In Our Time - Antarctica

Episode Date: June 24, 2010

Melvyn Bragg and his guests discuss the history of Antarctica.The most southerly of the continents is the bleakest and coldest place on Earth. Almost entirely covered in ice, Antarctica spends much of the winter in total darkness.Antarctica was first named in the second century AD by the geographer Marinus of Tyre, who was one of many early geographers to speculate about the existence of a huge southern landmass to balance the known lands of northern Europe. But it wasn't until the nineteenth century that modern man laid eyes on the continent.In the intervening two hundred years the continent has been the scene for some of the most famous - and tragic - events of human exploration. In 1959 an international treaty declared Antarctica a scientific reserve, set aside for peaceful use by any nation willing to subscribe to the terms of the agreement.With: Jane FrancisProfessor of Paleoclimatology at the University of LeedsJulian DowdeswellDirector of the Scott Polar Research Institute and Professor of Physical Geography at the University of CambridgeDavid WaltonEmeritus Professor at the British Antarctic Survey and Visiting Professor at the University of Liverpool.Producer: Thomas Morris.

This BBC podcast is supported by ads outside the UK. Thanks for downloading the In Our Time podcast. For more details about In Our Time and for our terms of use, please go to BBC.co.com.uk forward slash radio 4. I hope you enjoy the programme. Hello, at the southern extremity of this planet lies an icy, wind-swept and virtually uninhabitable landmass. Antarctica is the world's fifth largest continent,

a bleak and freezing place, almost entirely covered by ice, and plunged into darkness for much. of its long winter. The geographer, Marinas of Tyre, coined the name Antarctica in the second century AD, and many civilizations from the ancient Greeks onwards believed in the existence of a great undiscovered southern land, but it wasn't until the 1840s that humans laid eyes on the continent. Since the early years of the last century, the Antarctic has provided the scene for some of the greatest triumphs and tragedies of human exploration, most famously the death of Robert Falcon Scott on his return from the South Pole in 1912. Almost 50 years later, an

International Treaty set aside the entire continent as a scientific reserve and protected it from territorial claims. With me to discuss the history of the Antarctic from its origins to the Antarctic Treaty of 1959, and Jane Francis, Professor of Pellio-Clamatology at the University of Leeds, Julian Dardswell, director of the Scott Polar Research Institute and Professor of Physical Geography at the University of Cambridge, and David Walton, Emeritus Professor at the British Antarctic Survey and visiting professor at the University of Liverpool. Jane Francis, can we try to a beginning to this, has the continent of Antarctica always existed, if not what preceded it? Oh yes, it's a very old continent. It's one of the original very old continental core.

So if you imagine a picture of Antarctica that has a main round continent and there's an arm, a finger sticking off of it up to South America, and that's quite young. But the central core of Antarctica is about over three billion years old. And the interesting story about the Antarctic continent is that if we go back to about three billion years ago, that core was actually situated right at the equator, even poking into the northern hemisphere, and it was surrounded by other continents. So you wouldn't have recognized it as an Antarctic land mass at that point. And that mass of land over millions of years from about three billion years ago has gradually moved south until it sort of has positioned itself over the South Pole. And Antarctica has, it's

classically known as the kind of the core of this big ancient landmass called Gondwana that consisted of Antarctica at the hub of it, like a spokes of a wheel almost, and attached was South America, Africa, India and Australia. And so Antarctica's sort of history really belongs to that Gondwana continent. And then over time, what's happened is... What do you mean by time? I'm talking about millions of years here.

So over millions of years, Gondwana broke up so South America Africa and Australia have moved north This is all the tectonic place Shipping right The tectonic place have moved But Antarctica actually as a continent

