By Brooke Stamper
With safety training and ski practice behind us at Camp-17, we have begun to “hit it hard” as M. M. Miller would put it. Our daily routines have transitioned from gearing up to be outside and gathering our “glacier legs”, to spending time inside working on our research projects. The opportunities for place-based education are endless on the icefield and many students are taking advantage of the resources provided. I recently took advantage of an opportunity to set up GPS satellite receivers with Jason Amundson, Assistant Professor of Geophysics at the University of Alaska Southeast.
Jason and I rode on a snow machine and towed “the coffin”, a storage container with the bulky equipment in it. We traveled seven miles down glacier to a predetermined transect and placed our first of four satellite receivers just below the equilibrium line altitude, where the annual average snow accumulation and ablation are equal. We placed an additional three receivers at equal distances upglacier until we were at the convergence of the Matthes Glacier and Taku Glacier. The GPS receivers will continuously track the velocity of the glacier over a one-week period to determine what portions of the glacier respond most strongly to meltwater input, and to what degree. The project is simply exploratory at this stage. Our hypothesis is that the daily variation in glacier velocity will be higher in the ablation area rather than on the “high ice” in the accumulation area.
The historical and current GPS data collection has been at specific points on the icefield to gather long-term annual data on surface elevation and velocity. Most notably, Scott McGee and Ben Slavin set up stakes at set locations along a line that runs across the Taku Glacier from JIRP’s Cook Shack to Shoehorn Peak as well as a second set of stakes directly parallel to those stakes but starting from our favorite outhouse, curiously named “Dream Land”. On these stakes are placed black trash bags to allow us to better see the daily flow of Taku Glacier. Eventually, the stakes will begin to arc and there will be noticeable change in location of the stakes. This will give us a fantastic example of strain on the icefield and an explanation as to why there are more crevasses on the edges of glaciers as compared to the center. Because the margins of the glacier are influenced by friction, the differences in flow rates are greater; therefore, there are more crevasses we must mind when downhill skiing from the Nunatak that Camp-10 sits on.
Although all of the students have begun to work independently on our projects, we are all aware that our efforts, in total, are for the betterment of the knowledge and understanding of the Juneau Icefield. Together as classmates and expedition-mates we are all here for the furthering of science on glacial dynamics and how this specific environment fits into the greater Earth system.
The Crevasse Zone: GPS Glacier Surveying on the Juneau Icefield, Alaska - Scott McGee's great website devoted to JIRP surveying efforts.