"We collect ice. We break it. We see how tough it is compared to other ice." As summer in Southern Hemisphere approaches, Heating Planet blog will cover the coming massive ice melt phenomenon. Here is "Antarctica’s Greatest Mysteries" from New Scientist channel Sep 14 2025- transcript below
Over 0:07 the the last few years, we've seen a really dramatic decline in Antarctic sea ice. A decline that's happening much 0:14 faster than what we had anticipated could happen. 0:19 One way we try and convey how unusual something is is with statistics. We talk about a 1 in 10 year flood or a one in a 0:26 100redyear flood. And if you run those sorts of statistics for Antarctic sea ice last year, you get a number 0:33 somewhere between 1 in 7 12 million years and 1 in 7 billion years. Neither 0:39 of which make any sense in a record that's only 40 years long. 0:45 Antarctic sea ice plays so many vital roles in the world's climate system, in 0:50 the ecosystems around Antarctica, and more broadly. The regime shift will have 0:55 implications for the biology around Antarctica and in the Southern Ocean that depends on the sea ice for habitat 1:02 um both on top of the sea ice and underneath the sea ice. We saw the heartbreaking story of emperor penguin colonies where the ice 1:09 melted underneath before the chicks were fully grown and they all died. 1:17 But it will also have impacts on the rest of the climate system in Antarctica and particularly the way sea ice 1:23 interacts with ocean circulation and also the stability of the ice shelves around Antarctica. 1:29 Sea ice protects the Antarctic coastline and it protects the Antarctic ice shelves. So taking away that sea ice 1:35 would probably lead to more rapid disintegration of the ice shelves which hold back the ice on Antarctica. As that 1:42 sea ice disappears, the ice shelves disappear and the ice on Antarctica flows into the ocean. accelerating sea 1:47 level rise. In terms of global impacts of sea ice changes on weather, that is a a 1:54 scientific question that we're only just starting to unravel. There's some initial evidence suggesting that 2:00 rainfall over Australia could change by 15 to 20% because of the sea ice changes. Now, maybe 15% doesn't sound 2:07 like much, but if you're in an area farming wheat and you only just have enough rainfall, that could be the 2:13 difference between a crop that fails and a crop that you can harvest. 2:19 All of the indications seem to be pointing to this change being related to heat building up in the ocean and and 2:24 we're seeing um an enormous amount of heat being taken into the ocean as the climate warms. So, we know that the ocean is warming 2:31 and we know that that warming is caused by humans. We have quite strong evidence 2:36 tying the ocean warming to the sea ice loss. So I would say I'm quite confident 2:41 that what we're seeing is the long-term impact of human greenhouse gas 2:47 emissions. We can look at how Antarctic sea ice has behaved over the last few hundred years. 2:54 And when we do that, we don't see anything that looks anything like this dramatic decline we've seen over the 3:00 last decade. It could change to become even worse again in the future. There could be another rapid decline in 3:07 Antarctic sea ice. And we should do absolutely everything in our power to try and reduce the likelihood of those 3:14 bad futures. 3:21 Antarctica is changing very rapidly. What we're trying to do is understand how these cracks grow and predict the 3:28 timing of these big carving events that create very large icebergs. 3:35 We don't know what controls when they break off and how they break off. We don't really understand how much sea 3:42 level rise is going to be caused by ice shelves. 3:48 We collect a lot of ice cores. We break it. We see how tough it is compared to other ice. 3:54 There isn't much data on that because getting access to ice from Antarctica is difficult and you have to get it halfway 4:00 across the world without melting it. 4:08 Ice shells are very important on the global scale. They are the floating parts that surrounds the margins of the 4:16 continent. They hold back ice from the interior of the Antarctic continent. 4:21 There's been periods where we've had sudden ice shelf collapse or loss of ice shelves. The famous one is Lassen B in 4:28 the early 2000s. We had extreme warm temperatures one 4:35 year. We got a lot of melting on the surface and then a lot of fracturing and then that ice shelf completely 4:41 disappeared. It just disintegrated really rapidly. And that means that this ice that's flowing off of the continent 4:47 has nothing stopping it. So that ice can just completely flow out into the sea and it breaks up as icebergs and then 4:54 just contributes to sea level rise. 4:59 Antarctica contains the biggest ice sheet in the world. It has the potential to raise sea levels by tens of meters 5:06 and we are starting to see significant contributions to sea level rise from loss of ice from Antarctica. 5:13 A lot of the world's population live in coastal cities and around coasts. And so 5:19 this will quickly have a direct impact on coastal ecosystems, mass migration, 5:24 and for society as a whole. Antarctica loses about half of its mass 5:31 through iceberg production through carving. That's a very natural process and we expect that to happen nicely 5:38 continuously. The ice shelf grows, it breaks off, continues to grow again. But 5:44 we're seeing that this process is actually being changed by the climate and we want to understand what's 5:50 happening there. The big changes that have been happening are mostly in West Antarctica. So areas 5:56 like Thuait and Pine Island, the ocean is warming and a lot of the ice shelves are melting and thinning and that is 6:02 reducing their buttressing power. The effect of carving is less well understood. 6:16 I work on the brunt eye shelf where we have Halley research station. We are interested in the different drivers of 6:22 crack growth. This particular ice shelf has a number of active cracks within it. 6:27 So it's a dynamic ice shelf. It moves about 4 m a day, which is relatively 6:32 fast, but also it's had these what we call rifts, which is a full thickness crack 6:39 that goes right through the ice shelf and have led to several large carving events in the last four years. 6:46 The rift tip project is about trying to understand the rate and timing of why ice fractures and why we get these large 6:54 icebergs produced from ice shelves. Iceberg A81 was formed from chasm 1. 