WEBVTT 00:00:00.000 --> 00:00:02.350 Okay, let's get into this. When you think about 00:00:02.350 --> 00:00:04.910 Antarctica, you probably picture, you know, this 00:00:04.910 --> 00:00:08.570 vast white frozen emptiness. Right. A continent 00:00:08.570 --> 00:00:11.330 of ice. Exactly. But there's a specific part 00:00:11.330 --> 00:00:13.869 of it, a huge body of water called the Weddell 00:00:13.869 --> 00:00:17.089 Sea, that somehow manages to hold two completely 00:00:17.089 --> 00:00:19.489 contradictory world titles. Yeah, they really 00:00:19.489 --> 00:00:22.410 are polar opposites. On the one hand, it has 00:00:22.410 --> 00:00:25.129 the clearest water ever measured. I mean, we're 00:00:25.129 --> 00:00:26.710 talking clearer than a mountain lake, almost 00:00:26.710 --> 00:00:28.769 like distilled water. And on the other hand. 00:00:28.850 --> 00:00:31.210 On the other hand, historically, it's... known 00:00:31.210 --> 00:00:34.229 as the most treacherous, most dismal region on 00:00:34.229 --> 00:00:37.530 Earth. It was, for a long time, the place where 00:00:37.530 --> 00:00:40.609 explorers went to die. And that paradox, that 00:00:40.609 --> 00:00:44.310 stunning clarity. paired with the most extreme 00:00:44.310 --> 00:00:47.490 danger is exactly why the Weddell Sea is such 00:00:47.490 --> 00:00:49.829 a fascinating and critical place for us to dive 00:00:49.829 --> 00:00:52.250 into today. So this isn't just a big bay we're 00:00:52.250 --> 00:00:53.929 talking about. Oh, not at all. It's a foundational 00:00:53.929 --> 00:00:57.090 piece of the entire Southern Ocean. Yeah. Geographically 00:00:57.090 --> 00:00:59.130 speaking, you're looking at a massive bay that's 00:00:59.130 --> 00:01:01.609 bounded by coats land on one side and then the 00:01:01.609 --> 00:01:04.290 curving sweep of the Antarctic Peninsula on the 00:01:04.290 --> 00:01:06.689 other. And when we say colossal, we really do 00:01:06.689 --> 00:01:09.629 mean it. This is not some minor inlet. No. Absolutely 00:01:09.629 --> 00:01:13.189 not. We're covering an area of about 2 .8 million 00:01:13.189 --> 00:01:16.010 square kilometers. Wow. To give you some perspective 00:01:16.010 --> 00:01:19.049 on that, it's larger than Greenland. That's incredible. 00:01:19.390 --> 00:01:21.530 So, yeah, it's this vast, incredibly influential 00:01:21.530 --> 00:01:25.530 basin. And its unique position, its remoteness, 00:01:25.549 --> 00:01:29.659 is precisely why. It plays such a huge and often 00:01:29.659 --> 00:01:33.219 hidden role in regulating the entire global climate 00:01:33.219 --> 00:01:35.659 system. So if you want to understand the planet's 00:01:35.659 --> 00:01:37.799 deep ocean currents. You have to understand the 00:01:37.799 --> 00:01:40.280 Weddell Sea. It starts there. So for you, our 00:01:40.280 --> 00:01:42.859 listener, our mission today is to go way beyond 00:01:42.859 --> 00:01:45.340 just the map coordinates. We are going to trace 00:01:45.340 --> 00:01:48.299 the history of disaster and survival, especially 00:01:48.299 --> 00:01:51.099 the haunting story of Ernest Shackleton and his 00:01:51.099 --> 00:01:53.219 ship, the Endurance. And then we'll get into 00:01:53.219 --> 00:01:55.319 the science, the really cutting edge stuff. Yes, 00:01:55.359 --> 00:01:57.340 exploring that deep water formation. process 00:01:57.340 --> 00:01:59.700 that, and this is no exaggeration, effectively 00:01:59.700 --> 00:02:02.299 keeps the planet's entire ocean conveyor belt 00:02:02.299 --> 00:02:05.260 moving. And then we'll finish by looking at this 00:02:05.260 --> 00:02:09.740 hidden ecology that's just, it's redefining what 00:02:09.740 --> 00:02:12.319 complex life can even look like in the deepest, 00:02:12.419 --> 00:02:14.300 coldest, and darkest parts of the Antarctic. 00:02:14.590 --> 00:02:16.949 Some of these discoveries are genuinely mind 00:02:16.949 --> 00:02:19.349 -bending. They are. But before we jump right 00:02:19.349 --> 00:02:21.030 into the physics of it all, there's a quick but 00:02:21.030 --> 00:02:24.430 crucial note on geography we should make. Oh. 00:02:24.610 --> 00:02:27.449 This region isn't just defined by ice and water. 00:02:27.810 --> 00:02:31.689 It's also defined by competing claims. The Weddell 00:02:31.689 --> 00:02:34.729 Sea sits right within these overlapping Antarctic 00:02:34.729 --> 00:02:37.680 territorial claims. So you have multiple countries 00:02:37.680 --> 00:02:40.800 laying claim to this same patch of ocean. Exactly. 00:02:41.000 --> 00:02:43.280 The area is claimed by Argentine Antarctica, 00:02:43.560 --> 00:02:46.000 the British Antarctic Territory, and then it's 00:02:46.000 --> 00:02:48.000 also partially claimed by the Antarctic Chilean 00:02:48.000 --> 00:02:49.860 Territory. And why does that matter for a deep 00:02:49.860 --> 00:02:51.900 dive like this? I mean, from a scientific perspective. 00:02:52.199 --> 00:02:53.860 Well, it adds all these layers of complexity, 00:02:54.060 --> 00:02:57.039 you know. It affects who can research where and 00:02:57.039 --> 00:02:59.020 under what flag they're doing it. So when you 00:02:59.020 --> 00:03:01.500 see these huge expeditions, like the ones that 00:03:01.500 --> 00:03:03.400 found the Endurance or discovered that ice fish 00:03:03.400 --> 00:03:05.860 megacolony we'll talk about. They are almost 00:03:05.860 --> 00:03:07.979 always multinational collaborations. Because 00:03:07.979 --> 00:03:10.639 they have to be. They have to be. Now, the treaty 00:03:10.639 --> 00:03:13.560 system means that all those claims are, in theory, 00:03:13.719 --> 00:03:17.259 suspended. But in practice, national interests 00:03:17.259 --> 00:03:20.340 are still guiding logistical support, how resources 00:03:20.340 --> 00:03:23.599 get allocated, and this is the crucial part. 00:03:23.879 --> 00:03:26.460 the long -term monitoring of things like ice 00:03:26.460 --> 00:03:29.319 shelf health and deep water warming. So understanding 00:03:29.319 --> 00:03:31.340 the governance helps explain why it might be 00:03:31.340 --> 00:03:34.400 so hard to get a big coordinated project off 00:03:34.400 --> 00:03:37.139 the ground. Precisely. It's a scientific frontier, 00:03:37.319 --> 00:03:39.800 but it's also a geopolitical one. All right, 00:03:39.819 --> 00:03:41.400 let's start with the physical reality of the 00:03:41.400 --> 00:03:43.280 Weddell Sea because it is just an environment 00:03:43.280 --> 00:03:46.020 of profound extremes. This isn't just an empty 00:03:46.020 --> 00:03:49.439 patch of ocean. It's bounded and defined and 00:03:49.439 --> 00:03:51.580 fundamentally governed by ice, a lot of which 00:03:51.580 --> 00:03:54.379 is permanent. That's absolutely the key distinction 00:03:54.379 --> 00:03:56.020 here. If you look at the physical boundaries, 00:03:56.280 --> 00:03:58.719 the eastern limit is marked by a place called 00:03:58.719 --> 00:04:01.379 Cape Norvegia, which is on the Princess Martha 00:04:01.379 --> 00:04:04.139 coast in Queen Maud land. And to the east of 00:04:04.139 --> 00:04:06.180 that cape, you have the King Hawk on the 7th 00:04:06.180 --> 00:04:09.580 Sea. But the structure that really truly dominates, 00:04:09.599 --> 00:04:11.219 especially the whole southern part of the Wet 00:04:11.219 --> 00:04:15.120 L Sea, is the massive, permanent Filchneron. 00:04:15.599 --> 00:04:18.319 ice shelf. An ice shelf. So that's not sea ice, 00:04:18.339 --> 00:04:20.779 that's glacial ice floating on the ocean. Exactly. 