Has stayed over the South Pole So the interesting thing about Antarctica Although we think about it as a very cold icy planet It actually has been over the South Pole For at least 100 million years But without ice on it And we know from evidence of fossils of animals and plants

that it was actually quite warm in the past and the climate was warm even though it was at the South Pole. Can you give us some idea of how you determine things like it was quite warm 100 million years ago? What details? You've mentioned fossils but can you just give us a bit more detail

of the evidence that you used to deduce this? Well, for example, I work on fossil plants so what we've done over the past few years my research teams and other geologists going way way back. Some of the earliest fossils that were found on Antarctica were actually plant fossils and I think that's a wonderful paradox about Antarctica

there isn't much rock in Antarctica and David will tell you more about this but where you do find rock I'm willing to bet that within a few minutes you'll find a piece of fossil wood because plant fossils covered Antarctica for much of its history and they're preserved there in the rocks

so we can take the wood and the leaves we can reconstruct the forest and we can actually work out what the temperature was It sounds like the biggest conjuring tree. You can re-take the wood under leaves from and we can reconstruct the forest. In a proper scientific and analytical techniques. I know, I believe you can do it. I just want to know how you do it.

Well, it's based on how plants respond to climate today. So we can look at the types of plants that lived in Antarctica. And we can see that they were very similar. And probably relatives are tropical forests that live near the equator today. So we know that there must have been high levels of rainfall and the temperatures were high. And we can actually work out what the temperatures were. So we know it was fairly tropical, even though Antarctica was over the South Pole.

David Wharton, can we take that on? Jane deferred to your night and said you'll know more about this, but the warmings and the coolings and the history of the... the history of the continent. Take us to about 35 million years ago. As an ecologist, of course, I'm struggling that far back because the history is written in the fossils and in the sedimentary. areas. But we know that

there were dinosaurs there. We know that there were giant penguins there. Six foot tall penguin? Indeed, according to the reconstruction of the penguin from a single metatarsal that was found by Nordenskould around 100 years ago. It's amazing

what you can do with one bone. So we know that it was a much more interesting content in many ways as far as a flora and fauna were concerned. And using the data that we've got we've been able to show that the forests actually, as Jane has said, are closely related to some of the ones that you find currently in South America. We know what the tree species

were, we know what the understory was like, we have fossil pollen and so on. But then the ice sheet started forming and it gradually expanded. Can you give us some idea of, A, when it started forming and how it started forming? Well, this is Julian's speciality, I have to say, but let's say the dispute over when it started forming has been going on for some years and it depends precisely what model you use but I think around 35 million years ago is the generally agreed point at which

the nucleation of the ice sheet began and it may have begun in a single place or in two places at the same time and it gradually spread and it now covers almost all the continent and during that time of course the climate and the continent changed and it got gradually colder. The forests were pushed to the edge.

The range of species there changed and were left now with the largest animal in the Antarctic being a wingless midge about three millimeters long. You mentioned you pointed over to Julian and so I'll go to Julian now, come back to you in a minute or two. Let's take this ice sheet and how it was formed and tell us more about it. Well, the ice sheet appears to have begun to form at the same time as South America moved away about 35 million years ago from the tip of South America.

And winds and the ocean currents effectively isolated Antarctica from the rest of the global climate system. And it's at that point that the ice really began to form. Now, of course, the continent is covered by ice up to almost five kilometres in thickness, and only less than 1% of Antarctica is. not ice covered. The average thickness is about three kilometres and the ice builds up through the year-on-year accumulation of snow. The way that ice sheets behave in general is what we call the mass balance or the state of health. That is to say the inputs of snow, which in Antarctica can only be about five, ten centimetres a year at most, over the whole continent are balanced

against the flow of ice because ice flows like a metal close to its melting point. And ice flows then from the centre to the edge of the continent, a mass is lost to balance the precipitation gains through the production of icebergs and basal melting of the floating margins. And if the ice sheet is in an equilibrium with the climate at any point over the last 35,000 years, then what comes in at the top is more or less balanced.

35 million years, did you mean? 30 million years or so. Can you tell us more about this flow? So it's always moving, flow. Flow suggests a river. Well, that's why I said ice is like a metal nearer. because it's crystal deformation. It's not actually liquid flow at all. Ice, in fact, moves slowly a few metres a year by that crystallographic internal deformation. There are what we call

ice streams embedded within the ice sheet and those flow much, much faster. Those can flow at several kilometres per year. The reason they flow faster is because water is present over parts of the bed of the ice sheet and that water is essential for the lubrication and the faster the flow of the ice. And that water is derived not from surface melting, because the Antarctic has very little surface melting at all even in summer, but actually from the geothermal heating of the base, and that water lubricates the ice and parts of it flow very fast. And in fact, those ice streams, where they reach the periphery of Antarctica, are the areas from which the vast bulk of mass is lost. So if we understand the behaviour of ice streams in a time-dependent

