The first time, you come down for the adventure," begins the adage. "The second time for the money. And the third time because you can't function anywhere else any more."

A century after the heroic age of Antarctic exploration – this year marks the centenary of Sir Ernest Shackleton's Endurance expedition – thousands of people now earn their living on Antarctica, treading in Shackleton's footsteps every day, on their way to work. From sailors to scientists, conservationists to climbing instructors, they pursue their professions on the frozen edge of the planet, in a working environment that was, within living memory, a vast, deadly unknown.

Simply getting to work involves what must rank as the world's worst commute: a two-day crossing of the Drake Passage, from the tip of South America to the outer reaches of the Antarctic Peninsula. The Drake is where three oceans (the Atlantic, Southern and Pacific) come crashing together in an epic battle for supremacy – as a result, crossing it can be notoriously violent.

There are now reckoned to be more than 4,000 people living and working in continental Antarctica at its peak each summer between November and March – a figure which doesn't take into account the tourist expedition vessels and their scores of staff. That's a population about twice the size of the Isles of Scilly's inhabiting a land mass not much smaller than South America. But that population is growing.

The largest single habitation is the coastal site of McMurdo, several thousand kilometres to the south-west of the Peninsula. The US base on Antarctica has grown into a frozen frontier town. More than 1,200 workers are based here every summer, while 250 hardened professionals endure the permanent night of Antarctic winter. But it's not all bad. Staff live in an environment that includes bars, road signs and even an ATM. Last year, McMurdo even saw its first Tinder date.

Not surprisingly, given McMurdo's size and increasing importance as the gateway to the South Pole, American citizens make up a quarter of workers – the biggest group by far. But another 30 countries have permanent professionals working down there, including the seven nations with official land claims to the Seventh Continent: Chile, Argentina, Australia and New Zealand (all geographical claims), Norway, France and Great Britain (all historical).

As working environments go, things don't get much tougher. This is, after all, the place with the record for the coldest documented temperature on Earth. But these workers keep coming back year after year, some for decades. Why? The photographer Mark Chilvers and I travelled across the Drake Passage to find out.

The writer and photographer travelled to Antarctica as part of Jaeger's Endurance project, celebrating the centenary of Shackleton's expedition, which the clothing company originally sponsored; see jaeger.co.uk for more. Expedition cruises to Antarctica with Quark Expeditions begin from £3,900, based on three sharing a cabin. For more: 0808 120 2333, quarkexpeditions.com

Meet the people who call Antarctica home Show all 6 1 /6 Meet the people who call Antarctica home Meet the people who call Antarctica home THE ADVENTURER Climbing and skiing guide Jean Cane, 45, who grew up in Yorkshire, works as an IT contractor in Sydney for six months of the year to fund her 'other' life, as an adventure-sports instructor on expedition cruises to the Antarctic Mark Chilvers Meet the people who call Antarctica home THE SEAMAN With more than 300 crossings of the Drake Passage to his name, the Ukrainian Oleg Klaptenko, 44, is one of the most experienced captains working in Antarctic waters. He is currently skipper of the ‘Ocean Diamond’, an ice-strengthened expedition vessel Mark Chilvers Meet the people who call Antarctica home THE SCIENTIST A professor of Oceanography and Coastal Sciences at Louisiana State University, Dr Dr Mike Polito, 35, has travelled to Antarctica regularly since 2000. He works with Penguin Lifelines (penguinlifelines.org), collecting research samples and video footage from across the continent to help us better understand and protect penguins Mark Chilvers Meet the people who call Antarctica home THE ALL-ROUNDER In 1995, Liesl Schernthanner, 48, took a sabbatical from her career in academic research to work with the US Antarctic Program. She never went back to her ‘real job’. The American has worked all over Antarctica, including the South Pole, where she met her British husband at a research base. This season, she is working in a conservation role for the UK Antarctic Heritage Trust, looking after historic bases on the Peninsula Mark Chilvers Meet the people who call Antarctica home THE HISTORIAN Antarctic historian and Polar guide Jonathan Shackleton, 63, is a cousin twice removed of the late polar explorer Ernest. He has travelled to Antarctica 37 times, leading historical tours. He lives in County Cavan, Ireland, close to where Ernest was born, and is the author of 'Shackleton: an Irishman in Antarctica' Mark Chilvers Meet the people who call Antarctica home THE POSTMAN Sub-postmaster Stephen Skinner, 29, was brought up in County Durham. An early obsession with the stories of Scott, Amundsen and Shackleton led to his ‘15-year mission’ to get to Antarctica. He finally achieved it for the first time this season, beating off scores of applicants to secure the role of sub-postmaster at Port Lockroy, the historic British base where he also helps to maintain the museum (ukaht.org) Mark Chilvers