00:04:20.899 --> 00:04:23.220 These are gigantic floating tongues of glaciers 00:04:23.220 --> 00:04:25.300 that have flowed off the continent and they fringe 00:04:25.300 --> 00:04:27.769 almost the entire southern rim of the sea. And 00:04:27.769 --> 00:04:29.730 these shelves, even though they're enormous, 00:04:29.870 --> 00:04:33.370 are also the most dynamic and, I guess, vulnerable 00:04:33.370 --> 00:04:35.689 parts of this environment, aren't they? They 00:04:35.689 --> 00:04:37.610 are. They're like the planet's canaries in a 00:04:37.610 --> 00:04:41.230 coal mine. They are incredibly volatile indicators 00:04:41.230 --> 00:04:44.110 of climate stress. And the sources for this dive 00:04:44.110 --> 00:04:46.709 mentioned some pretty dramatic changes. Yes, 00:04:46.709 --> 00:04:49.730 the dynamics have been visibly, shockingly dramatic 00:04:49.730 --> 00:04:53.110 in recent decades. Specifically, certain ice 00:04:53.110 --> 00:04:55.009 shelves along the east side of the Antarctic 00:04:55.009 --> 00:04:56.949 Peninsula, which used to cover something like... 00:04:56.939 --> 00:04:59.060 like 10 ,000 square kilometers of the sea surface, 00:04:59.259 --> 00:05:02.220 had completely disintegrated by 2002. Wait, 10 00:05:02.220 --> 00:05:04.480 ,000 square kilometers? That's a huge area of 00:05:04.480 --> 00:05:06.980 ice structure to just disappear. It's massive. 00:05:07.540 --> 00:05:10.040 Gone in a very short period, geologically speaking. 00:05:10.300 --> 00:05:12.560 What does that do locally when you lose that 00:05:12.560 --> 00:05:14.279 much floating ice? What are the consequences? 00:05:14.800 --> 00:05:16.620 Well, the immediate local effect is you suddenly 00:05:16.620 --> 00:05:18.920 have these large areas of open water where there 00:05:18.920 --> 00:05:22.259 used to be bright white ice. It dramatically 00:05:22.259 --> 00:05:24.959 changes the reflectivity of the albedo, so the 00:05:24.959 --> 00:05:27.899 ocean absorbs more solar energy. And it heats 00:05:27.899 --> 00:05:30.180 up. It heats up. But maybe more importantly for 00:05:30.180 --> 00:05:33.199 the whole planet, these ice shelves act as buttresses. 00:05:33.420 --> 00:05:36.100 They're like a cork in a bottle, physically holding 00:05:36.100 --> 00:05:38.399 back the massive land -based glaciers behind 00:05:38.399 --> 00:05:40.959 them. So when the shelf goes... The inland glaciers 00:05:40.959 --> 00:05:43.279 speed up their flow into the ocean, and that 00:05:43.279 --> 00:05:45.720 contributes directly to global sea level rise. 00:05:46.160 --> 00:05:48.620 Now, the Phyllis Neuron Ice Shelf itself is... 00:05:48.800 --> 00:05:51.560 Still vast, but the losses along the peninsula, 00:05:51.660 --> 00:05:53.740 they signal this profound instability in the 00:05:53.740 --> 00:05:57.079 whole local marine environment. Okay, so let's 00:05:57.079 --> 00:06:00.600 shift from that dynamic, treacherous ice to the 00:06:00.600 --> 00:06:04.139 stillness and the purity of the water itself. 00:06:04.980 --> 00:06:07.300 This is where we get to the Weddell Sea's record 00:06:07.300 --> 00:06:10.259 -setting clarity. I just have a hard time wrapping 00:06:10.259 --> 00:06:13.139 my mind around how a sea surrounded by constantly 00:06:13.139 --> 00:06:16.160 melting, grinding ice can also be the clearest 00:06:16.160 --> 00:06:19.129 water on Earth. It is astonishing. And the finding, 00:06:19.230 --> 00:06:21.449 it comes from this really rigorous oceanographic 00:06:21.449 --> 00:06:23.629 research that was done by the Alfred Widener 00:06:23.629 --> 00:06:26.589 Institute way back in 1986. And how did they 00:06:26.589 --> 00:06:28.750 even measure that? They used one of the simplest, 00:06:28.870 --> 00:06:32.029 oldest scientific tools in the book, the Sechi 00:06:32.029 --> 00:06:33.790 disk. For anyone who doesn't know, could you 00:06:33.790 --> 00:06:35.970 remind us what a Sechi disk actually is? Of course. 00:06:36.170 --> 00:06:39.529 It's literally just a circular disk. Traditionally, 00:06:39.529 --> 00:06:41.810 it's about 30 centimeters in diameter, and it's 00:06:41.810 --> 00:06:43.569 painted in these alternating black and white 00:06:43.569 --> 00:06:45.920 quadrants. And you just... Lower it into the 00:06:45.920 --> 00:06:48.259 water. You lower it into the water, and the depth 00:06:48.259 --> 00:06:50.480 at which the observer on the ship loses sight 00:06:50.480 --> 00:06:52.879 of it, that measures the water's transparency. 00:06:53.399 --> 00:06:55.879 It's an old method, but it's incredibly effective 00:06:55.879 --> 00:06:57.860 for measuring suspended particles in the water. 00:06:58.060 --> 00:07:00.379 So in most oceans, you might see it for, what, 00:07:00.439 --> 00:07:04.199 20 or 30 meters? If you're lucky. In many coastal 00:07:04.199 --> 00:07:07.480 areas, much, much less. So what was the number 00:07:07.480 --> 00:07:09.980 they recorded in the Weddell Sea? The disk was 00:07:09.980 --> 00:07:13.579 visible at an astonishing depth of 80 meters. 00:07:13.800 --> 00:07:18.259 80. 80 meters. That's 260 feet. I'm trying to 00:07:18.259 --> 00:07:19.939 picture that. That's like standing on top of 00:07:19.939 --> 00:07:22.160 a 26 -story building and being able to clearly 00:07:22.160 --> 00:07:24.459 see a pizza box on the sidewalk below. That's 00:07:24.459 --> 00:07:27.240 a great analogy. That level of transparency is 00:07:27.240 --> 00:07:30.660 just, it's virtually unheard of in any natural 00:07:30.660 --> 00:07:32.639 body of water on the planet. And what's the big 00:07:32.639 --> 00:07:34.779 scientific takeaway from a reading like that? 00:07:34.879 --> 00:07:37.360 What's the implication? The scientists who made 00:07:37.360 --> 00:07:39.980 that measurement, they correlated that extreme 00:07:39.980 --> 00:07:43.060 clarity to the purity of distilled water. Wow. 00:07:43.720 --> 00:07:45.639 The implication is that there is a near total 00:07:45.639 --> 00:07:48.060 absence of suspended material in the water column. 00:07:48.199 --> 00:07:51.459 So that means two things. First, very little 00:07:51.459 --> 00:07:53.720 silt or sediment is getting into the water, probably 00:07:53.720 --> 00:07:55.819 because it's being trapped by those massive ice 00:07:55.819 --> 00:07:58.060 shelves. And the second thing. Second, and this 00:07:58.060 --> 00:08:00.160 is critical, it means there are extraordinarily 00:08:00.160 --> 00:08:03.199 low concentrations of phytoplankton. The microscopic 00:08:03.199 --> 00:08:05.899 plant life that forms the base of the food chain. 00:08:06.339 --> 00:08:08.259 Exactly. The very stuff that typically makes 00:08:08.259 --> 00:08:11.540 ocean water a bit cloudy or green. So that connects 00:08:11.540 --> 00:08:13.199 directly to the ecology we're going to talk about 00:08:13.199 --> 00:08:15.579 later. If the water is that clear because there's 00:08:15.579 --> 00:08:18.740 no phytoplankton, it means the foundational food 00:08:18.740 --> 00:08:21.879 source for the entire marine ecosystem is incredibly 00:08:21.879 --> 00:08:24.459 scarce, at least in that surface layer. Precisely. 00:08:24.459 --> 00:08:27.519 It creates this highly specialized nutrient poor 00:08:27.519 --> 00:08:30.879 yet light rich environment in that upper layer, 00:08:31.000 --> 00:08:34.559 which is a sharp contrast to the productive plankton 00:08:34.559 --> 00:08:36.639 dense waters you find almost everywhere else. 00:08:36.759 --> 00:08:39.960 So you have this pristine, almost sterile water. 00:08:40.299 --> 00:08:42.779 Yet historically, it's feared more than any other 00:08:42.779 --> 00:08:45.639 sea on the planet. Let's dig into that fearsome 00:08:45.639 --> 00:08:49.009 reputation. How did it get the name most treacherous? 00:08:49.110 --> 00:08:52.090 That dread is just, it's so deeply rooted in 00:08:52.090 --> 00:08:54.330 the experiences of the first explorers. There's 00:08:54.330 --> 00:08:56.769 a book from 1950, The White Continent by Thomas 00:08:56.769 --> 00:08:59.669 R. Henry, and he really codified the sea's terrifying 00:08:59.669 --> 00:09:02.669 reputation. He set it apart from all other Antarctic 00:09:02.669 --> 00:09:05.009 regions. What did he say specifically that captured 00:09:05.009 --> 00:09:07.210 this dread so well? He wrote it, I'm quoting 00:09:07.210 --> 00:09:09.730 here, that the Weddell Sea is the most treacherous 00:09:09.730 --> 00:09:12.149 and dismal region on Earth. That's a strong statement. 