6:59 Chasm 1 was this large rift that we expected to form at some point. The ice 7:05 shelf had got as big as we knew it had got before and then that crack eventually propagated through the ice 7:10 shelf and then the iceberg broke off. The other crack was aptly named 7:15 Halloween crack because it was found on Halloween and this grew really quickly and it was less expected. has led to us 7:23 realizing that maybe the way this process has happened we don't understand as well as we should. So if we can't 7:28 understand how and when ice fractures and produces icebergs, we don't really understand how much sea level rise is 7:35 going to be caused by ice shelves. 7:42 The first time I saw Halloween crack, we were flying towards Halu station out of the little twin otter plane and you see 7:49 this large opening and you just go, "Wow, it's huge. It's open water, this 7:55 vast expanse that if you were on one side of it, you could be convinced that maybe it's just sea and that there's not 8:02 ice on the other side of it. But as you fly over the crack, the further and further you get towards the tip of it, 8:09 it just gets narrower and narrower. And then we landed in the plane to do 8:15 some uh surveys around the very tip of Halloween crack. And all that remained was this very, very tiny hairline little 8:24 fracture in the surface of the snow. and myself and the field guide were walking along tied up with a bamboo stick trying 8:31 to find where this crack was. And that's in sort of 50 kilometers that the crack 8:37 has gone from this massive massive thing to just this tiny little hairline fracture that you can hardly even see. 8:45 What the whole project is designed to do is fill in the gaps between 8:50 understanding what's happening at the small scale with crack growth and the large scale with iceberg production. We 8:57 think it all comes down to sort of centime millime ice crystal scale of where that crack goes. It's such a small 9:05 process that we're trying to understand with all this large equipment and these large expeditions. The main thing that 9:13 we're doing here is joining all these things together on a specific crack on a 9:18 specific ice shelf. And so we're getting a full view of everything from the microscale to the wider impact on the 9:25 actual iceberg formation. 9:32 Our research station Hali uh is down here. The area we've been working in 24 9:38 25 season is up here at the tip of Halloween crack. So this is about a 50 9:44 km drive. 9:50 The crack has been growing since 2013. We've been monitoring its width very 9:56 closely. We've been monitoring strain rates around the tip of that crack. And more recently, we've set up seismometers 10:04 around that crack. It's quite amazing what we can do with 10:09 the satellite imagery these days to understand how cracks are growing, but it doesn't tell us about what's 10:14 happening in the subsurface. Um, for that we've been using radar measurements. So, driving a Scdoo with a 10:21 radar system towed behind which can image the properties of the ice at 10:27 depth. We can also use that to find cracks that are not necessarily visible at the surface. 10:33 In Antarctica, we actually see quite different characteristics of this reactoring. Whether that's on the brunt 10:39 shelf where I've been to or Lars and sea ice shelf kind of tends to do the complete opposite of what we'd expect. 10:45 We want to understand why it is that when ice fractures, it goes through certain types of ice more so than other 10:52 types of ice. So, I use geohysics to try to do that. The previous season, I'd gone over to 10:58 this bit of ice and installed two instruments that were there to track if 11:04 the ice did break off. And then we turned up this year and they're just 11:09 gone. The ice is gone, the instruments are gone, and you have this real understanding of the scale of what we're 11:16 studying. 11:21 We also collect lots of ice cores where we're really looking at the very small scale properties. So we drill down to 11:27 over 130 m and we roughly recover a core every 80 to 90 cm. 11:34 When we're in the field and and drilling the ice, it's it's quite a exciting 11:39 process. We need the cores to be in a real pristine condition. They can't have any 11:44 fractures or anything in them that we've created. You've obviously accidentally drop a 11:50 couple and theoretically they're worth about £8,000 per meter is the price that 11:56 Bass puts on them. The ice has to be taken back to Halley. 12:03 Then at the end of the season, it was collected and then loaded onto the Sir David Atenburgh ship. 12:09 It's a long process. So we had to wait around 9 months to see the ice again. 12:14 That's quite a nervous process when it arrives here. You want to make sure that it's still in the same shape that it was 12:22 when when we originally logged it. The ice has just moved in a regular 12:27 freezer van. Often the driver will ask us what we're what we're transporting and is always quite excited when they 12:33 hear that it's ice from Antarctica. Relief when you finally get your hands on them. You often get very friendly 12:40 people wanting to help carry the boxes off of the off of the lorry with no grace in decorum and you're sat there 12:46 thinking they've made it this far, not broken. Please, we don't want them broken. 12:52 We pick and choose the cores that we want. We then use this scanner here where we're able to take a really high 12:57 resolution photograph of the cores and from that we can look at whether or not there's any ice or features in the core 13:03 that we can't necessarily see with our eyes. And then we take the cores through to the other freezer where we cut and 13:09 prep them. And that's where we do all our analysis. 13:20 This is one of our really hard continental ice bits of uh bits of ice 13:26 that is really uniform, like really uniform bubbles, really strong, really 13:32 old. Um, the smaller the bubbles, the older the ice tends to be. And that's 13:38 why people use it for chemical analysis, cuz any sort of bubbles that are trapped inside it still preserve the conditions 13:44 of the climate at the time that they were trapped. This one is around 128 m deep from the ice shelf. And then 13:52 as we melt it, we'll see what's going on inside the ice and the bubbles. We think from the size of the bubbles it could be 13:58 anything from sort of a 100,000 years old to 500,000 years old which for ice is not that old. Um this ice was formed 14:06 somewhere way in land on the continent of Antarctica and is then eventually flown off into the ice shelf. 