After our lake surveys, it was time for us – the aquatic team of the expedition – to head to the most northwestern place of our expedition, Tuktoyaktuk! The aquatic team, that’s Bill, Ingeborg, Mareike, Tim and me, Münevver.
Travelling on the Freedom Highway
On August 21, we say good-bye to the terrestrial group of our team and drive north on the recently built Inuvik-Tuktoyaktuk Highway. The locals also call it “Freedom Highway”. From the road we can see very huge and various types of pingos (ice-cored hills). 1350 pingos can be found around this region with some reaching 49 meters high and 300 meters across the base. For centuries, Inuvialuits travelling by water or land used pingos as navigational aids.
Change of plans
In Tuktoyaktuk our Canadian colleagues welcome us with a very delicious dinner and discuss our research objectives for the upcoming days. We had planned to do all of our research based on the research vessel Ukpik. However, the boat could not reach Tuktoyaktuk on time due to sea ice conditions in Alaska and we need a new plan. Thankfully, our Canadian colleagues Scott Dallimore, Nicole Couture and Byron Molloy from the Geological Survey of Canada can help us. They have arranged two other boats, one from Aurora Research Institute (ARI) and one from Geological Survey of Canada (GSC), and together we develop new strategies for our marine surveys.
Frozen soil in summer
Our first boating destination was Tuk Island where many thermo-erosional niches at the base of the bluffs occur. Some of these niches are as deep as 4 m because the soil contains significant amounts of ice. The soil is exposed to the surge of the warm ocean water which melts the ice and then easily erodes the soil.
Temperature is the most important parameter to determine the state of permafrost. To measure permafrost temperature, the Geological Survey of Canada has drilled four boreholes and installed thermistor on and in front of the Tuk Island. In summer, only the upper layer – the active layer – of the soil thaws. Below the active layer, the ground stays frozen all year long.
For me, it is incredible to see frozen soil in summer.
Edited by: Sina Muster