00:09:12.509 --> 00:09:15.210 A very strong statement, and he contrasted it 00:09:15.210 --> 00:09:16.870 directly with the other side of the continent, 00:09:17.070 --> 00:09:19.929 specifically noting that the Ross Sea was, in 00:09:19.929 --> 00:09:22.269 his words, relatively peaceful, predictable, 00:09:22.570 --> 00:09:26.620 and safe. If it wasn't always about having the 00:09:26.620 --> 00:09:29.120 thickest ice, what made the treachery here so 00:09:29.120 --> 00:09:31.639 unique? Henry pointed out that it wasn't just 00:09:31.639 --> 00:09:33.720 the sheer volume of ice, but the nature of how 00:09:33.720 --> 00:09:36.860 it formed and moved. He wrote about these treacherous 00:09:36.860 --> 00:09:39.360 flash freezes. Flash freezes? Yeah, where the 00:09:39.360 --> 00:09:41.379 sea could just freeze over rapidly, unexpectedly, 00:09:41.779 --> 00:09:44.519 trapping ships almost instantly and embedding 00:09:44.519 --> 00:09:47.789 them in the pack ice. This extreme speed and 00:09:47.789 --> 00:09:50.210 total unpredictability made any kind of navigation 00:09:50.210 --> 00:09:52.850 a nightmare. He actually noted that ships couldn't 00:09:52.850 --> 00:09:55.129 reliably find a path to the coast until as late 00:09:55.129 --> 00:09:57.529 as 1949. And you mentioned an anecdote, sort 00:09:57.529 --> 00:09:59.389 of a myth, that really gets at the psychological 00:09:59.389 --> 00:10:01.909 toll of this place. Yes, and this is just to 00:10:01.909 --> 00:10:03.850 underscore how alien and fearsome this place 00:10:03.850 --> 00:10:06.509 felt to those early sailors. Henry passed on 00:10:06.509 --> 00:10:09.149 an account of a mythical sighting of a green 00:10:09.149 --> 00:10:12.110 -haired merman in the icy waters. A green -haired 00:10:12.110 --> 00:10:15.110 merman. It sounds completely absurd to us today. 00:10:15.710 --> 00:10:18.049 but it speaks volumes about the sheer terror 00:10:18.049 --> 00:10:20.350 and the psychological strain that must have just 00:10:20.350 --> 00:10:23.590 blended reality and hallucination for explorers 00:10:23.590 --> 00:10:25.710 who were stranded in this profoundly isolated, 00:10:26.129 --> 00:10:29.049 dangerous, and unpredictable place. The green 00:10:29.049 --> 00:10:31.029 -haired merman is definitely a detail that sticks 00:10:31.029 --> 00:10:33.429 with you. So to round out the geography before 00:10:33.429 --> 00:10:35.789 we get into the exploration history, the sources 00:10:35.789 --> 00:10:39.049 mention all these seabed features, banks, knolls, 00:10:39.049 --> 00:10:42.600 troughs. Why are those important? They are absolutely 00:10:42.600 --> 00:10:44.500 critical for understanding the deep sea physics, 00:10:44.559 --> 00:10:46.700 which is what we'll get into in Section 4. The 00:10:46.700 --> 00:10:48.340 sources list features like, you know, Albert 00:10:48.340 --> 00:10:51.620 Bank, Ben Bank, Hoffman Trough. These bumps and 00:10:51.620 --> 00:10:53.320 valleys on the seabed, they're like the plumbing 00:10:53.320 --> 00:10:55.299 of the system. They steer the water. They steer 00:10:55.299 --> 00:10:58.100 the water. They dictate exactly where that dense 00:10:58.100 --> 00:11:00.340 sinking water, the global engine we're going 00:11:00.340 --> 00:11:02.100 to talk about, is channeled. They can create 00:11:02.100 --> 00:11:04.960 bottlenecks or guide the currents. And that directly 00:11:04.960 --> 00:11:07.200 influences the speed and the direction of the 00:11:07.200 --> 00:11:09.679 deep ocean masses that eventually flow out of 00:11:09.679 --> 00:11:15.529 the Antarctic to the rest of the world. The physical 00:11:15.529 --> 00:11:17.889 environment of the Weddell Sea has made it the 00:11:17.889 --> 00:11:20.350 stage for some of the most dramatic stories in 00:11:20.350 --> 00:11:23.750 Antarctic exploration. Stories of survival, tragedy. 00:11:24.269 --> 00:11:27.629 Its very name carries so much historical weight. 00:11:27.830 --> 00:11:31.649 It really does. The sea was named in 1900, but 00:11:31.649 --> 00:11:34.070 not by its discoverer. It was named in honor 00:11:34.070 --> 00:11:37.090 of a Scottish sailor, James Weddell. And he found 00:11:37.090 --> 00:11:39.940 it much earlier than that. Much earlier. He discovered 00:11:39.940 --> 00:11:43.240 it back in 1823, though at the time he originally 00:11:43.240 --> 00:11:46.220 called it the King George V's Sea after the ruling 00:11:46.220 --> 00:11:48.379 monarch. And when Weddell made that discovery, 00:11:48.620 --> 00:11:51.279 he managed to get pretty far south, didn't he? 00:11:51.379 --> 00:11:53.960 He was remarkably successful for that era. He 00:11:53.960 --> 00:11:56.639 reached a latitude of 74 degrees south, which 00:11:56.639 --> 00:11:58.580 was a major achievement. But there was another 00:11:58.580 --> 00:12:00.519 claim around that time, wasn't there? There was. 00:12:00.720 --> 00:12:03.500 In that same year, an American sealing captain 00:12:03.500 --> 00:12:06.139 named Benjamin Morell claimed he'd discovered 00:12:06.139 --> 00:12:09.110 a place he called New South Greenland. which 00:12:09.110 --> 00:12:11.590 he placed about 10 or 12 degrees east of the 00:12:11.590 --> 00:12:13.730 sea's actual boundary. And that turned out to 00:12:13.730 --> 00:12:16.929 be not real. It was later disproved when the 00:12:16.929 --> 00:12:19.649 area was more thoroughly explored. Morrell's 00:12:19.649 --> 00:12:22.110 claims sort of highlight the navigational uncertainty 00:12:22.110 --> 00:12:25.049 and sometimes the outright fabrication that marked 00:12:25.049 --> 00:12:27.490 some of those early ventures. But it also just 00:12:27.490 --> 00:12:30.049 underscores how difficult it was to accurately 00:12:30.049 --> 00:12:33.779 map and penetrate this specific region. So after 00:12:33.779 --> 00:12:36.480 Waddell, who pushed the boundary further? The 00:12:36.480 --> 00:12:38.740 furthest south penetration before we get to the 00:12:38.740 --> 00:12:41.419 modern era was achieved by a man named William 00:12:41.419 --> 00:12:45.740 Spears Bruce in 1903. Every single degree you 00:12:45.740 --> 00:12:48.500 gained heading south was a brutal, hard -won 00:12:48.500 --> 00:12:51.039 battle against the ice. And speaking of brutal 00:12:51.039 --> 00:12:53.620 battles, that brings us to the early 20th century 00:12:53.620 --> 00:12:57.419 and the disastrous but also heroic Nordenskild 00:12:57.419 --> 00:13:01.279 expedition. Ah yes, between 1902 and 1903. That 00:13:01.279 --> 00:13:03.500 story really highlights the volatile nature of 00:13:03.500 --> 00:13:05.080 the ice right around the Antarctic Peninsula. 00:13:05.399 --> 00:13:08.080 The leader was Otto Nortenskild. Right. He led 00:13:08.080 --> 00:13:09.799 the Swedish Antarctic expedition. And the hostile 00:13:09.799 --> 00:13:11.740 conditions they faced are sort of memorialized 00:13:11.740 --> 00:13:14.320 in the geography itself. His expedition ship, 00:13:14.320 --> 00:13:16.399 the Antarctic, gave its name to the Antarctic 00:13:16.399 --> 00:13:18.120 Sound. Which is the channel that separates the 00:13:18.120 --> 00:13:20.580 tip of the peninsula from Dundee Island. That's 00:13:20.580 --> 00:13:22.580 the one. And it has a very chilling nickname. 00:13:22.960 --> 00:13:26.399 Iceberg Alley. Iceberg Alley. It is notorious 00:13:26.399 --> 00:13:29.320 for the sheer concentration of massive icebergs 00:13:29.320 --> 00:13:31.700 that calve off the glaciers and ice shelves there. 00:13:31.820 --> 00:13:34.799 It makes passage exceptionally dangerous, even 00:13:34.799 --> 00:13:37.500 for modern icebreakers. And for Nordenskild's 00:13:37.500 --> 00:13:40.120 wooden ship, it was fatal. It was. The conditions 00:13:40.120 --> 00:13:43.100 proved lethal. The ship was crushed by the ice 00:13:43.100 --> 00:13:46.240 and sank in 1903. And that event triggered this 00:13:46.240 --> 00:13:49.539 incredible multi -year survival ordeal for the 00:13:49.539 --> 00:13:51.799 crew who were split into different parties. It's 00:13:51.799 --> 00:13:54.570 just... It's hard to imagine today. It was a 00:13:54.570 --> 00:13:57.149 supreme test of endurance. Norton skilled himself 00:13:57.149 --> 00:13:59.370 and three of his men were forced to spend two 00:13:59.370 --> 00:14:02.470 brutal, completely isolated winters, two full 00:14:02.470 --> 00:14:05.210 years, in a makeshift cabin they built on a place 00:14:05.210 --> 00:14:07.690 called Snow Hill Island. Two winters. Two Antarctic 00:14:07.690 --> 00:14:09.850 winters. They survived on the absolute minimum 00:14:09.850 --> 00:14:12.950 of supplies, constantly battling the cold, the 00:14:12.950 --> 00:14:15.509 darkness, the sheer mental strain of total isolation. 