way, we understand the state of health and the mass balance of the ice sheet. So it isn't that it's flowing downhill from the south pole it's that something happened to the ice itself. Thermal heating, what are you talking about now? This is the radioactive heat from decay in the centre of the earth. That is what melts the base of the ice. In fact, if you look at a temperature profile through an ice sheet, it's always coldest at the top because we've actually got the very cold, minus 50 degrees, Antarctic winter,

and warms progressively to the base, and it's dependent on the thickness, as to whether the base actually reaches the melting point or not. Would that suggest that this five kilometres of ice trap water underneath, which is warm? What happens is that the ice, the three five kilometres of ice, actually insulates the bed against the cold surface, and that allows the basal geothermal heating to have the effect of melting at the bed. How old is the oldest ice on the continent?

The oldest ice that's been observed on the continent, and there's a three-kilometer plus drill core that's been acquired recently from central East Antarctica. The oldest ice in that is estimated to be about 750,000-800,000 years old. It is likely that there are slightly deeper areas of the East Antarctic ice sheet where the accumulation rate, the build-up of snow year-on-year may be slower, where one might get back just over a million years. But essentially, the precipitation that fell, let's say a million years ago,

will all have flowed through the ice sheet and being carved off as icebergs by now. So probably a limit of around about a million years for the oldest ice that we might recover. We've recovered 800,000 years worth of record so far. So it flows to the edges and breaks off as icebergs and they begin to drift. Yes, they drift off and melt preferentially once they reach warmer water

several hundred kilometres, sometimes even 1,000 kilometres away from the margin of the ice sheet. Back to you for a moment or two then, David. Can you, about 35 million years ago and just be on from that? not sick of that pedantically, but coming forward from there. Can you give us some idea of what people would have found there? I mean, you began with the dinosaur, I presume not the dinosaurs 35 million years ago. They'd gone.

If you go to the growth of the ice sheet, then 35 million years ago you got forests, real forests with big trees, and you can find those tree trunks, as Jane has suggested, still lying there on the surface. A whole tree trunk, which is maybe 20 or 30, 30 metres long of fossil wood, you would find associated with them a variety of insects. As the Antarctic has become steadily more covered by ice, then the diversity of the organisms has decreased because there isn't anywhere for them to be. So we're now left with this margin of land.

Less than 1% of the Antarctic is actually ice-free, including the mountains and the coast. the edges and it's on those tiny bits that the remains of the floor and fauna are living. No trees, no shrubs, no flowering plants except in a few areas of the Antarctic Peninsula. Almost no insects, no spiders,

no beetles, no weevils and so on. So just a few little springtails, some midges and so on. We have one of the most depoporporate floraes and faunas in the world. Lycans, mosses, one grass and one flowering plant. Jane. Yes, the history of the ice buildup is really interesting

and one that's taxing a lot of geologists and geographers and scientists in Antarctica at the moment because, as David said, we see evidence in the rock record for the very first ice. And then how did the climate cool enough to really put Antarctica in the deep freeze that it is now? And how does that relate to the Arctic ice cap as well? And it's a really interesting story because the two don't work together. And I think what the rock record, we have to look back to the rock record, initially at 35 million years ago. What that shows is that probably the ice caps came and went.

And the climate was beginning to get cold a little and then it oscillated and warmed up a little bit. And in fact, we do find some really unusual deposits very close to the South Pole, up the Beardmore Glacier where Scott and his party went to try and conquer the South Pole. And very close to the South Pole, there are some deposits with leaves and insects in, few million years ago.

So we know that the ice caps came and went a little bit. And then something happened, and probably as Julian said, it's this intense period of cooling when Antarctica really went into deep freeze and that's really wiped out most of the old plants. And as David said, then we have these few mites left.

And it's only then when Antarctica went into deep freeze, which is probably a few million years ago, that the earth became... Seriously, I'm not being silly, what do you mean by a few million years ago? Two or three million years ago. Right. Yeah, really, really, maybe eight, we can go about eight to ten.

