Science Friday - Massive Iceberg Breaks Off Antarctica, Revealing Wonders Below

Episode Date: April 2, 2025

In January, an iceberg the size of Chicago splintered off from the Antarctic Peninsula and drifted away in the Bellingshausen Sea.As luck would have it, a team of scientists was nearby on a research vessel, and they seized the chance to see what was lurking on the seafloor beneath that iceberg—a place that had long been covered, and nearly impossible to get to.They found a stunning array of life, like octopuses, sea spiders, and crustaceans, as well as possible clues to the dynamics of ice sheets.Host Ira Flatow talks with the expedition’s two chief scientists: Dr. Patricia Esquete, marine biologist at the University of Aveiro in Portugal, and Dr. Sasha Montelli, glaciologist and geophysicist at University College London.Transcripts for each segment will be available after the show airs on sciencefriday.com.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. Today on the podcast, how a little luck and great timing helped scientists see under an Antarctic ice sheet. We knew that there is life under ice sheets, but it was extremely surprising the degree to which life was thriving, diverse, colorful. In January, in iceberg, the size of Chicago, splintered off from the Antarctic Peninsula and drifted away in the Belling's Housand Sea. As luck would have it, a team of scientists was nearby on a research vessel, and the scientist seized the chance to see what was lurking on the seafloor beneath that iceberg, a place that had long been covered and nearly impossible to reach. They found a stunning array of life, octopuses, sea spiders, crustaceans, and possible clues into the dynamics of ice sheets.

Joining me are the Expeditions to Chief Scientist, Dr. Patricia Eskiskeye's. Kete is a marine biologist at the University of Avairo in Portugal, Dr. Sasha Montelli, glaciologist and geophysicist at University College London. Welcome both of you to Science Friday. Thank you for having us. Thank you. Sasha, you happen to be in the right place at the right time. Tell us about what your original mission was. Our science agenda was merged from two different proposals. One was Patricius, another was mine. Patricius' agenda was mostly biological. investigations of this very poorly investigated areas of Antarctic Peninsula. And my team was aiming to discern the ice ocean interactions, the melting of ice on a range of timescales from tens of

thousands of years to industrial era to the present. Tell us how you happened to be at the right place at the right time. Yeah, we had this plan of researching the whole, the seafloor of the whole Bellinghaus and City pretty much. And because of the ice condition, the ice coverage this year, there was way more ice than we expected at the beginning. We found ourselves restricted to the run entrance, which is an area that is limited by three ice shelves and islands on islands. To put it really well, we were lucky and we were prepared. We were exploring very inaccessible areas and we were exploring an explored area. So we were very much prepared to explore a new leaf pose area at the moment.

Now, let me just quote Louis Pasteur, who said, look, prefers the prepared mind. So you were really prepared. What went through your mind when you saw that the iceberg had capped off? Well, there was a really amazing moment. And the first thing that crosses your mind is we have to go there. Yeah, there was no doubt to just look at each other's and say, let's go there right now. Wow.

So now you were fortunate enough to study the seafloor under an ice sheet. Why is it so hard to do that? You can imagine, well, ice shelves are continuations of ice sheet that is grounded. So interior of intoxic ice sheet, you can find ice that is 12,000 meters thick, extremely thick. And then you can imagine ice sheet flowing towards its edges and thinning like a pile of honey, viscous honey. And then as it flows towards the margins towards the sea, it thins and flows into the water, ocean water.

And it thins to the extent that it becomes buoyed and reaches flotation point. So then this floating ice shelves, which are essentially fringes of Antarctic ice sheet, that is grounded, they can extend over the area's size of France and there are countries of meters thick. So it's extremely difficult

to get underneath there. It's perhaps one of the most remote areas in the world in terms of subsurface, the seafloor. Yeah. So the only way to do a comprehensive study like we did, interdisciplinary comprehensive study, is to, if you're lucky enough that the ice shelf rapidly disintegrates or calves of a huge iceberg, because otherwise it's just impossible

simply because this remotely operated vehicle are attached by cable to vessel. And so cables just, even if they were willing to deploy those under an ice shelf, just cables wouldn't be long enough to go, you know, as far as 20 kilometers, say, beyond the Calvin Front. So, yeah, so ice shelves are just among the most remote and hostile areas, and as simple as that. Oh. Okay. So you're motoring on over to this wonderful piece of real estate underwater of this part of the sea floor that has not been exposed before. What do you expect to see and, Sasha, and what did you actually see? So it was embracing the unknown really because, again, nobody really has done much work under a nutshell.

