Written by Chris Polashenski
Since our last post from site 1A-20, which is on the southern, ocean-ward limb of the peninsula we’ve been working on, we’ve traveled North by Northeast over the top of the divide and into ice that flows toward Nares’ strait and the Arctic Ocean. As soon as we crossed the divide, the character of the snow changed. We left the high winds and beautiful dune and barchans formations behind in a matter of minutes and entered a flat land gleaming with surface hoar frost – clearly the storm had never been on this side of the divide. Stopping in at camp and pitching the tent gave our next sign of change. At 20cm, the tent stakes hit something hard- last summer’s melt layer. In 100 miles of driving we’d crossed from 160+ cm of annual accumulation to 22cm. This is truly a desert.
With such low accumulation, our 2 meter deep pit took us back approximately 9 years, possibly 10. The uncertainty arising from the fact that it is difficult to estimate how much snow melted away last year – at least one year’s worth, but maybe more. All of the melt re-froze in deeper layers, so we could examine how much there was in the pit wall, but more may have been beneath the bottom of our pit. Drilling in for our 10 meter temperature (we actually make a 13 meter hole) took us back around 60 years. Pretty cool.
Though we’re still headed north, and 600 miles or so from Summit station, we’re starting to think about our exit strategy. Our plane home leaves on June 6th, and we need to be back at Summit before June 4th to get packed out. This part of the traverse had always been a bit fuzzy in the plans. You’ll see if you look at our planned route only 4 waypoints set for our return route. The primary science objectives were all along the GriT traverse route that we’ve already completed. Since we had to drive back, however, and since we were already so far out, several important secondary goals were on the radar. First is to get deep into the low accumulation zone on the North side of this divide to sample for black carbon. We are very curious whether black carbon deposition is predominantly a dry (without precipitation, just settling out) or wet process (falling entrained in snow). The huge precipitation gradient we’ve crossed provides a nice natural experiment for checking on this. Second, we wanted to validate what the satellites had indicated for melt extent and severity last year. A couple areas of interest were pointed out by our friend and collaborator Son Nghiem here in the North, and on the Eastern side of the ice sheet down toward Summit. Finally, at least on the abbreviated list, our friends in Joe McConnell’s research group are drilling a firn core out at Tunu camp in far northeastern Greenland. Dragging our ground penetrating radar in to their site could connect what we’ve seen all along to a very detailed analysis, providing us a better idea what we’ve seen, and them a better idea of how spatially representative their core is.
Alas, now that the days are numbered and our fuel jugs are dwindling, we’ve had to make our plans for which secondary objectives to hit, and which to abandon. We want to do it all, but with 100 mile driving days for the next week, the plans we’ve made will already pack in about as much excitement as we can handle.
Or so we thought.
Today while driving along, somewhat bleary eyed on smooth terrain at about 40 miles into our 106 mile run I caught something strange in the distance. Distances being hard to estimate, first it looked like a bird, but as it came closer to focus it was clear it was much too far away. Maybe a flock of geese? Mmm. geese. Nope that’s not right either. I stopped and whipped out the binoculars. It was a twin otter (a highly capable 2 propeller bush aircraft). Weird. We’re a long way from anything. And it had just dropped in out of the clouds and was making tight circles, about 3 miles down our route. Are they landing to meet up with us? We drove on toward it at top speed as it set down and landed. Who was this? Did someone decide to bring us fuel? (we’d like that). Running in we could see a couple figures and a weather station. We had happened by pure chance upon Koni Steffen, a renowned researcher from Switzerland, and formerly CIRES in Boulder, Colorado as he’d flown in with a group to maintain a weather station in the network we’re adding to on this trip. We hadn’t even taken the coordinates of the weather station in advance, so had no idea we were driving right by it, had the plane not come out of the sky. Koni and I had emailed back and forth when we wrote the proposal for this work to the National Science Foundation, but never met in person. What a way to meet! Handshakes, smiles, and amazement all around, and an exchange of Swiss chocolate (Koni’s group) for caribou jerky (from us) ensued. The Icelandic pilots, David and Kiddi, one of whom had never driven a snowmachine, asked to take the sleds for a spin. Some hilarious sub-standard driving ensued. We joked that we should get to take the plane for a spin in exchange! As a pretty good consolation we got a few cokes and a couple Icelandic yogurts (best yogurt on earth!). After half an hour or 45 minutes of chatting with the first people we’d seen in weeks, and receiving an open invitation to stop in at the Danish NEEM camp on our return south in a few days, we parted ways with our unexpectedly met colleagues and continued off to our evening’s camp 60 miles to the North.
Tonight’s pit was a whopper – only 18 cm of accumulation, but the melt hit this area hard. Several layers of ice a few inches thick each made for a 4 hour dig. Now at 3 am we’re all ready for some hard sleep after an exciting day. Tomorrow we’ll make our furthest North camp – Ultima Thule!