The second sea expedition to conduct Seamstress experiments is ongoing on board the new Norwegian research vessel Kronprins Haakon. The expedition started from the Longyearbyen port (Svalbard) on the 19th of October and will end at the same port on the 9th of November. The expedition is led by Jochen Knies from the Norwegian Geological Survey (NGU) and co-director of CAGE.
Together with colleagues from CAGE we have been wishing for several years to collect sediment samples from the west Svalbard margin using the Calypso coring tool that can retrieve up to 20-24 m of sediments. By collecting sediments at these depths in the area we would be able of reconstructing processes associated with the last 2-3 glaciations (> 150.000 years ago). For the purpose of the SEAMSTRESS project, such information is key for understanding the mechanisms that controlled the periodic release of methane in the geological past. In addition, Calypso cores are known for their excellent quality and preservation of the sediments collected and these are ideal samples for continue records and for the geotechnical tests (to search for spatial strength variation) we will conduct as part of our collaboration with the Norwegian Geotechnical Institute (NGI).
In February this year, I presented a proposal to CAGE- Center for Arctic Gas Hydrate, Environment and Climate and interested groups from the Department of Geosciences, to conduct a joint expedition for collecting for the first time these > 20 m long Calypso sediment cores along the continental margins in the Fram Strait. These samples are needed to conduct a wide range of cross-disciplinary studies like for example paleo temperature reconstruction. The proposal was accepted with great interest and together with Jochen Knies we have spent a couple of months coordinating the expedition. The expedition is taking place now. We had originally planned for more than 15 sampling stations in Fram Strait that will provide data for current and future national and international collaborations. This expedition relies on the use of the Calypso core instrumentation operated by the University of Bergen (UiB).
In addition, a novel experiment is being conducted as a collaboration between UiT and Ifremer in the framework of SEAMSTRESS. Colleagues from Ifremer are on board with their in-house developed pressure and temperature rod (the Piezometer). This is a thin rod with sensors all along for measuring pressure and temperature in the sediment down to a depth of ca. 10 meters. By having these sediment properties we can investigate how water masses affect the thermal field that in turns affects the dynamics of gas and stability of frozen gas (hydrates) in the sediment. We can also search for spatial differences in the pressure field near the seafloor that controls the release of methane to the ocean.
Preparation for this expedition has relied on strong cooperation from UiB, the Norwegian Institute for Marine Research (HI or IMR), the Norwegian Geotechnical Institute (NGI) and the French Institute for Exploration of the Sea (Ifremer) technicians.
We have been receiving news from our colleagues at sea and it is possible to follow their posts at https://cage.uit.no/frontpage/news-archive/. They are certainly not having a boring cruise since the experiments has turned out to be highly challenging, both technically and weather wise.
Text: Andreia Plaza-Faverola
Picture: Jochen Knies