There were some studies that are fairly limited in scope and in geographical coverage just because they usually would drill a borehole through an ice shelf. And then they would put a fairly small drone through the borehole. And then they would be able to see something. We knew that there is life under ice shelf. So that was not perhaps a surprise that we sold life itself, but it was extremely surprised in the degree to vision. Life was thriving, diverse, colorful. So that was the major surprise was.

Patricia, tell me a bit about that. So you drop this camera, it goes down to the seafloor. Paint me a word picture of what you're seeing as the camera is lowering. So actually we have a remote-operated vehicle, an ROV, which is not just a camera. It's just, effectively, it's a robot that can go thousands of meters under the surface. And it can not only, it not only has cameras, also have arms and can and has capacity of samples. So the first thing we saw, I remember it very well because it was quite amazing for us.

The first thing we saw was a huge, a massive barrel sponge with that crab on it. and other critters around and hanging on the sponge. And then another sponge and then another one. And all of them were not only huge, but also had other species living on top of them. That's already quite amazing, amazing, because that tells you that the ecosystem is very mature and well established because you have long-lived species like the sponges

and also several species living on top of it. So you have biodiversity, you have species interactions, you have biomass, and that tells you this is a very well-established and mature ecosystem. And that was pretty amazing. As Sasha was saying, we knew that there will be some life under the ice shell, but because the amount of ice on top of it, it cannot be fed by photosynthesis happening in the surface, that that will be the normal setting.

The food needs to come from somewhere else. So where did the food come from? How did it get its food if it wasn't raining down on it for all those years? That's one of the big questions, and that's something that we still need to study with more detail. We need to, and this next step will be to understand how that ecosystem functions, where the food comes from. It's certainly through the current, so bilateral transport instead of vertical transplants, set of vertical transport, but where exactly is it coming from and how that's something

that we need to keep studying and figure out. So is that ecosystem, a diversity of life you saw down there? Is it similar or different to other parts of the Antarctic seafloor? It was pretty similar, and that's one of the thing that actually makes it surprising and and amazing is that it's really very similar, at least, to other ecosystem that we had been studying nearby in the days before and the weeks before. So that means that means that the conditions can be very similar

than in other more exposed areas. So what other critters did you see down there? Did you have a favorite? I have several favorites. I have two favorites. Tell us about them. Yeah. One of my favorites is an is.

isopod is more like a stream, but you need to imagine it as like a flat stream that kind of crawls in the sand. I like that particular one because I'm a taxonomist and I study these kind of animals and that one of them was probably very likely a new species. Wow. So I not only liked it, but also will get to name that species. Who are you going to name it after? I don't know yet. Yourself? No, that's something we never do. I'm a glyceologist, so I'm obviously not that competent in species,

but I can say that to me, the major highlight was when we descended to see this outcrop, black rock, the wall, almost vertical wall, layers of strata. But on top of it, there were also almost like hanging gardens of corals of different, different colors. If you imagine, you know, very gentle, pastel-colored sunset, so from purple to orange to white. And that was the first thing we saw one of the dives. And to see it as a first thing,

it was just absolutely stunning and exhilarating. After the break, the sea life wasn't the only surprise beneath the ice. You look at the Yosemite, this huge sort of very sharp. cleaved. So now put it underwater and put ice shaft on top of that. Well, as a geologist, I think both of the public doesn't realize there's a whole continent

under that ice, right? There's a lot of rocks there. Yes, yes, yeah. Describe what, is the floor flat or is it got mountains and ridges and things there? Because you're what, 1,300 meters down? It is extremely rugged, yeah. So the amplitude, you can imagine,

you can even think of it as mountain range under an ice shaft. So the shallowest bait we encountered was as shallow as 100 meters, if not shallow, actually. At some point, at some point, the captain actually had to urgently turn the ship around because every second basically is being reduced by 10 meters. So they clearly go into something extremely shallow areas. But then at the same time, right adjacent to it, so next door, 10 kilometers, a few miles away. the depth was as high as 1,300 meters.

