Zoe Burton / Anaesthetics Registrar / Wessex Deanery, UK
Is there anything more badass than a polar volcano? Ask Dr Zoe Burton – she took a break from anaesthetic training in Portsmouth to be an expedition doctor in Antarctica. Zoe describes the life, the challenges and the medicine at the foot of Mount Erebus.
Boom! I feel a shockwave reverberate through the snow and ice beneath my tent. Ten minutes later we are racing up to the crater rim of Mount Erebus to find evidence of lava “bombs” that may have been thrown clear of the crater and landed on its flanks. It is 2am and around -40°C, but a beautiful still sunlit night with a fairytale carpet of cloud floating below us.
Soon enough we find a steaming honeycomb-coloured lava bomb, still warm enough to sizzle satisfyingly when snow is thrown on its surface. Tim takes an old aluminium ice axe shaft and hacks through the cooler crust into the red-hot molten core. At over 950°C it quickly starts to melt the axe shaft. It is phenomenal to see glowing molten lava ejected directly from the bowels of the earth, whilst thousands of miles of Antarctic snow and ice stretch out around us as far as the eye can see.
My Own Quest for Adventure
I am an Anaesthetics trainee with interests in high altitude medicine, medicine in the developing world and physiology in the extremes. Most of my friends and family will tell you that I have had more time out of medicine than in training. Whilst this is not quite true, I have endeavoured to weave some more unusual medical experiences into the conventional career path. Since reading the tales of the early explorers in Chris Bonnington’s Quest for Adventure as a child, Antarctica has always held a particular fascination. Whilst I have worked as an expedition doctor in both the high Arctic and the Himalaya, where I undertook my research for a Masters in Mountain Medicine, Antarctica remained a somewhat elusive dream.
Many of us find it tricky to strike a balance between global adventures and advancement in medical training let alone professional exams, family commitments and medical rotas. However, in November 2014, the stars finally aligned and I first found myself in a position to work in the Antarctic at a high altitude camp on Ross Island. For the last two seasons now, I have worked at one of the most phenomenal natural sites in the world. Unbeknownst to many, on Ross Island exists an active volcano called Mount Erebus. It was first discovered in 1841 by Sir James Clark Ross and named after one of his ships. “Erebus” was a Greek god of darkness, the son of Chaos – a fitting name for a volcano with an exploding lava lake rising out of the vast expanse of white and ice at the foot of our earth.
Every year a team of 6-8 volcanologists, geo-physicists and technicians travel to the volcano to monitor its activity and conduct their research out of the Mount Erebus Volcano Observatory (MEVO). MEVO’s base is on the caldera at Lower Erebus Hut (3402m), which was built in 1992 after the previous hut was unexpectedly surrounded by huge lava bombs. All of MEVO’s operations are conducted through the United Sates Antarctic Program (USAP) with funding from the National Science Foundation (NSF). My role on Mt Erebus is as a field assistant providing support for scientific projects and as a doctor dealing with medical problems as they arise once in the field.
Training at McMurdo
Prior to field deployment, each team member undergoes training at McMurdo Station, the United States Antarctic Program’s largest base on the continent. This includes field safety training, helicopter safety, environmental and waste training, communications and skidoo training. Part of my role was to conduct the high altitude related illness training which included preventative measures, signs and symptoms, chemical prophylaxis and treatment. I demonstrated the use of the Gamow bag, oxygen cylinders and, in conjunction with field safety staff in McMurdo, I developed a simple Mt Erebus AMS flowchart guideline.
In terms of medical facilities, McMurdo General Hospital is staffed by a physician, a NASA Resident and two Physician’s Assistants. It has capacity for six in-patients, has a 2-bedded resus room, x-ray facility, a dental room, a hyperbaric chamber, facilities for basic lab tests and two ultrasound machines. On Mt Erebus itself there is a bountiful supply of oxygen and availability of two Gamow bags. Comprehensive field medical kits include a high altitude drugs pack, which constitutes nifedipine, dexamethasone and acetazolamide.
In order to reach Lower Erebus Hut (3402m), the team passes through an acclimatisation camp called “Fang Camp” at just under 3000m. Traditionally we have spent two nights here prior to ascending to Lower Erebus Hut at 3402m.
It is worth mentioning the difference between “high altitude” in temperate climates and that at the poles. Due to the extreme cold (usually around -25-40°C in summer months) and latitude (77.5° South), the physiological altitude experienced is generally considered to be 300-400m higher than that measured above sea level. Thus the elevation at Fang is easily sufficient for people to experience symptoms of Acute Mountain Sickness (AMS) if not cerebral oedema (HACE) and/or pulmonary oedema (HAPE). The vast majority of all in-puts and take-outs from field camps in the US program are conducted by helicopter. Consequently, the ascent profile is initially from sea level directly to over 3000m. Historically, most people have experienced AMS at Fang and there has been at least one evacuation due to HACE. Whilst a slower ascent would be preferable, access other than by helicopter is limited by steep glacial terrain.
Over the last two years I have used the Lake Louise Score (LLS) for AMS in order to guide sensible decisions regarding further ascent to Lower Erebus Hut and further up the mountain to work on the crater rim at 3794m. Each team member completes a daily score sheet relating to their heart rate, oxygen saturations, symptoms, activity level and maximal and sleeping altitudes. My data show that most team members experience AMS at some point during the acclimatisation process.
