Rothera isn't exactly tropical at the moment but on the 21st of last month we passed an important date in our calender, the first sight of the sun at Rothera since the 5th June. Not as long an absence as at some Antarctic bases but enough justification for us to celebrate by getting our sunglasses and shorts out - inside of course. At present the sun is still very weak and the light very watery. July is usually the coldest month at Rothera. August starts cold but towards the end of the month the temperature starts to creep back up as the Antarctic spring approaches. So far our thermometer has dropped slightly below -31·C. With a strong wind the wind chill factor can make low temperatures feel even colder. Exposure to these conditions for too long can play havoc with exposed skin. We cover up as much as possible and when out regularly check each other for tell-tale white patches on each other's skin. This is a warning that we might be starting to suffer from frost nip and care should be taken. We're provided with good clothing so most of the edge is taken out of the cold. On a still day it's a joy to be out in the calm, clear dry air. To our colleagues at Halley research station in latitude 75.5·S (and Lucy and Seamus who were there last winter) this is all banana belt weather as they can be experiencing temperatures down to minus 50 and below.
The winter trips have started again. I'm sure that I mentioned the trips out in an earlier letter but just to recap we all get the chance to travel out from base with one of the field assistants. Everyone gets two trips out, one before midwinter and one after midwinter. One thing that is usually hoped for that good sea ice will form so that we can travel from our home on Adelaide Island across Lauberf Fiord to the islands on the eastern side and possibility the Antarctic Peninsula itself. Favourite destinations are the huts on Blaiklock Island, Horseshoe Island and Stonington Island. I know I've also mentioned San Martin the Argentine base on Debenham Island. San Martin is about five miles short of Stonington . I'm pleased to say that the sea ice has held good and as I write Mark, Rob T., Steve W., and Simon A. are staying with the Argentines and are having a mighty fine time too from what we are hearing over the radio. They'll be heading back soon so that the next trips can get out - Ian and Si B. are off with Jez and Oz. It's fingers crossed all round for the sea ice to stay and good weather so we all get a good trip. We're also hoping that the guys at San Martin manage to get over to Rothera to see us.
To set off on a field trip we travel with what is called a full unit. We travel in pairs, each person on a ski-doo towing a sledge. Between the two sledges we have enough spare food for two people to last 30 days, fuel for the ski-doos, fuel for the primus stove and tilley lamps, a radio, a medical box, pots, plates, mugs, cutlery, sleeping gear, rescue equipment, spare clothing, a box of our own personal things like books and diaries, and of course the tent. The two sledges are arranged so that if one is lost both persons can survive from the other. That isn't to say that everything is duplicated - for example we have the main large tent (called a pyramid tent) on one sledge and the smaller emergency tent (called a pup tent) on the other.
How the two ski-doos and sledges travel is dependent upon the ground to be covered. Travelling over ice there is the ever-present danger of crevasses. To combat this each person wears a climbing harness so that they can be connected to a rope attached to their ski-doo. The lead ski- doo then has a tow rope leading to the first sledge, from there another rope leads back to the second ski-doo, (where of course the driver is linked to the ski-doo by a rope too) and finally from the second ski-doo there is a tow rope to the final sledge. This is called linked travel. The second ski-doo is driven under power even though there is the link rope to the first sledge. This is actually quite hard to do ! The ski-doo has to be driven at the same pace as the leader so that the rope isn't run over but at the same time isn't too tight. The Field Assistant always drives the lead ski-doo. With their experience they are in a position to judge the safest route ahead, but by being linked should there be a fall into a crevasse the weight of what's behind will hold in the snow and break the fall. The driver will remain harnessed to the ski-doo and can quickly be recovered from the crevasse. This is a very rare occurrence indeed as we are careful as to where we travel. Like all things in the Antarctic environment we have to be aware of it and prepare for it, however unlikely it may be.
On my pre-midwinter trip Lucy, Steve W., Simon A. and I headed out from Rothera and travelled through what is called the Shambles Glacier to head south to the southern tip of Adelaide Island to the Chilean base called Carvajal. Carvajal used to be a British base called Adelaide and was operated until Rothera was built in the 1970s. The Chileans took over and now operate it as a summer only base, so unfortuantly no one was there. We did leave them a little present and a note for when they return in October. The wildlife there was worth the trip with many fur and elephant seals on the beaches around the place. The journey and our camps along the way were also an incredible and rewarding experience.
Travelling across sea ice is quite a different matter. Before the BAS Director in Cambridge gives us permission to travel off Adelaide Island, we have to ascertain that the sea ice is safe enough for travel. We gauge this by studying satellite pictures and monitoring how the sea ice withstands strong winds. If the ice is still around after a fierce blow our confidence in it is increased. We then start drilling to test the thickness of the ice. Once routes have been tested and drilled they can then be travelled, but are still regularly drilled to check again. We are especially careful around certain areas where it is known that the ice is prone to be weaker, for example in areas where there are strong currents or tides. For ski-doo travel we don't link up on sea ice. In the unlikely event of one ski-doo breaking through the ice the driver has to be able to jump clear and we don't want one ski-doo to drag the other into the water behind it. On sea ice we all carry ice axes and throw lines as well as hot drinks and spare clothing in case someone should fall through. Sea ice is never camped on because of the risk of it breaking up and floating off.
When we do make camp we use pyramid tents. They're bright orange and shaped like a pyramid!! Famous early Antarctic explorers such as Shackleton, Mawson, Amundsen and Scott would recognise much of the equipment we use. Certainly the tents have changed very little. To put them up we pace out where the four poles are going to go and then dig a hole in the snow for each one. We then put each pole in a hole and check that the tent is adjusted satisfactorily. Each of the four sides is then secured with guy ropes and snow is heaped around the valance to stop the wind finding a way under. Inside a ground sheet is spread out. Down the middle of the tent we arrange some of the sledging boxes in away that gives us room to set up the cooker and prepare our food as well as a little "table" space. The tilley lamp is hung from a line in the top of the tent. As well as light the tilley gives off plenty of warmth. The radio is put on the box furthest from the entrance with the aerial passing out of the air vent at the top of the tent. We can then call into Rothera to say that we are safe. Our boots go in the space between the inner tent and the outer tent and our personal boxes at the foot of our sleeping bags. To keep warm we spread a lilo on to the ground sheet followed by a compressed foam mat, then a sheepskin and then our sleeping bag. We actually have two very warm sleeping bags one inside the other and both then placed inside a canvas cover to offer them protection and keep them clean. Believe me it's lovely and warm - but a lot of bulk. It certainly wouldn't fit in a rucksack for a weekends walking.
Well I think that's probably enough for this time. I hope that I haven't sounded too dramatic here. Whatever gets done in the Antarctic we always set out to do safely, and part of that is preparing for problems. Fortunately the biggest problem we tend to come across is who ate all the chocolate and hid the tea spoon !
Take care, Stuart.
Stuart Wallace, Rothera Research Station, Adelaide Island, Antarctica