. The presence of snow and the possibility to use snow machines is facilitating all our field operations. With Susan, John, Baptiste and Craig we have been running a variety of "motorized" geophysical experiments, in which the geophysical device is towed across the tundra by the snowmachine. 

The ground penetrating radar, for example is giving us a good idea on what lies beneath the snow pack. First, we see that the snowpack is thicker above ground depressions (i.e., polygonal troughs); second, based on the reflections in the radar data we see that the permafrost that lies at depths greater than 1 m is anything but homogeneous. We have noticed a number of reflectors, likely part of a network of ice wedges and intervening layers. We will be learning a lot more about the deeper ground ice and its relationship to active layer and snow variability once we assemble and jointly interpret the entire datasets. 

Undertaking geophysical fieldwork in the cold has always its peculiarities. We have to fiddle with many tiny little cables that connect into instruments. Some of these often break. Patience and resistance to frustration is something you quickly learn when you work with instruments and delicate cables in the cold. As always, it is a privilege to work up here in the magnificent, bright, Arctic spring with such a nice group of people.
Delicate fiber optic cables connect the radar antenna to the recording console
Team standing ON the Arctic Ocean (sea ice extends out ~4 miles from shore". From left to right: Baptiste Dafflon, Craig Ulrich, Susan Hubbard, John Peterson and me (Alessio Gusmeroli)