Tara (ship)
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The Tara is a French research vessel that has already undertaken research trips on the coasts of Greenland , South Georgia and Patagonia and was used as an ice drift station between 2006 and 2008 .
The north polar journey of Tara
The eight-person crew under Etienne Bourgois intentionally freeze the boat in the pack ice a good 800 kilometers north of the Siberian Tiksi at 79 degrees, 53 minutes north latitude and 143 degrees, 17 minutes east longitude . From there, the expedition drifted 5200 kilometers with the ice and covered 2600 kilometers to the west as the crow flies. On January 21, 2008, she was released again about 100 km east of Greenland at about 72 ° north latitude. The Tara came on their drift to 160 kilometers of the North Pole zoom, closer than the Fram of Fridtjof Nansen . On February 23, 2008, the Tara reached her home port of Lorient .
technology
The expedition used the same technique that Nansen had tried to reach the North Pole with in 1893. The almost 35 meters long and around ten meters wide schooner has a round hull that is pushed upwards when it freezes in the ice and sits on the ice. For this purpose, the ship moored on September 5, 2006 on an ice floe three by one and a half kilometers in size. The way to the starting point of the expedition was cleared by an icebreaker . In total, the ship spent two polar nights in the Arctic. Between April and September 2007, more scientists were also flown in and pitched their tents next to the Tara .
Scientific goals
The expedition members studied the effects of climate change . This included meteorological observations up to a height of two kilometers with helium-filled probes; a determination of the radiation balance , measurements of water content, density and thickness of the snow layer, as well as the thickness of the ice floes; Investigation of the water layers for temperature and salinity with probes attached to cables down to a depth of 4000 meters. The seawater was examined for its content of the oxygen isotope 18 O in order to determine the proportion of fresh water from the mainland. The 126 I iodine isotope was used to trace whether residues from the reprocessing plants in La Hague and Sellafield had reached the Arctic.
The scientists were particularly amazed at how fast the ice drifted; the record was 120 nautical miles in ten days, which corresponds to one kilometer per hour. The Tara needed less than half as much time for its drift with the ice as the Fram 110 years earlier , although the Tara covered a distance several 100 km longer. The expedition was able to confirm that the ice cover at the North Pole is shrinking. The mean ice thickness of 1½ to 2 m was only about half as much as it was twenty years earlier. In addition, ice that is perennial is increasingly being replaced by annual ice, which thaws away completely in summer.
The air was specially examined for its ozone , mercury and bromine oxide content . The background to these measurements is the phenomenon that in spring mercury and ozone disappear completely from the air near ice, for which bromine oxide is held responsible. A pollen trap also caught pollen .
In the biological part of the work program, plankton was collected to determine the primary production of the ocean. Psychrophilic bacteria are so adapted to life in the cold that they manage to survive even in ice. Birds should also be observed, especially the Ivory Gulls , which are threatened with extinction , as well as the songs and ultrasound clicks of whales .
The project was funded by the EU as part of the “Damocles” program. It was part of the International Polar Year , which had been declared for 2007/2008.
Previous owners
Under the name Seamaster, the ship belonged to the New Zealand sports sailor Sir Peter Blake , who was murdered by river pirates on the ship in December 2001 during an expedition in the Amazon Delta.
literature
- Charlie Buffet: La dérive express de la goélette "Tara" illustrious la fragilité de la banquise arctique , Le Monde, 23 February 2008, page 7.
- JW Bottenheim, et al .: Ozone in the boundary layer air over the Arctic Ocean - measurements during the TARA transpolar drift 2006–2008. Atmos. Chem. Phys., 9, 4545-4557, 2009, abstract
- Exploring the Oceans le journal oceans No. 5, 2009 (pdf, 13.4mb, English)
Web links
- Tara Expedition website
- Tara Arctic , arte.tv; With the tare into the heart of climate change , documentation, 92 min., ARTE February 26, 2011.
Individual evidence
- ↑ a b Patrick Filleux: Researchers freeze ship , Spiegel Online , September 11, 2009.
- ↑ Tare profile ( Memento of the original from February 15, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. oceans.taraexpeditions.org, accessed February 28, 2011
- ↑ TARA ARCTIC 2007-2008: The Great Arctic drift , DAMOCLES, Understanding climate in the Arctic, June 27, 2008, accessed on February 28, 2011
