Lightboxes and Circadian Rhythms
Looking Back Towards Base
From right to left: Laws, Piggott, BART caboose and Simpson platforms
The above view is taken from just below my favourite spot on base. The Laws platform lies at the centre of a large oval that describes the perimeter with a diameter of upto a couple of miles; it is this oval that effectively defines the extent of our world for most of the periods of darkness. Hence ski-ing, walking or even running (a sport reserved for super-fit Field Assistants), around the perimeter is an attempt to explore the very edges of this world and an important diversion from the necessary and mostly enjoyable proximity of the 17 other inhabitants of this isolated microcosm.
Aurora Over the Piggott
As one heads back towards the Laws from the Optical caboose (one of the science cabooses housing important new radar equipment), on the southern edge of the perimeter, the SHARE windtail- the mound of snow that accumulates behind any object on the snow surface- creates a rolling hill that shields the south from the bright lights that spill off the platforms. As you crest the brow of the windtail it feels as if it were a meadow with the bright lights of a village laid out below. This sense of delight is heightened by an absence of vehicles in the southern sector of the base at any time of the year (given the delicate science equipment), which means that the snow, bar the low-lying sastrugi, is a pleasure to ski across.
Drums
Moving fuel round base with a 'dozer
A majority of my work through the darkness is spent in running one of the biomedical science projects on base. Halley provides an ideal location for the study of the role of light in the regulation of human circadian rhythm. Circadian ('around a day') rhythms manifest themselves most obviously in our sleep-wake cycles, yet many other physiological and biochemical processes vary over this time frame. This rhythm is generated endogenously (that is from within ourselves) and probably by every cell in the body, though it is regulated from a part of the brain called the suprachiasmatic nucleus. If we were left in a dark room with minimal external stimuli we would revert to our own internal circadian rhythm. The exact length of the cycle, however, varies significantly between individuals; some people have an innate cycle length of 23.5 hours while some may be as long as 27 hours, though the majority lie at around 24.5 hours.
Aurora Over the Halley Signpost
Given that our body would prefer to work off a cycle that is not exactly 24 hours long, it is clear there needs to be a mechanism that resets (entrains) the internal clock so that it synchronises with the world around us. Light is one of the most important cues in this synchronising with the external world. Given the disappearance of the sun here, for 3 months of the winter, those wintering tend to develop problems associated with the inability to synchronise their internal clock with the 24 hour day, the most obvious being sleep disturbance.
Lightbox Exposure
Work over the previous 20 years here has had benefits not only for subsequent winterers, in modification of ambient lighting on the main platform but is also applicable to all environments where there are extended periods of low ambient light. However, as worldwide we move to living 24 hour days, it is in the understanding of shift work and the health problems associated with it, that the work at Halley has had a wider impact. If you want to read more then try this link to pages at the University of Surrey. For more in depth reading the following review is a good place to start: Arendt J. Melatonin, Circadian Rhythms and Sleep. New England Journal of Medicine 343: 1114-1116.
Die Feuerzangenbowle
Tom introduces us all to a German pre-Christmas tradition as we head towards the mid-winter celebrations
The emphasis of the study this year in brief, is to see whether an exposure to a high intensity bright light for an hour in the morning, improves sleep-wake cycles, activity and cognitive performance. The study runs over the period of sundown and is dependent upon the willing and enthusiastic participation of many of those on base. As sociable as it may seem sitting in a room together for an hour in front of bright lights, the whole hour seems to pass in polite silence in order not to disturb the sensibilities of some of those on base who are not at their best in the mornings.
Moving Rubbish off the Laws
When it comes to waste regardless of each operator's international obligations (the Antarctic Treaty obliges all of its signatories to remove nearly all the waste that they produce from the continent), there is a strong ethical case for doing so and minimising the effect that we have on this near-pristine environment. During the winter the base doctor at Halley traditionally takes responsibility for the waste management role that is important as part of keeping the base running; it is the same this year and takes on average a day a week of my time. It does not mean that I go round emptying every bin or sorting it but like a glorified Antarctic bin-man, I ensure it is correctly packaged, compressed and ready to ship out come the first call of the Shackleton.
Manhauling the Food Waste
(Thanks to Ant Dubber for the photo)
We send back to the UK and Falkland Islands a phenomenal amount of the waste that is produced here for recycling, from the everyday plastics and cardboard to waste oil and photo processing chemicals, there is very little either on the industrial or domestic side that cannot be recycled and as a result the sled on the outgoing cargo line part-filled with waste destined for landfill, is far outnumbered by those labelled for recycling.
Sune Overhauling Primus Stoves
Winter gives the opportunity to clean and maintain all the field kit before next season
Again, in a situation not dissimilar to our water use, it is an eye-opener to quite how profligate we are at home with our waste and how much could be recycled saving energy and raw materials, not so for Tom, our German colleague on, for him this is not unusual- reflecting quite how far we lag behind Germany in minimising the amount of rubbish we simply bury.
More Aurora
Demonstrating some of the more transient colours seen in the displays
The picture below illustrates nicely our standard outdoor kit around base for mild weather or when out digging- as in the melt tank in this case. Depending on how cold it is, people wear trousers or shorts and a t-shirt or warmer top underneath the ubiquitous padded boiler suit.
Dean Modelling at the Melt Tank
These orange all-in-ones start off the colour of the jacket in the photo but rapidly fade from daily wear and the harsh UV when the sun is around. The jackets, known as a 'windy', made from the same cotton Ventile material as the pyramid tents but thinner, are great windproof pieces of kit. On the feet, we wear mukluks, boots with a separate warm liner and given the industrial work around the place all have steel toe-caps. Goggles, hat, padded gloves and a 'neckie', a hoop-like piece of material that covers the face and neck completes the ensemble. As it gets colder (anything below -25), the priority is to ensure that all exposed skin is well covered to prevent it getting frostnipped (the early, reversible stage of frostbite).
The Laws Platform
