Dec 21 - South Georgia
Date: 21st December 2003
Noon Position : Noon position lat 52 31.3S long 51 38.1W
Distance Travelled since Immingham : 16254 Nautical Miles
Air temperature @ Noon today : 7.7 degrees C
Sea temperature @ Noon today : 7.8 degrees C
The News in brief.
You find us this week heading towards South Georgia. The voyage should be a brief one, seeing us back in the Falklands around the 29th December, its purpose being to conduct a personnel exchange on behalf of AWG. You might remember from our first trip to South Georgia this season that AWG is the company conducting the clean-up of the old whaling station at Grytviken. The weather is presently calm, but the forecast looks a little lumpy. We'll just have to see what tomorrow brings and hope it's good for a call into Bird Island on our way.
After completing the science programme last Sunday it was full steam for Stanley, arriving on Tuesday afternoon. It was a period of mixed emotions as people were leaving the vessel, even if they would be home for Christmas. This time the ship was also undergoing some changes in addition to the usual scientific movements. The two cadets, Liam Beaton (Engineering) and Peadar O'Confhaola (Deck), are heading back to college and we wish them both all the best for the future, Michael Golding (Third Officer) is also off to college for his next qualification. Finally we were very sorry to see Captain Elliott departing us at this time, but send him all our very best for the future. This means we are now under the command of temporary Master Robert Paterson for the remainder of this voyage.
To fill in the rest of the gaps our team has been bolstered by Dave King joining as Second Officer and Joanne Cox as Third. Regular readers might see something familiar in these two photographs below. You'd normally see Dave on the ship's other crew working under Captain Burgan and Joanne was the Deck cadet with us last season. She recently obtained her Officer of the Watch certificate, so congratulations to her.
|Dave King (Second Officer)
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|Joanne Cox (Third Officer)
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The week also saw a little change of scenery for the ship herself as we travelled round to Mare Harbour to discharge Rothera's waste. Mare Harbour is the military port and much closer to the waste disposal facilities, so reducing the number of miles that the lorries had to travel. All completed we departed on Saturday afternoon passing the patrol vessel HMS Leeds Castle (see below) as we left. It's a bit of a week for us and navy ships, we've also been asked to meet up with the ice patrol vessel HMS Endurance and deliver the Christmas mail, as we'll be working in the same area. It'll be a pleasure as we know only too well ourselves how much mail means to morale on a ship. So hopefully pictures of her next week.
The Science Bit In The Middle...
Diatoms are us!
Seven weeks ago during our second call to Stanley a piece of science started behind the scenes. It was then that Claire Allen (BAS) joined the ship under the Collaborative Gearing Scheme. This funding initiative allows projects to run alongside more formal cruises as they require no additional resources than are available during the ship's normal passages. After conducting the first cruise by herself, Claire was joined by Catherine Stickley from Cardiff University for the last leg to Rothera.
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The aim of the project was to make an assessment of the types and quantities of diatoms existing in the waters across the Scotia Sea. A similar survey had occurred in 2002 to assess the species composition of the summer diatom community, this cruise would survey the make-up of the spring community.
The first question raised by those on board was; what were Geological scientists doing being interested in biology? Apparently this is to improve their understanding of fossil records, in particular those that are found in sediments cores from the Scotia sea. Once mapping the distribution of the diatoms within the Scotia Sea today is completed, it will be compared to those found in upper layers of sediment cores. This will allow researchers to look at how preservation differences biases the fossil record. This will mean they can interpret the signal of past ocean conditions from the fossils much more accurately. Understanding changes in past ocean environments will help to predict what may happen in the future under different climate conditions.
So what are Diatoms?
Diatoms are the most important primary producers worldwide Acting, as they do, as an important source of the oxygen we breathe, because being plants they absorb carbon dioxide and expel oxygen in return. They are microscopic phytoplankton (marine algae) ranging in size from 2 - 200 micrometers in diameter. They are made-up of overlapping halves, these are referred to as valves, and are made of silica. It is these silica "shells" that settle to the sea bed when the plants die and are then found in the sediments and fossil record. In fact, they are so numerous in the southern ocean diatoms have formed an ooze belt surrounding Antarctica.
How to they grow?
By division is the simple answer, but there is a little more to it than that and the cycle is shown diagrammatically below. In general, we start with the normal "vegetative" cell this is made up of two halves known as valves. Inside of this two more valves develop to form a second cell as shown. The cells can then separate to form separate cells or chains. This rate of division can exceed once per day. Hopefully you see in the diagram that because the new valves form inside the "parents" then each successive generation is smaller than the previous. This size reduction cannot go on forever or they would cease to exist. Instead they reach a critical size known as the fertile cell size, at this point the diatoms sheds their silica shells as they form a large sphere with an organic membrane (or Auxospore). It is inside this membrane that a new cell of maximum size forms, allowing the division process to start all over again.
The image below shows one of the diatom chains that have been seen on this cruise. The picture was taken down the eye piece of the microscope using a ordinary digital camera! You can make out the chloroplasts (the yellowy-green blobs!) inside the cell which is the part of the cell which conducts the photosynthetic process (i.e. turning carbon dioxide into oxygen).
The above image is what can be seen onboard using a light microscope, which is used for identification and population counts. However, once the samples are returned to the UK they can be examined in much more detail using an scanning-electron microscope (SEM). An SEM was used to produce the images of diatoms shown below and gives you an idea of the amazing shapes and delicate structures of these phytoplankton. Images courtesy of Dr. J. Pike (Cardiff University), click to enlarge.
This week we have been mostly working, with a small amount of time set aside for decorating the ship in preparation for Christmas. Some people, like motorman Charlie Smith have even added a festive touch to their cabins.
Its 4pm. Robert the mate is doing his rounds while the ship is alongside at Rothera. Suddenly, a mooring line parts and flies back under tension onto the ship. Three people are hit and fall to the deck. One, Claire Allen, a scientist, starts screaming and holding her arm. Another, Alex Tait, lies motionless on the deck, a puddle of blood forming under his head. The third casualty, Pauline Sackett lies groaning quietly on the deck, not moving. The emergency call is put out....but the doctor is not on board!!!! (What's new? - Ed.)
A major medical incident is declared. Peader O'Confhaola, our deck cadet, triages the three casualties on deck, being sure first of all to get rid of Claire as she is making far too much noise. He then arranges their transport, Alex with a stiff neck collar and spinal immobilisation, Pauline with oxygen, up two decks to the bar where Hamish and the catering crew have organised an emergency casualty assessment area.
However, before Pauline arrives in the bar, she has deteriorated. Advanced first aider Kenny Weston has his hands full looking after Alex, who is unconscious and not responding. Fortunately, the 2nd mate, Andy Liddell is on hand to make a rapid assessment and to organise an emergency satellite phone call to the Accident and Emergency department in Derriford hospital, Plymouth. Pauline's life is saved and she can be evacuated back to Stanley on the Dash.
Meanwhile, Alex, thanks to Kenny, is coming round and looks like making a full recovery. Claire, thankfully, has finally stopped making so much noise and can be mended with a plaster cast and a cup of tea.
|Triaging casualties at the scene.
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|Pauline Sackett, looking a bit green after her stretcher ride.
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Further assessment of the unconscious casualty in the bar.
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Tune in next week for more high drama........
A final thought until next week...
Well what can we say except;
A Very Happy Christmas to all our readers
Good Luck for 2004.
Thank you for your letters and support in 2003. Don't forget to login for you regular fix of life the JCR way in 2004. We'll be right here!