Due to the fairly extreme ascent profile, the use of acetazolamide is common for both AMS prophylaxis and treatment. In several cases this year, I recommended an extra night sleeping at Fang camp for acclimatisation purposes in response to the data I collected. Subsequent self-reported AMS scores were lower as a result and scientists were able to start on scientific work at the crater rim sooner than previously.
Not Just the Altitude
Last year, I was called to Fang Camp to assist in an incident involving life-threatening carbon monoxide poisoning. This was due to partial combustion of propane whilst cooking in a tent on a windless night. This has since lead to significant changes in both stove training and the availability of safety equipment – audible carbon monoxide alarms and immediate availability of oxygen.
The incident served as a stark reminder of both the remote nature of Erebus and the confusing similarities between symptoms of carbon monoxide poisoning and HACE. The individuals concerned made a swift recovery with 100% oxygen therapy and co-ordination by satellite phone of a late night emergency medical evacuation by helicopter in marginal weather conditions to McMurdo (at sea level). Hyperbaric chamber treatment was available but not clinically necessary.
This season, I have thankfully had little to contend with aside from a couple of ophthalmic high altitude related issues and moderate AMS. I was able to take advantage of excellent remote advice from Dan Morris, an expert in high altitude related ophthalmic problems. The extremely experienced Diploma in Mountain Medicine (DiMM) community was also able to offer me support regarding the subsequent management of the carbon monoxide case last year, for which I remain grateful. Since I am a UK doctor with no licence to practice in the United States, my medical input here from a legal standpoint is largely limited to Good Samaritan acts. In the management of such cases I remain in close liaison with the McMurdo-based physician.
Goosebumps on Erebus
Mount Erebus is undoubtedly one of the most awe-inspiring and fundamentally beautiful places I have ever had the privilege to visit. It was first climbed in 1908 by members of Shackleton’s expedition. In 1912, Captain Scott’s Terra Nova expedition conducted a geological survey on Erebus. Circles of stones used to weigh down tent valances remain visible at two protected historic sites. These sites remain exactly as they did over a century ago since Erebus is a non-accumulation zone where there is no significant drifting of snow due to persistent high winds. As a result, environmental rules are strict and everything that is brought in must be taken out. This includes urine, so everyone rapidly becomes adept at peeing into a Nalgene bottle!
On a clear day from Erebus’ crater rim you can see across the Ross Ice Shelf and the sea ice of McMurdo Sound to the Trans-Antarctic mountain range. Ross Island is home to the historic huts of Scott and Shackleton at Cape Evans and Cape Royds respectively, and Mt Bird and Mt Terror, two other dormant volcanic peaks. The volcano’s crater itself is 350m deep and harbours a longstanding exploding convecting lava lake, of which there are only two others in the world.
It is possible to walk around the circumference of the crater in a few hours whilst peering into the bubbling cauldron which persistently vents a hybrid of volcanic gas. The plume can be seen travelling for miles depending on the ambient humidity. As gas escapes from the warm ground lower down the volcano, “fumaroles” form where hot vented air collides with the cold Antarctic atmosphere, condensing to form impressive ice towers. Underneath these towers exist a complex network of stunning ice caves. Entry to the caves is permitted for scientific mapping and gas sampling purposes. Abseiling into these vast surprisingly warm caves feels otherworldly; quiet and windless caverns filled with huge intricately delicate feathery ice crystals, blue domed ceilings and imposing ice stalactites and stalagmites.
Glamorous as this all may sound, on most days my main role is to walk up the volcanic scree littered with Erebus crystals to the crater rim carrying anything from 30kg batteries, radar antennae to GPS equipment and solar panels in an effort to promote the furthering of science. We sleep in tents, cook in the warmth of the Lower Erebus Hut and for the most part get around by driving across the moonscape caldera on skidoos. Every now and then, the volcano reminds us of its almighty power and explodes producing an almighty bang! What follows is best described as a “bomb hunt”, the aim being for the bomb disposal team to record the highest temperature inside a lava bomb – thus giving some indication of the true temperature of the lava lake.
Whilst all this seems a bit far-fetched from Anaesthetics, it has been a fantastic medical adventure, another insight into physiology at the extremes and a rare opportunity to work in such a little visited part of the world. For now, Erebus’ breath-taking beauty gives me goosebumps whilst working on the crater on a daily basis. I am frequently reminded of what a privilege it is that my Antarctic dream has become a reality.
My husband Tim has worked for the US Antarctic Program for a number of years and for the British Antarctic Survey prior to that. It is largely due to Tim and Phil Kyle, the Principal Investigator for the MEVO scientific operation, that I was given this opportunity. I owe it to my open-minded Program Director and College Tutors in Wessex Deanery that I was able to take up this opportunity in 2014 at only four weeks notice. I am also grateful to the entire MEVO team for helping me gather AMS data and for sharing their knowledge of the volcano and their enthusiasm for scientific work in such an austere environment. Finally I would like to thank USAP and the NSF for funding this endeavour on Mt Erebus.
(Photos: Zoe and Tim Burton)