Saturday, 20 April 2013

Final steps of our South Georgia expedition by Melanie Leng

 
The ANT-XXIX/4 cruise “terrestrial” team, From left to right in the photograph are:
Dr Ole Bennike (macrofossil expert and polar researcher from the Geological Survey of Denmark and Greenland), Professor Martin Melles (Quaternary geologist from the University of Cologne), a fur seal, Dr Duane White (geochronologist and glaciologist from University of Canberra), Benni Ritter (Masters student from the University of Cologne), Dr Finn Viehberg (an expert in micro crustaceans from the University of Cologne) and lastly I am on the far right.

I have finally arrived on the Falkland Islands after an epic field trip to South Georgia. We have been dropped off by the Polarstern and this is the final step before we leave for the UK in a few days. The last 3 days at sea have been eventful, we took many marine sediment cores from off the South Georgia  shelf (mainly from Possession Bay), looking not only to reconstruct the environmental history (for example from the geochemistry of diatom silica) but also to search for glacial deposits to define the maximum extend of the South Georgia ice sheets and to look for gas hydrates. Preliminary scanning of the cores has revealed many potential ash layers which may be used for dating when correlated to known past volcanic activity. The cores are carefully stowed and we will be starting work on them in the summer when they finally make land. The teams on ship interested in  submarine volcanoes have been remotely sweeping the ocean bed using various types of scanning equipment and have found deep sea chimneys, gas seeps and high temperatures associated with the edges of caldera type structures. There are some observational evidence using video of animal communities and abundant microbial mats in these hot spots.  

Black Browed Albertross, thanks to G. Driessens

Meanwhile the bird and mammal biologists have found concentrations of animals which they think are associated with large abundance of krill off South Georgia for example. Over 12.5 thousand birds (albatross, petrels, shearwaters, prions, penguins) have been identified and nearly 2000 mammals (dolphins, whales, seals). Bird and mammal activity was slow after leaving the relative protection of South Georgia, but Black Browed and Wandering Albatross as well as the Giant Antarctic Petrel were still common.


Church Cathedral with the Whalebone
arch on the Port Stanley promenade
(Port Stanley is twinned with Whitby in the UK)
The arrival into Port Stanley from the sea was quite dramatic. We were stuck on ship for 24 hours as the weather was deemed too bad for us to disembark from the Polarstern to the small transfer craft. The plan was then to helicopter everyone off ship but then it became too foggy. Finally a man with a white boat showed up and we were transferred. Entrance to Port Stanley was through the wide Berkeley Sound, we passed the Victorian Cape Pembroke lighthouse, and the infamous Yorke Bay where sand dunes rise behind the white sandy beach which is now a restricted area due it being mined in the 1982 conflict. Stanley is located on the southern shores of Stanley Harbour. The harbour is littered with the shipping remains of the bygone maritime trade in the 19th century, although fishing is still one of the islands major economies. Indeed there are many Japanese fishing ships in the harbour right now. Stanley is quite a colourful capital with multicoloured houses along tidy streets. Along the long promenade stands the cathedral (with whale bones), the museum and the many memorials to past conflicts.

The Polarstern ploughing through the waves in the final step
to the Falkland Islands
In this final blog I would like to thank the rest of the ANT-XXIX/4 cruise especially the “terrestrial” team (top photo!). There were 50 scientists on the cruise (mostly from Germany but with a notable BAS presence) but only 6 of us made land on South Georgia to undertake the terrestrial work. So a big thank you to the terrestrial guys for their good company and hard work. 
Mel Leng
Melanie Leng has just finished an expedition to South Georgia, see her previous blogs, and follow her on twitter @MelJLeng

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