And that's Wednesday about your account, really. Yeah, yeah, very, very, you know, relatively a few days ago, geologically speaking. And that's when the Arctic cooled, and we get into what we would call, you would call our ice age. And so the Arctic is cooled much, much more recently. But now Antarctica is what we call in the deep freeze state, and it's fairly stable. But even in the deep freeze state, if we look at the ice score record for the last 800,000 years, one can see a series of glacial interglacial cycles where the temperature appears to have varied by between

let's say 10, even 15 degrees centigrade with arguably about 8 or 9, 800 or 90,000 or 90,000 years colder than today and then maybe 10, 15, 20,000 the interglacial Antarctica about the same temperature as now and of course that resulted in the waxing and waning

of the ice sheets across the Antarctic continental margin. So 20,000 years ago, the ice sheet was extended by 3, 400 kilometres further than it is today. And that, of course, is why in turn, global sea level was minus 120 metres, 18,000, 20,000 years ago because that ice has effectively come from the global hydrosphere, from the oceans, through precipitation. Jane Francis, there were rumours that this existed. I mean, the Greeks thought there must be something down there to balance something that was up there. Antarctica is against the Arctic, isn't it? The word itself.

But as far as we know, the first sightings by humans was in the 19th century. Persis might have seen it early, but we have no record of that. Why did it take so long? I think it just took a long time for people to go south. I mean, like you say, people, even far as the back goes as the Greeks,

they thought that there must be a continent in the South Terra Australis or Terra Incognita that balanced the world. And it was when explorers were able to actually sail around Africa and around India, they realised that those continents weren't joined to a southern land, but they still thought there must be something further south. It's pretty inhospitable the seas to the south.

And it was early explorers, James Cook, got very close to Antarctica and saw some of the sub-Antarctic islands, but didn't manage to get any further south. I mean, it's pretty nasty when you get to Antarctica on a ship and you start meeting all the icebergs and the sea ice. But then some of the... Early explorers went further and further south and then they actually managed to find the Antarctic continent.

David Walton, let's get to the Antarctic exploration now. Can you tell us about the first people to get there, to walk on it? Let's have the story of the human exploration. Forever disputed, I think we have to begin with because many nations would like to claim to have been the first to be there. What we know is that after Cook discovered... And the date of that? 1775.

His account of his voyage actually noted that there were lots of fur seals down there. And that immediately caused commercial interest to grow in, especially in the UK, but also in the United States. And the sealing era began collecting fur seal skins when millions of animals were slaughtered. Now those sealers actually were pursuing cash profits. and so where they went was commercially in confidence. So we don't in many cases know exactly where they went. But wherever there was land and there were first seals, they were going there. So they may have been the first people, for example,

to explore some of the areas of the Antarctic Peninsula. It doesn't sound as much exploring as slaughtering. Well, indeed it was. And they filled their ships with the skins and sailed them to China where they were made into slippers. So that was the first real commercial exploitation of the Antarctic. in the early part of the 19th century. By 1830, they'd slaughtered almost all of the fur seals in the Antarctic.

And then they moved on to the elephant seals after that for oil. So the Antarctic isn't pristine. It's actually been used for commercial benefit for the last 150, 200 years. Have seals that started breeding again now? Yes, the fur seals were put under protection in the early part of the 20th century. and from a very small population they've come back and there are now several million of them.

So that's been a success story. The elephant seals were reduced to small numbers but they've also come back as well. So those bits have recovered. The bit that didn't recover was the whaling stocks. Whaling started in the Southern Ocean in a big way around about 1904 with the establishment of the stations on South Georgia

and since then they've stripped a large part of the whale population out of the southern ocean and it simply hasn't recovered in the same way that the fur seal stocks have. Why not? Why not? Well, one of the possible reasons, unprovable, is that whales compete with seals and others for food. They eat krill, this little shrimp-like organism. If you take a large number of whales out of the system, there's a lot of krill,

and so the seal population expands to eat the krill, and when the whale, the whale, tried to come back, there isn't the krill available. They have a competing predator for it. And so it's simply, maybe there isn't enough food. Maybe the whale stocks have got so low in some cases like blue whales that the whales themselves are not meeting to breed. So there's several possible explanations for this, but despite protection for quite a long time now,

only some of the whale stocks have begun to recover. Blue whales, hardly any. Julian Darrell, the next stage we're going to do is being called the heroic age of exploration in which a lot of Antarctic exploration which a lot of British people were involved.