00:14:16.169 --> 00:14:18.029 The fact that they survived is a stunning testament 00:14:18.029 --> 00:14:20.730 to human tenacity, but it also just screams volumes 00:14:20.730 --> 00:14:22.789 about the unforgiving nature of the environment 00:14:22.789 --> 00:14:25.549 that trapped them. But the story that truly, 00:14:25.629 --> 00:14:28.690 truly defines the Wet Elsie's treachery is the 00:14:28.690 --> 00:14:31.190 one that was a catastrophic failure that somehow 00:14:31.190 --> 00:14:33.950 became the ultimate survival story. Shackleton 00:14:33.950 --> 00:14:35.990 and the Endurance. Shackleton and the Endurance. 00:14:36.149 --> 00:14:38.909 The 1915 disaster is the definitive illustration 00:14:38.909 --> 00:14:42.240 of the Wet Elsie's power. Shackleton's Imperial 00:14:42.240 --> 00:14:45.200 Transantarctic Expedition was aiming to be the 00:14:45.200 --> 00:14:47.500 first to cross the continent on foot. But they 00:14:47.500 --> 00:14:49.720 never even made it to land. They never even set 00:14:49.720 --> 00:14:52.179 foot on the continent proper. Their ship, the 00:14:52.179 --> 00:14:54.659 Endurance, became trapped in that rapidly closing 00:14:54.659 --> 00:14:57.500 pack ice we talked about. So those flash freezes 00:14:57.500 --> 00:14:59.980 that the writer Henry mentioned. That phenomenon 00:14:59.980 --> 00:15:03.629 was their undoing. The ice just closed in, pressing 00:15:03.629 --> 00:15:06.029 on the hull for months, until the ship was eventually 00:15:06.029 --> 00:15:08.809 crushed and sank beneath the ice. And what followed 00:15:08.809 --> 00:15:11.509 for the crew is just legendary. It is. They spent 00:15:11.509 --> 00:15:14.889 15 months living on the pack ice itself, a constantly 00:15:14.889 --> 00:15:18.269 shifting, cracking, moving platform of ice, drifting 00:15:18.269 --> 00:15:20.649 north at the mercy of the Weddell Gyre and the 00:15:20.649 --> 00:15:24.029 winds. That journey, just the transition from 00:15:24.029 --> 00:15:26.470 being on a ship to being on the ice, and then 00:15:26.470 --> 00:15:28.730 finally getting to Elephant Island in lifeboats, 00:15:28.789 --> 00:15:32.250 and Shackleton's own journey for rescue, it's 00:15:32.250 --> 00:15:34.850 one of the greatest feats of survival ever recorded. 00:15:35.029 --> 00:15:37.250 It's an absolute miracle they all survived. But 00:15:37.250 --> 00:15:39.730 the story has this remarkable modern postscript 00:15:39.730 --> 00:15:42.309 that tells us even more about the Weddell Sea 00:15:42.309 --> 00:15:44.649 itself. The discovery of the wreck. Exactly. 00:15:44.710 --> 00:15:48.009 In March of 2022, the wreck of the Endurance 00:15:48.009 --> 00:15:50.330 was finally discovered. And the condition it 00:15:50.330 --> 00:15:52.509 was in was shocking, right? It was reportedly 00:15:52.509 --> 00:15:55.610 in a state of remarkable preservation, almost 00:15:55.610 --> 00:15:59.929 frozen in time at a depth of 3 ,008 meters. That's 00:15:59.929 --> 00:16:02.850 nearly 10 ,000 feet down. Yes. The environment 00:16:02.850 --> 00:16:06.350 down there, intensely cold, deep, and very low 00:16:06.350 --> 00:16:09.259 in oxygen, acted as a perfect preservative. You 00:16:09.259 --> 00:16:11.039 can still read the name Endurance on the stern. 00:16:11.200 --> 00:16:13.759 But the location of the wreck, it wasn't exactly 00:16:13.759 --> 00:16:15.720 where they thought it would be. No, it was found 00:16:15.720 --> 00:16:18.059 four miles away from where the historical records 00:16:18.059 --> 00:16:20.620 predicted it sank. And that four -mile discrepancy 00:16:20.620 --> 00:16:22.639 tells us something fundamental about the physics 00:16:22.639 --> 00:16:25.500 of the sea, doesn't it? It really does. It highlights 00:16:25.500 --> 00:16:28.500 the extreme chaotic nature of the ice flows that 00:16:28.500 --> 00:16:30.779 were carrying them. Four miles is a big difference. 00:16:31.200 --> 00:16:33.899 The ice where the Endurance sank was not a static 00:16:33.899 --> 00:16:37.179 block. It was this turbulent, dynamic environment 00:16:37.179 --> 00:16:40.679 of constantly moving, sharing flows, all dictated 00:16:40.679 --> 00:16:42.799 by those powerful surface winds and the underlying 00:16:42.799 --> 00:16:45.000 currents. So that small difference in the wreck 00:16:45.000 --> 00:16:47.480 site confirms just how relentless and unpredictable 00:16:47.480 --> 00:16:49.960 the whole region is, even with our modern technology. 00:16:50.299 --> 00:16:52.740 It's a frozen monument to the sea's power to 00:16:52.740 --> 00:16:56.049 destroy, and then paradoxically... To preserve. 00:16:56.289 --> 00:16:58.850 OK, so we've covered the deadly history, the 00:16:58.850 --> 00:17:01.409 geographic extremes from that 80 meter water 00:17:01.409 --> 00:17:04.670 clarity to the constant crush of the ice. But 00:17:04.670 --> 00:17:07.049 the reason the Weddell Sea truly matters on a 00:17:07.049 --> 00:17:09.309 global scale, the reason everyone everywhere 00:17:09.309 --> 00:17:12.049 should care about this remote body of water is 00:17:12.049 --> 00:17:14.490 found deep below the surface. Right. Not in the 00:17:14.490 --> 00:17:16.970 surface dramas, but in the specific physics of 00:17:16.970 --> 00:17:19.769 its deep water. It is. And this isn't an exaggeration. 00:17:19.769 --> 00:17:21.930 One of the world's most critical climate engines. 00:17:22.150 --> 00:17:25.660 It is a fundamental global driver. Yes. And to 00:17:25.660 --> 00:17:28.180 really understand this engine, it helps to quickly 00:17:28.180 --> 00:17:31.240 connect its modern oceanography back to its deep 00:17:31.240 --> 00:17:34.380 geological roots. It actually have a shared ancient 00:17:34.380 --> 00:17:36.960 history with the southern tip of South America. 00:17:37.160 --> 00:17:40.539 How does an Antarctic sea connect geologically 00:17:40.539 --> 00:17:44.000 to Patagonia? Well, the formation of the Weddell 00:17:44.000 --> 00:17:46.420 Sea is a story of tectonic plates moving apart. 00:17:47.019 --> 00:17:49.400 It's tied to what's called extensional tectonics 00:17:49.400 --> 00:17:52.220 back in the Jurassic period. This process created 00:17:52.220 --> 00:17:55.059 something called the Rocas Verdes Basin, which 00:17:55.059 --> 00:17:57.559 was essentially a back -arc basin that stretched 00:17:57.559 --> 00:17:59.839 between the two landmasses before they fully 00:17:59.839 --> 00:18:02.640 separated. So the Weddell Sea is what's left 00:18:02.640 --> 00:18:04.900 of that ancient basin. It's the surviving extension 00:18:04.900 --> 00:18:07.420 of it, yes. So they were once connected, but 00:18:07.420 --> 00:18:10.019 their paths diverged pretty dramatically. Precisely. 00:18:10.019 --> 00:18:12.539 Later on in the late Cretaceous and Cenozoic 00:18:12.539 --> 00:18:15.240 eras, the South American part of that basin got 00:18:15.240 --> 00:18:18.299 squeezed. It was subjected to intense compressional 00:18:18.299 --> 00:18:20.700 tectonics, and it buckled and folded into what 00:18:20.700 --> 00:18:23.000 we now know as the Magdalene's Basin. But the 00:18:23.000 --> 00:18:25.599 Weddell's sea part didn't get squeezed. It escaped 00:18:25.599 --> 00:18:28.460 that compression, it stayed relatively stable, 00:18:28.680 --> 00:18:31.799 and it preserved its structure as a deep oceanic 00:18:31.799 --> 00:18:35.079 basin. And that geological foundation, this deep, 00:18:35.140 --> 00:18:39.079 stable, relatively uniform basin, is the necessary 00:18:39.079 --> 00:18:42.299 prerequisite for the massive, continuous oceanographic 00:18:42.299 --> 00:18:44.279 processes that we see happening there today. 