14:12 So if you melt this ice you'll hear it bubbling. As the little bubbles inside the change 14:19 in air pressure they release. We melt it in the freezer and as we're melting it, 14:24 we're able to extract the gases off of the core and we're also able to keep the liquids. We can look at different types 14:31 of chemistry that could be to do with the amount of sea ice that was present in Antarctica at that time of year. It 14:36 could be to do with volcanic activity. And we use all that to both understand the chemistry of the climate in the 14:42 past, but also age our ice. So without that, we haven't really got a good understanding of how old the ice is that we're studying. 14:53 What we don't really have at the British Antarctic Survey is a capability to do 14:59 physical property analysis of ice. The BASS team reached out to us with our 15:04 long-standing history of working on ice. I'm particularly interested in how geomaterials deform stop and 15:10 understanding ice is a very similar problem to rocks just under different conditions and different style. Well, we have five uh ice labs. We have a lot of 15:18 equipment uh built by our excellent engineers here uh at UCL and we can squash things and I'm excited to squash 15:24 anything. You give me to me and we'll squash it. Here the problem is coming up with some experiments where they can 15:31 actually measure in a control environment the strength of ice uh in 15:36 the context of the ice shelf that they're working on. If you have a large fracture that goes 15:43 from top to bottom of the ice sheet, you're going through this material. Just like if you're tearing a piece of paper 15:48 or tearing a piece of card, you need to know if you're tearing card or paper because one's going to be easier than 15:53 the other. And that will control where the fracture goes. 16:01 The idea here was to actually get core and actually bring it here and test that under some very controlled temperature 16:07 conditions, controlled rates and speeds. How does the ice fracture as a function of depth? 16:14 Well, it's pretty exciting, you know, having a having a freezer full of ice that has come from Antarctica. 16:21 Significant amount of field work has gone on and logistics to get it from where it was drilled to bring it here. I 16:28 certainly lose sleep on whether this stuff will melt. Uh that's for sure. I wake up in a hot sweat. 16:34 What controls the strength of a material is the things that are within it. So many things that are crystalline 16:40 essentially have a grain size and a grain size is a primary control on how things break. On ice, we have to look at 16:46 that under the microscope because these grains are really small. And to do that, we make a thin section. 16:52 We essentially take a really thin piece of ice, glue it to a piece of glass using 16:59 just cold water, and then file it down until it's one grain thick. And then we can use polarized light to see the 17:05 orientation of the crystals, the size of the crystals, and that tells us about whether or not there's been any sort of 17:11 stress on the ice that could have made those crystals grow in a certain direction, whether or not the fracture has maybe pushed the crystals into a 17:18 sort of direction. It also tells us maybe about how long the ice took to grow, if it's melt, if it's fresh snow, 17:25 if it's old. So, we can learn quite a lot from the crystal structure. This is ice from quite shallow on the ice shelf, 17:32 maybe around like 15 m. And it's got this really, really clear ice that would have been formed when there was melt at 17:39 the surface and it's percolated into the ice shelf um and then refrozen at a 17:45 later date. So, we're going to look at what's inside it. 17:50 Yeah. So, this is just a a light board and 17:58 this is just polarized paper. Um, when we look at the sample at the moment, it just looks like regular regular ice. 18:05 This is our melt and this is our fern, our shallow snow. 18:11 And then when we put the the polarized paper on, we can really clearly see the 18:16 crystals. So, our melt has really really quite big crystals. Uh, these bits here. And then 18:22 the fern in between this like almost snow transitioning into ice doesn't really have large crystals at the 18:29 moment. It's pretty fresh, pretty shallow, pretty new. Um, hasn't had time to grow into any sort of large crystal 18:35 at the moment. This is one of our samples from a little 18:41 bit deeper down where we've got our fern and then our melt. Looks really nice. It looks like magic, doesn't it? And 18:47 that's very useful because it allows us to tell us things about the orientation of the crystals and how they were 18:52 formed. And if, for example, they were stressed, also the changes in colors would be representative of that as well. 18:58 Because we see completely different colors, it actually means that there's probably been no stress acted on it. 19:03 That all the grains are completely randomly orientated. If they were all pink or all green, then they'd all be 19:09 facing the same direction, which means that something has made them form in that way or made them move in that way. 19:16 Random scattering of crystals is actually the most common thing. So that's what we'd expect it to look like. 19:22 If there had been some sort of structure in the ice, then we would think that 19:28 there's some sort of stress acting on the ice shelf to push the crystals into a certain orientation or it's that the 19:34 fracture, the tip of the fracture is actually causing the crystals to change orientation. 19:41 What we then do is test how does the ice fracture as a function of depth under some very controlled temperature 19:47 conditions, control rates and speeds. We have to prepare samples, chop the core 19:53 up to make semicircles. So, what we've got here is a hydraulic 19:59 press and I can put about one ton of load uh maximum on a sample. We're not going to need to use anywhere near that 20:06 for the ice. It's much much weaker. But it's been custom designed and assembly to essentially load our sample. There's 20:12 two rollers here and here. And then we'll slowly increase a control rate the piston coming down and we'll increase 20:18 the stress uh until it breaks. In here is a load cell. This measures um and sends it a signal back to the computer 20:25 telling us exactly what the load is. What we've also got is a high-speed camera uh that's set to record at about 20:31 18,000 frames per second. That should show us the fracture propagating. You can see here the sample zoom in. We're 20:38 going to load this down. It's going to come down. What we're hopefully going to see is that fracture propagate across 20:43 zero 0.01 mm/s is what we're going to bring that down at consistently. Start 20:49 ready. Start experiment. This is the distance going down. So 20:56 that's 18.7 mm. You see we're now at 18.5 mm. So let's move 2 of a millimeter. 