A day or two earlier, Jason and I had uncoiled the thermistor string that goes in this hole to straighten it out and help it go down the hole easier, so dropping that down became the next project. I attached a couple large weights to the end to help it drop smoothly, and we got it all the way down without incident.
This thermistor string was encased in a plastic sheath, to help it survive the internal motion of the glacier. But the sheath had some memory of being coiled...
Uncoiling it, however, presented many opportunities for performance artwork.
Seventy five years from now, some hiker may come across this stake in the deglaciated valley.
Down it goes!
That afternoon we decided to have a BBQ while it was still sunny. We had tried this a few times in the past at dinner time, but it always managed to become snowy or cold by dinner time, so it wasn’t much fun for the cook. This afternoon was sunny and warm, and we outside, listening to a 70s mix on Terry boombox. By evening the drill was packed up and ready to go, and most were talking about taking the next day off to hike up to the Hanging Glacier and get a view.
The next morning, a Monday, I called Dirk to check weather to see if we could arrange our third core flight. The weather elsewhere seemed fine, but on the glacier it was kind of marginal. Earlier in the morning it had been snowing, and there were still lots of clouds and overcast around. But Dirk said the satellite imagery showed mostly clear in our area, and everywhere else was great, so we decided to go for it. Once again it was a mad scramble to get a load ready for him. In the upper cirque, where the cores were stored, it was a blizzard, but at the ski-way it was sunny. Unfortunately by the time I brought the last load down the hill, the cloud level dropped to the ski-way level and put it in a solid fog. We heard Dirk buzzing around a short while later. It was still clear down at our camp, and after a conversation with Dirk on the air-to-ground radios, he decided to set down somewhere on the tundra to wait for our weather to clear. I also gave him my Iridium phone number so he could call back to check without having to lift off, since the radios did not have that kind of range. Though foggy, it was still warm, and I took a nap on the snow machine while Jason did the same on a snowbank. About an hour and half later, there were noticeable signs of improvement, and within an hour of that it was bright and sunny and Dirk was parked next to us. We loaded him up with a bit more ice than normal, as conditions seemed good and we wanted to be sure that the remaining ice would fit into a single load. This time he took off in about half the distance, reminding us how important and variable surface conditions are, and how different things are in civilization where the expectation is typically that everything should go according to a plan despite the vagaries of nature.
By the time we returned to camp it was late afternoon, but we still wanted to get started on our next camp move. So we spent some time on Jason’s computer checking out the options for the final site. At our previous two locations, work had been done in either the 1950s or 1970s, so we had some idea of what to expect. The conditions of the new site were largely unknown. Until about 10-20 years ago, this lower cirque had been an accumulation area, much like the other cirques. Recently, however, it has been at or below the equilibrium line, and so has been losing mass. My hope is that a temperature profile from here will tell us something about this transition from accumulation to ablation area, as well as perhaps something about conditions 100 years ago when the glacier was still growing. The reason temperature comes into play is for the same reasons as in the upper cirque – when the surface melts within an accumulation area, the refreezing of meltwater in lower layers warms those layers. So, without having done any calculations to support this..., I expect that we will see a cold upper layer representing conditions of the past 10 years when no accumulation has been present, a warm inner layer representing conditions of much of the 20th century, and possibly a cold lower layer representing conditions during the 19th century when the area was accumulating snow but the surface was not melting as much as today.
Once we had some coordinates selected from the computer, we headed up to the site with a light load to check conditions and pick the final spot. Though uphill all the way, it was a pretty gentle slope, and the snowmachine didn’t have much difficulty getting us where we wanted to go. Once near the site, we decided on a spot that seemed to be in the heart of what was once the accumulation area. It was on top of a broad, low dome. Here a weather station had been placed in the 1970s. It had subsequently been buried by accumulation, but in the last few years had melted out. So we picked a spot about 100 meters upglacier from that station, knowing that at least 30 years ago there had been accumulation there.