PS 117 - Weekly Report No 1 | 15 – 20 December 2018
A full loaded vessel
As planned, Polarstern pushes away from the pier in Cape Town on 15 December at 4pm, taking off for her 117th expedition to the Antarctic.
Actually, it was nearly 10 months ago, when this expedition took shape in a meeting of all scientific groups involved, the logistic department of AWI, the shipping agency Laeisz managing Polarstern, and Heli Service International GmbH, which operates the helicopters on board.
After months of preparations, the first scientists boarded two days ago to start unloading the many containers with scientific equipment while still in port, whereas most scientists embark today just after noon. Prior to departure, in front of Cape Town’s impressive Table Mountain (Fig. 1). safety instructions were given, including a trial run of the emergency gathering at the meeting point on the helicopter deck and the proceeding to the assigned life boats. On Polarstern this is, in fact, quite easy, as every deck is equipped with outside stairs port and starboard, which directly take you there.
The first days at sea – at unusually low seastate - are governed by learning to find your ways and organizing the scientific parties and their equipment. Laboratories are assigned and set up and in spite of a total of 53 scientists, pilots and technicians on board, in the end everybody finds a suitable space to work. The 8 laboratory containers, which we took aboard for this expedition, help alleviating the spatial constraints, though notwithstanding, even the smallest space is occupied during this expedition. The working deck is particularly crowded as containers and large equipment occupy most of the space there, leaving only limited space for the deck work proper.
With the setting sun of day two of our expedition, the physical oceanographers commence their work just outside the South African EEZ. Four years ago, our French colleagues had deployed bottom pressure sensors on the sea floor which we are about to recover now. Housed in a glass sphere of only about one half metre diameters, these are fine instruments, but notoriously difficult to spot on the large ocean surrounding us once they surface. Releasing their anchor in response to a hydroacoustic signal, they are to break the surface about 1½ hours later. During this first recovery, it is already pitch black at this time, yet an integrated flasher (Fig. 2) leads the way to the instrument, and shortly later it is safely aboard. Three days on and we host 5 of these instruments aboard and the French program is completed.
Meanwhile the other groups on board did not go idle. The laboratories were set-up, instruments started and the calm conditions were used to begin the bird and marine mammal (Fig. 3) observations and to undertake first tests with the two large Dutch instruments on board: the SUIT, a special net to be operated directly under the sea ice, and the Ultra Clean CTD, a device to collect deep water samples under the cleanest of conditions. With currently 6 Bft and 4 m waves from the side, further tests of these instruments are, however, currently postponed, while we seek to sneak south between several looming low pressure systems to avoid losing valuable time should we have to weather storms.
We will report about this and the further progress of our expedition in our upcoming weekly report (not before 6 January due to the AWI’s closure over the season). Until then, all participants of this expedition wish all our relatives, friends and those interested in our work, at home or at sea, a peaceful and happy Christmas, and a great start into the coming year.