Suddenly, everything had to go very fast: In the night from Friday to Saturday, the researchers discovered a dangerous crack in the ice close to their ship. He almost cut the connection between the "Polarstern" and the research camp on a floe. With a helicopter, the team managed to recover important equipment just in time.
The "Mosaic" expedition led by the German Alfred Wegener Institute (AWI) is not only the largest research trip of recent years but also takes place under special extreme conditions. For a whole year, a total of 300 scientists in the ice of the Arctic Ocean want to investigate how global warming affects the winter Arctic (read an extensive background).
Currently, the perceived temperatures are beyond the -30 degrees. There is total darkness around the ship, until March the crew will not see the sun at any time of the day. On board is the time of the Japanese capital Tokyo, to structure the day.
The ship drifts on its own with the Arctic sea ice in the area around the North Pole. Currently at 85 degrees north latitude and 129 degrees east longitude, it is in a region where the effects of global warming are already evident: the Arctic heats up more than the rest of the planet. Sea ice cover, at 5.75 million square kilometers, is the lowest ever since the start of measurements some 40 years ago. This is shown by current data analyzes by the AWI and the University of Bremen.
"The global warming, and in particular the very hot in the Arctic last summer have meant that the ice is thin and not very stable," reports "Mosaic" expedition leader Markus Rex directly from the "Polarstern" in an email to the SPIEGEL.
Markus Rex / Alfred Wegener Institute
Over the research camp "Ocean City" on the ice the full moon has risen
Since the beginning of the month, the "Polarstern" is anchored to an originally 2.5 x 3.5 km plaice. At least with its northern part, the expedition team is very satisfied: here are several layers of ice pressed over each other, sometimes several meters thick. A stable floe is important to the success of the mission.
"The scientific investigations expand, starting from this stable basis, into the surrounding thinner parts of the floe," describes expedition leader Rex. The crew calls this stable area "the fortress". The only - albeit uninvited - guests are polar bears. At least two animals had already approached the ship in recent days. They were sold with pop-up ammunition of a signal pistol.
Esther Horvath / Alfred Wegener Institute
Two polar bears near the "Polarstern". When the picture was taken, no one was on the ice.
However, researchers must also be cautious about so-called melt pools. There the ice had already disappeared in the summer, now they are covered only with a 20-30 centimeter thin layer from the autumn. This is not thick enough to use heavy equipment like runway bulls on the ice. "That was not to be expected after this warm summer," says Rex. The technique would come into play as the ice thickens and becomes more stable during the winter. Currently, however, snowmobiles can already be used on marked trails.
The "Polarstern" and their floe have already survived several storms. From the weather data from the ship can be read that the wind speeds were sometimes beyond 50 kilometers. That corresponds to wind force seven to eight. At least the "fortress" did not seem to be affected by the storms - "while the thinner area of our plaice has broken many times, deformed and wide areas are not accessible in phases," says Rex.
"Carefully optimistic that the base holds"
"Of course it can not be ruled out that even the stable area of our plaice will break," says Rex. "The risk can not really be stated, but we are cautiously optimistic on the basis of past experience that the base holds."
Measurements will be carried out in different camps on the ice, "Met City" for the weather observation and "Ocean City" for ocean analyzes are being set up. The structure on the "Mosaic" floe was modular and designed to break the ice in question, Rex said. "We would first cut the power lines along cracks or shear zones and wait until the ice situation calmed down."
Later, one would reshape the structure according to the conditions and relocate the power lines again. "The whole concept is very flexible and adapts to the changing circumstances." Part of the measurement technology, the so-called distributed network, works autonomously anyway. The buoys and measuring units had been dropped on the ice with a helicopter and a Russian icebreaker up to 50 kilometers from the "Polarstern". Again, the team had to fight with very thin ice floes.
