19 Jan - A Fin-tastic week!
RRS James Clark Ross Diary
Noon Position: 60° 06.5 S, 49° 59.4 W)
Distance Travelled since Grimsby: 19367.0 Nautical Miles
Air temperature @ Noon today: 0.7°C
Sea temperature @ Noon today : 0.3°C
Weather: Good, S, 4, 987.8 mb
A Fintastic week!!
In a week where science never stopped we have been lucky enough to see some very rare sights. The bioscience cruise is now in full swing with the scientists working 12 hours shifts and continuing to hunt the krill. We briefly saw land, the Inaccessible Islands and Coronation Island but for the rest of the week have been a pelagic expedition. Due to a rearrangement on the schedule, a visit to Signy has been delayed and the number of transects changed. As you can see below work continues from the balmy days to the cold and snowy nights. I wonder which shift is better?
Iceberg of the week
Whilst watching a series of huge and spectacular icebergs passing the ship I saw, what at first sight looked like, an island that had not been there 5 minutes before. The island was green with huge waterfalls flowing down it's sides. On closer inspection the land was slowly rocking backwards and forwards in a most unland like fashion. Russ and Koen, watching for whales from the monkey island, had seen the huge berg capsize alongside the ship. The green colour is from the algae growing on it's underside. Using their calibrated video camera (used for estimating a whale's distance from the ship) they measured the size of it and grabbed some images of the berg still rocking from side to side. Have a look at the sequence below to see it rolling. The iceberg was estimated to be 6.3 km away and at it's highest point was 54 m high and 170 m across. A rough calculation gives a weight of 10 million tons (equivalent to 640,000 million ice cubes!)
Doug Bond 007, Licensed to Krill
Your mission 007 - Find out how krill moves undetected across the Scotia Sea.
The main suspect - Ocean currents.
The weapons at your disposal - expendable bathythermographs, undulating oceanographic recorders, acoustic doppler current profilers and a small force of elite ARGO and ARGOS buoys.
You have three assistants. Salty Sal, a highly trained and experienced post-doc assassin. Pablo, a smooth aristocratic jewel thief and underwater specialist. Alex, half-wit tea boy.
The background to your mission:
Krill have been noted to be gathering in huge numbers near South Georgia and mysterious ocean currents are thought to be to blame. Several shadowy underwater international currents are thought to be responsible. Working in fast flowing units called jets, they smuggle innocent krill rapidly across the Scotia Sea. Once caught in the icy grip of a jet, krill are thought to be unable to swim against it and are helplessly transported to South Georgia like leaves in a gale. Once they are near their island prison the poor krill are unable to return to their breeding grounds in the Antarctic Peninsula and are mercilessly eaten by whales, birds and seals.
The brains behind this illegal smuggling operation is thought to be the ACC. The Antarctic Circumpolar Current is responsible for the movement of water from west to east across the Scotia Sea. It is thought that rapid flowing streams of water called jets (caused by gradients in the salinity/temperature characteristics) within the main mass of slow moving water may be to blame. These quasi-political fronts are known as the the Polar Front (PF), the Southern Antarctic Circumpolar Current Front (SACCF) and the Southern Boundary (SB) are ever moving and can only be detected by underwater work using a CTD.
The latest satellite imaging reveals a complex and ever changing situation. The first picture below reveals a satellite image of sea surface height showing high and low areas. The contours show peaks and troughs that correspond to huge clockwise and anticlockwise eddies with in the region being studied. The second image shows different colours in the water (caused by algae bloom) and reveals the complexity of the currents with many eddies seen near the Falkland Islands. The third picture shows the surface temperature of the Scotia Sea and again demonstrates the dynamic and chaotic sea movement. Click the images to enlarge them.
The latest evidence from acoustic studies revealed that krill live at different depths in the water (see the picture below). This is important as the wind affects the surface layer of the sea and blows it north compared to the deeper layers. This may separate the krill living at different depths and transport them to different areas of the Scotia Sea. This may be a possible explanation for the lack of krill larvae at South Georgia as the larval stages live deeper compared to the adults and are therefore transported to a different destinations.