00:18:44.519 --> 00:18:46.819 Okay, so let's get to those processes. Deep water 00:18:46.819 --> 00:18:49.539 formation. This is where the physics of the Weddell 00:18:49.539 --> 00:18:52.460 Sea directly impacts, well, billions of people. 00:18:52.579 --> 00:18:54.700 It governs the global thermohaline circulation. 00:18:55.259 --> 00:18:57.619 How significant is the Weddell Sea in that context? 00:18:58.000 --> 00:19:01.539 Its role is, it's... Possibly irreplaceable. 00:19:01.619 --> 00:19:04.480 The Weddell Sea is one of only a tiny handful 00:19:04.480 --> 00:19:07.099 of locations on the entire planet where deep 00:19:07.099 --> 00:19:09.160 and bottom water masses are formed at scale. 00:19:09.339 --> 00:19:11.680 And these sinking masses of water are what drive 00:19:11.680 --> 00:19:13.799 the whole system. They're the motors. They drive 00:19:13.799 --> 00:19:15.839 the global thermohaline circulation, which people 00:19:15.839 --> 00:19:18.119 often call the global conveyor belt. And that 00:19:18.119 --> 00:19:20.660 belt is responsible for distributing heat, storing 00:19:20.660 --> 00:19:23.079 carbon, carrying oxygen, and moving nutrients 00:19:23.079 --> 00:19:25.119 all across the world's oceans over thousands 00:19:25.119 --> 00:19:27.660 of years. That is a huge amount of responsibility 00:19:27.660 --> 00:19:30.019 for one remote sea. So walk us through it step 00:19:30.019 --> 00:19:33.099 by step. How does the water get dense enough 00:19:33.099 --> 00:19:36.059 to kick off this planet wide conveyor? The main 00:19:36.059 --> 00:19:38.839 mechanism involves two processes that are coupled 00:19:38.839 --> 00:19:42.759 together. Brine exclusion and wind cooling. Together 00:19:42.759 --> 00:19:44.880 they facilitate something oceanographers sometimes 00:19:44.880 --> 00:19:48.000 call cabling. Cabling. It's a term for when water 00:19:48.000 --> 00:19:50.579 masses mix and then sink because their combined 00:19:50.579 --> 00:19:53.859 density increases. So first you have brine exclusion. 00:19:54.400 --> 00:19:57.660 As the intense Antarctic cold forces new sea 00:19:57.660 --> 00:20:00.319 ice to form really rapidly on the surface, the 00:20:00.319 --> 00:20:03.240 salt gets rejected. So the ice itself is freshwater. 00:20:03.579 --> 00:20:06.420 The ice is freshwater, but the brine, this super 00:20:06.420 --> 00:20:08.980 -concentrated salt solution, is pushed out into 00:20:08.980 --> 00:20:10.900 the remaining liquid water underneath. Which 00:20:10.900 --> 00:20:13.259 makes that water incredibly salty, and therefore... 00:20:13.660 --> 00:20:17.259 Exactly. It massively increases the water's salinity 00:20:17.259 --> 00:20:20.039 and thus its density. At the same time, you have 00:20:20.039 --> 00:20:23.619 these intense, dry, cold Antarctic winds that 00:20:23.619 --> 00:20:25.839 are just constantly battering the surface, cooling 00:20:25.839 --> 00:20:28.279 that newly salty water down dramatically. So 00:20:28.279 --> 00:20:30.180 it's getting saltier and colder at the same time. 00:20:30.299 --> 00:20:33.000 The perfect combination. It creates this exceptionally 00:20:33.000 --> 00:20:36.160 cold, dense water mass that is now significantly 00:20:36.160 --> 00:20:38.299 heavier than all the water surrounding it. And 00:20:38.299 --> 00:20:40.720 gravity takes over. Gravity takes over. It sinks. 00:20:41.369 --> 00:20:44.089 It cascades off the continental shelf break and 00:20:44.089 --> 00:20:47.809 just descends into the abyss. And this forms 00:20:47.809 --> 00:20:50.849 the Weddell deep water and the Weddell bottom 00:20:50.849 --> 00:20:54.049 water masses. Which then flow out and power the 00:20:54.049 --> 00:20:56.250 conveyor belt. They flow northward, spreading 00:20:56.250 --> 00:20:58.890 their cold, dense characteristics throughout 00:20:58.890 --> 00:21:01.750 the world's deep oceans, literally powering the 00:21:01.750 --> 00:21:03.750 whole system. It sounds like a really stable 00:21:03.750 --> 00:21:06.410 perpetual engine. But you mentioned earlier that 00:21:06.410 --> 00:21:08.609 it's showing signs of stress. What is the latest 00:21:08.609 --> 00:21:11.170 research saying about its current state? Well, 00:21:11.230 --> 00:21:13.349 the process is incredibly sensitive to global 00:21:13.349 --> 00:21:15.670 changes. The sources we're looking at highlight 00:21:15.670 --> 00:21:17.730 that scientists have measured multi -decadal 00:21:17.730 --> 00:21:20.630 warming and, crucially, a loss of density in 00:21:20.630 --> 00:21:22.910 the deep water masses of the Weddell Sea just 00:21:22.910 --> 00:21:25.430 over the last decade. Density loss. How is that 00:21:25.430 --> 00:21:28.150 even measured? And what does a tiny change actually 00:21:28.150 --> 00:21:31.450 mean for the conveyor belt? Well, density is 00:21:31.450 --> 00:21:33.910 highly sensitive to both temperature and salinity. 00:21:34.430 --> 00:21:36.930 A shift of even a few hundredths of a degree 00:21:36.930 --> 00:21:39.829 Celsius can be hugely significant when you're 00:21:39.829 --> 00:21:42.130 talking about these vast volumes of water. So 00:21:42.130 --> 00:21:44.430 what's causing the density to drop? It could 00:21:44.430 --> 00:21:46.650 be a couple of things. If the surface water gets 00:21:46.650 --> 00:21:49.029 a little warmer, or if increased glacial melt 00:21:49.029 --> 00:21:51.170 from the continent adds too much fresh, less 00:21:51.170 --> 00:21:53.849 dense water into the mix, the whole sinking process 00:21:53.849 --> 00:21:56.269 can slow down or weaken. And if that continues? 00:21:56.690 --> 00:21:59.190 If the density loss continues, the water masses 00:21:59.190 --> 00:22:02.000 don't sink as effectively. you could end up with 00:22:02.000 --> 00:22:04.160 a stratification, a layering of the deep ocean. 00:22:04.619 --> 00:22:07.339 This, in turn, weakens the conveyor belt, which 00:22:07.339 --> 00:22:09.759 reduces the transport of heat north, and just 00:22:09.759 --> 00:22:12.359 as importantly, reduces the supply of oxygen 00:22:12.359 --> 00:22:15.279 and nutrients to the deep sea. So the stability 00:22:15.279 --> 00:22:17.759 of the entire global ocean is balanced on the 00:22:17.759 --> 00:22:19.700 physics of salt being pushed out of ice in this 00:22:19.700 --> 00:22:22.380 one remote sea. That's a powerful thought. It 00:22:22.380 --> 00:22:24.599 really is. So once that dense water is formed, 00:22:24.759 --> 00:22:26.779 how does it get circulated out? It's governed 00:22:26.779 --> 00:22:29.240 by a massive rotation, right? The Weddell Gyre. 00:22:29.380 --> 00:22:32.660 The Weddell Gyre, yes. It's this immense circulation 00:22:32.660 --> 00:22:35.660 pattern that organizes all the water within the 00:22:35.660 --> 00:22:39.299 sea. It's cyclonic, which means it rotates clockwise 00:22:39.299 --> 00:22:41.519 in the southern hemisphere. And it's primarily 00:22:41.519 --> 00:22:43.680 driven by the wind, although that underlying 00:22:43.680 --> 00:22:46.660 flow of dense water heavily influences its deeper 00:22:46.660 --> 00:22:49.680 structure. And what's the gyre's ultimate job 00:22:49.680 --> 00:22:52.359 in this global movement? It's both the internal 00:22:52.359 --> 00:22:55.539 machinery and the final exit ramp. The gyre has 00:22:55.539 --> 00:22:58.359 this northward flowing current along its western 00:22:58.359 --> 00:23:00.359 boundary, right up against the Antarctic Peninsula. 00:23:00.579 --> 00:23:03.460 That current is the primary way that these water 00:23:03.460 --> 00:23:05.960 masses, including the Weddell Deepwater, leave 00:23:05.960 --> 00:23:08.599 the sea and enter the wider world ocean. And 00:23:08.599 --> 00:23:10.380 it mixes into the South Atlantic from there? 