So the huge range of depth, you can imagine, you can imagine some, you know, Yosemite probably could be a good example of that. So if you look at the Yosemite, very, very sharp cliff, very high amplitude. So now put it underwater and put ice sharp on top of that. And so that's kind of the landscape that you see there. So did you actually discover something that was not charted before? Yes, this was the first map ever in that area. So that's obviously quite exciting.

And this maps, it's not just for the sake of mapping. It's not mapping for the sake of mapping. It's these maps really, these shapes that are preserved on the seafloor, they really tell us something about the history of ice, not only in sediment, because sediment, obviously, like an ice course, sediment course, the history of climate and history of environmental change in the area, but also the shapes of the sea flow. We see some features like elongated stripes that tell us something about the history

and configuration of flow of ice, which is extremely important in terms of providing longer-term context into behavior of ice and into the changes that we see from the satellite era and observable record. Patricia, how do you think the ecosystem and all the corals and the jellies and all those animals you saw down there, how are they going to fare with no ice above them if they've had it for, Lord knows how many, maybe thousands of years, right? That's actually another very, very, very question. And also very important to investigate. Why? Because, first of all, whatever is feeding those ecosystems is doing it very effective.

because as we say, there's a lot of biodiversity, a lot of biomass, a lot of life, beautiful life. Because of the climate change, we know that Antarctica is losing ice year by year and ice shelves are collapsing and it will be happening more frequently. So, yeah, there's some urgency then to what you're doing.

There is, it's going to be very important to actually understand how ecosystems, not only directly under the ice, but also in the neighborhood will react and will be able to cop with or will change or not with all this ice melting.

Yeah. Yeah. Do you plan on going back, both of you, Sasha? That would be lovely. I think it also provides the opportunity for us to, because we have, as we just discussed recently, we have this really nice time zero

event and we know exactly where we acquire data to very high precision so we can go back there exactly same locations to exactly same sponge individual sponge and see how they changed over time yeah and also to the same corals which is also very interesting and very important because the corals for instance they depend a lot on the current on the current regime so being able to go back exactly to that point in which all those corals, all these are, those a range of colors and species and interactions were happening and seeing whether it changed or not or how it's going to be very, very important. We definitely need to go back.

Yeah, you know, I've been to Antarctica and now how exciting it is to be there. You know, they say we know more about the surface of the moon than we know about what's under the bottom of the ocean. You must feel like explorers, right? something brand new that you've discovered. We are explorers. So I was saying, really our aim was to study and map and sample areas that have never been sample or mapped before. So, yeah, we were exploring and we just got to explore something a bit more special than we expected.

You know, here in the United States, we're fearful of research being cut back by the new administration. you folks are not part of the American science community, so you can continue to do your work. Who's funding the work that you're doing? The philanthropic organization called Schmidt Ocean Institute, which is based in the United States, ironically. So I guess it's quite sad the funding costs, because ultimately I think there are no borders in understanding

the world around us. I think that this limitation of a major, major science power is just limitation to the whole world, really, in terms of science. So I think the world around us needs to be studied more. Well, I want to thank you both for taking time to describe this terrific work that you're involved in. And good luck to you, and I wish you pleasant sailing next time you go back. Thank you so much. Thank you very much. You're welcome. Dr. Sasha Montelli is a glaciologist and geophysicist at University College in London.

Dr. Patricia Esquete is a marine biologist at the University of Eviro in Portugal. That's about all the time we have for now. A lot of people help make this show happen. Jordan Smudjik. Charles Bergquist. George Harper. John Dancosky. I'm Ira Flato.

Thanks for listening.