Introduction
Under the sunny blue sky of Juneau (we swear this is not fiction!), we, six intrepid JIRPers- Scott McGee (Alaska), Paul Winter, Martin Lang (Germany), Tristan Amaral (New Hampshire), Alex Mischler (Yukon), Saskia Gindraux (Switzerland)- took off from the downtown floatplane harbor. We packed Albert’s shiny DHC-3 ‘Otter’ floatplane with our camping gear, backpacks, a ton of macaroni cheese and spam, and land survey instruments, then flew to the touristy Taku Lodge. We passed over the spectacular Norris, Taku and Hole-in-the-Wall glaciers and had an aerial peek of the icefield we will be traversing later! From the Lodge, two small boats adapted to shallow water brought us directly to the Taku terminus.
Taku is the largest glacier flowing from the Juneau Icefield in South-East Alaska. Unlike other glaciers, it has the particularity to be advancing (over the past 100 years). The scientific community is interested in the rate of the glacier’s advance which is precisely the reason why JIRPers are sent there to measure the terminus’s extent every year.
Arrival at the Taku terminus
Airmail delivery at camp
Study Area
Mosquitoes loved us... for dinner. And breakfast. And lunch. We had to fight to keep the bites and itchiness below insanity levels. The kitchen meshed shelter was an absolute must for our endeavor. Our base camp from June 26 to June 30 was located on Oozy Flats. This outwash consists mostly of sedge, grass, lupine, fireweed, cow parsnip, driftwood, alder and balsam poplar. Where the Taku Glacier meets the land is a sopping wet landscape of mud, gravel, buried brush and ice.
Inventory of local forces:
Aerial: the 53 Artic Terns Kee-arr!! Defense System against the rest of the world, a few bald eagles, common ravens, herring gulls, all quickly chased away by terns. Two hummingbird spies were regularly hovering around the tents, some warblers and sparrows were also singing for us. We cannot forget the noisy floatplanes and helicopters. But nothing compared to the 1,763,388,182 blood-thirsty mosquitoes and millions of flesh tearing flies.
Terrestrial: unseen unheard track-making wolves, the resident grizzly bear and a wandering moose, plus a family of curious voles.
Naval: essentially obnoxious speedboaters, including a nerve-wrecking airboat out for a Friday night rip on Taku River…
Wolf and Grizzly bear tracks in silt
Mosquitoes on the mesh of the cooking shelter
Methods
In order to make measurements, we carried 2 sets of Trimble 5700 differential GPS. The Trimble is a ridiculously expensive and cumbersome backpack wired to an antenna and controller, making for a very precise GPS. There was no field base station since we could use the Juneau Airport Continuously Operating Referential Station (CORS) in post-processing to increase accuracy and precision of waypoints up to 1cm.
We split in two 3-person teams and took waypoints at the ice margin, whenever ice was visible or probed under silt deposit, with a 40m interval approximately or whenever the terminus feature was relevant. For each waypoint, we waited in position for 30 seconds to average points taken and reduce error. We backed up each Trimble with handheld GPS (Magellan Meridian Platinum) for the same waypoints and for 30 seconds WAAS average for backup.
Making your way through unsupportive silt mud and rocky push moraine was extremely strenuous. It was necessary to either sneak in nap in the warm air current flowing from the glacier surface (and keeping mosquitoes away) or to play a quick game of pétanque (the famous French bowl game) with rounded rocks on flat silt to stay energized.
To finish off a day of surveying, when back in camp we would reach for a can of glorious SPAM, open and slice its content, fry in a pan until the imagination tells you there’s bacon in it and then eat. And repeat (until satisfied and/or disgusted).
Scott explaining how to use both GPS instruments
Walking on the edge of the glacier overriding alder trees
Fieldwork
The first day we split up into two teams (Team Europe and Team North America) and each headed in opposite directions along the edge of the terminus. Needless to say, travelling along the terminus was unbelievably treacherous. After each walking about one mile in opposite directions, taking survey points along the way, the two teams regrouped and debriefed over delicious spam pilot bread sandwiches. It was discovered that Team Europe only collected 35 GPS points while Team North America recorded close to 70! (According to Martin however, the terminus where Team North America surveyed was akin to the “Autobahn” whereas the section they hiked over was more like the Himalayan mountain range).
Day two began with instant oatmeal and sausages and a second swarm of very hungry mosquitoes. All six of us travelled in the same direction and collected about 35 more collective points before getting stopped by a raging outlet river that flanked the side of the terminus. This section of the terminus was extremely hard to travel over as we (Alex) encountered hip-deep mud, hard stream crossings and very steep cobbly push moraine slopes. Again, the day’s work was debriefed with spam sandwiches which were later followed by an enormous quantity of mac and cheese.
The third day we hiked up on the terminus to explore this vast extent of ice. We were getting more comfortable walking around with crampons and route finding over crevassed terrain. We reached a viewpoint of the Norris Glacier terminus, west of the Taku before turning back for more spam! Our plan for the next day came from the skies: an airdrop containing a note from Al, along with chocolate, caramel and pop tarts. The next morning we will be picked up by boat for the return trip to the lodge then to Juneau under pouring rain.
Analysis
A comparison between the points taken in June 2013 and in June 2014 reveals that the terminus position was not moving evenly and has been mostly stable: minor retreat in some areas of 5-10 meters, minor advance in some areas of 10-15 meters. We calculated an overall average advance of less than 1.5m only which is barely visible from an aerial view as shown in the map below. This is a reduction in the rate of advance as compared to the past several years.
Overall the trip was a success as we collected the data we needed, got our stomachs almost accustomed to the gruesome expedition diet and did not get fully devoured by mosquitoes. All the while we were able to admire the beautiful, ever-changing expanse of the landscape as both researchers and explorers.
From left to right, Saskia, Tristan, Alex, Martin, Scott and Paul