21:03 So, we're waiting for essentially a kick in the stress. There we go. And we're starting to load the sample now. It's 21:09 going up nicely. Oh, no. Increasing stress. Beautiful signal 21:16 there. Great. That was a really nice one. 21:22 So, this is the fractured surface of the ice that we've just broken through. So, we'll measure the length of that edge 21:28 and then use that to calculate the fracture toughness. So this is the background levels where there was no 21:33 load on the sample. And as the piston came down, you can see that there's a load being increased. It's nonlinear 21:40 because ice has cracks in it. And uh you see a nice linear elastic phase here. And then you can see stress build up. 21:47 And then you see there's a crack and there's a stress drop. But we certainly in in previous uh cores that we've 21:53 experimented on from this batch, we've had samples much much weaker and samples much much stronger which clearly relate 21:59 to the the microructures. And what you can see is that the 22:05 fracture is there. If I skip go forward one frame, the fracture is here. So it's moved from here which is about a 22:10 centimeter and on the next frame it's moved from there. So it's moved about a centimeter in 22:16 118,000 of a second. You're talking about rupture tip speeds there of 22:22 approaching a kilometer per second. So really, really fast. 22:28 We're actually finding that the weak fern snow is surprisingly stronger than 22:34 previously thought. There are lots of assumptions uh in the literature that this stuff is actually quite weak. We're actually seeing that the shallow snow is 22:40 actually a lot stronger. In particular, we're finding these melt layers are much stronger. 22:46 Nobody has measured that to my knowledge. The strength of these layers so far. So there's clearly different aspects of the ice structure. Some 22:54 things that we know and some things that are completely new in terms of variation of the strength. We are systematically 22:59 going down through all of the ice measuring a variety of different parameters which is really going to help us in terms of feeding that into the 23:06 larger scale models. 23:11 We're essentially getting the missing pieces of the puzzle to understand 23:16 what's quite a complicated dynamic evolution of the ice shelf over the last 10 years. This is some kind of example 23:24 of our model output. This is in just a two-dimensional form of the front and 23:29 ice shelf where the colors represent the stress with depth. And this dark area is 23:35 a representation of an area where a crack has appeared. This shows how over 23:41 time the crack evolves and the stress near the crack tip evolves. And once it 23:46 exceeds a certain threshold, the crack can penetrate all the way through the ice and the carving event happens. 23:55 And so what what we can see with our new model is a time scale for when a new ice front appears, how long it takes to 24:03 create enough stress that will create a new crack and another carving event. So 24:08 that's kind of an exciting point that we've got to with the model so far. We can run the model forward in a kind of 24:15 predictive way and find out what the future behavior of this particular eye shelf will be. Somewhere like Thuait 24:22 Glacia where we're seeing some of the biggest impacts of climate change. The cracks in that area are less well 24:28 understood and it's much more difficult to work there. It's harder to access and 24:34 it's more dangerous cuz the ice is moving. uh more quickly. The work we're 24:40 doing and the models that we're producing will be applicable to areas like Thuait and the rest of the 24:45 Antarctic margin. 24:53 We need to do this research. We have to go to Antarctica and collect this data and model Antarctica to be 25:00 able to understand how it's changing and really reduce our uncertainty in in how 25:05 that's happening to have an impact and make a change. 25:12 We want to give policy makers the information that they need. To some 25:17 extent it's frustrating that not enough is being done about it. Um, from the 25:22 policy side, I do feel like doing the science is is 25:30 important and there's a range of sea level rise, but it it's all higher than 25:35 it currently is. We need to be as certain about numbers that we're providing such that there's no there's 25:42 no excuse not to do anything because this is very certain. We can tell you with confidence that this is how things 25:49 are going to go. To me, this is my first entry into an 25:56 area where I feel I can genuinely provide some expertise that will help to something that is really important, 26:02 fundamentally important for the future of humans on the earth. And if I can provide laboratory data easily that will 26:10 help researchers, then that's as exciting as it gets. 26:16 It's like nowhere else you will ever go and you're there and it's just it's so quiet and so beautiful and the sky is so 26:24 blue often it's like a real blue that you don't get to see anywhere else and it's just yeah really magical. 26:33 You you would think that the excitement of going would fade over time but um for 26:40 me it doesn't really. It's a it's a beautiful place. 26:48 And it's uh it's a shame to see it changing so quickly. 26:54 We're going to start though with a special report on Antarctica. Sometimes climate change news. It can 27:00 all be a bit drip drip blurs into war and just overwhelming and depressing. And it can be hard to tease out those 27:06 stories that really, you know, need to be you have to sit up and listen to really. Um but this is one of those. Our 27:12 Australia reporter James Woodford. He's been in Hobart, Tasmania with nearly 500 researchers for a conference that was 27:19 built as an emergency summit for the future of the Antarctic. Rowan caught up with him to hear all about it. 27:25 James, I want to hear about the general vibe at the meeting. Uh, but first, there was one statistic that really 27:31 captured everyone's attention there and and for you, you were saying this captured the seriousness of the entire 27:37 climate crisis. Yeah, thanks Rowan. Uh look there the the mood at the conference at the summit 27:44 was definitely somber and at times just everybody just trying to make sense of 27:50 the enormous changes that are taking place down in the Antarctic and normally 27:56 statistics can make people feel pretty sleepy. Uh so bear with me on this one. 28:01 As many listeners will be aware, there there was a precipitous drop off in the 28:07 extent of the winter sea ice around Antarctica in 2023 28:13 and again in 2024. 2024 was nearly as bad as 2023. 