A deadly weapon in your armamentarium are buoys. ARGO buoys are deployed and sink to 2000m. Every 10 days they rise to the surface and sample the water column on the way up. Once on the surface they make contact with a satellite and send their data and position back to the stealth ship, JCR. They provide excellent intelligence of deep currents and the water above them. A second weapon is an ARGOS buoy. These buoys float on the surface but are attached to a 'holy sock' that floats at either 20 or 50m. The 'holy sock' drags the buoy with the currents at that specific depth. Satellite tracking can follow their movements and thus indicate the dark ways of the Scotia Sea currents. This international trade of innocent crustaceans has no respect for national boundaries and must be investigated!
Here is the latest known picture of the hostage, Mr Krill:
Your mission objectives:
- Use covert surveillance of the ACC and it's jets to gain information on it's location and speed.
- Surround the jets with buoys to monitor it's movements.
- Communicate with other agents investigating the mysteries of the krill.
Good luck with your mission 007. This message will autolyse in 10 seconds......
On Tuesday afternoon whales were sighted on the horizon as we were stationary on dynamic positioning. A large group of whales approached the ship and it soon became clear they were big whales from the size of their blows. As they came closer, our resident whale spotters identified them as fin whales. These are the second biggest whales and can grow to 24m in length. Approximately 12-14 whales circled the ship and came within a few metres of the hull. Groups of whales slowly cruised around the ship and were obviously very interested in what we were doing. They passed underneath the ship and blows were seen at regular intervals. Ana and Debbie deployed a sono buoy and listened to the acoustic calls and recorded several hours of whale calls. The whales were estimated to be up to 20m long (which is wider than the JCR) and could weigh up to 100 tons each. They stayed around the ship for two hours as we continued with the CTD and only dispersed when we moved away from our position. Later in the day blue whale calls were heard but blue whales were not sighted.
Fin whales are known as the 'greyhound of the oceans' as they are sleek fast animals that can swim at speeds of up to 25 knots (10 knots faster than the JCR - Ed). They have asymmetrical pigmentation on their jaws with white on the right side and black on the left. They are cosmopolitan and appear in all the worlds oceans. 750,000 fin whales were killed in the last century and current population estimates are only a small fraction of this. Their low frequency calls can travel hundreds of miles.
What scientists get up to in their spare time
With the traditional excesses of Christmas and New Year behind us it is time to get down to the gym. Taking advantage of a now nearly empty cargo hold (it's still got a container and digger in) Richard, our chef, decided to lay on some circuit training sessions. The man who tempts us with lashings of yummy food is now helping to take away the inevitable consequences. Each session involves copious quantities of pain as we all sweat it out with Richard's encouragement. I like to think I can then deserve the full fried breakfast, porridge, kippers, toast and cereal I have for breakfast the next day......
Happy Birthday Doug Bone. Our very own heroic Antarctic explorer and the Fuhrer of fishing had his twenty first birthday on the JCR....again! Doug took time out of his hectic schedule of constantly fixing the UOR to have a celebratory dinner.
The evening, turned into a spontaneous fancy dress party. Everyone certainly got into the spirits of things and had a good night. At some stage in the evening a traditional toy of the JCR bar was pulled out and everyone was expected to have a go at using the "talcum powder pipe". Created in the mists of time from vital engine parts, the pipe is made from several tubes of brass and the cylinder at the end is full of very fine talcum powder. There is a highly skilled technique that allows experienced salty seadogs to blow down the mouth piece and turn the wheel. However the steep learning curve always ensures that several unlucky people will just end up blowing talc all over their faces for the mirth of onlookers. Be warned!
Send us the money or the bear gets it!
A small friendly bear has been found stowed away on the good ship. It answers to the name of Rufus and is being looked after by George the Bosun. The cute little bear even has his own passport and has an ambition to sail round the world. He says a big Hi to all the crazy people back in Ruby's Bar especially Steve and Sarah. (He is now getting ideas above his station and thinks he is a Polar Bear - Ed)
Thankyou this week to: Richard for the circuit training
Coming up next week: Much of the same!