Can you tell us how that kicked off? In our societies, Royal Society for instance, was quite a bit to do with it, wasn't it? Absolutely. Scott's Discovery Expedition, 1901 to 1904, was jointly sponsored by the Royal Society and the Royal Geographical Society. Am I right in saying before that being this

secretary of Royal Society is a Clement Markham who was a geographer who was very interested in the Antarctic? and organised, said that it should be done properly. In the same way that Barrow, the second secretary of the Admiralty, had stimulated work in the Arctic in the 1820s, Clements Markham was the driver of the heroic era of Antarctic exploration, and he picked out Scott as a young Navy officer

who was capable of leading an expedition. Sorry, I don't want to interrupt you, but just to get it clear for everybody, when you use that exploration, we're talking about several things, So we're talking about scientific exploration, geographical exploration. Can we just elaborate that word and then go on. Exactly so.

And I think one of the distinctive things about both Scots expeditions was that it was exploration and science. I would define exploration as simply going there, getting there and coming back. And the science is actually the understanding of and even the mapping of and the accurate demarcation of the poles. And Scots expeditions, both the discovery and the later Terenova expedition,

were probably benchmarks in the establishment of interdisciplinary science in Antarctica. So both Scott's expeditions had twin aims. Scott's first expedition, Scott and his two companions, were the first people to press into the interior of Antarctica, the first people to go anywhere but to the coast. And they walked most of the way across what they called the Great Ice Barrow, which we now know to be the Ross Ice Shelf, and first saw the trans-Antarctic mountains as a barrier to penetration

onto the high polar plateau where the South Pole sets. But at the same time, people back at the base were making a series of observations on biology, oceanography, glaciology, geology, and that's the very distinctiveness of both Scots expeditions. And I think you're right that that's rooted in their support from the RGS and the Royal Society. Geographical Society and the Royal Side itself.

Jane, James Pantros. Yeah, yes, and even, you know, Scott's dramatic expedition to the South Pole, which we may talk about, I mean, even though he's trying to get to the South Pole and it was a really sort of tragic expedition that Amundsen got there first, he still was focusing on the science. And there's a lovely story about, well, a bit tragic story, really. On the way back they were coming down,

the Scot and his party were coming down the Beardmore Glacier. And on a day of nice weather, they stopped at a small island of frock at top of a mountain that's sticking over the ice sheet and found some fossil plants. And this is what they actually set out to do. Before they left the expedition, there was a lady called Marie Stopes that you may know of with a different reputation because she actually was a scientist, a geologist,

and she then became very famous for family planning. But she convinced Scott that somewhere down in Antarctica, he should find fossil plants, particularly this fossil plant called Glossopteris, which is a very distinctive leaf. And Glossopteris had been found on all the southern continents, the other southern continents, South America and Africa and Australia. and she asked Scott to see if he could find these fossil plants

to prove that Antarctica was once part of this big landmass called Gondwana and therefore helping to prove the theory of continental drift that all the continents were once together and they drifted apart and actually Mary Stobes wanted to go to Antarctica herself good for her and she badgered Scott but I think he said my dear lady we can't take you to Antarctica but Scott did find these fossil plants called Glossopteris on his way back from the pole and although they met

their tragic death as they came back the box of leaves came back with them and are now in museums ready for study so they're very very famous relics of that kind of position let's go to Scotland Hamilton now in 1911

the so-called which race for the South Pole David Walt can you outline for us we can take a bit time of this what happened and what I mean people think they know the story but in reading the notes of this program you three there's quite a lot of the story that is new to me anyway, even though there's been a fine novel written

about it by Barrel Bainbridge, England. It's still... Anyway, where you go? Well, Britain was an imperial power in those days, and the Antarctica was one of the last unexplored areas of the world. Scott's first expedition hadn't got to the pole, but it