28:20 And in 2023, there was 1.55 28:26 million square kilometers below the expected average extent of sea 28:32 ice, which was the lowest recorded since satellite data. That's just to give some 28:39 context, that's an area six times the size of the United Kingdom. You know, 28:46 it's just an enormous area. I think everyone was pretty alarmed by that, but 28:53 now researchers have calculated just how incredibly dramatic that 29:00 collapse in sea ice actually was. Nery Abram from the Australian National 29:07 University. She told the summit this was seven standard deviations off the mean 29:13 for what the extent of sea ice should have me should have been. Um this means 29:20 we're not talking about a 1 in 10year event or a 1 in 100year flood. This was 29:28 an event that models would have predicted could only occur somewhere 29:33 between 1 in 7 12 million years to 1 in 29:38 700 billion years. All right. So basically impossible on a 29:45 planet that's only 5 billion years old. Um well what does that mean? That's a incredible incredible number. Is that an 29:52 it's obviously an outlier but what you know is there a mistake there? What what how do they explain that 29:58 exactly? Obviously that kind of a number is impossible. And really what it's a 30:03 product of is that no one could have foreseen that Antarctic sea ice would 30:09 have dropped off a cliff in the way that it has. Abram says that in just a decade, the decrease in the Antarctic is 30:17 equivalent to that lost in the entire northern hemisphere in the past 45 30:24 years. Even more alarming is the projection that Antarctica could 30:29 possibly experience summers that are essentially free of sea ice before even 30:35 the Arctic, which is projected to reach that point sometime before 2050. 30:40 Wow. I think we're we're up in the northern hemisphere here. We're we're much more aware of the problems in the 30:46 Arctic. And and a phrase I often use um is what happens in the Arctic doesn't 30:51 stay in the Arctic. uh you know, in other words, if we lose the summer sea ice in the Arctic, it has these huge 30:58 knock-on effects. Um and so I take it it's the same uh in the Antarctic. 31:03 Yeah, exactly. You know, as we're we're starting to learn with the northern hemisphere, you know, with some of the 31:09 changes in the ocean currents, some of the very similar things are starting to take place in the in the Antarctic. And 31:17 I wish I could just say to you that this drop off in sea ice in the Antarctic was 31:23 only of academic interest, but unfortunately that would be a white lie. 31:28 And I'm sorry, no pun intended. In fact, in in fact, researchers are now 31:34 scrambling to try to understand what the implications of this are. 31:40 Firstly, they want to know whether this is a new normal for Antarctic sea ice. 31:46 And the consensus at the conference, like every scientist that I spoke to 31:51 after Abram's presentation said that it is unlikely that sea ice extent will 31:58 return to what it was before it began to fall in 2016. 32:03 But it also has these huge global scale climate and ecological consequences. 32:10 For a start, having that much less ice is going to lead to much more heat being 32:17 absorbed by the ocean just because it's not reflecting the sunlight back into space. And it also changes the salinity 32:25 of the Southern Ocean. But perhaps the biggest worry is that the sea ice acts 32:31 like a protective barrier or apron around the entire continent that stops 32:38 the ice shelves on the Antarctic coastline from being buffeted by waves 32:44 and exposed to more of these warm currents. Right. So it would accelerate the the 32:50 the ice cap itself. And did they talk about that at the conference? Yes, they did, Rowan. There was a 32:56 gripping presentation from Sarah Thompson at the University of Tasmania. 33:02 She spent last summer camped on the Denman Shackleton ice system with her 33:08 team and they were drilling through 200 m of ice shelf to reach the ocean 33:14 underneath. And her results show that for the first time that warmer modified 33:22 circumpolar deep water is getting into the cavity under the ice shelf. And at 33:28 the point where their drill hole was located, the underside of the shelf 33:33 seems to be melting at a rate of about 2 m per year. Again, that might sound 33:40 academic, but if the Denman Shackleton ice shelf melts, that's 1.5 m of global 33:49 sea level rise just on its own. Wow. Well, so how are people taking this 33:55 there? I mean, these are kind of these people, they're climate scientists, glaciologists, you know, they're well 34:02 aware of the problem, but was it shocking even for them? Yes, they they 34:08 were really shocked by the presentations of their colleagues and some of them said to me that after the drop off in 34:16 sea ice in 2023 that they just kind of hoped that 2024 things would bounce back 34:23 and they're definitely not confident that uh we're going to see 34:28 any kind of a return to previous levels of Antarctic sea ice. And a summary that 34:36 really has stayed with me since the conference was from Ed Dodridge, who's 34:42 also from the University of Tasmania, and he summed up the disaster unfolding 34:48 with just one word, and that was grim. 34:53 Okay. I thought you might say a swear word, but grim. Uh, yeah, it is grim. Um, James, thanks very much for 35:00 reporting that. Great. Thanks very much for having me, Ron. Yeah, we were hearing there on a little bit about the work of Sarah 35:06 Thompson. She is from the University of Tasmania. Um James met with her and she was talking about the melting and uh all 35:12 the warming going on and while she was waiting for a flight to Antarctica, I got in touch with her um and asked her 35:18 to tell us a bit more about her work and uh here's here she is. One of the most challenging things working in East 35:23 Antarctica is that we think the most significant changes are actually happening in one of the places that's 35:29 most difficult to measure and that's underneath the ice shelves where the ice is being melted by the warmer ocean 35:35 water. We know from other regions that ice shelves act a little bit like dams. If they start to weaken or break up, 35:42 then ice from the continent can flow more quickly into the ocean, contributing further to sea level rise. 35:48 As a whole, the region that we're currently working on holds a potential 1.5 meters in sea level rise 35:54 contribution, but we don't really have a very good understanding about the rate of change or the time scales over which 36:00 it might happen. Wow. Imagine working on the melting of the underside of the ice sheet. Yeah. No. Um I asked her what it's like 36:07 doing that actually and also what it's like being a climate scientist in this period of crisis. And also I wanted to 36:14 get a flavor of of