Experts from the University of Göteborg conducted the oceanographic survey and gathered microbiological samples. In turn, the team led by geochemist Ellen Damm from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) was responsible for measuring the methane. “The measurements were taken directly on board. As such, the raw data is already available.” She adds: “In between sampling sites, we used our Picarro gas analysis unit to gather air samples. These automatic measurements offered us valuable atmospheric data.” The final results, expected to be available sometime in the next two weeks, will be combined with the oceanographic data. The chemical and physical oceanographic data will allow conclusions to be drawn concerning methane transport and what happens to the gas in the water.
One important goal of the expedition was to gauge the potential effects of the methane leak on organisms in the ocean and atmosphere. As Damm explains: “Microorganisms can feed on methane. As such, ideally the leak could produce increased microbial activity, which would lead to partial absorption of the gas.”
When it comes to how much gas has already been released into the atmosphere, and to whether there could be other leaks to the atmosphere when e.g. storms occur, further research is needed. “That completely depends on the meteorological conditions,” says Damm. “The question of which happens faster – the gas being released into the atmosphere, or microbial consumption in the water – is critical for how the escaping methane affects the climate.” At the same time as the ship-based expedition, there were two helicopter-based methane-measuring flights, coordinated by the Technische Universität Braunschweig and the German Aerospace Center (DLR).
A second expedition is planned for early December. In a subsequent evaluation of the gas leaks in the Nord Stream pipeline, Damm hopes to create a time series to facilitate the modelling of such events and help respond to such situations faster in future.