As we entered the second week, everyone was looking forward to getting to the Greenland coast and to the front of 79-N Glacier. Until this point, all science had been largely successful, but now we were entering sea ice.
The RV Polarstern is an icebreaker, so its reinforced hull should be no match for any sea ice – frozen ocean water up to about 3 metres thick, rather than 100s-1000s of metres thick ice shelves and ice sheets – that gets in its way. Loud scraping and banging sounds can be heard as we pass through the ice, with what could be described as moderate turbulence for those more used to flying. When the ship encounters thicker sea ice, it charges and beaches its bow on the ice, using the weight of the ship to break through. It sounds risky, but seems very effective. If the ice isn’t caught straight on, however, then the ship can slowly roll far from side to side. During these times – and similar to when in rough sea – the soup is only served half full.
While movement is not impossible in sea ice, ship-based science is heavily hampered. Suitable open water is required to deploy or retrieve science equipment. Several moorings – which had been recording ocean conditions over the last year – could not be recovered as they were somewhere beneath the densely-packed sea ice. Several of our key sediment coring locations were also in this area, and sadly had to be abandoned.
Sea ice also means the possibility of polar bears. It was after a couple of days of ploughing through sea ice, when we heard the announcement “[Something in German…] ..ice bear”. At that moment, everyone’s ears pricked up. We all stopped what we were doing, grabbed ours cameras and ran outside to the deck. There was not one, but three polar bears! They – what looked to be a mother and two large cubs – were snacking on a recently killed a seal and hanging out on a piece of nearby sea ice. It was amazing to see this cuddly, ferocious killer in its natural habitat and, as it turned out, this was not going to be my only polar bear encounter.
Near to the coast, this fragmented drift ice, which had survived the summer, was replaced by newly formed nilas sea ice. Cloud and fog was also ever-present. It was at this stage of the cruise when helicopter operations were to be in full force. We had five sites that together required 4-6 days on the ground. Unfortunately, bad weather and a high demand for the helicopter meant that we didn’t get to any of these sites. Only by joining another small team, did we manage to get to land, but that was only for 40 minutes. Two other opportunities to collect samples were abandoned because of polar bears at or near to the sites – I’m not sure I’d win a fight with a polar bear, even with a rifle in-hand.
Two rock samples from our brief excursion is better than nothing, but far less than expected from a 5-week research cruise. These will be used in combination with the offshore sediment cores to understand the retreat history of the ice sheet in north-east Greenland.
It was sad to leave the coast and the sea ice. Those groups who came away with very little were left feeling cold. The winter came early for our research cruise.
Our transit to Bremerhaven, Germany, consumed most of the final week, with 4-5 metre waves for a lot of that time. I well and truly had my sea legs (and sea stomach) by now. The smell of soil and sight of trees welcomed our return to land. We were also all very grateful for stable ground.