what it's just like being there. And that's your day job, you know, for us stuck in offices here. 36:20 What's it like? And here she is. Being able to work in this field and make a contribution, however small, to 36:26 our understanding of these systems in Antarctica is such a unique opportunity. Being able to better predict the impact 36:33 that they might have on our future is something that makes me hopeful. I think the more we understand, the better 36:39 placed we are to face future challenges and to start to mitigate some of the changes that we see. Antarctica is an 36:46 amazing and challenging environment to regularly work in. And there are moments every now and then, especially when 36:52 you're out on an ice shelf for weeks at a time, and you look up and the realization of where you are and just 36:58 how incredible that is, hits you all over again. But I think for me, one of the really remarkable aspects of working 37:05 somewhere like Antarctica is the diversity of amazing people that it attracts, all with different skills and 37:11 experiences. And that's often what makes working in this kind of environment so unique. 37:17 Well, it almost makes you want to be a polar biologist. Um, it does sound amazing. Um, but what about the ecology 37:23 of the region? What do we know about how much that's likely to change? Yeah. Well, that's a really good question. Uh, something I wondered 37:29 about. So, I I hunted down another biologist, a climate change biologist, Sharon Robinson from the University of 37:35 Wllingong. Um, and she specializes in the Antarctic. Been there loads of times. And this is what she said to 37:40 that. As ice retreats with global heating, areas of land are exposed and vegetation can expand and colonize these 37:47 new areas. So, in some areas, especially on the Antarctic Peninsula, we can see 37:52 clear evidence of newly green areas. But Antarctica is essentially a desert. 37:58 There isn't much snow and it hardly ever rains. Plants grow really slowly, about 1 to 3 mm a year in the case of the 38:04 mosses. Most of the vegetation relies on the snow and ice banks to melt and 38:09 provide a steady stream of water through the summer. In some areas, those snow and ice banks are disappearing or losing 38:16 connectivity with the vegetation. And then we see previously gloriously green areas turning gray as they dry out. 38:24 Seeing lush green areas that you've seen in the past turn gray is really sad. I 38:30 really worry that we will lose some of Antarctica's rich biodiversity like these ancient moss forests along with 38:35 the tiny animals like tardigrades or moss picnics that live within them off 38:41 the coast. We're losing sea ice at alarming rates. This can be catastrophic for the animals like emperor penguins 38:48 that breed on the ice and for the tiny animals on the seabed below that rely on the shade from sea ice to keep the algae 38:55 from overgrowing them. So that was good to hear degrades get a shout out there. Old new scientist favorite there. Yeah, 39:02 definitely. It's interesting that the continent it's it's sometimes greening, but at other times when the ice is gone, you also 39:08 lose the green areas. And she mentioned there the threat to emperor penguins. There was a mass breeding failure last 39:13 year for for some of those because of the loss of sea ice. Yeah. Yeah. I mean, well, that's why it's an emergency summit. It's very 39:20 precarious up there. How does it feel knowing that you're 39:26 holding a milliony old ice? Uh quite terrifying actually. 39:36 Antarctica is a really key aspect of the global climate system because it is the 39:41 only place that we will retrieve these long records of atmospheric conditions 39:47 by drilling ice cores. And this particular core, a best guess, we're really hoping it's more than one and a 39:53 half million years old. We look into the past to look at other 39:59 time periods, other analoges for the climate and how it has changed before so that we can use that information to 40:06 better predict the future. 40:12 So the previous oldest ice we have goes back 800,000 years, which is a staggering time scale. But the 40:19 motivation really for this new record is to extend that and particularly over the 40:24 last million years because this is a really important time period when we think we went through quite a 40:29 significant climate transition that we still can't explain. This new ice core this beyond epica 40:36 oldest ice core is a big European collaboration. The drillers successfully reached bedrock at 2.8 km in January of 40:43 this year and just recently we have been taking shipment of these boxes. Here are 40:48 the oldest ice sections. And this is what we're going to analyze. So we're looking at the section of core that 40:53 spans the period from 700,000 years to the unknown age. 41:00 The drilling itself took place over 4 years and before that there are 3 years or so of surveying uh to choose the 41:07 exact location to pinpoint the best location for drilling. In those four years we're just there in the summertime. So, we're there, you know, 3 41:14 months or so trying to fit in as much drilling as we can per year uh to get that done. In the end, we drilled down 41:20 to 2,800 m. So, that was done across the four seasons. The first season, we had 41:26 the setting up, drilling a pilot hole to just past 100 m. The next year, we come back, carry on down to 800. The 41:33 following year, down to 1,800. And then finally last year the team finished off going from 1,800 meters to 2,800 meters 41:41 and getting that very oldest ice that we're so interested about. 41:55 So the ice cores are particularly powerful in understanding how the atmosphere has changed and this is what 42:02 really makes us so different from the marine sediments for example. So marine records they're fantastic. They can go 42:08 back a lot further in time maybe 5 million years in fact but at a very very 42:13 low resolution. So perhaps one data point per thousand years. Whereas potentially within this particular ice 42:20 core, we can actually extract enough information to look at the changes more on century to century time scales and 42:27 understand the climate and the atmospheric changes all in one go. I'm a 42:32 little bit nervous myself about holding it because it is so incredibly valuable. So many people have put their time and 42:39 their careers and their effort into drilling this particular core. There are a lot of things that can go 42:45 wrong when you're when you're drilling an ice core, but drilling was remarkably smooth. The drill we used for this project, it's very fast. It can drill up 42:52 to 4 1/2 mters at a time, which doesn't sound like