had helped greatly in improving the way in which the British thought they could mount an expedition to get to the pole, and it had also brought some good science back. And so the second expedition built on the expectations of the first and tried to improve the way

in which they set out. Now when they set out on Terenova for the Antarctic... We're talking about Scott's expedition. Scott's second expedition. When he set out the second time, he thought he was actually going to be going there on his own because

he believed at that time at Amundsen was going to the North Pole. And it turned out that Amundsen had actually decided to change his mind and Amundsen sent him a telegram saying, which he got in New Zealand saying that he was going to be going to the South Pole and so suddenly there was a competition

it didn't start out as one but that's the way it turned out so both of them landed in the Antarctic and there was a difference of approach Amundsen's objective was to get to the South Pole and get back and he was a consummate explorer of the sort that Julian has described in that everything was sacrificed towards doing the job

and so he took dogs and he knew how to handle the dogs and he was prepared to sacrifice the dogs. Scott didn't think about it in the same way he wasn't as dedicated solely to getting to the South Pole because the science was important to him and so the differences between

the two expeditions was that Amundsen was determined to get to the pole and back and he never lost a man. He ate the dogs, and the dogs ate each other. I put a lot of people off this programme. That's a historical fact, Saddle. Scott did it differently, and he failed to get back. He got to the poll 33 days after Amundsen had

and collected some of the memorabilia. What's even less known, of course, is at the same time that Amundsen was organising himself to go to the pole, the Japanese turned up, totally unexpectedly. Expedition led by Nobu Shirazi aboard the Kanamaru was the first Japanese expedition to the Antarctic, and they turned up in the Bay of Wales, set up camp there, and found that Amazon's ship was floating just down the road, as it were.

So it was a really odd occurrence. One thing that was new to me very much, that the speed of change from summer to winter in the Antarctic is much greater than the previous experience in the Arctic where it was great. So I hadn't known this at all, but one of the reasons why Scott was 11 miles from his base camp only was because they'd run out of supplies because it had become very cold very suddenly,

and they had brought summer supplies, as it were, and not winter supplies. This says a lot about the Antarctica. It doesn't say anything about bad planning of that. It says a lot about bad luck, I presume, or you tell me, Joie. Well, I think it's not so much bad luck. It's just that's the way the Antarctic changes very quickly from summer to winter,

and they just didn't know that before. They assumed that the temperatures, when they came down from the plateau, onto the ice barrier, would actually be much higher than they turned out to be. And that was really the reason why Oates, Scott, both got badly frostbitten. They were basically a month too late, and the Antarctic, unlike the Arctic, actually switches incredibly rapidly from summer to winter, and that's because the interior of Antarctica is so far away from the warming effect of the ocean. The interest in Antarctic exploration rather fell off after what's been called this heroic period, didn't it?

I think people felt the pole's been done now, so the challenge of just getting there and getting back had disappeared. I mean, Amundsen's switch from the North Pole to the South Pole was precisely because he thought that Piri and Cook had got there. And although Byrd, the American, overfrew the South Pole in 1928-29, and nobody went back to the pole overland until the Fuchs and Hillary, Commonwealth Trans-Antarctic expedition of the 1950s. The Americans, of course, had established a base at the pole about a year and a half before. They'd flown in.

But they'd flown people in. So nobody actually went back to the pole. until the 1950s. And I think it's largely because issues of both science and sovereignty in places around Antarctica were much easier to get to than the South Pole itself took primacy over the intervening period. Jane, over the next few decades, after the First World War,

how did research objectives change with regard to Antarctica? Yes, as Julian said, I think the sort of the race for the pole took the focus off the sort of adventurers. bit and then people started actually looking at the science in Antarctica and they made maps of the geology, they looked at the biology and so they started doing the real science and trying to build up the history in the geology of Antarctica. Of course at that time they also looked at some of the mineral

resources which we don't know to do now because of the treaty which we'll come on to later but they started trying to understand the continent and what it was all about and what its history was. Can we talk now David Walton about who began to claim Antarctica? use the word, we were still an imperial power, we went around, claiming things, actually, they were sticking flags in the eyes and saying, this is ours,

weren't they? And so it was Norway. So, which nations most convincingly and most threateningly claimed the Antarctic as their territory? Well, we started in 1908 with the letter's patent claim to what is now British Antarctic territory, and there was

