Day 16-17: We move to our new home down glacier
With the hole finished, the drill team lost no time in breaking down the drill and making it ready to transport downglacier to our next site. It was a beautiful morning, though a bit odd in that we essentially had blue skies and light snow. While the drill team packed, Jason assembled some GIS files to help us plot our next drilling location. We knew where we wanted it to within about 100 meters, but now it was time to choose THE spot. The purpose of this hole is to help us better understand the strange ice dynamics we observe here, about 5 kilometers down from our current location, by planting another thermistor string in the hole. We know from prior work that a substantial part of the ice surface motion we measure here is due to enhanced basal motion, meaning that the ice is either sliding over its bed or deforming a sediment layer beneath it. We also strongly suspect that the lowermost ice is at the freezing point, rather than -10C or so like the ice near the surface. Though the primary purpose of the drilling effort is to install the thermistor string, since we are using a coring drill to make the hole we will also save some of the core. This time we will only save small sections every few meters, so that we can analyze the ice fabrics, which will tell us something more about the ice dynamics here. So we based our final site selection mostly on the unusual ice dynamics in this region, partly on the ice thickness data from Bernhard and Frank, partly on the basis of wanting to use the thermistor string we would plant in this hole as a long-term mass balance and velocity marker, and lastly on a final investigation of surface conditions within a 50 meter area by Jason and I.
Taking down the drill mast.
Once the drill was packed up, the drill team took a well-deserved afternoon off to explore the area while Jason and I went to pick the final spot and assess how difficult our move was going to be. For our first move, from the skiway to our current location, the big issue was getting cargo up the hill (and getting stuck a lot). This time the issue was getting down the hill without a large sled load, and preventing the sled from going faster than the snow machine and pushing it out of the way. I rigged up some chains in a U shape to ride under the sled, such that the heavy load would press the chains into the snow and slow it down. This system proved to work great, and we were able to shuttle several loads to the new location that evening without incident. What turned out to be perhaps more interesting was the low snow cover on the glacier, such that we had to pick our way through meter high ridges of exposed ice to keep going from snow patch to snow patch. Travelling on the ice itself was nearly impossible because it was so slippery, so we could only cross short sections perpendicularly to get to the next snow patch. Fortunately the ridges were mostly aligned in the direction we wanted to go, so Jason was able to show off his half-pipe moves while skiing in front of me. In any event, we found a nice gentle route and it proved to be a safe and effective one for the 20 or so loads we shuttled over the next few days.
Jason, skiing ahead of the snow machine.
Jason, ski bum.
The crux of the move was transporting the winch. The weather on our main move day was quite similar to the day before, with blue skies and light snow, so it did not slow us down much. We began by shuttling some more loads of drill gear downglacier while everyone packed their personal stuff and broke down their tents. Once I had Terry and Bella