Research diving in Antarctic
100 years ago, it might take 4 years round trip to go from the northern hemisphere and get to the Antarctic. These days it is possible to get to the Antarctic with less than 48 hours of travel time (there is typically a 72 hour holding period in New Zealand for persons travelling through the US Antarctic program). The Antarctic is the region around the Earth's South Pole, The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence. The region covers some 20% of the Southern Hemisphere, of which 5.5% (14 million km2) is the surface area of the continent itself.
The main base which they are working from is known as McMurdo Station, and it holds about 1000 people during the summer and 200 in the winter. Everybody who will work in the field must complete survival school, this consists of several tasks including sleeping in whatever you build for the night.
The ice which covers the open water can be 7m thick, so the first step when planning a dive is to create a hole. This is usually done with the aid of explosives, leaving a hole of slush, which must first be removed by a diver. Before the first dive is done though, they must kit up. O-rings tend not to seat when the ambient temperature is extremely cold, typically approaching -40c. Outside dives – including set up – can be done in milder temperatures. Shelters will often be employed. So the divers take a tent of sorts which they can set up, and place a heater in. To keep the hole open and stop it freezing over they often place a hut over the hole.
The kit they use is a little different to our tropical equipment as they have to use a spare first stage, in case one freezes, so most diving is done using double tanks, or a special single tank with a valve that allows two first stages to be independently mounted. It is good practice to have a pony bottle as well. The compressors they use are identical to the ones we use here in Mexico. Diving can be done using a free swimming buddy system or using surface supplied equipment.
Once they are down, they are rewarded with 250m+ visibility, seals, orcas, soft corals, sponges, nudibraches, scallops, jellyfish, sea stars and feather stars, although life here is very slow growing. They can dive under moving icebergs, and find ice walls that nobody knows if they are permanent, or seasonal. Every dive offers something new.
The project which Dr Pollock is working on is the collection and study of a single cell organism called Astrammina rara. There are many other projects working from McMurdo, more information on these can be found on the links below.
http://www.esf.org/index.php?id=855
http://www.antarctica.ac.uk/
http://www.nsf.gov/div/index.jsp?div=ANT
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