Adventdalen on Spitsbergen, like many other glacial valleys in the High Arctic, is punctuated by groundwater methane springs. A year ago, we started exploring these active greenhouse gas sources.
Text: Dimitri Kalenitchenko, CAGE and Alexander Tøsdal Tveit, Department of Arctic and Marine Biology, UiT .
Photos: D. Kalentichenko
The exploration is conducted by using advanced molecular technics combined with geochemical and physical measurements. With our first field campaign in 2019, we aimed to understand the fate of the greenhouse gases released through these seeps. Most importantly, we wanted to know whether most of the methane is consumed by microorganisms or released to the atmosphere. As it turns out, our first findings contributed to more new questions than answers. This year we went back with the objective to collect samples below the ground surrounding the methane seeps. We hoped that being able to collect water and sediments beneath the surface would improve our understanding of these fascinating ecosystems.
Among all methane sources, “Lagoon Pingo” is the methane spring that is the easiest and fastest to reach in Adventdalen. After a short rib boat ride, we would walk for an hour with coring and sampling equipment stored in our backpacks. The coring equipment consists of a 30 kg corer able to reach the microbes hidden below the muddy surface of the methane spring. We managed to sample up to 4 cores daily using a sliding manual hammer to push the coring stainless tube deep into the mud. All operations were slowed down by the constant wind blowing on the site and the corrosive mud sticking to our equipment and clothes. After 7 days of intense work, we managed to complete our survey of this easy-access site. Next, we sought to explore the other methane seeps in Adventdalen.
Professor Andrew Hodson (UNIS) safely guided us across marshes, peats, and rivers to the visually most spectacular site. The 25km hike killed our feet, but it turned out to be the best day of the entire field campaign. In the middle of Adventdalen, an impressive hill called Innerhytte is located. It rises 15 meters out of the ground, in the middle of a river. Out of this rocky hill flows sparkling groundwater saturated with methane and CO2 that originates from underneath the permanently frozen soil layer, the permafrost. To support the future in-depth exploration of this new site we have created a 3D model using a drone to help plan future missions to this remote greenhouse gas source.
All the frozen samples collected are now on their way to Tromsø and will soon reveal which methane eating microorganisms are hidden beneath the ground, and how they make a living consuming the large natural gas sources that seep out of Arctic landmasses.