THE ADVENTURER

Jean Cane, 45

Climbing and Skiing Guide

Cane, who grew up in Yorkshire, works as an IT contractor in Sydney for six months of the year to fund her ‘other’ life, as an adventure-sports instructor on expedition cruises to the Antarctic

“I’ve seen a lot of people Antarctified. They come down to work for whatever reason, then get bitten by the bug. They return year after year and Antarctica becomes their normality.

“Nothing can prepare you for how stunning this place is: it’s like working inside a high-definition movie. In the space of a day you can see enormous ice cliffs collapse, minke whales play a few feet away and penguins popping up all over the place. The Peninsula is crammed with life, never still or quiet.

“Our working lives are full-on during the season. We have sessions in the morning and afternoon, and often have to bolt down lunch in five minutes then run back, ice axe in hand. We operate off expedition ships, and some of my favourite moments come sitting on the deck when everyone else has gone for dinner, just looking up at the mountains.

“But it has a dangerous face, too: the conditions can turn on you very quickly, and the wind scares me. I worry about being stranded on the ice with clients if the weather closes in and the boats can’t get to us. I’ve seen some pretty bad conditions on the Drake Passage, 70-knot winds and waves so big that when you jump, you land on the other side of the room. It doesn’t matter how rough the crossing is, though; as soon as you see those mountains, it’s always worth it. I’ve been Antarctified for years now.”

THE SEAMAN

Oleg Klaptenko, 44

Ship's Captain

With more than 300 crossings of the Drake Passage to his name, the Ukrainian is one of the most experienced captains working in Antarctic waters. He is currently skipper of the ‘Ocean Diamond’, an ice-strengthened expedition vessel

“I’d never want to work in places like the Caribbean or the Indian Ocean because they always look the same. Antarctica shows us so many different faces, not only season by season, but trip by trip.

“The Drake Passage can be completely calm or extremely bad. Once there was a gale so strong that a German icebreaker lost its bridge windows as the waves smashed them! I like a good storm, but there are limits.

“I love working around 4.30am when it’s calm. You’ll never see scenery like it anywhere else in the world: deep-red clouds and pure white mountains, with whales playing around you. At times like that you see just how small you are; you understand your humanity a lot more.”

THE SCIENTIST

Dr Mike Polito, 35

Penguinologist

A professor of Oceanography and Coastal Sciences at Louisiana State University, Dr Polito has travelled to Antarctica regularly since 2000. He works with Penguin Lifelines (penguinlifelines.org), collecting research samples and video footage from across the continent to help us better understand and protect penguins

“The life of most Antarctic scientists involves one to three months down here, collecting samples and raw data, before heading home and analysing that information for the rest of the year. The longest I’ve spent down here at a time is five-and-a-half months, living in a hut at a remote field camp. It was incredible to watch Antarctica change over an entire season, and the wildlife evolve around it.

“Penguins are excellent indicators of the health of the Antarctic environment, and we have 60 cameras across the continent monitoring them. When I see a penguin, I see an amazing scientific sampling device. They head into the water, they find food and they bring it back to their chicks. By observing how well they’re doing that, we can reach a better understanding of how things such as climate change, commercial fishing and other human impacts are affecting the food web here.

“The adult penguins usually ignore us, especially if they’re breeding. The chicks, though, particularly around six weeks old, can be very friendly. If you sit down somewhere, they’ll come and check you out, peck at your shoelaces, that kind of thing.

“Professionally, it’s very collaborative down here, and it has to be. The conditions and logistics are so tough that you have to work with the expedition ships and the scientists at nearby bases if you want to get anywhere. If you try to do your own thing – to be the only penguin scientist in Antarctica – you’re never going to answer the big questions. Together we achieve a lot more.”

