The cruise PS115.1 on Polarstern focuses on a geoscientific research program, which has the aim to clarify the geological development of the northern North Atlantic and the shelf area of the surrounding regions.
New samplings of near-surface seabed sediments help to reconstruct the sediment basin development since the opening of the Arctic ocean almost 60 million years ago. Additionally, analysing microbiological communities in the Arctic sediments is part of the working program.
Models explaining the sedimentary basin evolution of the Arctic ocean not only hold information for science but also help establishing a verifiable rating of the resource potential of this so far poorly evaluated area. There are incomplete data bases concerning risk assessment in the possible future usage of those resources. The BGR Hannover’s aim of the GREEMATE project which is conducted in cooperation with AWI Bremerhaven, UFZ Leipzig and the University of Bremen is to contribute to both topics. Furthermore scientists from GEOMAR Kiel, further AWI work groups and scientists of the Laboratory of Polar Ecology Bruxelles are on board to work on additional projects.
All scientific instruments had been installed by the PS115.1 participants during the three day stopover of RV Polarstern in Tromsø. Preparation works could be completed and all permissions concerning the scientific research had been granted well in time, so that PS115 started towards the destination area, which had been estimated to be about 450 sea miles away. Very contrary to the summer heat at home, the temperatures in the research area were expected to be only a little bit above the freezing point.
The required transit time was filled with the obligatory security and rescue instructions, as well as all necessary preparations for the survey operations in the dedicated research area.
Before reaching the Greenlandic waters, the actual research area, a first geological sampling on the East Greenland Ridge was conducted. A successful dredge-pull delivered an unexpected amount of sampling material, which is going to be used for the petrographic analysis and age determination to understand the genesis of the ridge structure. In the course of the first week we have continued the geological sampling on the adjoining shelf with the gravity corer as well as the multicorer. The gained material will be used by the different groups on board. Accordingly, the reviewing of the material for the following geomicrobiological, organic-geochemical, and further sedimentological investigations is very diverse. While the geological and chemical labs were busy since the middle of the week, the geophysical group was testing individual scientific instruments. After completing the testing on Thursday the first seismic streamer of 600 meter length was deployed and recorded the first seismic profile heading West until the nearshore. We were expecting increasingly thick ice, thus we wanted to gather experience first in case of expected collision caused by changing ice conditions in order to deal fast an safely to prevent damage on any of the instruments. Thanks to the colleagues from German Weather Service on board we have a daily weather and ice forecast available. Unfortunately, the prevailing weather situation with fog does not provide good framework conditions for seismic operations with long towed equipment which demands good visibility in ice covered areas. An interruption of seismic profiling on the following day due to a necessary repair of the airguns was used for another sediment sampling on the surrounding flat shelf regions. After 24 hours the geophysical profiling could be resumed on a profile parallel to the coast towards the North.
Since the ice conditions for the further profiling towards the North are promising, it was decided that the seismic streamer could be extended to 3000 meters to allow for a better data quality. Since Sunday afternoon the marine geophysics is continuously acquiring seismic, magnetic and gravity data, which will come to an end when reaching the 81st degree of the Northern latitude. Our operations are supervised by two contracted marine ecologists of the company Seiche/UK to ensure minimum impact of our activities on the marine wildlife, such as whales. They are also ensuring that all regulations and requirements for mitigation measures of the Greenland authorities are being adhered to.
On board everyone is doing just fine.
Best regards on behalf of all colleagues on Polarstern
Volkmar Damm
(12.08.2018 Position 80°15’N, 6°51’W)
