22 September - 28 September 2008 (Reykjavik – Bremerhaven)

Monday afternoon, after more than 24 hours of station time, the oceanographic buoy array had finally been installed on the ice floe. Some scientists left the floe feeling a little sad since they were not able to finish the construction of an igloo before the vessel departed. However, we continued our voyage westwards to sample the sediments of the Mendeleev Ridge. Here, the ocean was almost completely covered by large ice floes. To proceed, the vessel was under full power to push against the pack ice. This was especially difficult since we were towing a 300 m long streamer and the airgun array. Full concentration of the nautical officers was needed to allow a continuous seismic profiling. Furthermore, bad visibility (fog, darkness) and fast icing of the helicopter rotors did not allow for regular ice reconnaissance flights to optimise the ship track.

At the foot of the Mendeleev Ridge, the geophysists had to terminate their programme. The ice became very dense and the streamer was towed across the floes several times. Two days later, at 179°W, the weather allowed for a long-range flight to investigate the planned route. The satellite images were confirmed: approx. 60 km further out the pack ice was much more open. Meanwhile, the geologists continued their sampling programme without any problems. Approx. each 8 hours, new sediment material was delivered on the deck by the kastengreifer and gravity corer. The cores, at maximum 7.5 m long, were immediately processed for further analyses back home in the labs. The entire geological sampling programme took more than a week’s time and was extremely successful.

At the end of the geological transect, we had planned to probe a seamount west of the ridge. In the days before, there were some discussions if the seamount really exists. Its shape on the map seemed too regular. The seamount had a size of 30x40 km, and an altitude of approx. 700 m above the sea floor. Arriving at its position, there was deep disappointment: the seafloor was completely flat. The fact that such a large feature exists only on the map reminded us of the fact that the bathymetric charts of the Arctic Ocean rely still on very sparse data sets. While continuing our westward route, the main programme of the oceanographers started. During the next 700 km of steaming, automatic buoys will be deployed on ice floes and measurements to investigate the temperature, salinity and pressure of the different water masses will be conducted.

Today, we steamed the entire day through an area which must have been open water a few days before. We could observe how an ocean freezes. It started with “pan cake ice”: little tiny floes just 30 cm in diameter and not thicker than 10 cm. However, the satellite images show that we will enter thick pack ice again next week.

Everybody is healthy and send its greetings to the people at home.

Wilfried Jokat
September 28, 2008
81°00`N 155°00’E, -2.0°C