00:23:10.619 --> 00:23:12.920 Exactly. You mentioned it has a complex vertical 00:23:12.920 --> 00:23:14.980 structure. So what does an ocean sandwich look 00:23:14.980 --> 00:23:17.200 like in the Weddell Sea? It's a very specific 00:23:17.200 --> 00:23:19.680 layered stack. At the very top, you have a cold, 00:23:19.759 --> 00:23:22.400 low salinity surface layer, which is heavily 00:23:22.400 --> 00:23:24.890 influenced by melting ice. Okay. That's separated 00:23:24.890 --> 00:23:27.210 from the layers below by a pretty thin layer 00:23:27.210 --> 00:23:30.569 called a picnicline. And a picnicline is what 00:23:30.569 --> 00:23:33.069 exactly? It's the layer where the water density 00:23:33.069 --> 00:23:35.890 changes very rapidly with depth. So it's a major 00:23:35.890 --> 00:23:38.670 transition zone. And beneath that picnicline, 00:23:38.750 --> 00:23:41.789 you have this thick, crucial layer known as Weddell 00:23:41.789 --> 00:23:45.950 Deepwater, or WDW. Now, the WDW is often described 00:23:45.950 --> 00:23:49.920 as relatively warm and salty. How can water that's 00:23:49.920 --> 00:23:52.359 thousands of feet deep in the Antarctic be considered 00:23:52.359 --> 00:23:55.980 warm? It's the paradox of salinity. The WDW is 00:23:55.980 --> 00:23:57.960 relatively warm. We're talking maybe a degree 00:23:57.960 --> 00:24:00.319 or two above freezing. But that's compared to 00:24:00.319 --> 00:24:02.680 the frigid surface water and the even colder 00:24:02.680 --> 00:24:05.000 bottom water. And where does this warm water 00:24:05.000 --> 00:24:07.380 come from? It actually originates from warmer, 00:24:07.519 --> 00:24:10.759 saltier deep water masses that circulate southward 00:24:10.759 --> 00:24:13.490 towards Antarctica from other oceans. Because 00:24:13.490 --> 00:24:15.829 it's so salty, it's still very dense, dense enough 00:24:15.829 --> 00:24:18.130 to sit beneath the colder surface layer, which, 00:24:18.230 --> 00:24:20.690 despite being colder, is much fresher -less salty 00:24:20.690 --> 00:24:23.890 and therefore less dense. And below the WDW. 00:24:23.890 --> 00:24:26.950 Below the WDW, you finally have the really cold, 00:24:27.049 --> 00:24:29.809 really dense, newly formed Weddell bottom water, 00:24:29.910 --> 00:24:32.230 the stuff that just sank. Given how important 00:24:32.230 --> 00:24:34.849 the gyre is, you'd think quantifying its circulation 00:24:34.849 --> 00:24:37.190 would be a top priority. Has that been easy to 00:24:37.190 --> 00:24:39.609 do? Quite the opposite. It's been historically 00:24:39.609 --> 00:24:42.880 very, very difficult to quantify. Early data, 00:24:42.980 --> 00:24:44.859 things like geopotential surface height measurements, 00:24:45.160 --> 00:24:48.099 they only indicated very weak surface currents. 00:24:48.299 --> 00:24:51.259 Which was misleading. Very misleading. Because 00:24:51.259 --> 00:24:53.299 we know the Weddell Sea is this massive source 00:24:53.299 --> 00:24:56.460 of dense, sinking water. Researchers have always 00:24:56.460 --> 00:24:58.579 expected there to be a much stronger, deeper 00:24:58.579 --> 00:25:01.420 circulation along that western boundary, driven 00:25:01.420 --> 00:25:04.180 by the continuous input of all that heavy water 00:25:04.180 --> 00:25:06.839 from the south. So weak currents at the top are 00:25:06.839 --> 00:25:09.720 masking a powerful, deep river of water below. 00:25:09.779 --> 00:25:12.640 That's the idea. The available historical data 00:25:12.640 --> 00:25:15.519 just hasn't really allowed for an accurate quantification 00:25:15.519 --> 00:25:17.839 of the volume transports, you know, how much 00:25:17.839 --> 00:25:21.140 water is moving and how fast in that deeper density 00:25:21.140 --> 00:25:24.019 -driven flow. Modern oceanographic tools are 00:25:24.019 --> 00:25:26.019 constantly trying to capture that number because 00:25:26.019 --> 00:25:28.660 knowing the exact output of the engine is vital 00:25:28.660 --> 00:25:30.930 for all our climate models. Okay, let's shift 00:25:30.930 --> 00:25:32.910 back to the surface drivers, the winds. Wind 00:25:32.910 --> 00:25:36.450 cooling is key to the deep water formation. But 00:25:36.450 --> 00:25:38.569 the meteorology of the Western Weddell Sea is 00:25:38.569 --> 00:25:40.430 really unique, isn't it? It's channeled by the 00:25:40.430 --> 00:25:43.130 geography of the Antarctic Peninsula. It is a 00:25:43.130 --> 00:25:46.369 remarkable atmospheric interaction. A defining 00:25:46.369 --> 00:25:49.049 feature of the Western Weddell Sea climate is 00:25:49.049 --> 00:25:51.809 the dominance of these exceptionally strong surface 00:25:51.809 --> 00:25:54.990 winds that run precisely parallel to the spine 00:25:54.990 --> 00:25:57.049 of the Antarctic Peninsula. And the peninsula 00:25:57.049 --> 00:25:59.970 is a very tall, narrow mountain range. Exactly. 00:26:00.029 --> 00:26:03.009 The winds are channeled and intensified by the 00:26:03.009 --> 00:26:05.269 topography itself. What direction do they move 00:26:05.269 --> 00:26:07.609 and what effects do they have? They carry intensely 00:26:07.609 --> 00:26:09.750 cold air from the continent towards the lower 00:26:09.750 --> 00:26:12.789 latitudes, and they eventually turn into southwesterlies 00:26:12.789 --> 00:26:15.990 as they move farther north. But crucially, this 00:26:15.990 --> 00:26:19.009 persistent flow acts as a continuous conveyor 00:26:19.009 --> 00:26:22.279 belt for ice. It forces all the pack ice and 00:26:22.279 --> 00:26:25.000 the smaller icebergs northeastward out into the 00:26:25.000 --> 00:26:27.359 South Atlantic. So the wind isn't just cooling 00:26:27.359 --> 00:26:30.579 the water, it's physically exporting ice out 00:26:30.579 --> 00:26:33.200 of the sea. Constantly. And this is what creates 00:26:33.200 --> 00:26:35.559 that long -known, razor -sharp contrast between 00:26:35.559 --> 00:26:37.559 the conditions on the two sides of the Antarctic 00:26:37.559 --> 00:26:40.140 Peninsula. The eastern Weddell side is perpetually 00:26:40.140 --> 00:26:42.339 harsh and ice -choked, while the western side 00:26:42.339 --> 00:26:44.799 can be comparatively milder and more open. That 00:26:44.799 --> 00:26:47.359 process of cold air piling up sounds incredibly 00:26:47.359 --> 00:26:50.480 complex. Can you walk us through the meteorological 00:26:50.480 --> 00:26:53.640 mechanism that creates these powerful channeled 00:26:53.640 --> 00:26:57.160 winds? Certainly. These strong northward winds 00:26:57.160 --> 00:26:59.180 along the east side of the peninsula are usually 00:26:59.180 --> 00:27:01.400 generated by one of two large -scale weather 00:27:01.400 --> 00:27:05.279 systems. The first and simpler one is an intense 00:27:05.279 --> 00:27:08.359 low -pressure system, a cyclone, that forms out 00:27:08.359 --> 00:27:11.140 over the central Weddell Sea, and that just pulls 00:27:11.140 --> 00:27:13.410 the air masses toward it. And the second scenario? 00:27:13.730 --> 00:27:15.930 The second, and I think more interesting situation, 00:27:16.250 --> 00:27:20.269 involves a broad, stable flow of cold, dense 00:27:20.269 --> 00:27:23.089 air moving from east to west in the lowest part 00:27:23.089 --> 00:27:25.910 of the atmosphere, say the lowest 500 to 1 ,000 00:27:25.910 --> 00:27:28.089 meters. And it's directed right at the Antarctic 00:27:28.089 --> 00:27:30.630 Peninsula. And the mountains act as a solid wall. 00:27:30.890 --> 00:27:33.329 A complete barrier. When this stable, cold air 00:27:33.329 --> 00:27:35.829 hits that narrow, tall mountain range, it can't 00:27:35.829 --> 00:27:37.970 easily flow over it. So instead, the air begins 00:27:37.970 --> 00:27:39.970 to pile up against the eastern edge of the range. 00:27:40.170 --> 00:27:42.339 A traffic jam of cold air. Perfect description. 00:27:42.759 --> 00:27:46.059 This process of cold air piling up creates a 00:27:46.059 --> 00:27:48.779 persistent high -pressure ridge, which is focused 00:27:48.779 --> 00:27:50.920 mainly over the eastern peaks of the mountains. 00:27:51.259 --> 00:27:54.039 And that ridge then deflects the incoming air 00:27:54.039 --> 00:27:56.559 current sharply to the right, thanks to the Coriolis 00:27:56.559 --> 00:27:58.660 effect in the southern hemisphere. So instead 00:27:58.660 --> 00:28:00.819 of crashing into the mountains, the wind is forced 00:28:00.819 --> 00:28:02.920 to just rush along the mountain wall, creating 00:28:02.920 --> 00:28:06.099 this continuous, intense flow. Exactly. It's 00:28:06.099 --> 00:28:08.079 like turning a fire hose down a narrow channel. 