a further adjustment that in 1917. But that actually also butted against claims that we'd made in terms of other areas of the Antarctic, what is now Australian Antarctic Territory and what is now New Zealand Antarctic Territory, the Ross Dependency. We made those claims, imperial claims,

and then transferred the rights to them to those countries separately. So the Australians took over the bit that we'd claimed previously in East Antarctica, and so did the New Zealanders. But our activities spurred others into thinking about whether they should make claims. So the French made a claim, a very tiny strip of Terradaliland in 1994, and then the other countries came along. Suddenly the Norwegians wanted to make a claim and they got in just two weeks before the Germans got there in 1939 because the Germans mounted an expedition to make them an imperial power and make a claim

to the Antarctic, followed by the Argentinians and the Chileans and so on. So that's how you ended up with this set of pie slices of claims. And Julian, the Second World War changed the situation. Can you explain why? I'm still talking about the political situation. The Second World War, I think after the Second World War, in the immediate aftermath of the Second World War, the Americans decided that they wanted to have some action

in addition to Bird. Bird actually dropped a flag out of his plane when it flew over in the late 1920s. Not the same as sticking it in the ground, does it? It's not the same at all. No, it's rather easy. Kind of like bombing it rather than clamming it. So the Americans, immediately after the war, went back with a huge multi-ship thousands of people, aircraft expedition called Operation High Jump.

And that was really to establish their activities on Antarctica. And from then on, they set up a series of expeditions, which translated into what is still known today as their annual Deep Freeze expeditions. And from, as I say, 195, they actually established a base at the South Pole. David Alderman. Yeah, I just want to come back in here because, During the Second World War, the British government became very concerned about whether or not German raiders would be able to operate in the Antarctic area and get to the convoys coming out of Argentina. And so they established a thing called Operation Taborin, a secret operation where they sent people to bases down in the Antarctic.

We built those bases in the Antarctic in 1943 and 44 to watch for German raiders and report on their presence. and actually that was the start of the continuous British occupation of the Antarctica from that point on we've continued to live and work in the Antarctic year round. Jane? But the interesting thing was although obviously Operation Tabarin was there for a sort of political point of view in the war, but what the people actually did were there, you can imagine you couldn't just sit around all day looking for ships out at sea, they actually were scientists doing science. And some of the most valuable early science from Antarctica was done during some of these

campaigns and although they had probably a different political agenda some of the rocks that were collected some of the mapping was done was some of the most valuable in the early days of science or is it all different nationalities and in fact the science that we do today builds on some of those early foundations

I mean the meteorological records that were kept from those expeditions right the way through to today are absolutely the baseline about climate change in Antarctica can we talk about I would like to move to this international geophysical year 578 and the Antarctic Treaty System because it is an extraordinary thing

that the fifth biggest continent in the world is as it is. Can you tell us as it is and why it is as it is, David? Yes, it all started really in 1948 when the Americans thought it would be a great idea to have a condominium to manage the Antarctic and they talk to some of their allies including the British about getting together to do this.

As part of this, they set up a committee of the National Research Council to come up with a research, plan for the Antarctic. And that research plan actually was used by one of the members of that committee, Lloyd Berkner, as the basis for suggesting a new international polar year, which eventually became the international geophysical year. Lloyd Berkner was an amazing operator in the American system. He was a atmospheric physicist who was into rocketry and so on. And he bridged the gap between the military complex in America and the academic complex in America

and talk to the politicians about it. And his ability to pull strings and so on meant that what was put together for the International Geophysical Year, which was a brilliant international programme of research, actually was built on a geopolitical strategy of the United States to demilitarise the continent and make sure that the Soviet Union couldn't actually build military stations there.

So as it is now, it is a demilitarized continent. It has no central government. It doesn't belong to anybody except the 40 plus countries which are doing proper research there and they have the right to inspect each other's bases. Am I right so far? You are indeed and the inspection is the crucial element because when the treaty was agreed

both the Soviet Union and the Americans suspected each other all the time of building bases and introducing rockets and nuclear missiles and so that was the first disarmament treaty. really in a way in that both the Americans and the Russians could inspect each other's facilities without any limits and so they could make sure that military installation were not going to take place in the Antarctic.

