Dec 14 - Drake Passage
Date: 14th December 2003
Noon Position: Noon position lat 56 03.2S long 57 39.9W
Distance Travelled since Immingham: 15963 Nautical Miles
Air temperature: 5.6°C
Sea temperature: 6.9°C
The News in brief.
Another week is drawing to a close and you find us once more Stanley bound. Well that is when we're underway in between scientific stations as we are undertaking the annual Drake Passage CTD survey, but more of that later.
Apologies once again for the late publication of last week's diary and if you think you've missed an edition click here; last weeks diary.
Last Sunday saw us in the hustle and bustle of base relief and none comes bigger for the JCR than Rothera. This hive of activity went on until early Tuesday afternoon when we sailed. All the cargo was delivered and 1000 m3 of waste removed. This included the rest of last season's clean-up waste which we didn't have room for during our March call (See; "It's rubbish at Rothera". Below are a few pictures of cargo operations.
Mind you some onboard obviously have far too much energy. Even after twelve hours of cargo work they were able to run around for a full 90 minutes on the football pitch. Monday evening saw the JCR All Stars taking on the Rothera Renegades in a tough ninety minute battle which resulted in a nil - nil draw. Though I believe we are claiming mitigating circumstances; they stole one of our players!
Football at Rothera and no stands to spoil the view.
Click to enlarge.
For those of us who found all this energy expenditure too much to take, a walk around the point to take in the scenery and local wildlife was more the order of the day. Nick Dunbar (ETO) didn't even have to go that far before being approached by this Adelie penguin on the jetty (below left). However, we did find this Weddell seal on the beach behind the base.
Tuesday saw us on our way back up the Peninsula heading for the start of science, after a brief call back into Port Lockroy on Wednesday. Our first CTD station on Thursday afternoon close to Elephant Island gave us the chance to produce the panorama below. Elephant Island was home to the men Shackleton left, while he and five others sailed to South Georgia in order to gain help.
The Science Bit In The Middle...
Drake Passage repeat hydrography section. (JR94)
The Southern Ocean is a major component of the coupled ocean-atmosphere climate system. It connects all the other major oceans and influences the water mass characteristics of the deep water over a large proportion of the world. Hence the Southern Ocean plays a pivotal role in global ocean circulation, which in turn regulates the global climate. The major Southern Ocean current, the Antarctic Circumpolar Current (ACC), transports large volumes of water west to east around the world, typically around 136 million tonnes per second. Measurements of the total amount and detailed structure of the transport in the ACC can provide critical tests of numerical model dynamics, as well as of proposed examples of the global ocean circulation, ocean variability and climate change. The Drake Passage is an advantageous location to observe the ACC. At this choke point between South America and the Antarctic Peninsula the meridional spread of the ACC is constrained and transport measurements can be attempted.
The Drake Passage section is possibly the most important section of the Southern Ocean, partly due to its accessibility and being the narrowest point, but is also the immediate link between the Pacific and Atlantic Oceans. Scientists from Southampton Oceanography Centre (SOC) and British Antarctic Survey have been conducting sections across Drake Passage since 1993. These hydrographic sections consist of a number of stations across Drake Passage (Figure above).
At each station, with the ship hove to, we lower a package of instruments (CTD) from the ship to near the seabed, measuring pressure, temperature, salinity and water velocities. In addition at ten depths, water samples are captured in bottles. These samples are analysed onboard ship to make a very precise determination of the sample's salinity - variations in salt of the order 1 part per million can be measured.
By making repeat measurements we can begin to understand the natural variability of the amounts, properties and flow rates of the different water masses in the Southern Ocean. These observations are the base line from which future changes may be determined. Therefore, with a long time series of observations it may be possible to attribute variability to changes in atmospheric forcing - climate change.
Above are some sample results from a previous cruise as the ones for this aren't in quite yet. Click to enlarge. The left hand diagram show temperature across the section with the Falklands being to the left-hand side and the right-hand drawing shows the salinity across the same section.
This week in Rothera was the culmination of a stunning trip down the peninsula, quite possibly the most beautiful place in the world. The trip down was accompanied by fantastic weather and flat calm seas, and we were fortunate enough to witness night after night of glorious sunsets and stunning sunrises.
The scenery began in the middle of the night in the Neumayer channel, a narrow waterway which zigzags its way down to Port Lockroy. As the scenery became more dramatic the light grew and the wildlife came out to play. Just as things could hardly have been more perfect, we were joined by a pod of Minke whales, cruising along effortlessly at the bow.
Near the bottom of the Neumayer Channel, before it opens out into Bismarck Strait, is where Port Lockroy, BAS's Base A is situated. We spent a few hours there discharging cargo and passengers, watching the penguins and soaking up the sunshine. All too soon however it was time to leave Rick, Pete and Dave to their tiny island and to sail further south, this time through the Lemaire Channel. Once again the views were incredible and we could hardly believe how fortunate we were to be in the presence of such astonishing beauty.
As the channel widened, we found ourselves in pack ice surrounding the Argentine Islands. After an hour spent pondering the best route through the ice (and a quick forty winks for me) we put in our small work boat, Sooty, and weaved our way through the floes to visit Vernadsky research station. This Ukrainian base was once British, having been handed over to the Ukrainians in 1996. They are very proud of their home and keep it in the most pristine condition imaginable. They hosted our small deputation for the afternoon, giving us a tour of the base and then inviting us to the bar for the inevitable round of vodka and coffee. Little did I expect the coffee didn't have any water in.....pure coffee granules! Staggering out we had just one more duty- to visit the generator sheds, seen below. These are fully functional and yes, you could eat your lunch off the floor.
|The football pitch and generator shed at Vernadsky. Click to enlarge.|
From Vernadsky it was a full day's sailing to Rothera, where old friends were waiting to meet the ship and the inbound personnel. On arriving everyone was treated to a fine display of driving from our Captain, and little resistance from the icebergs that had parked themselves at our spot on the wharf. The instant cargo work was finished it was off to the base for walks, skiing, football games and catching up with old friends.
I have never felt so safe on a hill, accompanied as I was by 2 doctors, 2 mountaineers, a mechanic and a meteorologist. In near perfect conditions we had a fantastic time being towed up the hill on ski-doos and then skiing down. The scenery was spectacular and the evening was rounded off with a cup of tea at the caboose. Before we realised, it was 11pm and time to go back to base.
|Being towed up the hill by ski-doo, and preparing to ski down. Click to enlarge.|
The following evening I joined a training group, camping out on the plateau in traditional Antarctic pyramid tents. We melted snow for cooking, made a delicious (ish) chicken balti washed down with ration biscuits and marmite. Once most people had turned in for the night, Dougal Ranford, Rob Smith and myself went skiing in the late evening sunshine up to an open col with spectacular views of the ice cliffs surrounding the bay below. With 24 hours of daylight it is easy to forget how late it is and when we finally did turn in at 2am the sky was still bright and starless.
|Pyramid tent and sledges; the top of the col in the midnight sun. Click to enlarge.|
Early morning found us packing up, rolling up our thick sleeping bags, loading the sledge and heading back to base, ship and open sea. The cargo work finished, we said good-bye once again to our friends on base, and turned the ship north, in search of those beautiful channels and sunsets after a week of constant daylight.
|Moonlight sea ice. Click to enlarge.|
A final thought until next week...
This week will see us in and out of the Falklands once more, after which we head for South Georgia for our next round of calls.
However, we'll leave you with a few pictures form Rothera.