a lot when you're trying to get down to 2,800 m, but it makes a big 42:59 difference. We hang that drill on a wire and lower it into the hole. So, we'll drill 4 1/2 m, raise the drill up to the 43:05 surface, pull that ice out, start processing it, logging it, packing it away, ready to come back to Europe. Uh, 43:11 and then we'll send the drill down again. And we repeat that process over and over again. Now, obviously, the the 43:18 deeper you get in your drilling, the longer that process takes. So, the season that I was there, we were 43:23 drilling between 800 and 1,800 m. Uh, it could take up to an hour just to lower 43:29 the drill down to where we last got, another half hour to drill the next 4 1/2 or so meters, and then an hour to 43:36 come up again. So, at least 2 and 1/2 hours between sections. And you can start to see how over 2,800 meters, it 43:44 takes a long time to get this work done. 43:54 We're not analyzing the full core. That's a huge amount of information. What we're really focusing on is just 43:59 the very oldest part. And this particular core is from the very bottom part of the the the record. And a best 44:06 guess, we're really hoping it's more than 1 and a half million years old. So, we're going to overlap with the previous 44:12 oldest core and then extend back in time. And we have 190 m to go through. 44:17 So, this bag here, this is a meter long section. So, we've got 190 of these that 44:23 we need to melt and analyze. Yeah. So, it is it is a lot of pressure 44:29 having the oldest ice on Earth here. Um, yeah, it does keep me awake at night a little bit. The tricky thing with this 44:35 type of analysis is that once it's melting, everything in the lab has to be ready to go and has to be calibrated and 44:42 working and collecting good quality data. So the ice has to be kept really cold because if it's not then uh certain 44:50 things in the ice can start to degrade. So to keep it in pristine condition, we have to keep it minus 20 or below. But 44:57 we always keep it - 255. And actually a lot of the shipping uh logistics from 45:02 Antarctica are even colder than that. So minus 40 and that really preserves the samples in a really good condition. 45:10 We load the ice onto our melt head which is a goldplated piece of metal which is 45:16 heated. So the ice melts from below. In the center of that there is a hole which we have tubing. The tubing comes through 45:23 to the labs. So it comes through the port from the freezer into the lab. It actually comes through this tubing here 45:29 which you can see starting to get wet. All the uh interesting bit of the ice comes through this uh tube here. It goes 45:36 through this part which is the debubbler. So the debubbler separates the air that's trapped in the ice core 45:42 from just the liquid melt water. It goes through these pumps and it goes to this part here, a splitter, and it splits off 45:48 to eight or so uh different instruments and then it feeds the entire lab. 45:57 It's a full complete continuous record from the present day to as old as the 46:02 oldest ice in this sample is. And you know it's at least 1.2 million years old at the bottom. Could be 1.5. It could be 46:09 older. We won't know until we've finished the analyses. It's having that continuous record of what the climate was like on Earth. Uh and direct 46:17 measurements. You know, people often talk about the atmospheric air that gets trapped in ice cores. That's a very 46:22 direct measurement. But the number of proxy measurements you can make are huge. There's the classics of looking at 46:28 the isotopes of the elements in the water itself. In the water ice itself, um they're an excellent proxy for what 46:34 the temperatures were like in the areas around. You can look at uh ash that's come from major volcanic eruptions. The 46:40 kind of eruptions that will cover the whole world in ash. You can see that in the ice. I've you know I've drilled 46:45 samples of ice and you can see this little yellow band where this ash is stuck there. You can look at biology in 46:51 the ice. you know, stuff that's been microscopic um phytolanton that have been uh blown in from the sea and end up 46:57 on the land. Uh you can infer so many different things. 47:10 So interestingly, there's evidence from other archives from marine records that suggests that prior to a million years 47:17 ago, our transitions from glacials to interglacials. So these are from extremely cold conditions to the 47:23 relatively warm conditions we're experiencing today. There's evidence to suggest that they were much shorter. So 47:29 about every 40,000 years. Whereas what we've seen more recently in our record is that these glaciations are lasting 47:35 much longer, 100,000 years. And this is allowing big ice sheets to form over the 47:41 northern hemisphere. And there doesn't seem to be much of an explanation as to why that transition occurred. why a 47:48 million years ago we weren't having these 100,000year cycles. And it's very relevant for today because at the time 47:55 the evidence is suggesting that a million years ago our ice sheets maybe weren't as big and that suggests that 48:01 sea levels would have been higher and there's also evidence that potentially the greenhouse gas concentration was 48:06 also higher. So these are all analoges of how we think our future climate is 48:12 headed. The way that the oceans and the 48:17 atmosphere interact is we're all one big connected system and Antarctica in terms of paleocclimate is so important. We 48:24 want to understand what's going to happen in the future and at the moment our predictions are relying on a very 48:29 short observational period. What we do is we look into the past to look at other time periods, other analoges for 48:36 the climate and how it has changed before so that we can use that information to better predict the 48:42 future. 49:09 The analysis showed that everywhere we looked for microplastics, We found them. 49:15 And this is really important for us to understand globally because Antarctica has been considered a 49:22 remote location, somewhere that is separated from the rest of our planet where us as 49:28 humans live daytoday. 49:52 The microplastics that we found during this study were mostly microfibers 49:58 and these fibers um come from all forms of textiles. Um and this is not just our 50:04 clothing but also maybe our furniture and insulation even in in our wiring 50:10 systems. Our 50:39 results were suggestive that there are these multiple pathways that are 50:45 bringing pollutants like microplastics into Antarctica. So really if we're finding microplastics 50:52 there and we know that they've come in from multiple other places across the world then I think it is a really 51:00 important message for all of us that by only addressing plastic challenge 51:07 together as a global community are we going to get a reduction in these types of emissions. 