There is a sense, Sir Joan Francis, that science was the driver in all this in setting up and that they did this in order to have this massive, snowy desert, open laboratory down there. Can you tell us what sciences have developed? In one of your notes, I've got there 11 Earth scientists, are being explored. There's Aurora and air glow I'm reading here. Cosmic rays, geomagnetism, gravity, ion physics, study of the Earth,

suburbos atmosphere, and so on and so forth. So can you ask more about that? Well, it's a fantastic natural laboratory. So, for example, if you take atmospheric science and space science, you can go to Antarctica and the scientists can work there very high on the top of the eye sheet. So they can work at high altitude, the atmosphere, is very clean, there's very little pollution there, no pollution there at times. And they can really see space. They can work on cosmic rays, on the ozone hole.

This is where the ozone hole was first discovered, of course. And so it is a fantastic natural laboratory. And when you actually get to Antarctica, you can forget the politics. A lot of the countries, you know, even though there have been in the past territorial claims, we all work together. And in fact, because it is such a remote and difficult place to work, it's really key, actually, that the nations work together and big, international collaborative projects, particularly today when we're in the era of big projects and very

expensive projects. So some of the most successful projects at the moment are multinational projects that are working on very, very big science questions, which of course requires boats and planes and a lot of kit to get to Antarctica and work in very difficult conditions. It's actually a really exciting place to do science now. Julian, you said earlier the keeping of the meteorological records continuously has been the basis of the science. Can you tell us, can you give listeners some more idea of how that place is, Jane has begun this and being very, coloured it in very well, but just give us more idea of how valuable that is being for the development of sciences.

I think one thing we really want to understand today is how our environment is changing and for that we need baseline information and in Antarctica because nobody went there, you know, the first people to go to the interior was Scott and his companions. Those actually are some of the very first meteorological measurements and those can be put together with those of the British Antarctic survey and the Falkland Islands Dependency Survey and others since the 1950s.

To provide a picture of what Antarctica was like then and what in particular the Antarctic Peninsula was like 50 years ago and we can show that the temperature has changed by three degrees centigrade since that time. I think that's extraordinary. What great discoveries do you expect to come out? of the signs down there, David Waltham? Well, the greatest discovery probably in the past

30 years in the Antarctic was the discovery of the ozone hole, which actually changed our perception of the way in which we affected the atmosphere and so on. But not only that, the fossils in the Antarctic, as Jane has said, have changed the way in which we understand continental drift, they've changed the way in which

we understand paleo climate, the way in which we build the models on which our future projections are going to be. So for us, the most important question at the moment is, can we get as many data sources together as possible to understand what is happening to the ice sheet? And I think that is probably the most important question.

And there's still a huge amount we don't know, and there's still a huge amount of exciting things that we're just finding out. For example, 20 years or so ago, it was discovered there were large bodies of water in cavities beneath the Antarctic ice sheet, the largest one covering 5,000 square kilometres and being 500 metres deep. That was thought initially that the water had been isolated there for several million years

and the notion was that we would eventually sample that water and there would be ancient bacteria and so on in there. Very recently using satellite radar altimeter which can measure changes in the surface elevation of the Antarctic very accurately. It's been shown that those lakes actually drain into one another and therefore the plumbing system of Antarctica is much more dynamic than we previously thought.

And the scale of science now is fantastic. I mean, there are still people who go in the field, you know, as geologists and we look at the rocks and we make maps still. I mean, there's only a very small area of the continent that's exposed. So as the ice recedes, we'll have more to look at. But we're also doing big science now with satellites, looking at the extent and the changes in the ice sheet, just using satellites.

Big, big science. Do you like going there? I love it. Just take me there again. Thank you all. Very much. Next week we'll be talking about the life of King Athelston, grandson of Alfred the Great, and the first monarch of all England. He had legal codes, first king to use imprisonment as a form of punishment. Thank you for listening. If you've enjoyed this Radio 4 podcast, why not try others, such as Thinking Aloud, where Laurie Taylor discusses the latest social science research. To find out more, visit BBC.co.com.uk forward slash Radio 4.