After a night of repositioning the drill and coring about 20 meters, the drill crew slept during the day as Jason and I headed downglacier to explore the lower valley to prepare for a hydrological monitoring during summer. Most of the snow and ice that melts on the glacier during summer ends up at the stream which emerges from under the terminus. By studying the stream and its dynamics, we can potentially learn many things about how the glacier works. For example, we know from previous studies using GPS to measure ice velocity, that the glacier moves faster on hot sunny days than it does on cloudy days. The reason has something to do with meltwater reaching the bottom of the glacier and by studying the stream that comes out we can gain more clues about exactly how this increased meltwater makes the ice move faster. But studying streams is problematic and time-consuming, because the fast moving water tends to damage or wash away instruments there, so we’ve not spent much time there due to limited resources. This summer we hope to make up for that, so we need to figure out where to place our instruments now, while it is still easy to walk around there.

The snow cover was still quite thin on the way down, with lots of bare ice exposed and increasing numbers of rocks towards the terminus, so the skiing not much fun. On the way, however, we came across a set of wolf tracks, heading up-glacier towards our camp. They looked quite fresh, probably from the night before. We’ve seen fox tracks before on the glacier, and lots of caribou tracks in the valley below, but no wolf before, so this was something new. The tracks continued down to the terminus, and as we entered the frozen stream channel it was clear the wolf had come up from the valley below, traveling over the aufeis.


Ripples of frozen water build and remobilize the aufeis field. Did the wolf that passed over it (tracks on left) notice or care?

A field of aufeis coats the valley floor every winter. Aufeis is ice that forms when a spring continues to bubble up water through winter, and freezes as it flows downhill. In this case it flows for many kilometers, with a thickness reaching more than 4 meters in places. It makes a nice highway for traveling on foot, whether by two or four legs, as it smooths over the all of the rocks. It is thick enough that patches last throughout the summer, and we have hiked over this often as it much quicker than scrambling over valley wall rocks or trying to skirt the fast flowing stream. Today we hiked all the way down to the natural wier, a constriction formed as the stream erodes through solid bedrock. It turned into a blistering hot day, and the ice surface melted and run in sheet flow beneath our crampons. All along the way, we continued to see wolf prints in the snow patches, and at the wier, it was clear that he scaled the 2 meter ice cliff that becomes a raging waterfall in summer. In the 1970s, this site was used for stream gaging, but having scoped the valley to this point, we decided to use the spot not far from the terminus for our studies, where the stream forms a single channel through old basal till, conveniently located next to our camp site.


The river coming from McCall Glacier is eroding through bedrock here, forming a natural wier. There is a 2 meter drop of frozen waterfall here, which our local wolf managed to scale.


Though there is a two meter drop over this frozen waterfall, our local wolf seemed to have no trouble scaling it, as seen by his tracks. We turned around here, as we only had claws on two of our legs. (Click on the panorama and drag to look around, press Shift to zoom in, Command (Mac) or Control (PC) to zoom out.) Enlarge this panorama


Heading back up towards camp, following our four legged friend.