00:28:08.410 --> 00:28:10.630 The mountains convert a general flow of cold 00:28:10.630 --> 00:28:13.269 air into a high -velocity channeled wind that 00:28:13.269 --> 00:28:15.549 defines the climate of the western Weddell Sea. 00:28:15.849 --> 00:28:18.849 It's a perfect, relentless, cold wind machine, 00:28:19.069 --> 00:28:22.230 constantly driving that brine exclusion process 00:28:22.230 --> 00:28:27.230 that the deepwater engine needs to run. The surprisingly 00:28:27.230 --> 00:28:29.839 rich ecology. The great irony of the Weddell 00:28:29.839 --> 00:28:32.180 Sea is that this environment, which we've defined 00:28:32.180 --> 00:28:34.339 by its lethality, its constant churning ice, 00:28:34.559 --> 00:28:36.799 and its almost distilled water clarity suggesting 00:28:36.799 --> 00:28:38.819 a food desert. Right, suggesting there's nothing 00:28:38.819 --> 00:28:41.240 to eat. Is in reality home to some of the most 00:28:41.240 --> 00:28:44.119 vast, complex, and frankly rule -breaking ecosystems 00:28:44.119 --> 00:28:47.400 on the entire planet. That juxtaposition is truly 00:28:47.400 --> 00:28:50.519 amazing. Even at the surface, the sea supports 00:28:50.519 --> 00:28:53.109 a lot of characteristic fauna. You have the whale 00:28:53.109 --> 00:28:55.470 seal, which is named for the sea itself, along 00:28:55.470 --> 00:28:58.269 with killer whales, humpback whales, mink whales, 00:28:58.789 --> 00:29:01.670 leopard seals, and crab eater seals. So despite 00:29:01.670 --> 00:29:04.450 the difficult ice, these large mammals are thriving. 00:29:04.650 --> 00:29:06.930 They are. They thrive on the upwelling and the 00:29:06.930 --> 00:29:09.710 local concentrations of food that happen, even 00:29:09.710 --> 00:29:11.740 in that harsh environment. And of course, the 00:29:11.740 --> 00:29:14.539 most iconic residents, the penguins. The Adelie 00:29:14.539 --> 00:29:16.740 penguin is really the dominant species here. 00:29:16.859 --> 00:29:19.720 It's highly adapted to that harsh, high latitude 00:29:19.720 --> 00:29:22.839 environment. We see these immense nesting grounds, 00:29:23.039 --> 00:29:26.740 most notably a massive colony of over 100 ,000 00:29:26.740 --> 00:29:29.740 breeding pairs of Adelies. And that's centered 00:29:29.740 --> 00:29:32.099 on a place called Volcanic Paulette Island. And 00:29:32.099 --> 00:29:34.059 there was also the discovery of an emperor penguin 00:29:34.059 --> 00:29:36.539 colony, the northernmost one, which connects 00:29:36.539 --> 00:29:38.440 back to that theme of treacherous navigation. 00:29:38.880 --> 00:29:41.869 Yes, that's a great point. Around 1997, scientists 00:29:41.869 --> 00:29:44.509 discovered the northernmost known colony of emperor 00:29:44.509 --> 00:29:47.029 penguins, just south of Snow Hill Island. Which 00:29:47.029 --> 00:29:48.690 was a surprise because they're typically found 00:29:48.690 --> 00:29:51.569 much further south. It was a big surprise. But 00:29:51.569 --> 00:29:54.930 just accessing that colony emphasizes the sea's 00:29:54.930 --> 00:29:58.089 inherent difficulty. To get there, you need a 00:29:58.089 --> 00:30:01.589 powerful ice -class research vessel, and it has 00:30:01.589 --> 00:30:03.430 to be specifically equipped with helicopters. 00:30:03.930 --> 00:30:06.309 Why the helicopters? Because the persistent, 00:30:06.450 --> 00:30:09.460 heavy, and unpredictable pack ice... often makes 00:30:09.460 --> 00:30:11.920 surface navigation completely impossible, even 00:30:11.920 --> 00:30:14.460 for the best icebreakers. You have to fly in 00:30:14.460 --> 00:30:16.380 over it. Okay, now let's get to the real rule 00:30:16.380 --> 00:30:19.079 breakers. Life that is thriving, where science 00:30:19.079 --> 00:30:21.519 previously said it absolutely could not. Let's 00:30:21.519 --> 00:30:22.859 start with the discovery under the permanent 00:30:22.859 --> 00:30:26.740 ice shelf. This just, it fundamentally challenges 00:30:26.740 --> 00:30:29.339 our understanding of biological energy and survival. 00:30:29.680 --> 00:30:32.319 This 2021 finding is still sending shockwaves 00:30:32.319 --> 00:30:34.420 through the biological community. Scientists 00:30:34.420 --> 00:30:37.609 reported finding sessile organisms. So things 00:30:37.609 --> 00:30:39.670 like sponges and other unidentified suspension 00:30:39.670 --> 00:30:41.730 feeders that filter food from the water. And 00:30:41.730 --> 00:30:43.490 they found them growing on a boulder. Under the 00:30:43.490 --> 00:30:46.170 vast Filtneron ice shelf. Let's nail down the 00:30:46.170 --> 00:30:48.009 specifics of the location because the numbers 00:30:48.009 --> 00:30:50.430 are just unbelievable. They are. The depth of 00:30:50.430 --> 00:30:54.589 the discovery was 12 ,233 meters down. And of 00:30:54.589 --> 00:30:58.349 that, 872 meters was solid, permanent ice above 00:30:58.349 --> 00:31:01.190 them. Okay, so nearly a kilometer of ice. And 00:31:01.190 --> 00:31:04.480 then the critical distance. They were located 00:31:04.480 --> 00:31:08.680 a staggering 260 kilometers. That's over 160 00:31:08.680 --> 00:31:12.069 miles from the nearest open water. from the nearest 00:31:12.069 --> 00:31:14.769 possible source of sunlight or surface -level 00:31:14.769 --> 00:31:18.289 nutrients. But sponges are filter feeders. They 00:31:18.289 --> 00:31:20.210 need food particles sinking down through the 00:31:20.210 --> 00:31:23.769 water to eat. How on earth does food travel 260 00:31:23.769 --> 00:31:27.269 kilometers sideways underneath hundreds of meters 00:31:27.269 --> 00:31:29.970 of permanent ice? That is the $60 million question. 00:31:30.369 --> 00:31:32.930 This discovery just completely shattered the 00:31:32.930 --> 00:31:35.970 conventional limits for where a sessile benthic 00:31:35.970 --> 00:31:38.450 community, so a fixed bottom -dwelling community, 00:31:38.589 --> 00:31:40.960 can survive. So what are the theories? How could 00:31:40.960 --> 00:31:43.359 they be surviving there? Scientists have proposed 00:31:43.359 --> 00:31:45.759 a few hypotheses, and none of them really fully 00:31:45.759 --> 00:31:47.940 explains the scale of what they found. Okay. 00:31:48.099 --> 00:31:50.400 One possibility is that the deep ocean currents 00:31:50.880 --> 00:31:52.599 which are guided by those seabed features we 00:31:52.599 --> 00:31:54.799 talked about, are moving organic particles along 00:31:54.799 --> 00:31:57.240 the bottom very efficiently and over these vast 00:31:57.240 --> 00:31:59.720 distances. But the energy required to sustain 00:31:59.720 --> 00:32:02.539 a filtering community over 260 kilometers is 00:32:02.539 --> 00:32:05.220 just immense. What's another idea? Another hypothesis 00:32:05.220 --> 00:32:08.460 involves extremely low metabolic rates. These 00:32:08.460 --> 00:32:11.079 organisms might be growing incredibly, incredibly 00:32:11.079 --> 00:32:13.980 slowly. They might only be consuming just enough 00:32:13.980 --> 00:32:16.819 food to survive for decades or even centuries, 00:32:16.900 --> 00:32:19.380 rather than thriving in a traditional sense. 00:32:19.619 --> 00:32:21.779 They could be ancient. Could they be using some 00:32:21.779 --> 00:32:24.400 other food source, like chemosynthesis, something 00:32:24.400 --> 00:32:27.319 not based on photosynthesis at all? That's a 00:32:27.319 --> 00:32:29.259 possibility, too, though it's less likely for 00:32:29.259 --> 00:32:31.660 standard sponges. The particles they're filtering 00:32:31.660 --> 00:32:34.500 could be ancient, having sunk. Years or centuries 00:32:34.500 --> 00:32:37.599 ago. Or they might be relying on some previously 00:32:37.599 --> 00:32:40.200 unmeasured geological or chemical input from 00:32:40.200 --> 00:32:42.400 the seabed itself. So no matter what the answer 00:32:42.400 --> 00:32:45.079 is, the fact that they exist forces us to redraw 00:32:45.079 --> 00:32:46.960 the map of where life is possible. Completely. 00:32:47.059 --> 00:32:49.940 It suggests these vast hidden ecosystems could 00:32:49.940 --> 00:32:52.640 exist anywhere. You have a stable rock surface 00:32:52.640 --> 00:32:55.210 and even a minimal current flow. even in permanent 00:32:55.210 --> 00:32:57.410 darkness, miles under a permanent ice sheet. 