From Longyearbyen through Fram Strait towards Northeast Greenland

Where are we going? What are the major goals of this expedition? The overall scientific goal of the marine-geological shipboard and following onshore work is to investigate the variability of key environmental parameters in the Fram Strait during warm periods (interglacials) of the geological and historical past. Of special interest are the last interglacial (Eemian, around 130-120 thousand years ago) and the Holocene (last about 12 thousand years). Key environmental parameters are the extent, density, and nature of the sea-ice cover, the properties of the water masses (temperature, salinity and stratification), the rates and causes of changes of these parameters, and the coupling of Fram Strait variability to the Arctic Ocean and the North Atlantic. On short (multidecadal to centennial) time scales details of this variability are unexplored so far, except for the Holocene in the eastern Fram Strait. To analyze the short-term climate variability, during the Expedition PS93.1 long sediment cores will be obtained from areas with potentially high sediment accumulation and analyzed for a large variety of paleoceanographic and paleoclimatic proxies in home laboratories and in collaboration with international partners. Target areas were selected on the NE Greenland continental margin, in the central Fram Strait and on the western Svalbard margin.

In addition to the marine-geological program that is the major focus of this expedition, several supplementary programs will be carried out:

·         Recovery of oceanographic mooring systems and deployment of Sea-Gliders in the central Fram Strait (physical oceanography)

·         Sampling of phytoplankton for cultural experiments (biology), and

·         Measurements of water vapor and its isotope signature (atmospheric chemistry/glaciology)

Besides the scientific research program of Expedition PS93.1, a “Floating University” will be held onboard Polarstern under the umbrella of the International Research Training Group “Processes and impacts of climate change in the North Atlantic Ocean and the Canadian Arctic  - ArcTrain”. Within this program, about 20 Canadian and German PhD students will be introduced to technical aspects of field work in marine sciences as well as to the concepts of teamwork, interdisciplinary and international collaboration and project leadership.

Tuesday, 30 June 2015. The first working day is dedicated to oceanographic work: Moorings are to be recovered – long chains of instruments for long continuous measurements of temperature, salinity and current velocity. They were left behind in the central Fram Strait last summer because of extreme sea-ice conditions and lack of ship time.

The search for the first mooring remains unsuccessful. However, a new mooring can be deployed at the same location, which resembles more a UFO than the usual chains (Fig. 2). The second mooring is located 12 miles toward the east. The sun returns and visibility improves. Many people gather on the bridge and the uppermost deck to spot the orange and yellow glass spheres that mark the upper end of a mooring. These flotation devices are finally discovered around lunch time. Because of the calm and sunny weather it is an easy task to bring them in. At about 20:00 three out of four moorings are on deck – a successful day for our oceanographers!

Around the same time the geologists are still searching for the perfect location to deploy the “kastenlot” (a coring device with a large rectangular cross section that greatly reduces the perturbation of the sediments). Then exactly at midnight the 12 m-long device equipped with a 3.5 t weight on top penetrates the sea floor at 79°12.2’N, 04°40.0’W and a water depth of 1570 m.  Expectations are high when the kastenlot returns to deck (Fig. 3), and indeed, judging from the muddy outside the penetration depth was about 7.5 m. But how long is the sediment core really? What is actually inside the metal case? These questions we can only answer when the case is opened.

Wednesday, 1 July 2015. In the early morning hours, we are heading towards the north. Temperatures are decreasing, and we sight the first sea ice at 3:00 am at 79°14’N, 04°30’E. Four hours later we encounter the first sea ice directly. At noon thick fog is developing, and the sea ice is becoming denser and denser. Hopefully, we can continue our sight survey using the Hydrosweep and Parasound systems to map the seafloor and the uppermost sediment layers. Fortunately, the fog is clearing up, the helicopters can take off to check the ice conditions and find a way through the ice.

As early as 5:30 am on this day a few lucky people get to see a female polar bear with her two cubs (Fig. 4).