51:26 We haven't seen an East Antarctica shelf collapse, at least in our lifetimes. For the last 20 years or so, since 2000, 51:32 it's been losing a little bit here and there, but not much. But then, right at the beginning of 2020 or so, it started 51:38 sort of having itself every few months. One fast thing that happened was that uh 51:43 weather event last week. I I wouldn't say that it's the entire story, but it certainly added a pressure onto the 51:50 those ice shelves that we haven't seen before. And so that's why the timing was sort of interesting. I guess 2 days it basically was gone. 51:58 This is an ice shelf where there's been no groundbased research ever. So we're left to only see from our satellite 52:05 observations and and uh you know make our our educated guesses at what's going 52:11 on from there. 52:55 Even if the men die, there is still the opportunity that someone will find these negatives and understand the story. 53:02 We've used the story of Shackleton to demonstrate the relationship between the evolution of photography but also the 53:09 evolution of the technology at the time. He was involved from the very outset 53:14 with Captain Scott on the Discovery expedition moving through to the uh the Nimrod expedition then of course the 53:20 endurance and then ending with the quest. In each of those expeditions, there is an evolution of photography and 53:28 also perhaps an evolution of the way in which Shackleton recognizes the power of photography. 53:35 The discovery expedition. He is uh the first person in the world to actually 53:41 take an aerial photograph of the continent. They are the very first images that show how the great barrier, 53:47 the great ice barrier could be surmounted and showed the way forward for um successive expeditions. 53:56 on the what was the Imperial Trans Antarctic Expedition led by Shackleton which is otherwise known as the Endurance. The plan had been for 54:04 Shackleton to cross from one side of Antarctica to the other what was considered at the time during the heroic 54:10 age of exploration as being the last great opportunity. 54:15 Frank Hurley's story is is is a really interesting one. Hurley was instructed to document the the entire journey. 54:24 One of the nickname that was given to Frank Hurley is a warrior with a camera. 54:30 He was completely fearless. The most iconic images are the images 54:37 taken during the polar night showing the ship in profile. To set those images up, 54:43 Hurley travels away from the ship. set up a sequence of electric flares and he has the flares charged and fired at 54:50 exactly the right moment. So there would have been this extraordinary flash of light in otherwise complete sort of 54:57 pitch darkness. To me that image conveys the whole sense of the isolation of being in the Antarctic. 55:06 Once the ship starts to show signs that it's going to be um damaged and then mortally damaged by um the conditions, 55:13 Hurley takes on a role of what one could consider to be a true documentary photographer. 55:21 At the point when the ship finally um kees over, the pressure becomes too much and the ship is effectively crushed by 55:27 the ice. He actually records the very poignant moment when the masts on the ship finally give way. He's at that 55:35 point rescued um probably about a quarter of the glass plate images that 55:41 he's taken. Shackleton insists that um the the saved glass plate negatives are 55:46 carried on the onward journey despite the fact that each man can only take a couple of pounds of weight of personal 55:51 effects. Even if the men die, there is still the opportunity that someone will find these negatives and understand the 55:57 story. The image that shows them waving is is a really important one. When that picture's taken, it is the men waving 56:03 goodbye to the James Ked. When it comes back to the UK, because of the power of the picture, um there are various 56:10 versions of it where the image of the James K has been cut out and replaced with the image of the Yelcho, which is 56:15 the rescue ship. It also demonstrates another aspect of creativity of what today we would consider to be Photoshop 56:23 taken on the the Quest expedition, Shackleton's final expedition. The use of um the autochrome process to take 56:30 some photos just demonstrates how how far technology has has expanded since the beginning of the the discovery 56:35 expedition. Autochromes were very early color 56:41 process uh which is fairly innovative and had not been used in polar exploration. They are based on three 56:47 different colors of potato starch. To the back of that is attached a photographic emulsion. 56:53 In 1920, Shackleton is planning his next expedition. He approached my grandfather, John Quiler, who he'd met 57:00 at Dalich College where they were at school together. And very magnanimously, my grandfather steps in and says, "I'll 57:05 fund the whole thing." They head down to South Georgia and literally on arrival, Shackleton has a massive heart attack 57:11 and and and dies. My grandfather broke the news to Lady Shackleton. She took a 57:16 few days to think about it, but then said, "Our darling would would prefer to be buried in South Georgia." There's 57:22 very few things that remain. These glass plates are one of them. They've sat in a box for most of those hundred years and 57:28 and this is the first time really they've been brought out. There's a couple in uh in London before Quest 57:34 departs. There's a couple in Madiraa in Funshell Harbor. Then there's some photographs on South Georgia of the 57:40 countryside of Glacia. There is several of the building of the memorial k and the crew assembling at the ken to pay 57:46 their respects. My grandfather particularly wanted to see the output. you know, he invested in the technology 57:52 that went into the ex expedition. You know, I think he he'd think it's beyond far beyond time that they've been put on 57:58 display. I think what draws people like Shackleton to go back to Antarctica is a 58:03 combination of their expertise and their knowledge, but also this enormity of the alien landscape um and the the knowledge 58:09 that actually we are specs as human beings in that environment. Even on the quest expedition, the the 58:16 men who'd been two or three times were saying, "We can't explain it. It's it's it's under the skin and it just draws 58:23 you back in. It's it's it's just a a magnetic place-
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