00:32:57.549 --> 00:33:00.029 That is truly profound. And speaking of vastness, 00:33:00.130 --> 00:33:02.329 that same year brought another discovery of life, 00:33:02.430 --> 00:33:04.910 not isolated under the ice, but thriving on the 00:33:04.910 --> 00:33:08.569 seafloor in colossal numbers, the icefish megacolony. 00:33:08.650 --> 00:33:11.910 This discovery, made by the same Alfred Wigener 00:33:11.910 --> 00:33:14.690 Institute with their research vessel RV Polarstern, 00:33:14.769 --> 00:33:17.920 was equally historic. They found a colony of 00:33:17.920 --> 00:33:21.240 approximately 60 million Jonah's ice fish. 60 00:33:21.240 --> 00:33:24.859 million? 60 million active nests. And these fish 00:33:24.859 --> 00:33:26.779 are instantly recognizable because they're one 00:33:26.779 --> 00:33:28.559 of the only vertebrates known to have transparent 00:33:28.559 --> 00:33:31.619 blood. They completely lack red hemoglobin. Transparent 00:33:31.619 --> 00:33:33.920 blood, that's a stunning adaptation to the coal. 00:33:33.960 --> 00:33:37.200 It's an incredible adaptation. In the extremely 00:33:37.200 --> 00:33:40.380 cold, oxygen -rich waters of the Antarctic, not 00:33:40.380 --> 00:33:42.640 having hemoglobin actually reduces the viscosity 00:33:42.640 --> 00:33:45.259 of the blood. It allows it to flow more freely 00:33:45.259 --> 00:33:47.339 and efficiently at temperatures near freezing, 00:33:47.480 --> 00:33:50.380 which is absolutely critical for survival in 00:33:50.380 --> 00:33:53.079 that deep, frigid abyss. And 60 million fish 00:33:53.079 --> 00:33:55.700 in one area. That number is almost impossible 00:33:55.700 --> 00:33:58.539 to picture. What's the scale and the density 00:33:58.539 --> 00:34:01.000 of this breeding ground? The colony is estimated 00:34:01.000 --> 00:34:03.720 to cover around 240 square kilometers of the 00:34:03.720 --> 00:34:06.349 seabed. And the density? To put that into perspective, 00:34:06.630 --> 00:34:08.590 scientists observed an average of one active 00:34:08.590 --> 00:34:11.150 nest for every three square meters across that 00:34:11.150 --> 00:34:13.969 entire immense area. So this isn't just the largest 00:34:13.969 --> 00:34:16.090 fish breeding colony found in the Antarctic. 00:34:16.230 --> 00:34:18.469 It's the largest known fish breeding colony discovered 00:34:18.469 --> 00:34:20.889 anywhere in the world, by far. And what does 00:34:20.889 --> 00:34:23.090 that tell us about the deep Weddell Sea as a 00:34:23.090 --> 00:34:25.670 habitat? It underscores that the abyssal conditions 00:34:25.670 --> 00:34:29.230 of the Weddell Sea, so cold, stable, and incredibly 00:34:29.230 --> 00:34:32.150 consistent over time, provide a perfect protected 00:34:32.150 --> 00:34:35.809 environment. It's a nursery for these very specific 00:34:35.809 --> 00:34:39.190 cold adapted species to organize and reproduce 00:34:39.190 --> 00:34:42.130 at a scale we simply don't see in more turbulent 00:34:42.130 --> 00:34:44.949 environments. So the stability is the key, while 00:34:44.949 --> 00:34:47.179 the surface is a chaotic nightmare. The deep 00:34:47.179 --> 00:34:49.320 Whittle seawater masses provide this remarkably 00:34:49.320 --> 00:34:52.039 consistent habitat, and that allows these slow 00:34:52.039 --> 00:34:54.199 -growing, highly specialized species like the 00:34:54.199 --> 00:34:56.559 icefish to establish these massive protected 00:34:56.559 --> 00:34:59.159 nurseries far from surface predators and chaos. 00:34:59.460 --> 00:35:02.019 It shows that the most treacherous sea is also, 00:35:02.159 --> 00:35:05.300 paradoxically, a cradle of life. Hashtag, hashtag, 00:35:05.320 --> 00:35:08.440 hashtag, cc's. Conclusion and takeaway. So, we've 00:35:08.440 --> 00:35:10.239 wrapped up our journey through the Whittle Sea 00:35:10.239 --> 00:35:12.239 and what a collection of contradictions it is. 00:35:12.420 --> 00:35:15.980 We started with that central paradox. The clearest 00:35:15.980 --> 00:35:19.079 water on Earth, yet at the same time, a deadly, 00:35:19.179 --> 00:35:22.159 ice -choked navigational nightmare that famously 00:35:22.159 --> 00:35:24.739 trapped Shackleton and his crew. Then we trace 00:35:24.739 --> 00:35:27.199 its absolutely essential role as a global climate 00:35:27.199 --> 00:35:29.860 engine, a deep water factory that's powered by 00:35:29.860 --> 00:35:32.639 wind cooling and Brian exclusion physics that 00:35:32.639 --> 00:35:34.860 dictate how heat is distributed and stored across 00:35:34.860 --> 00:35:37.469 all the world's oceans. And then, most surprisingly, 00:35:37.590 --> 00:35:39.710 we found that beneath all that chaos and that 00:35:39.710 --> 00:35:43.250 strange clarity, this remote body of water harbors 00:35:43.250 --> 00:35:45.469 life in conditions we previously thought were 00:35:45.469 --> 00:35:47.949 impossible. Filtration feeders surviving 260 00:35:47.949 --> 00:35:51.070 kilometers under permanent ice. And a 60 million 00:35:51.070 --> 00:35:54.050 strong colony of transparent blooded fish all 00:35:54.050 --> 00:35:56.750 thriving in the frigid abyss. So if there is 00:35:56.750 --> 00:35:59.269 one single essential nugget of knowledge that 00:35:59.269 --> 00:36:01.449 you should take away from this deep dive, it 00:36:01.449 --> 00:36:04.030 is the fundamental global significance of its 00:36:04.030 --> 00:36:06.429 hydrophysics. Its role in... deep water formation. 00:36:06.750 --> 00:36:09.809 Exactly. The WETLC's contribution to deep water 00:36:09.809 --> 00:36:12.550 formation and the thermohaline circulation is 00:36:12.550 --> 00:36:16.750 absolutely positively irreplaceable. The efficiency 00:36:16.750 --> 00:36:18.789 of that ocean engine determines the ventilation, 00:36:19.070 --> 00:36:21.090 the nutrient renewal, and the temperature stability 00:36:21.090 --> 00:36:23.789 of ocean basins all over the world. So the stability 00:36:23.789 --> 00:36:26.250 and consistency of that process is paramount. 00:36:26.699 --> 00:36:29.340 The future of the global ocean climate is just. 00:36:29.820 --> 00:36:33.000 It's inextricably linked to the complex, density 00:36:33.000 --> 00:36:35.840 -driven physics happening in this one remote 00:36:35.840 --> 00:36:38.780 Antarctic region. And this brings us to the final 00:36:38.780 --> 00:36:41.500 provocative thought for you to consider. We know 00:36:41.500 --> 00:36:44.000 that the deep sea ecology we just discussed That 00:36:44.000 --> 00:36:46.519 60 million strong ice fish colony, the sponge 00:36:46.519 --> 00:36:49.440 is 260 kilometers from open water, is completely 00:36:49.440 --> 00:36:52.300 reliant on the extremely cold, consistent, and 00:36:52.300 --> 00:36:54.639 stable conditions provided by that wet old deep 00:36:54.639 --> 00:36:57.420 water. But as we mentioned, scientists are already 00:36:57.420 --> 00:36:59.300 measuring multi -decadal warming and density 00:36:59.300 --> 00:37:02.260 loss in those very same deep water masses. It's 00:37:02.260 --> 00:37:04.239 a potential sign that the engine is already struggling. 00:37:04.639 --> 00:37:07.480 So if the fundamental stable cold water conditions 00:37:07.480 --> 00:37:10.320 that allow this unique specialized deep sea life 00:37:10.320 --> 00:37:12.800 to flourish begin to degrade because of climate 00:37:12.800 --> 00:37:16.659 change, What hidden specialized ecosystems, the 00:37:16.659 --> 00:37:19.039 ones currently dependent on the deep, cold and 00:37:19.039 --> 00:37:21.239 consistent environment of the Weddell Sea, might 00:37:21.239 --> 00:37:23.579 be irrevocably altered or even lost entirely 00:37:23.579 --> 00:37:25.920 before we ever even manage to discover them and 00:37:25.920 --> 00:37:28.960 understand how they survive? The clearest, deadliest 00:37:28.960 --> 00:37:31.320 sea isn't just a historical marvel. It is perhaps 00:37:31.320 --> 00:37:33.800 our most crucial and our most fragile planetary 00:37:33.800 --> 00:37:34.639 bellwether.