THE ALL-ROUNDER

Liesl Schernthanner, 48

Maintenance and Conservation Specialist

In 1995, Schernthanner took a sabbatical from her career in academic research to work with the US Antarctic Program. She never went back to her ‘real job’. The American has worked all over Antarctica, including the South Pole, where she met her British husband at a research base. This season, she is working in a conservation role for the UK Antarctic Heritage Trust, looking after historic bases on the Peninsula

“I hate being cold – I know, bad career choice – but I just smile so much in Antarctica that I wouldn’t want to work anywhere else. It’s difficult to have a bad day here, even when the conditions are challenging. You just have to look around you and appreciate the enormous pristine beauty and magic of the place: it puts everything else into context.

“This is my 15th summer in Antarctica, and I’ve never found a better office. I’ve had plenty of different jobs down here, from a ‘fuelie’ [looking after the tanks of marine grade diesel at the larger Antarctic bases] to a communications supervisor to a professional conservationist. Working here is challenging environmentally, logistically and physically, so accomplishing tasks is very rewarding.

“I’m genuinely impressed by anyone who gets a job down here – the interview and hiring process is full of hurdles. I’ve decided that 60 degrees south latitude is a great filtering mechanism: those who make it beyond there are usually hard-working, enthusiastic and fun. I’ve never been short of interesting colleagues.

“Often, I get to work with my husband, which is fantastic. It’s great being dropped off on a remote island to camp, work, and enjoy a beautiful place together.”

THE HISTORIAN

Jonathan Shackleton, 63

Antarctic historian and Polar guide

Shackleton, a cousin twice removed of the late polar explorer Ernest, has travelled to Antarctica 37 times, leading historical tours. He lives in County Cavan, Ireland, close to where Ernest was born, and is the author of ‘Shackleton: an Irishman in Antarctica’

“It’s very hard to put Antarctica into sentences, but it’s rather like leaving the planet. It hits you fully when you return to the real world and realise just how different it was. A lot of the attraction is the sheer power and raw beauty of nature here. It gets into your blood. The scenery makes my working life easier, because you can still look around and imagine what it was like for those early explorers in their wooden ships and woollen clothing.

“Part of my job involves camping on the ice with clients when conditions allow. It’s a thrill lying there in the perfect silence like Shackleton and his team – albeit in a modern bivvy bag rather than their wool sleeping bags. Treading in the footsteps of Shackleton and sharing that story with others is the main attraction, but I also love the natural history: the wildlife is incredible.

“I find I need less sleep and have loads more energy whenever I’m here; it’s fantastic. Antarctica always makes me feel younger.”

THE POSTMAN

Stephen Skinner, 29

Sub-postmaster

Skinner was brought up in County Durham. An early obsession with the stories of Scott, Amundsen and Shackleton led to his ‘15-year mission’ to get to Antarctica. He finally achieved it for the first time this season, beating off scores of applicants to secure the role of sub-postmaster at Port Lockroy, the historic British base where he also helps to maintain the museum (ukaht.org)

“Arriving at Port Lockroy for the first time was unforgettable. We came in on a Zodiac [rigid inflatable boat], through driving sleet and snow and it felt like being in a movie. We couldn’t see the base at all, then suddenly it just appeared out of the blizzard. We dumped our kit on the beach, grabbed some shovels and started digging to try to find the door.

“Working days here are very changeable. They invariably involve digging to clear the snow, but I also have maintenance tasks around the museum, painting and repairing. Then there are my postal duties. This is the most southerly public Post Office in the world, and all of the mail from here goes back to the UK to be sorted, via the Falkland Islands. We rely on passing ships and Royal Navy vessels to take the sacks of mail for us.

“We have some old-school science to do here for the British Antarctic Survey as well, which I love. Things such as ionospheric studies of the sky and timed monitoring of the penguin colony next to the base. The penguins are awesome. We don’t have television here, so we simply open the curtains and watch penguin TV.

“We get up at 7am each morning, but because of the constant daylight it’s easy to overwork. Time runs away and we catch ourselves unwittingly working past midnight, so we monitor ourselves carefully.

“I don’t miss the internet at all. I find I sleep a lot better down here because I’m not staring at a tablet screen just before going to bed. The things I do miss are really tangible – it’s primarily friends and family.”